Rajan R. Patil

*School of Public Health, SRM University, Chennai India* 

#### **1. Introduction**

34 International Perspectives on Global Environmental Change

Yuan, D.X., Cheng, H., Edwards, R.L., Dykoski, C.A., Kelly, M.J., Zhang, M.L., Qing, J.M.,

Zhang, P.Z., Cheng, H., Edwards, R.L., Chen, F.H., Wang, Y.J., Yang, X.L., Liu, J., Tan, M.,

Zhang, Y.G., Ji, J., Balsam, W.L., Liu, L., Chen, J., 2007. High resolution hematite and

Zhang, Y.G., Ji, J.F., Balsam, W., Liu, L.W., Chen, J., 2009. Mid-Pliocene Asian monsoon

year Chinese cave record. Science 322, 940–942.

578.

602.

Letters 264, 136–150.

Lin, Y.S., Wang, Y.J., Wu, J.Y., Dorale, J.A., An, Z.S., Cai, Y.J., 2004. Timing, duration, and transitions of the Last Interglacial Asian Monsoon. Science 304, 575–

Wang, X.F., Liu, J.H., An, C.L., Dai, Z.B., Zhou, J., Zhang, D.Z., Jia, J.H., Jin, L.Y., Johnson, K.R., 2008. A test of climate, sun, and culture relationships from an 1810-

goethite records from ODP 1143, South China Sea: co-evolution of monsoonal precipitation and El Niño over the past 600,000 years. Earth and Planetary Science

intensification and the onset of Northern Hemisphere glaciation. Geology 37, 599–

The United Nations Framework Convention (UNFC) on climate change defines climate change as, "a change of climate which is attributed directly or indirectly to the human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods" (UNFCC, 1992). The EU has defined dangerous climate change as an increase in 2 degrees celsius of average global temperatures. Since 1900, global temperatures have risen by 0.7 degrees celsius and are continuing to rise at an estimated rate of 0.2 degrees per decade. If left unchecked, this implies global warming of at least 1.4 degrees celsius (IPCC, 2001).

The United Nations Framework Convention on Climate Change (UNFCCC) was convened in 1992 with an overarching framework to address the challenges of climate change through inter governmental efforts. The objectives of the UNFCCC are: 1. To stabilize greenhouse gas concentrations to levels that prevent dangerous interference with the global climate system; and 2. To achieve these reductions within a time frame that allows ecosystems to adapt naturally to climate change, to ensure that food production is not threatened, and to enable economic development to proceed in a sustainable manner. The Kyoto protocol was developed in 1997 to reinforce the emissions reduction commitments of the UNFCCC. The protocol came into legal force in 2005 when it was ratified by 30 industrialized nations, creating legally binding targets for a 5 percent reduction in emissions below 1990 levels by 2012.

The World Metrological Organization and United Nations Environment Programme (UNEP), in an effort to combat the worsening situation, set up the Intergovernmental Panel on Climate Change (IPCC) in 1988. In recognition of the strong body of evidence that this panel has painstakingly collated, it was honored with the Nobel Peace Prize in 2007. The panel recently released their fourth assessment report which categorically states that the "warming of the climate system is unequivocal, as is now evident from observation of increases in global average air and ocean temperature, widespread melting of snow and ice and rising global average sea level". The fourth assessment report has already identified three areas in which human health has already been affected by climate change. These are: (I) alteration of distribution of some infectious disease vectors, (ii) seasonal distribution of some allergenic pollen species, and (iii) increased heat wave related deaths (Confaloneieri et al 2007).

That climate change impacts health in many ways was highlighted by the World Health Organization (WHO) when it chose to mark World Health Day on April 7 with the theme

Climate Change and Health Effects 37

increase the risk of deaths and non-fatal injuries. Climate change is expected to increase average temperatures as well as the number and intensity of heat waves. Heat waves are associated with increases in morbidity and mortality in the short term, especially in populations who are not adapted to extremely hot weather. Hot working environments also have non-fatal implications. Heat exposure increases the risk of having accidents. Hot working environments may decrease the ability to carry out physical tasks as well as have implications for mental task ability. Prolonged heat exposure may lead to heat exhaustion or heatstroke. In addition to the implications for health and well-being, climate change may through exposure of workers to heat stress have important direct effects on productivity

The Indian metropolitan city of Mumbai was besieged with India's heaviest downpour of the century in July 2005, killing nearly 600 people. According to the Indian Meteorological department, this was the heaviest rainfall ever received in a single day, anywhere in India, recording 94.4 cm in the last 100 years. It broke the record of the previous highest rainfall at one place in India, at Cherrapunjee in Meghalaya (83.82 cm recorded on July 12, 1910). Cherrapunjee in the Northeastern state of Meghalaya is a generally well-known for being the wettest place in the world. Extreme weather changes surpassing their usual statistical ranges and tumbling records in India could be an early warning bell of global warming. Extreme weather events like the recent record setting in the western Indian city of Mumbai, or the all time high fatalities due to the heat wave in southern Indian states, or increasing vulnerability of eastern Indian states to floods could all be a manifestation of climate change

Acute variation in temperature and precipitation, can lead to various Patho-Physiological (Hypo-Hyper thermia, heart stroke, burns, frost bites etc). Extreme weather events such as severe storms, floods and drought can have obvious results such as physical injuries and drowning. Rising sea-levels will also give rise to flooding leading to drowning and

There are many indirect effects as: communicable diseases e.g.: vector borne disease, diarrheal diseases; ecological disturbances impacting on agent- host-environment relationships; malnutrition resulting due to agricultural impacts leading to food security issues; environmental health related to air and water quality issues, and human behavior

Climate change is also expected to affect animal, human and plant health via indirect pathways. It is likely that the geography of infectious diseases and pests will be altered, including the distribution of vector-borne diseases, which are highly sensitive to climatic conditions. Extreme weather events might then create the necessary conditions for vector borne disease to expand its geographical range. Strengthening global, regional and national early warning systems is crucial, as are co-ordinated research programs and subsequent prevention and intervention measures (Martin et al,date??). As the ambient temperature of a region rises, the ecology changes and therefore populations of disease carrying animals or insects may increase as well. The rate of replication of the vector itself, or the pathogen (virus, bacteria) within those vectors can be sensitive to temperature. Changes in

(Nerlander, 2009).

population displacement.

**2.2 Indirect and chronic effects** 

**2.2.1 Vector borne disease** 

in the Asian subcontinent (Patil & Deepa, 2007).

issues such as migrations, and mental health.

"Protecting health from climate change"... The relationship between climate change and human health is multidimensional. The emerging evidence of climate change effects on human health (IPCC 2007) shows that climate change has: altered the distribution of some infectious disease vectors; altered the seasonal distribution of some allergenic pollen species; and increased heat wave-related deaths.

Health effects due to climate change is not a new phenomenon; literate, scholarly systems of medicine dating back more than 3,000 years are available for many parts of the world. Pathological signs in bones, fossil excreta and other items can be studied in archaeological material. Molecular techniques can yield additional information from such remains. In Europe, parish records, the diaries and publications of physicians and other archival material are a rich source of information. Thus, as with climatology, we can turn to a variety of sources for evidence of diseases in past climates (Reiter, 2007). Root cause analysis show that, social and economic developments [driving forces] exert pressure on the environment and, as a consequence, the state of the environment changes. This leads to impacts on e.g. human health, ecosystems and materials that may elicit a societal response that feeds back on the driving forces, on the pressures or on the state or impacts directly, through adaptation or curative action (Griffith, n.d)

The Intergovernmental Panel on Climate Change (IPCC) projected that changes in temperature, precipitation, and other weather variables due to climate change "are likely to affect the health status of millions of people, particularly those with low adaptive capacity" and stated that they had "very high confidence" that climate change is "currently contributing to the global burden of disease and premature deaths" (Paul et al, 2009).

The World Health Organization has concluded that the climatic changes that have occurred since the mid 1970s could already be causing annually over 150,000 deaths and five million disability-adjusted life-years (DALY), mainly in developing countries. The less developed countries are, ironically, those least responsible for causing global warming. Many health outcomes and diseases are sensitive to climate, including: heat-related mortality or morbidity; air pollution-related illnesses; infectious diseases, particularly those transmitted, indirectly, via water or by insect or rodent vectors; and refugee health issues linked to forced population migration. Yet, changing landscapes can significantly affect local weather more acutely than long-term climate change (Partz & Olson, 2006).

