**7.1 Biological water contaminants**

Water and food contaminated by microorganisms are major contributing factors for the emerging diarrheal diseases in the developing countries, and over 1 billion children under the age of 5 years are affected worldwide [26]. The high prevalence of deaths related to food and water contamination in developing countries could be attributed to several factors. For example, in many African

**47**

African countries.

*Unlocking Water Issues Towards Food Security in Africa DOI: http://dx.doi.org/10.5772/intechopen.86788*

within the dairy industry.

**7.2 Chemical hazards**

food safety challenges.

countries, milk and dairy production constitute an important source of livelihoods for most peasant and smallholder farmers. Furthermore, animal production has become part of agricultural diversification strategy for most African countries in an attempt to ensure food security. The intensification of animal production has also generated a considerable impact on the environment considering the fact that milk provides suitable condition for the growth of different kinds of microorganisms, and microbial hazards are the most important concern

Biological agents associated with water contamination that have an impact on food safety include enteric pathogens such as bacteria, viruses, and protozoa. A study conducted in North-West Province of South Africa reported that multi-drug resistant *Staphylococcus aureus* strains were detected in samples of raw, bulk, and pasteurized milk [43]. Other common biological contaminants are *Escherichia coli*. The *E. coli* bacteria belong to the intestinal microbiota of humans and animals and are generally not harmful. Certain *E. coli* strains, however, harbor virulence factors and can cause intestinal and extra-intestinal diseases. For example, Shiga toxinproducing *Escherichia coli* zoonotic bacteria have globally been associated with

Apart from animal product contamination, biological contaminants may also occur in crop products. Foodborne outbreaks from fruit and vegetable produce have caused economic loss, food wastage and loss confidence regarding the safety of fresh produce from most African countries. Studies on the safety of fresh produce have identified water as one of the key risk factors that contribute to contamination of the farm produce. Indeed, studies have shown that most foodborne diseases are caused by consumption of fresh, perishable foods sold in informal markets [44].

Generally, mycotoxins, heavy metals, and over-application of fertilizers and pesticides are considered to be the most important chemical factors impacting on food safety in most developing countries including the African region [45]. In nature, thousands of mycotoxins occur but only a few of them present significant

Mycotoxins are secondary metabolites mainly produced by fungal species from the *Aspergillus, Penicillium, and Fusarium genera*. They often develop during production, harvest, and storage of grains and nuts in the presence of water [45]. In the food production process, mycotoxins are among the most potent mutagenic and carcinogenic substances known. Ingestion of mycotoxins poses chronic health risks such as hepatotoxicity, genotoxicity, suppression of immunity, estrogenicity,

The adverse health effects of mycotoxins are compounded by the fact that they are not completely eliminated during food processing operations and can contaminate finished processed food products [55]. The presence of mycotoxins, particularly the aflatoxins, has generated a lot of interest in the food products from African countries. The work by Maxwell (1998) evaluated the presence of aflatoxins in human body fluids and tissues in relation to child health in the tropics. The findings showed that in Ghana, Kenya, Nigeria, and Sierra Leone, 25% of cord blood samples contained aflatoxins, ranging from 7 ng/L to 65 μg/L. The major classes of aflatoxins that were identified in the African countries include B1 and M1. **Figure 1** shows the chemical structures of the most prevalent aflatoxins in

Heavy metals have also contributed negatively to the food safety status in most African countries. As such, human exposure to heavy metals in Africa has become

nephrotoxicity, teratogenicity, and carcinogenic effects [44].

various foods of animal origin, especially beef and sheep meat [40].

#### *Unlocking Water Issues Towards Food Security in Africa DOI: http://dx.doi.org/10.5772/intechopen.86788*

*Food Security in Africa*

environmental resistance capacity.

current political instabilities.

**7. Water and food safety**

conditions are poor.

physical contamination.

**7.1 Biological water contaminants**

under low rainfall, which is a result of climate change. Furthermore, the country has been experiencing high rates of pollution and depletion due to water resource unavailability. This has had major impacts on Libya's economy and social and

Considering that Libya is one of the driest countries on a global scale with high temperatures, meeting and maintaining acceptable living standards for the future is extremely difficult, especially in relation to food security. Food sufficiency remains uncertain in Libya due to its political instability coupled with poor water quality and soaring human population [54]. The country is likely to experience severe and most devastating situations and high risks of food insecurity and malnutrition with

This section discusses the relationship between water and food safety. Water is seen as an essential component in the food chain, starting from production, processing, and eventually consumption. In addition, water pollution has historically impacted on food safety, which constitutes an important threat to human health, food, and nutritional security. In most sub-Sahara African countries, food safety problems vary in nature, severity, and extent. These challenges are often exacerbated by the effect of climate change and natural disasters such as floods and hurricanes, whereby food may become contaminated by surface water that has itself been contaminated by sewage and wastewaters. It is well documented that flood waters often pick up large quantities of wastes and pathogenic bacteria from farms, sewer systems, latrines, and septic tanks. Overcrowding of the survivors after disasters may aggravate the situation, particularly if sanitary

Any breakdown in vital services, such as water supply or electricity, also adversely affects the quality of food. In the absence of electricity, cold storage may be more difficult, if not impossible, and foods may be subject to bacterial growth. This may be obtained at any stage of the food chain, from production to consumption. Lack of safe drinking water and sanitation hampers the hygienic preparation

