**5. Potential ecological impacts of pesticides use in cocoa production**

A proper assessment of the effect of pesticides and other chemicals used during cocoa production and processing on the environment and human health, has to begin with an effective quantification of the chemicals released into the environment and their impact on various aspects of human life and the environment. For this purpose, one of the widely accepted modern methods for examining the environmental impacts associated with a service or a product is the life cycle assessment (LCA) technique.

## **5.1 Life cycle assessment methodology**

60 Pesticides in the Modern World - Risks and Benefits

While non-chemical means of managing cocoa pests and diseases are widely recommended, the need for agro-chemicals to manage cocoa pests and diseases is unavoidable and will continue for years to come. However, the effects of continued exposure of users of pesticides, environmental risks, issues of pest resistance and possible hazards for consumers require a re-examination of the benefits of pesticide application and the risks involved. Hence the introduction of Good Agricultural Practices (GAP) to considerably mitigate, if not eliminate, the problems associated with the excessive and unnecessary application of pesticides. High residue levels and tainting of the beans could lead to their rejection on the international market. Testing for residues is carried out following internationally agreed and validated methods (Moy and Wessel, 2000). Though some insecticide residues are sometimes found in the shells, they are hardly found in the nib which is used in chocolate

**4. Socio-economic impacts of pesticides use on the cocoa industry** 

obvious. What was not so obvious was the direct benefit to the cocoa farmers.

higher levels of education, the study showed.

the effect of inflation.

In terms of output the CODAPEC programme was a tremendous success, because it was able to resuscitate cocoa production in Ghana. The country continues to benefit not only because of increased output, but also because of the high prices the crop is currently enjoying on the international market. Thus the benefits to the economy as a whole were

In order to assess the impact of the programme on these farmers, Abankwa *et. al* (2010), conducted a study in a typical cocoa-growing district, Ahafo Ano South, located at the north-western section of the Ashanti Region of Ghana. The study found that while the farmers could not take their children to better basic schools, they were able to afford school uniforms and other basic educational needs for them. They also found that farmers were able and more willing to visit hospitals instead of self-medicating or using herbal treatment. The improvements brought about by the programme seemed to benefit more farmers with

One poignant conclusion of the study was that, while the price of cocoa was reviewed upwards every year over the first five years of the programme, these increments did not translate into increased purchasing power of farmers. They were not able to afford assets like radios, televisions, mattresses and vehicles any better, five years after the programme was started. Table 4 gives the nominal and actual farmers' income over the period 2001- 2005. While the nominal figures trend upwards annually as a result of the increases in cocoa price, the actual income (calculated using CPI of 1997 as base) goes down every year due to

Year Consumer Price Index Nominal Income Actual Income

2001 216.4 631.5 294.6 2002 246.2 679.9 276.2 2003 311.8 753.3 241.6 2004 351.2 805.5 229.4 2005 404.3 939.3 232.3

Table 4. Variations in Farmers' Income, 2001-2005 (Source: Abankwa *et al.* 2010)

manufacture.

The Society of Environmental Toxicology and Chemistry (SETAC), defines LCA as:

"an objective process to evaluate the environmental burdens associated with a product, process or activity by identifying and quantifying energy and materials used and wastes released to the environment; to assess the impact of those energy and material uses and releases to the environment; and to identify and evaluate opportunities to effect environmental improvements. The assessment includes the entire life cycle of a product, process or activity, encompassing extracting and processing raw materials; manufacturing, transportation and distribution; use, re-use, maintenance; recycling, and disposal" (Consoli *et al*, 1993).

The International Organization for Standardization (ISO) has also provided very relevant input to the definition of LCA. According to ISO 14040 (1997), LCA is

"a compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product system throughout its life cycle. A product system is a collection of materially or energetically connected unit processes, which performs one or more defined functions".