### **2. Health consequences of climate change**

Impacts of Climate Change on health are manifested directly due to heat, cold, and injuries or indirectly through changes in environment, agriculture, human behavior and migrations.

#### **2.1 Direct & acute effects**

Direct effects on health due to heat, cold, and injuries are some of the acute manifestations resulting due to climate change. These effects can easily be witnessed as a consequence of climate change either in the form of heat and cold waves or direct injuries resulting from heavy rains and wind speeds as witnessed in hurricanes.

#### **2.1.1 Direct effects of extreme events**

An increase in the frequency and intensity of extremes of temperature, precipitation and wind speed have clear implications for mortality and morbidity. Flooding and storms

"Protecting health from climate change"... The relationship between climate change and human health is multidimensional. The emerging evidence of climate change effects on human health (IPCC 2007) shows that climate change has: altered the distribution of some infectious disease vectors; altered the seasonal distribution of some allergenic pollen species;

Health effects due to climate change is not a new phenomenon; literate, scholarly systems of medicine dating back more than 3,000 years are available for many parts of the world. Pathological signs in bones, fossil excreta and other items can be studied in archaeological material. Molecular techniques can yield additional information from such remains. In Europe, parish records, the diaries and publications of physicians and other archival material are a rich source of information. Thus, as with climatology, we can turn to a variety of sources for evidence of diseases in past climates (Reiter, 2007). Root cause analysis show that, social and economic developments [driving forces] exert pressure on the environment and, as a consequence, the state of the environment changes. This leads to impacts on e.g. human health, ecosystems and materials that may elicit a societal response that feeds back on the driving forces, on the pressures or on the state or impacts directly, through

The Intergovernmental Panel on Climate Change (IPCC) projected that changes in temperature, precipitation, and other weather variables due to climate change "are likely to affect the health status of millions of people, particularly those with low adaptive capacity" and stated that they had "very high confidence" that climate change is "currently

The World Health Organization has concluded that the climatic changes that have occurred since the mid 1970s could already be causing annually over 150,000 deaths and five million disability-adjusted life-years (DALY), mainly in developing countries. The less developed countries are, ironically, those least responsible for causing global warming. Many health outcomes and diseases are sensitive to climate, including: heat-related mortality or morbidity; air pollution-related illnesses; infectious diseases, particularly those transmitted, indirectly, via water or by insect or rodent vectors; and refugee health issues linked to forced population migration. Yet, changing landscapes can significantly affect local weather

Impacts of Climate Change on health are manifested directly due to heat, cold, and injuries or indirectly through changes in environment, agriculture, human behavior and migrations.

Direct effects on health due to heat, cold, and injuries are some of the acute manifestations resulting due to climate change. These effects can easily be witnessed as a consequence of climate change either in the form of heat and cold waves or direct injuries resulting from

An increase in the frequency and intensity of extremes of temperature, precipitation and wind speed have clear implications for mortality and morbidity. Flooding and storms

contributing to the global burden of disease and premature deaths" (Paul et al, 2009).

more acutely than long-term climate change (Partz & Olson, 2006).

**2. Health consequences of climate change** 

heavy rains and wind speeds as witnessed in hurricanes.

**2.1.1 Direct effects of extreme events** 

**2.1 Direct & acute effects** 

and increased heat wave-related deaths.

adaptation or curative action (Griffith, n.d)

increase the risk of deaths and non-fatal injuries. Climate change is expected to increase average temperatures as well as the number and intensity of heat waves. Heat waves are associated with increases in morbidity and mortality in the short term, especially in populations who are not adapted to extremely hot weather. Hot working environments also have non-fatal implications. Heat exposure increases the risk of having accidents. Hot working environments may decrease the ability to carry out physical tasks as well as have implications for mental task ability. Prolonged heat exposure may lead to heat exhaustion or heatstroke. In addition to the implications for health and well-being, climate change may through exposure of workers to heat stress have important direct effects on productivity (Nerlander, 2009).

The Indian metropolitan city of Mumbai was besieged with India's heaviest downpour of the century in July 2005, killing nearly 600 people. According to the Indian Meteorological department, this was the heaviest rainfall ever received in a single day, anywhere in India, recording 94.4 cm in the last 100 years. It broke the record of the previous highest rainfall at one place in India, at Cherrapunjee in Meghalaya (83.82 cm recorded on July 12, 1910). Cherrapunjee in the Northeastern state of Meghalaya is a generally well-known for being the wettest place in the world. Extreme weather changes surpassing their usual statistical ranges and tumbling records in India could be an early warning bell of global warming. Extreme weather events like the recent record setting in the western Indian city of Mumbai, or the all time high fatalities due to the heat wave in southern Indian states, or increasing vulnerability of eastern Indian states to floods could all be a manifestation of climate change in the Asian subcontinent (Patil & Deepa, 2007).

Acute variation in temperature and precipitation, can lead to various Patho-Physiological (Hypo-Hyper thermia, heart stroke, burns, frost bites etc). Extreme weather events such as severe storms, floods and drought can have obvious results such as physical injuries and drowning. Rising sea-levels will also give rise to flooding leading to drowning and population displacement.

#### **2.2 Indirect and chronic effects**

There are many indirect effects as: communicable diseases e.g.: vector borne disease, diarrheal diseases; ecological disturbances impacting on agent- host-environment relationships; malnutrition resulting due to agricultural impacts leading to food security issues; environmental health related to air and water quality issues, and human behavior issues such as migrations, and mental health.

#### **2.2.1 Vector borne disease**

Climate change is also expected to affect animal, human and plant health via indirect pathways. It is likely that the geography of infectious diseases and pests will be altered, including the distribution of vector-borne diseases, which are highly sensitive to climatic conditions. Extreme weather events might then create the necessary conditions for vector borne disease to expand its geographical range. Strengthening global, regional and national early warning systems is crucial, as are co-ordinated research programs and subsequent prevention and intervention measures (Martin et al,date??). As the ambient temperature of a region rises, the ecology changes and therefore populations of disease carrying animals or insects may increase as well. The rate of replication of the vector itself, or the pathogen (virus, bacteria) within those vectors can be sensitive to temperature. Changes in

Climate Change and Health Effects 39

example, high temperatures can increase or reduce survival rate, depending on the vector, its behavior, ecology, and many other factors. Thus, the probability of transmission may or may not be increased by higher temperatures. The tremendous growth in international travel increases the risk of importation of vector-borne diseases, some of which can be transmitted locally under suitable circumstances at the right time of the year. But demographic and sociologic factors also play a critical role in determining disease incidence, and it is unlikely that these diseases will cause major epidemics in the United States if the

Climate is a major factor in determining: (1) the geographic and temporal distribution of arthropods; (2) characteristics of arthropod life cycles; (3) dispersal patterns of associated arboviruses; (4) the evolution of arboviruses; and (5) the efficiency with which they are transmitted from arthropods to vertebrate hosts. Thus, under the influence of increasing temperatures and rainfall through warming of the oceans, and alteration of the natural cycles that stabilize climate, one is inevitably drawn to the conclusion that arboviruses will continue to emerge in new regions. For example, we cannot ignore the unexpected but successful establishment of chikungunya fever in northern Italy, the sudden appearance of West Nile virus in North America, the increasing frequency of Rift Valley fever epidemics in the Arabian Peninsula, and very recently, the emergence of Bluetongue virus in northern

Chikungunya is a viral disease that is spread by mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common. There is no cure for the disease. Treatment is focused on relieving the symptoms. The proximity of mosquito breeding sites to human habitation is a significant risk factor for

The Indian capital city of Delhi reported its first ever case of Chikungunya in June 2007.Any new disease in any new region where it was previously not known to occur is certainly a cause of concern, as it is an emergence of a new infectious agent in a hitherto 'virgin' region. It could be a manifestation of disturbed equilibrium in the ecology of a given region. New epidemics in the new regions are a definite signs of an ecological ill health. Hence, if the ongoing climate change can lead to ecological disturbances, it is likely to bring in changes in distribution of vector borne disease like Chikungunya and other vector borne diseases (Patil,

Lyme disease, or Lyme borreliosis,is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. The disease is named after the town of Lyme, Connecticut, USA, where a number of cases were identified in 1975. Lyme disease is the most common tick-borne disease in the hemisphere. Early symptoms may include fever, headache, fatigue, depression, and a characteristic circular skin rash called erythema migrans. Left untreated, later symptoms may involve the joints, heart, and central nervous

Climate change will increase the geographical distribution of Lyme disease. Lyme disease is spread by blacklegged tick bites. A survey conducted from 1992 to 2006 indicates that the

public health infrastructure is maintained and improved (Gubler, 2001).

