Pesticide risks in Cameroon, Tanzania and the Gambia

Reducing the risks posed by pesticides presents particular difficulties in countries which have little or no institutional framework for the control of hazardous chemicals. The associated problems have been on the international agenda for more than two decades. A workshop in October considered lessons from four pilot case studies. Topsy Jewell reports.

As part of a very practical initiative to strengthen chemical management capacity in developing countries, the United Nations Institute for Training and Research (UNITAR) and the International Programme on Chemical Safety (IPCS), with the support of the European Commission, collaborated in running pilot case studies in four countries on Risk Management Decision-Making for Priority Chemicals.
    The pilot studies are part of a larger effort to improve chemical management in developing countries under the Intergovernmental Forum on Chemical Safety (IFCS), set up to implement decisions of the 1992 Earth Summit, specifically those agreed in Chapter 19 of Agenda 211. Early in the IFCS process, governments agreed to develop a National Profile to assess the available infrastructure for management of chemicals. The profiles are put together through participatory consultations with a wide range of stakeholders from government, to research, industry and public interest groups. Practical support comes from a programme serviced by UNITAR which is also developing an informal capacity-building network.
    The experiences gained in risk assessment case studies in Cameroon, Chile, Tanzania and the Gambia were discussed at a Thematic Workshop on Strengthening National Capacities for Risk Management Decision Making for Priority Chemicals, held from 4-6 October 1999 in Geneva, Switzerland. The meeting brought together 45 representatives from inter-governmental organisations, industry and public interest groups and produced a lively discussion and sharing of knowledge and expertise.
    Improved risk management decision-making will support the implementation of national laws and international agreements such as the Rotterdam Convention2 on Prior Informed Consent (PIC), and any future agreements on Persistent Organic Pollutants (POPs). 

On the case risk assessments
Each participating country set up a task force of experts selected from relevant government departments and identified a problem pesticide (Chile selected lead and so is not discussed here). This multi-stakeholder process was intrinsic to capacity building goals. The task force, with assistance of experts supported under this initiative, worked through the risk assessment procedure outlined in the Guidance Document and elaborated a risk reduction strategy for the selected pesticide. 
    The pilot studies followed an approach originally developed by the European Union (EU), but modified in order to be appropriate to developing country situations.
    The workshop participants were introduced to the ‘Uniform System for the Evaluation of Substances’ (USES), a mathematical model developed by the EU for estimating the risks posed by individual substances. The USES model applies national and international data to derive theoretical predictions for emissions, concentrations and effects of different chemicals on the environment and human health. Field studies conducted by national experts in each of the pilot countries provided ‘on the ground’ information about the risks of the chosen pesticide. The Geneva workshop recommended further adaptations in approaching risk management, based on the need to prioritise and be relevant for regulators and decision-makers in developing countries.

Case studies

CAMEROON
Problem identification
Cameroon selected pentachlorophenol (PCP) for evaluation3. PCP is currently used as a preservative in timber and wood products, one of the country’s economically important export industries. PCP is very toxic to humans and aquatic organisms, being contaminated by dioxin and furans and often formulated with high concentrations of lindane (a pesticide banned in Cameroon). Workers in the industry face a high risk of exposure to PCP and these risks extend also to the general population through PCP-treated furniture. Wood treated with PCP may also eventually lose its market in the EU due to the progressive reduction in the limits permitted for wood used in interior construction. 

Risk assessment
Following field studies, a timber park where logs are stored for export was identified for the risk assessment. The USES model was used to predict emissions to the environment and exposure in humans. However it was found that quantified assessments were difficult to do due to a lack of national baseline data and non-observance of relevant health and safety standards. The field studies revealed, for instance, that there is no standard for applicator equipment, workers do not use protective clothing or have systematic training, there is no follow up of workers health, and there is no official inspection of work places. Spilled products are not recovered and end up washed into the ocean. The risk assessment identified that there are strong grounds for concerns over exposure to workers during formulation and application.
    Exposure of the general population was not assessed quantitatively. It was reported that PCP-treated wood is variously used in furniture, interior structural supports in homes and food containers, together ensuring risks of exposure to most of the population. PCP is also used to treat cotton fibres in the textile industry. 