Fig. 2. Components of a Life Cycle Assessment (ISO 14040)

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 63

**INPUTS/OUTPUTS Amount Unit** 

Electricity, (from national grid) 3.1716E-01 MJ Diesel 5.3142E-02 Kg Petrol 8.9967E-03 Kg

Water 5.1274E+00 Kg Fertilizer (N:P:K 0: 22:18 + 9CaO + 7S + 6MgO) 1.4590E-01 Kg

 -Fungicides 7.4200E-03 Kg -Insecticides 8.0000E-04 Kg Land use 3.9218E-05 Ha

Chocolate 1.0000E+00 Kg Cocoa Liquor 3.1948E-01 Kg Cocoa Butter 2.3125E-01 Kg Cocoa Cake 2.6875E-01 Kg Cocoa Powder 7.5000E-02 Kg Cocoa Shells 9.8000E-02 Kg

Dust (PM2,5 - PM10) [Particles to air] 2.5000E-03 Kg Sulphur dioxide [Inorganic emissions to air] 8.0000E-03 Kg Heavy metals to air 3.5745E-05 Kg Carbon dioxide [Inorganic emissions to air] 2.3790E-01 Kg Carbon monoxide [Inorganic emissions to air] 8.4100E-03 Kg Pesticides to air 8.1308E-04 Kg

Biological oxygen demand (BOD) 5.0437E-12 Kg Chemical oxygen demand (COD) 9.8212E-12 Kg Nitrates 3.7500E-15 Kg Oil & Grease 1.0000E-14 Kg Phosphates 4.4204E-14 Kg Total dissolved solids 5.1525E-12 Kg Total suspended solids 4.1287E-12 Kg Heavy metals to fresh water 7.4761E-04 Kg Pesticides to fresh water] 3.6880E-03 Kg

Pesticides to soil 9.4477E-04 Kg Heavy metals to agricultural soil 4.1870E-05 Kg

Table 5. Summary of input/output data for the production of 1 kg chocolate from Ghanaian

**Energy Inputs** 

**Pesticides** 

**Products/By-Products** 

**Air Emissions** 

**Water Emissions** 

**Soil Emissions** 

(Source: Ntiamoah and Afrane, 2009.)

cocoa beans, 2004/2005 season.

Materials Inputs

The standard LCA methodology consists of four stages, namely, goal and scope definition, inventory analysis, impact assessment and interpretation of results. These are represented pictorially in Figure 2. The goal and scope definition means a clear statement of the reasons for performing the study, the intended use of the results and the specification of the basic parameters of LCA study, such as the functional unit, system boundaries, allocation rules, data quality and simplifications. According to ISO 14040:1997, the functional unit is defined as 'the quantified performance of a product system for use as a reference unit in an LCA study'. For a product this usually simply involves specifying the weight, volume or number of a unit amount. Thus it has to be clearly defined and measurable. The primary purpose of the functional unit is to provide a reference to which the input and output data can be normalized in a mathematical sense.

The LCI stage involves collecting data concerning resource usage, energy and materials consumption, emissions and products resulting from each activity in the production system. As mentioned above, all these in- and out flows are calculated on the basis of the functional unit. In the third phase, the LCIA phase, the data collected is classified into specific categories and aggregated. This stage is composed of several mandatory elements and there are also optional elements for normalization, grouping or weighting of the indicator results and data quality analysis techniques. Finally, the life cycle interpretation is a procedure to identify, qualify, check and evaluate the information from the results of the LCI and/or LCIA of a product system. It is important to appreciate the reversible nature of an LCA study. It may be necessary, at some point, to go back to the previous stage to question and probe the results obtained. This is commonly done in LCA analysis, and arrows have been turned round to emphasize this point.

In this study, LCA was conducted following the guidelines stated above to determine the potential environmental impacts of producing 1 kg of chocolate in Ghana. The boundaries of the system studied have been shown in Figure 1, the process flow chart for chocolate production. (Those processes with broken boundaries were excluded from the analysis.) The inputs and outputs data collected in this work from the field and standard LCA databases are summarized in Table 5. Using the ISO series and CML 2001 database from the Centre for Environmental Science at the University of Leiden for impact assessment, the results given in Table 6 were obtained for the quantified impact scores for the selected relevant environmental impact categories (Ntiamoah and Afrane, 2009). Data storage and analysis were performed using the GaBi 4 LCA software.

The overall scores show that freshwater aquatic ecotoxicity and human toxicity are the most significant environmental impacts made by the process. In order to examine closely the contribution of the various stages of production to the overall impacts, Figure 3 was plotted. The percentage contribution of each stage to the total impact score of each category is given in this figure. The cocoa production stage was identified as the key life-cycle stage in terms of environmental impacts, as it makes the largest contribution to five out of the eight environmental impact categories considered in the study. The figure shows that it this is the most predominant contributor to eutrophication, ozone depletion, freshwater aquatic ecotoxicity, human toxicity, and terrestric eco-toxicity, with average contributions greater than 95%. Indeed the production and use of fertilizers and pesticides account for almost all the environmental burdens in the cocoa production stage. The significance of each of these environmental categories which are prominent, in cocoa production will be examined in turn.