Europe (Gould, 2009)

**2.2.3 Chikungunya** 

Chikungunya.

2011)

**2.2.4 Lyme disease** 

system (Ryan, 2004)

precipitation patterns can alter the number of breeding sites available leading to explosive epidemics of the following varieties of vector Borne diseases: **Mosquitoes Borne Diseases** e.g., Malaria, Dengue, Chikungunia, Yellow fever, Filaria are some of most climate sensitive diseases in which there is a direct correlation with temperature and rainfall which can be demonstrated. **Rodent-borne diseases** e.g. leptospirosis, are commonly reported in the after-math of flooding. In some areas, drought may reduce the transmission of some mosquito borne diseases, leading to reduction in the proportion of immune persons and therefore a larger amount of susceptible people once the drought breaks. **Pests borne disease**: Pests could become even more important disease vectors as a result of climate change. The spread of Plague, West Nile and Lyme disease are indicative of impact of pests on public health.

#### **2.2.2 Malaria**

Climate factors, particularly rainfall, temperature and humidity, interact to greatly affect the development, behavior and survival of mosquitoes transmitting malaria. However, as the Intergovernmental Panel on Climate Change (IPCC) reports, despite known causal links between climate, malaria and transmission dynamics, there is still much uncertainty about the potential impact of climate change on malaria at local and global scales. This is in part due to the complexity and local specificities of malaria transmission. Different mosquito vector species and parasites react differently to various climate conditions. For example, a change in temperature can affect the growth of the parasite within the mosquito and a change in local climate may make it less suitable for one vector. This particularly applies to water habitats for mosquito breeding environmental and institutional factors). However, while there is substantial knowledge on mosquito vectors, there is uncertainty about how climate change may change and influence malaria transmission. Two impacts of climate change at least have to be considered as major factors: temperature and rainfall patterns. The less important, but easiest to model, is the direct effect of temperature. This has effects both on mosquito range and survival, and the period of time it takes for mosquitoes to become infectious following biting an infected individual; the shorter the period, the greater the vectoral capacity. For both reasons, higher temperatures are likely to lead to more malaria, but the effects of this should not be exaggerated, and changes in temperature are unlikely to occur with all other environmental factors remaining constant (DEFID, 2010).

**Vector Borne Zoonotic Disease]s [VBZDs**: Climate change may affect the incidence of VBZDs through its effect on four principal characteristics of host and vector populations that relate to pathogen transmission to humans: geographic distribution, population density, prevalence of infection by zoonotic pathogens, and the pathogen load in individual hosts and vectors. These mechanisms may interact with each other and with other factors such as anthropogenic disturbance to produce varying effects on pathogen transmission within host and vector populations and to humans. Because climate change effects on most VBZDs act through wildlife hosts and vectors, understanding these effects will require multidisciplinary teams to conduct and interpret ecosystem-based studies of VBZD pathogens in host and vector populations and to identify the hosts, vectors, and pathogens with the greatest potential to affect human populations under climate change scenarios (Mills et al, 2010). Most vector-borne diseases exhibit a distinct seasonal pattern, which clearly suggests that they are weather sensitive. Rainfall, temperature, and other weather variables affect in many ways both the vectors and the pathogens they transmit. For

precipitation patterns can alter the number of breeding sites available leading to explosive epidemics of the following varieties of vector Borne diseases: **Mosquitoes Borne Diseases** e.g., Malaria, Dengue, Chikungunia, Yellow fever, Filaria are some of most climate sensitive diseases in which there is a direct correlation with temperature and rainfall which can be demonstrated. **Rodent-borne diseases** e.g. leptospirosis, are commonly reported in the after-math of flooding. In some areas, drought may reduce the transmission of some mosquito borne diseases, leading to reduction in the proportion of immune persons and therefore a larger amount of susceptible people once the drought breaks. **Pests borne disease**: Pests could become even more important disease vectors as a result of climate change. The spread of Plague, West Nile and Lyme disease are indicative of impact of pests

Climate factors, particularly rainfall, temperature and humidity, interact to greatly affect the development, behavior and survival of mosquitoes transmitting malaria. However, as the Intergovernmental Panel on Climate Change (IPCC) reports, despite known causal links between climate, malaria and transmission dynamics, there is still much uncertainty about the potential impact of climate change on malaria at local and global scales. This is in part due to the complexity and local specificities of malaria transmission. Different mosquito vector species and parasites react differently to various climate conditions. For example, a change in temperature can affect the growth of the parasite within the mosquito and a change in local climate may make it less suitable for one vector. This particularly applies to water habitats for mosquito breeding environmental and institutional factors). However, while there is substantial knowledge on mosquito vectors, there is uncertainty about how climate change may change and influence malaria transmission. Two impacts of climate change at least have to be considered as major factors: temperature and rainfall patterns. The less important, but easiest to model, is the direct effect of temperature. This has effects both on mosquito range and survival, and the period of time it takes for mosquitoes to become infectious following biting an infected individual; the shorter the period, the greater the vectoral capacity. For both reasons, higher temperatures are likely to lead to more malaria, but the effects of this should not be exaggerated, and changes in temperature are unlikely to occur with all other environmental factors remaining constant (DEFID, 2010). **Vector Borne Zoonotic Disease]s [VBZDs**: Climate change may affect the incidence of VBZDs through its effect on four principal characteristics of host and vector populations that relate to pathogen transmission to humans: geographic distribution, population density, prevalence of infection by zoonotic pathogens, and the pathogen load in individual hosts and vectors. These mechanisms may interact with each other and with other factors such as anthropogenic disturbance to produce varying effects on pathogen transmission within host and vector populations and to humans. Because climate change effects on most VBZDs act through wildlife hosts and vectors, understanding these effects will require multidisciplinary teams to conduct and interpret ecosystem-based studies of VBZD pathogens in host and vector populations and to identify the hosts, vectors, and pathogens with the greatest potential to affect human populations under climate change scenarios (Mills et al, 2010). Most vector-borne diseases exhibit a distinct seasonal pattern, which clearly suggests that they are weather sensitive. Rainfall, temperature, and other weather variables affect in many ways both the vectors and the pathogens they transmit. For

on public health.

**2.2.2 Malaria** 

example, high temperatures can increase or reduce survival rate, depending on the vector, its behavior, ecology, and many other factors. Thus, the probability of transmission may or may not be increased by higher temperatures. The tremendous growth in international travel increases the risk of importation of vector-borne diseases, some of which can be transmitted locally under suitable circumstances at the right time of the year. But demographic and sociologic factors also play a critical role in determining disease incidence, and it is unlikely that these diseases will cause major epidemics in the United States if the public health infrastructure is maintained and improved (Gubler, 2001).

Climate is a major factor in determining: (1) the geographic and temporal distribution of arthropods; (2) characteristics of arthropod life cycles; (3) dispersal patterns of associated arboviruses; (4) the evolution of arboviruses; and (5) the efficiency with which they are transmitted from arthropods to vertebrate hosts. Thus, under the influence of increasing temperatures and rainfall through warming of the oceans, and alteration of the natural cycles that stabilize climate, one is inevitably drawn to the conclusion that arboviruses will continue to emerge in new regions. For example, we cannot ignore the unexpected but successful establishment of chikungunya fever in northern Italy, the sudden appearance of West Nile virus in North America, the increasing frequency of Rift Valley fever epidemics in the Arabian Peninsula, and very recently, the emergence of Bluetongue virus in northern Europe (Gould, 2009)

#### **2.2.3 Chikungunya**

Chikungunya is a viral disease that is spread by mosquitoes. It causes fever and severe joint pain. Other symptoms include muscle pain, headache, nausea, fatigue and rash. The disease shares some clinical signs with dengue, and can be misdiagnosed in areas where dengue is common. There is no cure for the disease. Treatment is focused on relieving the symptoms. The proximity of mosquito breeding sites to human habitation is a significant risk factor for Chikungunya.