Risk reduction strategy
The risk assessment identified occupational safety at the workplace as the main area for risk reduction action. Cameroon already has a number of institutional and regulatory measures to manage dangerous chemicals. It was noted that if these measures were effectively implemented and additional actions taken then this could bring about significant reduction in risks from dangerous chemicals. For example, there already exists legislation that requires those industries handling PCP routinely to monitor worker exposures. Lindane is a banned chemical and it was recommended that a process to test for lindane at the point of import or during use could help enforce the law. Additional, short term risk reduction measures which were identified included training for employees, the use of protective equipment, and suitable disposal of the product or waste. It was also recommended that wood treated with PCP should cease to be used for furniture and interior structural supports. In the long term, the use of alternative, less toxic wood preservatives was recommended. 

GAMBIA

Laying out mosquito nets soaked in insecticide.  Photo: Giacomo Pirozzi/PANOS Pictures

Problem identification
Gambia selected permethrin, an insecticide that is used to treat bednets in the country’s Malaria Control Programme. Permethrin is imported into the Gambia by the government and a number of aid agencies. 1,300 villages are involved in the programme and studies have shown that the use of the permethrin-impregnated bednets has reduced the number of fatalities from cerebral malaria. However, permethrin is a neuro-poison and as well as acting on the nervous system, can cause itching and burning sensations in exposed human skin. Permethrin is toxic to aquatic organisms and to bees.

Risk assessment
Base-line data to feed into the risk assessment – such as quantities imported and numbers of poisonings – were collected from several sources including hospitals, importers, and government departments. This exercise showed that the relevant data are hard to extract or are not available. Poisoning data are kept by hospitals but the identities of particular chemicals involved in poisoning cases are not recorded. Records kept by importers were also unsatisfactory due to lack of training of staff in many organisations. There was no monitoring data for pesticides in various environmental compartments such as the atmosphere. There were, however, data on alternative pesticides and the results of work done on plant extracts. 
    It was found that the USES model was not suitable for permethrin in the Gambia since the available data for input were not sufficient and the results based on international or ‘default’ data were not representative of the local situation. The use of the model however did have some value in the learning process. 
    Field studies were made country-wide to assess the situation on the ground. Central medical stores, divisional health teams, rural health facilities, village health workers and consumers were consulted. Of particular value was the finding that the village-level studies revealed practices not documented by other sources of data and were vital to informing the process of selecting risk reduction options. 
    Based on the assumption that the amount of permethrin in air at saturation is less than the WHO/FAO recommended acceptable daily intake, the task force made the assumption that the risk of exposure from sleeping under treated bednets is not significant. The field studies revealed that there are significant risks of exposure at a number of other stages of the chemicals life cycle. These included when the pesticide is decanted from the large imported drums, when the bednets are dipped by either the village health worker or by individuals in their own homes, when unlabelled containers are brought into the home, and from misuse of the chemical.

Risk reduction strategy
It was agreed that most of the risks associated with permethrin could be avoided if the users were fully aware of the dangers and were trained in safe handling. Investment in training and monitoring use was identified as crucial. Basic information such as the numbers of people using permethrin for home dipping needs to be recorded. 
    Risk reduction measures that were assessed to be both practical and affordable included notification by the importers of all imports, the provision of monitoring books at the village level, and a general programme of ‘sensitisation’ to communicate the risks of the chemical to users. 
    Other important risk reduction measures had to be rejected due to their cost. These included the issuing of protective gloves to all village health workers and the provision of hazard labels for small containers used for home dipping. In the long term, it was recommended that an alternative to permethrin should be developed based on a naturally occurring plant extract to reduce costs to the Malaria Control Programme and to remove the need for permethrin altogether.

TANZANIA
Problem identification
The insecticide endosulfan was selected for risk assessment since reports have indicated mismanagement and misuse during all stages of its life cycle. Endosulfan has been the leading cause of pesticide poisoning cases in Tanzania since 1987. It is also currently of great concern because it is being used for fishing in Lake Victoria which has caused widespread local food poisoning and has led to a ban on fish imports by the EU. Field studies confirmed many of the potential risks identified.