(Source: Ntiamoah and Afrane, 2009.)

62 Pesticides in the Modern World - Risks and Benefits

The standard LCA methodology consists of four stages, namely, goal and scope definition, inventory analysis, impact assessment and interpretation of results. These are represented pictorially in Figure 2. The goal and scope definition means a clear statement of the reasons for performing the study, the intended use of the results and the specification of the basic parameters of LCA study, such as the functional unit, system boundaries, allocation rules, data quality and simplifications. According to ISO 14040:1997, the functional unit is defined as 'the quantified performance of a product system for use as a reference unit in an LCA study'. For a product this usually simply involves specifying the weight, volume or number of a unit amount. Thus it has to be clearly defined and measurable. The primary purpose of the functional unit is to provide a reference to which the input and output data can be

The LCI stage involves collecting data concerning resource usage, energy and materials consumption, emissions and products resulting from each activity in the production system. As mentioned above, all these in- and out flows are calculated on the basis of the functional unit. In the third phase, the LCIA phase, the data collected is classified into specific categories and aggregated. This stage is composed of several mandatory elements and there are also optional elements for normalization, grouping or weighting of the indicator results and data quality analysis techniques. Finally, the life cycle interpretation is a procedure to identify, qualify, check and evaluate the information from the results of the LCI and/or LCIA of a product system. It is important to appreciate the reversible nature of an LCA study. It may be necessary, at some point, to go back to the previous stage to question and probe the results obtained. This is commonly done in LCA analysis, and arrows have been

In this study, LCA was conducted following the guidelines stated above to determine the potential environmental impacts of producing 1 kg of chocolate in Ghana. The boundaries of the system studied have been shown in Figure 1, the process flow chart for chocolate production. (Those processes with broken boundaries were excluded from the analysis.) The inputs and outputs data collected in this work from the field and standard LCA databases are summarized in Table 5. Using the ISO series and CML 2001 database from the Centre for Environmental Science at the University of Leiden for impact assessment, the results given in Table 6 were obtained for the quantified impact scores for the selected relevant environmental impact categories (Ntiamoah and Afrane, 2009). Data storage and analysis

The overall scores show that freshwater aquatic ecotoxicity and human toxicity are the most significant environmental impacts made by the process. In order to examine closely the contribution of the various stages of production to the overall impacts, Figure 3 was plotted. The percentage contribution of each stage to the total impact score of each category is given in this figure. The cocoa production stage was identified as the key life-cycle stage in terms of environmental impacts, as it makes the largest contribution to five out of the eight environmental impact categories considered in the study. The figure shows that it this is the most predominant contributor to eutrophication, ozone depletion, freshwater aquatic ecotoxicity, human toxicity, and terrestric eco-toxicity, with average contributions greater than 95%. Indeed the production and use of fertilizers and pesticides account for almost all the environmental burdens in the cocoa production stage. The significance of each of these environmental categories which are prominent, in cocoa production will be examined in

normalized in a mathematical sense.

turned round to emphasize this point.

were performed using the GaBi 4 LCA software.

turn.

Table 5. Summary of input/output data for the production of 1 kg chocolate from Ghanaian cocoa beans, 2004/2005 season.

Use of Pesticides in the Cocoa Industry and Their Impact on the Environment and the Food Chain 65

seep through acidic soils can harm aquatic ecosystems in the different lakes and rivers and in some severe cases, acidic water has been known to leave some water-bodies lifeless (Mannion and Bowlby, 1992). Acidification can be caused directly by acids and indirectly by acidic anhydrides (sulphur dioxide and trioxide and oxides of nitrogen) and ammonia.

> CML2001, Photochem. Ozone Creation Potential (POCP) [kg Ethene-Equiv.] CML2001, Ozone Layer Depletion Potential (ODP, steady state) [kg R11-Equiv.]