The Indian capital city of Delhi reported its first ever case of Chikungunya in June 2007.Any new disease in any new region where it was previously not known to occur is certainly a cause of concern, as it is an emergence of a new infectious agent in a hitherto 'virgin' region. It could be a manifestation of disturbed equilibrium in the ecology of a given region. New epidemics in the new regions are a definite signs of an ecological ill health. Hence, if the ongoing climate change can lead to ecological disturbances, it is likely to bring in changes in distribution of vector borne disease like Chikungunya and other vector borne diseases (Patil, 2011)

#### **2.2.4 Lyme disease**

Lyme disease, or Lyme borreliosis,is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. The disease is named after the town of Lyme, Connecticut, USA, where a number of cases were identified in 1975. Lyme disease is the most common tick-borne disease in the hemisphere. Early symptoms may include fever, headache, fatigue, depression, and a characteristic circular skin rash called erythema migrans. Left untreated, later symptoms may involve the joints, heart, and central nervous system (Ryan, 2004)

Climate change will increase the geographical distribution of Lyme disease. Lyme disease is spread by blacklegged tick bites. A survey conducted from 1992 to 2006 indicates that the

Climate Change and Health Effects 41

other diseases through influx or outpouring of infected population e.g. malaria parasitemia may alter the host and herd immunity leading to increased susceptibility. The vicious cycle

About Climate change affects food and nutrition security and further undermines current efforts to reduce hunger and protect and promote nutrition. Additionally, under nutrition in turn undermines the resilience to shocks and the coping mechanisms of vulnerable populations, lessening their capacities to resist and adapt to the consequences of climate change. Climate change further exacerbates the already unacceptably high levels of hunger and under nutrition. Climate change will increase the risk of hunger and under nutrition over the next few decades and challenges the realization of the human rights for health and adequate food. Climate change will affect nutrition through different causal pathways that impact food security, sanitation, water and food safety, health, maternal and child health care practices and many socioeconomic factors. Climate change negatively affects food availability, conservation, access and utilization and exacerbates socioeconomic risks and vulnerabilities. According to the IPCC if current trends continue, it is estimated that 200–600 million more people will suffer from hunger by 2080. Calorie availability in 2050 is likely to decline throughout the developing world resulting in an additional million undernourished children, 21% more relative to a world with no climate change, almost half of which would be living in sub-Saharan Africa. Climate change negatively affects nutrition through its impacts on health and vice versa. Climate change has an impact on water availability and quality, sanitation systems, food safety and on waterborne, food borne, vector-borne and other infectious diseases which eventually both increase nutritional needs and reduce the absorption of nutrients and their utilization by the body. Mitigation is critical to limit impact of climate change on food security and nutrition in low and middle income countries in the future. However, mitigation strategies should not increase food and nutrition insecurity. For example, bio fuel production can have a negative impact on food production and nutrition. Bio fuel production requires large amounts of natural resources (arable land, water, labor, etc.) that might thus be diverted from the cultivation of food crops10 (UNSCN, 2010).

About 46% of the DALYs attributable to climate change were estimated to have occurred in the WHO South-East Asia Region, 23% in countries in the Africa region with high child mortality and very high adult male mortality, and 14% in countries in the Eastern Mediterranean region with high child and adult male mortality. The relative risk estimates for malnutrition, diarrheal diseases, and malaria, respectively, projected for 2030 under the alternative exposure scenarios. The relative risks of malnutrition is directly proportional to underweight; this applies to all diseases affected by underweight (including diarrhea and

With "high" or "very high confidence" the IPCC predicts the following, by 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%. Agricultural production, including access to food, in many countries is projected to be severely compromised. This would further adversely affect food security and exacerbate malnutrition. According to the IPCC, GCC threatens the health, happiness and even survival of literally hundreds of millions of people, through increased risk of malnutrition

between malnutrition and life threatening infectious disease is well demonstrated

**3.1 Effect of climate change on malnutrition** 

malaria) (McMichael, 2004).

**3.2 Effect of climate change on food security** 

incidence of Lyme disease is increasing and rates are highest among children age 5–14 years. The number of reported cases of Lyme disease more than doubled during this time period.19 Children are especially vulnerable to tick bites because they tend to play outside and close to the ground (EPA, u.d) Effect of Climate change on other vector borne diseases

**West Nile virus** is spread by infected mosquitoes, and can cause serious, life-altering and even fatal disease. The main route of human infection is through the bite of an infected mosquito. Approximately 90% of West Nile Virus infections in humans are either without any symptoms or very vague symptoms with fever and generalized body pain. The temperature thresholds for WNV survival are not documented, but laboratory studies indicate that the ability of competent vectors to transmit the virus is favored by higher temperatures and the vector's temperature-dependent survival pattern. Climate change may lengthen survival periods of WNV-competent Anopheles) mosquitoes (Table 8) and possibly allow infected hosts (birds) to change their geographic range. These could result in changes in virus prevalence rates and distribution. Therefore, climate change may increase WNV transmission risk. Leishmaniasis. The current environment is conducive to Phlebotomus sandfly survival for several months. Climate change might decrease the number of days suitable for Phlebotomus ariasi. The risk of contracting leishmaniasis may become high.

**Mediterranean spotted fever.** The abundant and widespread distribution of the tick as well as the high prevalence of dogs infected with Rickettsia conorii. Because R. sanguineus has a remarkable ability to adapt to its environment, and disease transmission is highest during warmer months, even in harsher arid climatic zones where ambient temperatures exceed 35°C and soil temperatures exceed 45°C In fact, it is possible that climate change may prolong the peak season of MSF cases because of higher temperatures in spring and autumn. **Schistosomiasis:** Environmental conditions can be conducive to Schistosoma transmission, the competent snail population may be infected, and the risk of transmission could be high. Assuming ambient air temperatures as approximations of shallow water temperatures (which affect parasite and vector survival), it is clear that climate change might lengthen parasite Survival periods and vector survival. Focal introduction of the parasite from infected imported human cases to the currently non infected snail population is also possible. If a focal parasite-infected snail population were to occur, if a warmer climate scenario is assumed and that the infected vector population may with time widen its geographic distribution as the favorable temperature period for survival increases significantly, then disease transmission risk may increase toward a medium level (Casimiro, 2006).

### **3. Food security**

Climate change together with other factors can have serious implication on food security consequently resulting in Malnutrition due to following reasons:

**Decreased Agricultural Yield**: Agricultural production and food security are also linked directly to precipitation patterns – this impacts the nutritional status of the population. Excess or Scarcity of Water resulting from draught, floods, heavy rains can adversely affect agricultural output. Salinization of fertile land : **Rising sea levels** increase the risk of coastal flooding of agricultural land due to sea levels rise leading to decreased yield of crops resulting in malnutrition.**Population Migrations:** Population displacement and also rural to urban migration carries its own health risks e.g., malnutrition and increased risks of communicable diseases. Increased rates of malnutrition as they become more susceptible to

incidence of Lyme disease is increasing and rates are highest among children age 5–14 years. The number of reported cases of Lyme disease more than doubled during this time period.19 Children are especially vulnerable to tick bites because they tend to play outside and close to the ground (EPA, u.d) Effect of Climate change on other vector borne diseases **West Nile virus** is spread by infected mosquitoes, and can cause serious, life-altering and even fatal disease. The main route of human infection is through the bite of an infected mosquito. Approximately 90% of West Nile Virus infections in humans are either without any symptoms or very vague symptoms with fever and generalized body pain. The temperature thresholds for WNV survival are not documented, but laboratory studies indicate that the ability of competent vectors to transmit the virus is favored by higher temperatures and the vector's temperature-dependent survival pattern. Climate change may lengthen survival periods of WNV-competent Anopheles) mosquitoes (Table 8) and possibly allow infected hosts (birds) to change their geographic range. These could result in changes in virus prevalence rates and distribution. Therefore, climate change may increase WNV transmission risk. Leishmaniasis. The current environment is conducive to Phlebotomus sandfly survival for several months. Climate change might decrease the number of days suitable for Phlebotomus ariasi. The risk of contracting leishmaniasis may become high. **Mediterranean spotted fever.** The abundant and widespread distribution of the tick as well as the high prevalence of dogs infected with Rickettsia conorii. Because R. sanguineus has a remarkable ability to adapt to its environment, and disease transmission is highest during warmer months, even in harsher arid climatic zones where ambient temperatures exceed 35°C and soil temperatures exceed 45°C In fact, it is possible that climate change may prolong the peak season of MSF cases because of higher temperatures in spring and autumn. **Schistosomiasis:** Environmental conditions can be conducive to Schistosoma transmission, the competent snail population may be infected, and the risk of transmission could be high. Assuming ambient air temperatures as approximations of shallow water temperatures (which affect parasite and vector survival), it is clear that climate change might lengthen parasite Survival periods and vector survival. Focal introduction of the parasite from infected imported human cases to the currently non infected snail population is also possible. If a focal parasite-infected snail population were to occur, if a warmer climate scenario is assumed and that the infected vector population may with time widen its geographic distribution as the favorable temperature period for survival increases significantly, then disease transmission risk may increase toward a medium level (Casimiro,