Food safety has become a constant global concern apart from affecting human health; factors such as international trade and food security are also influenced. Consequently, most research institutions, healthcare institutions, and governments of several African countries have conducted comprehensive studies on the effect of water on food safety in various production chains. According to a recent study, the main water issues that affect food safety in low income countries include bacterial pathogens, followed by pesticide residues and healthy diet [40]. Although the reported evidence of food-borne disease is still limited, the known incidences of food borne disease in low income countries such as sub-Saharan African largely emanate from three major sources, namely biological hazards and chemical and

Water and food contaminated by microorganisms are major contributing factors for the emerging diarrheal diseases in the developing countries, and over 1 billion children under the age of 5 years are affected worldwide [26]. The high prevalence of deaths related to food and water contamination in developing countries could be attributed to several factors. For example, in many African

of food and increases the risk of food contamination.

**46**

countries, milk and dairy production constitute an important source of livelihoods for most peasant and smallholder farmers. Furthermore, animal production has become part of agricultural diversification strategy for most African countries in an attempt to ensure food security. The intensification of animal production has also generated a considerable impact on the environment considering the fact that milk provides suitable condition for the growth of different kinds of microorganisms, and microbial hazards are the most important concern within the dairy industry.

Biological agents associated with water contamination that have an impact on food safety include enteric pathogens such as bacteria, viruses, and protozoa. A study conducted in North-West Province of South Africa reported that multi-drug resistant *Staphylococcus aureus* strains were detected in samples of raw, bulk, and pasteurized milk [43]. Other common biological contaminants are *Escherichia coli*. The *E. coli* bacteria belong to the intestinal microbiota of humans and animals and are generally not harmful. Certain *E. coli* strains, however, harbor virulence factors and can cause intestinal and extra-intestinal diseases. For example, Shiga toxinproducing *Escherichia coli* zoonotic bacteria have globally been associated with various foods of animal origin, especially beef and sheep meat [40].

Apart from animal product contamination, biological contaminants may also occur in crop products. Foodborne outbreaks from fruit and vegetable produce have caused economic loss, food wastage and loss confidence regarding the safety of fresh produce from most African countries. Studies on the safety of fresh produce have identified water as one of the key risk factors that contribute to contamination of the farm produce. Indeed, studies have shown that most foodborne diseases are caused by consumption of fresh, perishable foods sold in informal markets [44].

#### **7.2 Chemical hazards**

Generally, mycotoxins, heavy metals, and over-application of fertilizers and pesticides are considered to be the most important chemical factors impacting on food safety in most developing countries including the African region [45]. In nature, thousands of mycotoxins occur but only a few of them present significant food safety challenges.

Mycotoxins are secondary metabolites mainly produced by fungal species from the *Aspergillus, Penicillium, and Fusarium genera*. They often develop during production, harvest, and storage of grains and nuts in the presence of water [45]. In the food production process, mycotoxins are among the most potent mutagenic and carcinogenic substances known. Ingestion of mycotoxins poses chronic health risks such as hepatotoxicity, genotoxicity, suppression of immunity, estrogenicity, nephrotoxicity, teratogenicity, and carcinogenic effects [44].

The adverse health effects of mycotoxins are compounded by the fact that they are not completely eliminated during food processing operations and can contaminate finished processed food products [55]. The presence of mycotoxins, particularly the aflatoxins, has generated a lot of interest in the food products from African countries. The work by Maxwell (1998) evaluated the presence of aflatoxins in human body fluids and tissues in relation to child health in the tropics. The findings showed that in Ghana, Kenya, Nigeria, and Sierra Leone, 25% of cord blood samples contained aflatoxins, ranging from 7 ng/L to 65 μg/L. The major classes of aflatoxins that were identified in the African countries include B1 and M1. **Figure 1** shows the chemical structures of the most prevalent aflatoxins in African countries.

Heavy metals have also contributed negatively to the food safety status in most African countries. As such, human exposure to heavy metals in Africa has become

**Figure 1.** *Chemical structures of aflatoxins prevalent in African countries.*

a major health risk and has received the attention of national and international environmentalists [47]. Rapid population growth, increasing urbanization, and the increasing appearance of slums and townships as a consequence of poor planning coupled with increasing industrial activities are some of the major factors that have contributed to the accumulation of heavy metals in food products. Africa has large deposits of mineral resources, and mining activities have increased with poor environmental regulations and compliance. Thus, heavy metals have constituted agents of toxic pollution of water, air, soil, and food products.

An environmental assessment report by the United Nations Environment Programme (UNEP) released in 2011, showed that drinking water, air, and agricultural soil in 10 communities from southeastern Nigeria contained over 900 times permissible levels of hydrocarbon and heavy metals [47]. The report further indicated that heavy metal pollution is a continental public health challenge in the sub-Saharan African region. Another study conducted in the Democratic Republic of Congo showed a 43-fold increase in the urinary concentration of cadmium, cobalt, lead, and uranium in human subjects including children living in mining areas compared to controls [56]. The increase in the levels of the heavy metals was largely attributed to ingestion of contaminated food products and water with toxic chemical compounds. The increasing negative effects on food safety from water and soil pollution have, therefore, potentially put more people at risk of carcinogenic diseases, particularly in food producing areas.