CML2001, Human Toxicity Potential (HTP inf.) [kg DCB-Equiv.] CML2001, Global Warming Potential (GWP 100 years) [kg CO2-Equiv.] CML2001, Freshw ater Aquatic Ecotoxicity Pot. (FAETP inf.) [kg DCB-Equiv.] CML2001, Eutrophication Potential (EP) [kg Phosphate-Equiv.] CML2001, Acidification Potential (AP) [kg SO2-Equiv.]

Chocolate manufacturing Cocoa processing Cocoa production Transportation

Fig. 3. Relative contribution of different stages of the life-cycle to the various environmental

The thinning of the ozone layer in the stratosphere is allowing increased levels of ultraviolet radiation to reach the earth, leading to diseases in humans (skin cancer and cataracts) and adverse effect on ecosystems. Ozone layer depletion is caused by the emission of halons and CFCs during the production of pesticides. These processes are based on complicated reaction systems, including both solid phase and gaseous phase reactions, and a limited number of substances are involved (Hauschild and Wenzel, 1998). Most notably methane, nitrous oxide, water vapour, chlorine and some bromine compounds, are responsible for the breakdown of ozone molecules. Human activities have increased the amount of substances involved in the breakdown of ozone and especially stable, long-lived chlorine and bromine containing hydrocarbons (i.e. chlorofluorocarbons or CFCs, tetrachloromethane, trichloroethane, etc.) are believed to contribute significantly. Fortunately the contribution to ozone-layer thinning, as a result of cocoa production and processing, turns out to be the

The use of pesticides is often advisable and sometimes essential when a crop is threatened. Integrated pest management is a concept which is now generally known and widely

Quantity view

categories

*Ozone layer Depletion Potential* 

least significant, according to Figure 3.

**6. Conclusion** 

100


\*DCB is 1, 4 dichlorobenzene, \*R11 is trichlorofluoromethane.

Table 6. Characterization results (overall impact scores) for the production of 1 kg chocolate in Ghana, obtained by using the CML 2001 method

#### *Eutrophication*

Eutrophication or nutrification is a measure of the over-fertilisation of soils and contamination of water-bodies with nutrients. In waters it causes excessive algal growth and negative modification of the aquatic ecosystems resulting in oxygen depletion and death of certain species. In soils, on the other hand, it promotes monocultures and loss of biodiversity (Heijungs *et al* (1992) and Guinee *et al* (2001)). Since nitrogen and phosphorus are the limiting nutrients for most of the aquatic systems, leaching of these nutrients into waterbodies results in eutrophication. High nitrate levels have been found in drinking water in developing countries. This has been linked to a disease known as *methaemoglobinaemia*, commonly referred to as the blue-baby syndrome, in agricultural areas (Pretty and Conway, 1988; Conway and Pretty, 1988). Although incidence of this disease in Ghana has not been reported in the literature, to the best of our knowledge, given the large amounts of fertilizer being used in cocoa production, possible contamination of water bodies need to be a matter of concern to stakeholders in the industry.

#### *Freshwater Aquatic, Terrestial and Human Toxicity*

From the results of Figure 2, not only are freshwater aquatic and human toxicity limited almost exclusively to the cocoa production stage, but they have the highest numerical values in the figure, which makes them more significant than the others. Terrestial toxicity, though not of the same magnitude as the other two, is nevertheless important. Toxicity to humans, flora and fauna is caused by a variety of substances, ranging from carcinogens to persistent toxins such as heavy metals which find their way into the food chain. The probability exists for harmful chemicals directly or indirectly poisoning some organisms and ultimately eliminating them from the ecosystem, and thereby restricting the biodiversity of the region and upsetting the food chain.

#### *Acidification*

Acidification is an indication of the gradual degradation of the soil and it is caused by acid solution formed when pollutants generated from the combustion of fuels are released into the atmosphere. In technical terms, it is caused by the build-up of protons in soils and lakes. Hauschild and Wenzel, (1998) describe it as a fall in the capacity of the soil to neutralize the acids that run through it. Higher acidity in certain types of soils can lead to the mobilisation of different fixed ions, which are then absorbed by plants to their detriment. Water which seep through acidic soils can harm aquatic ecosystems in the different lakes and rivers and in some severe cases, acidic water has been known to leave some water-bodies lifeless (Mannion and Bowlby, 1992). Acidification can be caused directly by acids and indirectly by acidic anhydrides (sulphur dioxide and trioxide and oxides of nitrogen) and ammonia.