Climate change together with other factors can have serious implication on food security

**Decreased Agricultural Yield**: Agricultural production and food security are also linked directly to precipitation patterns – this impacts the nutritional status of the population. Excess or Scarcity of Water resulting from draught, floods, heavy rains can adversely affect agricultural output. Salinization of fertile land : **Rising sea levels** increase the risk of coastal flooding of agricultural land due to sea levels rise leading to decreased yield of crops resulting in malnutrition.**Population Migrations:** Population displacement and also rural to urban migration carries its own health risks e.g., malnutrition and increased risks of communicable diseases. Increased rates of malnutrition as they become more susceptible to

consequently resulting in Malnutrition due to following reasons:

2006).

**3. Food security** 

other diseases through influx or outpouring of infected population e.g. malaria parasitemia may alter the host and herd immunity leading to increased susceptibility. The vicious cycle between malnutrition and life threatening infectious disease is well demonstrated

#### **3.1 Effect of climate change on malnutrition**

About Climate change affects food and nutrition security and further undermines current efforts to reduce hunger and protect and promote nutrition. Additionally, under nutrition in turn undermines the resilience to shocks and the coping mechanisms of vulnerable populations, lessening their capacities to resist and adapt to the consequences of climate change. Climate change further exacerbates the already unacceptably high levels of hunger and under nutrition. Climate change will increase the risk of hunger and under nutrition over the next few decades and challenges the realization of the human rights for health and adequate food. Climate change will affect nutrition through different causal pathways that impact food security, sanitation, water and food safety, health, maternal and child health care practices and many socioeconomic factors. Climate change negatively affects food availability, conservation, access and utilization and exacerbates socioeconomic risks and vulnerabilities. According to the IPCC if current trends continue, it is estimated that 200–600 million more people will suffer from hunger by 2080. Calorie availability in 2050 is likely to decline throughout the developing world resulting in an additional million undernourished children, 21% more relative to a world with no climate change, almost half of which would be living in sub-Saharan Africa. Climate change negatively affects nutrition through its impacts on health and vice versa. Climate change has an impact on water availability and quality, sanitation systems, food safety and on waterborne, food borne, vector-borne and other infectious diseases which eventually both increase nutritional needs and reduce the absorption of nutrients and their utilization by the body. Mitigation is critical to limit impact of climate change on food security and nutrition in low and middle income countries in the future. However, mitigation strategies should not increase food and nutrition insecurity. For example, bio fuel production can have a negative impact on food production and nutrition. Bio fuel production requires large amounts of natural resources (arable land, water, labor, etc.) that might thus be diverted from the cultivation of food crops10 (UNSCN, 2010).

About 46% of the DALYs attributable to climate change were estimated to have occurred in the WHO South-East Asia Region, 23% in countries in the Africa region with high child mortality and very high adult male mortality, and 14% in countries in the Eastern Mediterranean region with high child and adult male mortality. The relative risk estimates for malnutrition, diarrheal diseases, and malaria, respectively, projected for 2030 under the alternative exposure scenarios. The relative risks of malnutrition is directly proportional to underweight; this applies to all diseases affected by underweight (including diarrhea and malaria) (McMichael, 2004).

#### **3.2 Effect of climate change on food security**

With "high" or "very high confidence" the IPCC predicts the following, by 2020, in some countries, yields from rain-fed agriculture could be reduced by up to 50%. Agricultural production, including access to food, in many countries is projected to be severely compromised. This would further adversely affect food security and exacerbate malnutrition. According to the IPCC, GCC threatens the health, happiness and even survival of literally hundreds of millions of people, through increased risk of malnutrition

Climate Change and Health Effects 43

drinking water. Exposure may also occur via the inhalation of particulates or volatiles, or from direct contact with water bodies or agricultural soils (e.g., during recreation). The importance of each exposure pathway will depend on the pathogen or chemical type. The main environmental pathways from the farm to the wider population will be from

At a basic level, for many farmers the challenge will be whether they can continue to farm. Already rural livelihoods at household level are highly diverse, with farming accounting for a lower proportion of disposable income and food security for farming households than 20 years ago. For example, concludes that "diversification out of agriculture has become the norm among African rural populations." There is evidence that households moving out of poverty are those moving either completely or partially out of farming. It is likely that many households will respond to the challenge of climate change by seeking further to diversify into non-farm livelihood activities either in situ or by moving (or sending more family members) to urban centers. For these households, farming may remain as (or revert to) a semi-subsistence activity while cash is generated elsewhere. This would be simply a continuation of a wellestablished trend towards pluriactive, multi-locational families and the transfer of resources through urban–rural remittances. However, given the acute population and development related challenges faced by most African nations, many households will be forced to remain in the farming sector for livelihood and security for some time to come as the population in Africa undergoes a three-fold increase this century. This will lead to considerable demand for expansion of area under small-farm cultivation for staple crops. Farming for profit, particularly production for international markets, may therefore become more concentrated on fewer farms, as is already happening in the fresh vegetable export market from eastern and southern Africa. Companies with the capital to invest in controlling their production environment through irrigation, netting and crop protection in order to meet stringent quality and bio-safety requirements of European supermarkets are increasing their market share at the expense of smallholders. This should lead to further irrigation development, and contribute to

High temperatures, water scarcity and water abundance resulting from flooding or heavy precipitation have been shown to be related to diarrheal diseases. Heavy rainfall, even without flooding, may increase rates of diarrheal disease as sewage systems overflow.

A lack of availability of water for personal hygiene and washing of food may lead to an increase in diarrheal disease and other diseases associated with poor hygiene. It is important to note that high temperatures in itself an independent risk factor for increased rates of

Clearly, the health implications of changes to water supply are far-reaching. Currently, more than 3 million people die each year from avoidable water-related disease, most of whom are in developing countries. The effects of climate change on water will exacerbate the existing

implications of water shortages on human health (Water Aid u.d), as follows:

consumption of contaminated drinking waters and food (Alistair et al, 2009).

**3.5 Migration/shift in occupation** 

a recommended doubling of irrigated land by 2015.

**4.1 Climate change and water borne disease** 

Increases in soil run-off may contaminate water sources

diarrheal diseases, including salmonella and cholera.

**4. Water borne diseases** 

and starvation, and increased frequency of deadly weather events (Philos, 2010). In the socio-economics literature on rural livelihoods, it is widely accepted that farming households face three main sources of vulnerability : shocks (unexpected extreme events, for example the sudden death of a family member, or an extreme weather event), seasonal variations (including variations in periodicity and amount of rainfall) and long term trends (such as increases in input prices, or long term changes in mean temperature and rainfall). The problems from all three are likely to increase in intensity, particularly for farmers relying on rain-fed production. Small-scale farming provides most of the food production, as well as employment for 70% of working people. These small-scale producers already face the challenges of climate variability in current climates. For example, intra-seasonal distribution of rainfall affects the timing and duration of the possible cropping season, and periods of drought stress during crop growth. Cropping practices that are often used to mitigate the effects of variable rainfall (Challinor et al, 2007).

Looking at individual sectors, the equity implications of climate change are most pronounced for food security. Low-emission countries are, in general, more adversely impacted (in terms of projected future yield changes of staple crops), more exposed (in terms of the share of agriculture in gross domestic product and labor force), and less able to cope with adverse impacts (in terms of the current level of under nutrition). The analysis for human health also implies that those least responsible for climate change will be most affected by its adverse impacts. Countries with low emissions levels have, on average, a lower current health status (measured by infant mortality and life expectancy), higher socioeconomic vulnerability to extreme weather events, and already experience stronger adverse climate impacts on human health (Fussel, 2009).

#### **3.3 Pests**

The reproductive success of predators depends, food abundance and population density and their interactions may respond to changes in climatic conditions. Timing of reproduction may increase, during a period of temperature increase. Few studies have investigated how climate change affects predator–prey and parasite–host interactions, although such effects are widely predicted to be key for understanding community level effects of climate change. Theoretical studies suggest that predators and parasites may be particularly susceptible to the effects of climate change due to the direct effects of climate on the distribution and the abundance of prey and host populations, respectively. However, there are only few empirical studies indicating that the ability of hosts to defend themselves against parasites is strongly influenced by environmental conditions. The North Atlantic Oscillation has been shown to affect predator–prey cycles in the Canadian arctic. Studies of the great tit Parus major and its caterpillar prey have shown increasing mal-adaptation of timing of breeding to maximum availability of prey, providing a cause for concern (Nielsen & Moler, 2006).

#### **3.4 Effects of agricultural chemicals and pathogens on human health**

Humans may be exposed to agriculturally derived chemicals and pathogens in the environment (i.e., air, soil, water, sediment) by a number of routes, including the consumption of crops that have been treated with pesticides or have taken up contaminants from soils; livestock that have accumulated contaminants through the food chain; fish exposed to contaminants in the aquatic environment; and groundwater and surface waters used for

and starvation, and increased frequency of deadly weather events (Philos, 2010). In the socio-economics literature on rural livelihoods, it is widely accepted that farming households face three main sources of vulnerability : shocks (unexpected extreme events, for example the sudden death of a family member, or an extreme weather event), seasonal variations (including variations in periodicity and amount of rainfall) and long term trends (such as increases in input prices, or long term changes in mean temperature and rainfall). The problems from all three are likely to increase in intensity, particularly for farmers relying on rain-fed production. Small-scale farming provides most of the food production, as well as employment for 70% of working people. These small-scale producers already face the challenges of climate variability in current climates. For example, intra-seasonal distribution of rainfall affects the timing and duration of the possible cropping season, and periods of drought stress during crop growth. Cropping practices that are often used to

Looking at individual sectors, the equity implications of climate change are most pronounced for food security. Low-emission countries are, in general, more adversely impacted (in terms of projected future yield changes of staple crops), more exposed (in terms of the share of agriculture in gross domestic product and labor force), and less able to cope with adverse impacts (in terms of the current level of under nutrition). The analysis for human health also implies that those least responsible for climate change will be most affected by its adverse impacts. Countries with low emissions levels have, on average, a lower current health status (measured by infant mortality and life expectancy), higher socioeconomic vulnerability to extreme weather events, and already experience stronger adverse

The reproductive success of predators depends, food abundance and population density and their interactions may respond to changes in climatic conditions. Timing of reproduction may increase, during a period of temperature increase. Few studies have investigated how climate change affects predator–prey and parasite–host interactions, although such effects are widely predicted to be key for understanding community level effects of climate change. Theoretical studies suggest that predators and parasites may be particularly susceptible to the effects of climate change due to the direct effects of climate on the distribution and the abundance of prey and host populations, respectively. However, there are only few empirical studies indicating that the ability of hosts to defend themselves against parasites is strongly influenced by environmental conditions. The North Atlantic Oscillation has been shown to affect predator–prey cycles in the Canadian arctic. Studies of the great tit Parus major and its caterpillar prey have shown increasing mal-adaptation of timing of breeding to maximum availability of prey, providing a cause for concern (Nielsen

**3.4 Effects of agricultural chemicals and pathogens on human health** 

Humans may be exposed to agriculturally derived chemicals and pathogens in the environment (i.e., air, soil, water, sediment) by a number of routes, including the consumption of crops that have been treated with pesticides or have taken up contaminants from soils; livestock that have accumulated contaminants through the food chain; fish exposed to contaminants in the aquatic environment; and groundwater and surface waters used for

mitigate the effects of variable rainfall (Challinor et al, 2007).

climate impacts on human health (Fussel, 2009).

**3.3 Pests** 

& Moler, 2006).

drinking water. Exposure may also occur via the inhalation of particulates or volatiles, or from direct contact with water bodies or agricultural soils (e.g., during recreation). The importance of each exposure pathway will depend on the pathogen or chemical type. The main environmental pathways from the farm to the wider population will be from consumption of contaminated drinking waters and food (Alistair et al, 2009).

#### **3.5 Migration/shift in occupation**

At a basic level, for many farmers the challenge will be whether they can continue to farm. Already rural livelihoods at household level are highly diverse, with farming accounting for a lower proportion of disposable income and food security for farming households than 20 years ago. For example, concludes that "diversification out of agriculture has become the norm among African rural populations." There is evidence that households moving out of poverty are those moving either completely or partially out of farming. It is likely that many households will respond to the challenge of climate change by seeking further to diversify into non-farm livelihood activities either in situ or by moving (or sending more family members) to urban centers. For these households, farming may remain as (or revert to) a semi-subsistence activity while cash is generated elsewhere. This would be simply a continuation of a wellestablished trend towards pluriactive, multi-locational families and the transfer of resources through urban–rural remittances. However, given the acute population and development related challenges faced by most African nations, many households will be forced to remain in the farming sector for livelihood and security for some time to come as the population in Africa undergoes a three-fold increase this century. This will lead to considerable demand for expansion of area under small-farm cultivation for staple crops. Farming for profit, particularly production for international markets, may therefore become more concentrated on fewer farms, as is already happening in the fresh vegetable export market from eastern and southern Africa. Companies with the capital to invest in controlling their production environment through irrigation, netting and crop protection in order to meet stringent quality and bio-safety requirements of European supermarkets are increasing their market share at the expense of smallholders. This should lead to further irrigation development, and contribute to a recommended doubling of irrigated land by 2015.

#### **4. Water borne diseases**

#### **4.1 Climate change and water borne disease**

High temperatures, water scarcity and water abundance resulting from flooding or heavy precipitation have been shown to be related to diarrheal diseases. Heavy rainfall, even without flooding, may increase rates of diarrheal disease as sewage systems overflow. Increases in soil run-off may contaminate water sources

A lack of availability of water for personal hygiene and washing of food may lead to an increase in diarrheal disease and other diseases associated with poor hygiene. It is important to note that high temperatures in itself an independent risk factor for increased rates of diarrheal diseases, including salmonella and cholera.

Clearly, the health implications of changes to water supply are far-reaching. Currently, more than 3 million people die each year from avoidable water-related disease, most of whom are in developing countries. The effects of climate change on water will exacerbate the existing implications of water shortages on human health (Water Aid u.d), as follows:

Climate Change and Health Effects 45

El Niño is a phenomenon results in the namesake oscillation of wind and ocean currents, usually occurring every three to seven years, there is concern that climate change will increase its frequency or the severity of its consequences. These, in turn, change regional temperatures and precipitation patterns and lead to significantly increased rainfall. Several researchers have established a link between heavy rainfall and flooding—whether resulting from El Niño-associated events or from other meteorological impacts—and subsequent outbreaks of infectious diseases. Extreme meteorological events can easily disrupt water purification and storm water and sewage systems, as well as contaminate uncovered wells and surface water, leading to an increased risk of illness. These risks are even higher when a population lives in a low-lying area, where the land's hydrology causes draining tributaries to meet. Conversely, heavy rains and coastal events can also flush microorganisms into watersheds, affecting those up-coast as well. Nonsustainable development, such as that which contributes to deforestation and soil erosion, influences water contamination by destroying the land's natural ability to absorb runoff, resulting in water-contaminating

Climate change can result in increased temperatures in both ocean water and ambient air. Increased sea temperatures have a direct effect on the proliferation of plankton and algae in sea water. Vibrio species organisms, including V. cholera, thrive in particular sea conditions. Among these are warm water, moderate salinity, and number of aquatic invertebrates, all conditions influenced by climate change. In particular, the quantity of vibrio species may increase or the range of the bacteria may extend. Many causative agents of diarrheal disease have a seasonal variability, with peaks in the warmer months. Increased temperatures or higher temperatures for longer times can result in higher than expected diarrhea incidence. Finally, rises in sea level due to increased temperatures can lead to coastal flooding, which can force the use of contaminated water, overwhelm sanitation systems, or prompt migration into areas with insecure water and

Climate change has begun to negatively affect human health, with larger burdens projected in the future as weather patterns continue to change. The climate change-related health consequences like diarrheal diseases (Kristie, 2008). Recent studies examining the potential impacts of climate variability and change on the risks and incidence of water- and food borne illnesses conclude that that the risk of water- and food-borne illness will likely increase with climate change. Studies suggest that extreme precipitation events increase the loading of contaminants to waterways, climate change could increase the risk of illness associated with Cryptosporidium parvum, association between increases in the lagged monthly mean temperature and increases in the number of notifications of salmonellosis

Climate Change also change patterns of air movement and pollution, causing expanded or changed patterns of human exposure and resulting health effects. The formation of many

**4.3 El Niño and severe rainfall/flooding and potential health effects** 

mudslides(Reiter, 2007).

infections (Ebi et al, 2006).