Fig. 3. Relative contribution of different stages of the life-cycle to the various environmental categories

## *Ozone layer Depletion Potential*

64 Pesticides in the Modern World - Risks and Benefits

Acidification Potential (AP) 9.7351E-03 kg SO2 Eutrophication Potential (EP) 9.1568E-04 kg PO43- Freshwater Aquatic Ecotoxicity Potential (FAETP) 5.0797E+00 kg \*DCB Global Warming Potential (GWP) 3.5602E-01 kg CO2 Human Toxicity Potential (HTP) 4.4426E+00 kg \*DCB Ozone Layer Depletion Potential (ODP) 4.9805E-09 kg \*R11 Photochem. Ozone Creation Potential (POCP) 9.3002E-04 kg Ethene Terrestrial Ecotoxicity Potential (TETP) 6.3796E-03 kg \*DCB

Table 6. Characterization results (overall impact scores) for the production of 1 kg chocolate

Eutrophication or nutrification is a measure of the over-fertilisation of soils and contamination of water-bodies with nutrients. In waters it causes excessive algal growth and negative modification of the aquatic ecosystems resulting in oxygen depletion and death of certain species. In soils, on the other hand, it promotes monocultures and loss of biodiversity (Heijungs *et al* (1992) and Guinee *et al* (2001)). Since nitrogen and phosphorus are the limiting nutrients for most of the aquatic systems, leaching of these nutrients into waterbodies results in eutrophication. High nitrate levels have been found in drinking water in developing countries. This has been linked to a disease known as *methaemoglobinaemia*, commonly referred to as the blue-baby syndrome, in agricultural areas (Pretty and Conway, 1988; Conway and Pretty, 1988). Although incidence of this disease in Ghana has not been reported in the literature, to the best of our knowledge, given the large amounts of fertilizer being used in cocoa production, possible contamination of water bodies need to be a matter

From the results of Figure 2, not only are freshwater aquatic and human toxicity limited almost exclusively to the cocoa production stage, but they have the highest numerical values in the figure, which makes them more significant than the others. Terrestial toxicity, though not of the same magnitude as the other two, is nevertheless important. Toxicity to humans, flora and fauna is caused by a variety of substances, ranging from carcinogens to persistent toxins such as heavy metals which find their way into the food chain. The probability exists for harmful chemicals directly or indirectly poisoning some organisms and ultimately eliminating them from the ecosystem, and thereby restricting the biodiversity of the region

Acidification is an indication of the gradual degradation of the soil and it is caused by acid solution formed when pollutants generated from the combustion of fuels are released into the atmosphere. In technical terms, it is caused by the build-up of protons in soils and lakes. Hauschild and Wenzel, (1998) describe it as a fall in the capacity of the soil to neutralize the acids that run through it. Higher acidity in certain types of soils can lead to the mobilisation of different fixed ions, which are then absorbed by plants to their detriment. Water which

Impact Score Unit

Environmental Impact Category Overall

\*DCB is 1, 4 dichlorobenzene, \*R11 is trichlorofluoromethane.

in Ghana, obtained by using the CML 2001 method

of concern to stakeholders in the industry. *Freshwater Aquatic, Terrestial and Human Toxicity* 

and upsetting the food chain.

 *Acidification* 

*Eutrophication* 

The thinning of the ozone layer in the stratosphere is allowing increased levels of ultraviolet radiation to reach the earth, leading to diseases in humans (skin cancer and cataracts) and adverse effect on ecosystems. Ozone layer depletion is caused by the emission of halons and CFCs during the production of pesticides. These processes are based on complicated reaction systems, including both solid phase and gaseous phase reactions, and a limited number of substances are involved (Hauschild and Wenzel, 1998). Most notably methane, nitrous oxide, water vapour, chlorine and some bromine compounds, are responsible for the breakdown of ozone molecules. Human activities have increased the amount of substances involved in the breakdown of ozone and especially stable, long-lived chlorine and bromine containing hydrocarbons (i.e. chlorofluorocarbons or CFCs, tetrachloromethane, trichloroethane, etc.) are believed to contribute significantly. Fortunately the contribution to ozone-layer thinning, as a result of cocoa production and processing, turns out to be the least significant, according to Figure 3.