**5. Air quality and health** 

**4.4 Cholera and diarrheal diseases** 

sanitation availability (Fricas & Tylor, 2007).

**5.1 Effect of climate change on air quality** 

Water-borne diseases: result from the contamination of water by human/ animal faeces, or by urine infected with pathogenic viruses/ bacteria, both of which are more likely to occur during periods of flood.


Climate change may affect the growth and survival of disease-causing organism's related to water- and food-borne illness. The incidence of water- and food-borne illnesses, such as gastroenteritis and infectious diarrhea, is known to increase when outdoor temperature increases, or immediately following storms or floods. Extreme weather can result in the breakdown of sanitation and sewer systems, a loss of power for refrigeration, or inadequate means to thoroughly cook food, increasing the likelihood of water- and food-borne illness. Children are especially susceptible to water- and food-borne illness due to their developing immune systems. In fact, infectious diarrhea is responsible for approximately 1.5 million child deaths per year globally, disproportionately affecting children of developing nations (EPA u.d).

Knowledge about transport processes and the fate of microbial pollutants associated with rainfall and snowmelt is key to predicting risks from a change in weather variability. Although recent studies identified links between climate variability and occurrence of microbial agents in water, the relationships need further quantification in the context of other stresses. In the marine environment as well, there are few studies that adequately address the potential health effects of climate variability in combination with other stresses such as overfishing, introduced species, and rise in sea level. Advances in monitoring are necessary to enhance early-warning and prevention capabilities. Application of existing technologies, such as molecular fingerprinting to track contaminant sources or satellite remote sensing to detect coastal algal blooms, could be expanded. This assessment recommends incorporating a range of future scenarios of improvement plans for current deficiencies in the public health infrastructure to achieve more realistic risk assessments (Bose et al, 2001).

#### **4.2 Harmful algae bloom**

A worldwide increase in cyanobacterial (blue-green algae) sources has been observed in both coastal and freshwaters. These harmful algae blooms (HABs), which produce nerve and liver toxins, are longer in duration, of greater intensity, and are suspected of being tied both to increased temperatures due to climate change and nutrient runoff. Exposure to marine toxins has resulted in death and poisonings of California sea lions and Florida alligators. Human exposure is of concern through both drinking water contamination and recreational exposure (English et al, 2009).

Water-borne diseases: result from the contamination of water by human/ animal faeces, or by urine infected with pathogenic viruses/ bacteria, both of which are more likely to occur

 Water-washed diseases: those resulting from inadequate personal hygiene as a result of scarcity or inaccessibility of water (including many water-borne diseases and

Water-based diseases: those caused by parasites that use intermediate hosts living

Water-related diseases: borne by insect vectors that has habitats in/near water (such as

 Water-dispersed diseases: infections for which the agents proliferate in fresh water and enter the human body through the respiratory tract (e.g. legionella).Climate change and

Climate change may affect the growth and survival of disease-causing organism's related to water- and food-borne illness. The incidence of water- and food-borne illnesses, such as gastroenteritis and infectious diarrhea, is known to increase when outdoor temperature increases, or immediately following storms or floods. Extreme weather can result in the breakdown of sanitation and sewer systems, a loss of power for refrigeration, or inadequate means to thoroughly cook food, increasing the likelihood of water- and food-borne illness. Children are especially susceptible to water- and food-borne illness due to their developing immune systems. In fact, infectious diarrhea is responsible for approximately 1.5 million child deaths per year globally, disproportionately affecting children of developing nations

Knowledge about transport processes and the fate of microbial pollutants associated with rainfall and snowmelt is key to predicting risks from a change in weather variability. Although recent studies identified links between climate variability and occurrence of microbial agents in water, the relationships need further quantification in the context of other stresses. In the marine environment as well, there are few studies that adequately address the potential health effects of climate variability in combination with other stresses such as overfishing, introduced species, and rise in sea level. Advances in monitoring are necessary to enhance early-warning and prevention capabilities. Application of existing technologies, such as molecular fingerprinting to track contaminant sources or satellite remote sensing to detect coastal algal blooms, could be expanded. This assessment recommends incorporating a range of future scenarios of improvement plans for current deficiencies in the public health infrastructure to achieve more realistic risk assessments

A worldwide increase in cyanobacterial (blue-green algae) sources has been observed in both coastal and freshwaters. These harmful algae blooms (HABs), which produce nerve and liver toxins, are longer in duration, of greater intensity, and are suspected of being tied both to increased temperatures due to climate change and nutrient runoff. Exposure to marine toxins has resulted in death and poisonings of California sea lions and Florida alligators. Human exposure is of concern through both drinking water contamination and

during periods of flood.

in/near water (e.g. guinea worm).

typhus).

malaria

(EPA u.d).

(Bose et al, 2001).

**4.2 Harmful algae bloom** 

recreational exposure (English et al, 2009).

water resources

#### **4.3 El Niño and severe rainfall/flooding and potential health effects**

El Niño is a phenomenon results in the namesake oscillation of wind and ocean currents, usually occurring every three to seven years, there is concern that climate change will increase its frequency or the severity of its consequences. These, in turn, change regional temperatures and precipitation patterns and lead to significantly increased rainfall. Several researchers have established a link between heavy rainfall and flooding—whether resulting from El Niño-associated events or from other meteorological impacts—and subsequent outbreaks of infectious diseases. Extreme meteorological events can easily disrupt water purification and storm water and sewage systems, as well as contaminate uncovered wells and surface water, leading to an increased risk of illness. These risks are even higher when a population lives in a low-lying area, where the land's hydrology causes draining tributaries to meet. Conversely, heavy rains and coastal events can also flush microorganisms into watersheds, affecting those up-coast as well. Nonsustainable development, such as that which contributes to deforestation and soil erosion, influences water contamination by destroying the land's natural ability to absorb runoff, resulting in water-contaminating mudslides(Reiter, 2007).

#### **4.4 Cholera and diarrheal diseases**

Climate change can result in increased temperatures in both ocean water and ambient air. Increased sea temperatures have a direct effect on the proliferation of plankton and algae in sea water. Vibrio species organisms, including V. cholera, thrive in particular sea conditions. Among these are warm water, moderate salinity, and number of aquatic invertebrates, all conditions influenced by climate change. In particular, the quantity of vibrio species may increase or the range of the bacteria may extend. Many causative agents of diarrheal disease have a seasonal variability, with peaks in the warmer months. Increased temperatures or higher temperatures for longer times can result in higher than expected diarrhea incidence. Finally, rises in sea level due to increased temperatures can lead to coastal flooding, which can force the use of contaminated water, overwhelm sanitation systems, or prompt migration into areas with insecure water and sanitation availability (Fricas & Tylor, 2007).

Climate change has begun to negatively affect human health, with larger burdens projected in the future as weather patterns continue to change. The climate change-related health consequences like diarrheal diseases (Kristie, 2008). Recent studies examining the potential impacts of climate variability and change on the risks and incidence of water- and food borne illnesses conclude that that the risk of water- and food-borne illness will likely increase with climate change. Studies suggest that extreme precipitation events increase the loading of contaminants to waterways, climate change could increase the risk of illness associated with Cryptosporidium parvum, association between increases in the lagged monthly mean temperature and increases in the number of notifications of salmonellosis infections (Ebi et al, 2006).

#### **5. Air quality and health**

#### **5.1 Effect of climate change on air quality**

Climate Change also change patterns of air movement and pollution, causing expanded or changed patterns of human exposure and resulting health effects. The formation of many

Climate Change and Health Effects 47

indoors and who are less active. Asthmatics are also a potentially vulnerable subgroup

Pollen allergy currently affects significant proportion of the population. A warmer climate will lead to a longer pollen season and more days with high pollen counts. In addition, a warmer climate increases the risk of proliferation of new plants with well-known allergenic pollens like ragweed, plane tree and wall pellitory. The consequences will be more people with hay fever and pollen asthma, longer allergy seasons and an increase in the severity of symptoms, disease-related costs and demands on health care for diagnosis and treatment of more complex allergies. It is clearly identified that climate change can exert a range of effects on pollen, which might have consequences for pollen-allergic patients. The pollen season might become longer thereby extending the period in which patients suffer from allergy symptoms. This extension of the pollen season could be due to a prolonged flowering period of certain species, e.g. grasses, or the appearance of new species that flower in late summer, e.g. common ragweed. Climate change could cause an increase in heavy thunderstorms on summer days in the grass pollen season, which are known to increase the

Climate change alters the concentration and distribution of air pollutants and interferes with the seasonal presence of allergenic pollens in the atmosphere by prolonging these periods. The link between climate change and respiratory allergies is most importantly explained by the worsening ambient air pollution and altered local and regional pollen production. Laboratory studies confirm epidemiologic evidence that air pollution adversely affects lung function in asthmatics. Damage to airway mucous membranes and impaired mucociliary clearance caused by air pollution may facilitate access of inhaled allergens to the cells of the immune system, thus promoting sensitization of the airway. Consequently, a more severe immunoglobulin (Ig) E-mediated response to aeroallergens and airway inflammation could account for increasing prevalence of allergic respiratory diseases in polluted urban areas

Aeroallergens that may respond to climate change include outdoor pollens generated by trees, grasses, and weeds, and spores released by outdoor or indoor molds. Because climatologic influences differ for these different classes of aeroallergens, they are discussed separately here. As compared with pollens, molds have been much less studied. This may reflect in part the relative paucity of routine mold monitoring data from which trends might be analyzed, as well as the complex relationships among climate factors, mold growth, spore release, and airborne measurements.63 In addition to potential effects on outdoor mold growth and allergen release related to changing climate variables, there is also concern about indoor mold growth in association with rising air moisture and especially after extreme storms, which can cause widespread indoor moisture problems from flooding and leaks in the building envelope. Molds need high levels of surface moisture to become

The urban heat island effect, a combination of anthropogenic and climatologic heat, can increase urban temperatures as much as 5°C compared with rural locations and further

(Ebi, u.d).

**6. Climate change and allergies** 

chance of asthma exacerbations (sommer et al, 2009).

(D'Amato et al, 2010).

established and flourish (Kinney, 2008).

drive the formation of ozone.

**6.1 Molds** 

air-pollutants is determined in part by climate factors such as temperature and humidity. In addition the transport and dispersion of air pollutants away from source regions are strongly affected by weather factors. Climate change therefore influence pollutant concentrations, which in turn may affect health as air pollution is related to cardiorespiratory health

Climate and and air quality are closely coupled. Conventional pollutants, such as ozone and particle pollution, not only affect public health but also contribute to climate change. Ozone is a significant greenhouse gas (GHG) and particles can influence the climate by scattering, reflecting, and/or absorbing incoming solar radiation and interacting with various cloud processes. Due to climate change, the IPCC predicted "declining air quality in cities." In summarizing the impact of climate change on ozone and particle pollution, the IPCC concluded that "future climate change may cause significant air quality degradation by changing the dispersion rate of pollutants; the Chemical environment for ozone and particle pollution generation; and the strength of emissions from the biosphere, fires, and dust." Though a great deal of uncertainty remains regarding the expected future impacts of climate change on air quality, recent research suggests that such effects may be very significant, particularly on a local or regional scale (EPA, 2010)

Health effects of air quality the formation of many air-pollutants is determined in part by climate factors such as temperature and humidity. In addition the transport and dispersion of air pollutants away from source regions are strongly affected by weather factors. Climate change may therefore influence pollutant concentrations, which in turn may affect health as air pollution is related to cardio-respiratory health. Exposure to high levels of ground-level ozone, for example, which is formed from the exhaust of transport vehicles, increases the risk of exacerbations of respiratory diseases such as chronic obstructive airways disease and asthma, leading to hospital admissions or increased mortality. The number of forest and bush fires may increase as certain regions face longer periods of extreme dry conditions and such fires can contribute to air-pollution. The direction and magnitude of the effects of climate change on air pollution levels are however highly uncertain and there will be regional variations. National energy policies and transport policies should take into account the health effects of air-pollution40 and early warning systems for levels of air pollution can be implemented. Reducing emission from transport vehicles is a win-win solution contributing both improve health as well as reduce greenhouse gas emissions (Nerlander, 2009).

#### **5.2 Ozone**

Because ozone formation increases with greater sunlight and higher temperatures, it reaches unhealthy levels primarily during the warm half of the year. Daily peaks occur near midday in urban areas, and in the afternoon or early evening in downwind areas. It has been firmly established that breathing ozone can cause inflammation in the deep lung as well as shortterm, reversible decreases in lung function. In addition, epidemiologic studies of people living in polluted areas have suggested that ozone can increase the risk of asthma-related hospital visits and premature mortality. Vulnerability to ozone effects on the lungs is greater for people who spend time outdoors during ozone periods, especially those who engage in physical exertion, which results in a higher cumulative dose to the lungs. Thus, children, outdoor laborers, and athletes all may be at greater risk than people who spend more time

air-pollutants is determined in part by climate factors such as temperature and humidity. In addition the transport and dispersion of air pollutants away from source regions are strongly affected by weather factors. Climate change therefore influence pollutant concentrations, which in turn may affect health as air pollution is related to cardio-

Climate and and air quality are closely coupled. Conventional pollutants, such as ozone and particle pollution, not only affect public health but also contribute to climate change. Ozone is a significant greenhouse gas (GHG) and particles can influence the climate by scattering, reflecting, and/or absorbing incoming solar radiation and interacting with various cloud processes. Due to climate change, the IPCC predicted "declining air quality in cities." In summarizing the impact of climate change on ozone and particle pollution, the IPCC concluded that "future climate change may cause significant air quality degradation by changing the dispersion rate of pollutants; the Chemical environment for ozone and particle pollution generation; and the strength of emissions from the biosphere, fires, and dust." Though a great deal of uncertainty remains regarding the expected future impacts of climate change on air quality, recent research suggests that such effects may be very significant,

Health effects of air quality the formation of many air-pollutants is determined in part by climate factors such as temperature and humidity. In addition the transport and dispersion of air pollutants away from source regions are strongly affected by weather factors. Climate change may therefore influence pollutant concentrations, which in turn may affect health as air pollution is related to cardio-respiratory health. Exposure to high levels of ground-level ozone, for example, which is formed from the exhaust of transport vehicles, increases the risk of exacerbations of respiratory diseases such as chronic obstructive airways disease and asthma, leading to hospital admissions or increased mortality. The number of forest and bush fires may increase as certain regions face longer periods of extreme dry conditions and such fires can contribute to air-pollution. The direction and magnitude of the effects of climate change on air pollution levels are however highly uncertain and there will be regional variations. National energy policies and transport policies should take into account the health effects of air-pollution40 and early warning systems for levels of air pollution can be implemented. Reducing emission from transport vehicles is a win-win solution contributing both improve health as well as reduce greenhouse gas emissions (Nerlander,

Because ozone formation increases with greater sunlight and higher temperatures, it reaches unhealthy levels primarily during the warm half of the year. Daily peaks occur near midday in urban areas, and in the afternoon or early evening in downwind areas. It has been firmly established that breathing ozone can cause inflammation in the deep lung as well as shortterm, reversible decreases in lung function. In addition, epidemiologic studies of people living in polluted areas have suggested that ozone can increase the risk of asthma-related hospital visits and premature mortality. Vulnerability to ozone effects on the lungs is greater for people who spend time outdoors during ozone periods, especially those who engage in physical exertion, which results in a higher cumulative dose to the lungs. Thus, children, outdoor laborers, and athletes all may be at greater risk than people who spend more time

respiratory health

2009).

**5.2 Ozone** 

particularly on a local or regional scale (EPA, 2010)

indoors and who are less active. Asthmatics are also a potentially vulnerable subgroup (Ebi, u.d).