Fish caught from Lake Victoria, Tanzania, form a substantial part of the local diet, and are exported. Preventing contamination with edosulfan is crucial. Photo: Fred Hoogervorst/PANOS Pictures

Risk assessment
The USES model was used to quantify the risks posed by endosulfan under different conditions. Although time was very limited, the task force felt that useful experience had been gained. Some major shortcomings with the USES model were identified. For example, estimates of dietary intake are based on estimated residue levels in food produced by ‘good practice’. The field studies demonstrated that in many instances good practice is not applied, increasing risks of dietary exposure. It was also noted that endosulfan can enter the body through inhalation and the skin as well as in the diet. 
    The life-cycle assessment gave a more qualitative risk assessment. It was found that chemicals in general are being mismanaged and misused at various stages of the life cycle and there is a need for reducing the risks to health and the environment. 
    At the stages of formulation, transport, storage and repackaging accidents and leakages occur with risks of worker exposure, food poisoning and environmental contamination. Endosulfan is used in cotton, coffee, maize, vegetables and other crops and is applied with knapsack-sprayers by farmers with no protective clothing. There are risks to farmers directly and to the community through contamination of food and water, re-use of empty containers, and storage in the same place as food items. There are also risks to organisms in the environment. 
    The misuse of endosulfan for fishing brings risks of exposure to those consuming the fish, to the fishing families handling and storing the chemical, and to the aquatic environment. Other areas of misuse identified were use on stored grains destined for human and animal consumption, and use of endosulfan against pests in the home and on livestock. 
    Finally disposal is an area of concern. There exist about 12,075 kg of solid and 20,405 l of liquid waste endosulfan awaiting packaging and disposal. There are currently no safe mechanisms for disposal, containers are re-used and the environment at storage sites is contaminated through leakage and water run-off.

Risk reduction strategy
The task force agreed that endosulfan is effective in controlling pests and could not be restricted without a proven alternative pesticide. Some general risk reduction measures are already used to reduce the adverse impacts of pesticides in Tanzania. These include Integrated Pest Management (IPM), extension services promoting good practices and safe use of pesticides, and awareness raising. In addition, risk reduction measures were identified systematically for all of the risks identified at each stage of the chemical’s life cycle and were evaluated by the task force for their effectiveness, practicability, economic impact and monitorability. 
    Recognising that implementation of the proposed risk reduction strategy depends on availability of resources, the task force divided the measures into short, medium and long term categories depending on the nature of the risk and ease of implementation given currently available resources and mechanisms. 
    The task force also noted that the measures identified for endosulfan apply for most other chemicals. They recommended that rather than implementing a programme specific to endosulfan, the measures should be prioritised in the development of an Integrated Chemicals Management System in Tanzania.

Lessons learnt
Capacity building 
The most important outcome experienced by all the countries involved in the pilots was that they strengthened the capacity of those participating in understanding and applying risk assessment methods to local conditions of pesticide use. The case studies also fostered very valuable communication and interaction between the stakeholders involved in the risk management decisions. The participants at the October meeting recommended that the involvement of other stakeholders including NGOs, customs, monitoring and enforcement personnel would further enhance the benefits of this multi-stakeholder process. 

Risk assessments
The experiences of each country demonstrated that there is no one approach to risk assessment. The different approaches, including assessing risks throughout the life cycle of a single substance, assessing risks at a specified site, or assessing risks of exposure to the general population, are all valid. 
    There was a strong recommendation at the October meeting that the risk assessment process should not be a goal in itself but be used only if it helps to refine the identification of the problem. Risk assessment need not always be applied before risk reduction measures are addressed. It would be impossible to carry out risk assessments on a pesticide-by-pesticide basis. Instead it was recommended that if there is a realistic assumption that significant exposure to a hazardous pesticide is occurring, if a pesticide is being misused, or if the pesticide has already been banned in other countries, risk reduction measures are justified. 

Information resources 
The use of the computer model, USES, raised a number of important issues. There are major limitations to USES in countries where resources are scarce and data limited. Users of the model require training and access to computers. National and local base-line data are often not available. The input of default data or assumptions that are inappropriate for national or local conditions can end up masking important areas of concern. For example, assumptions of good agriculture practice or observance of health and safety standards could lead to an underestimation of the risks involved. A positive aspect of a quantitative approach though is that it can offer transparency and a means to audit the results in relation to the inputs.
    Qualitative life cycle analysis proved to be an effective approach to identifying risks. The major draw back is that much of the data and information required is either not available or requires resource intensive field studies. Basic information on imports of active ingredients or on levels of exposure, for example, are unavailable in many countries. 
    Even when official information is available, the results of the field studies demonstrated that there can be major discrepancies between official data and risks of exposure in practice. The field studies appear to have been of great value in illuminating problems and giving qualitative assessments of the risks of exposure. Field studies also provide opportunities for more stakeholders to inform the assessment process. The October meeting recommended that more time and resources should be allocated for field studies to identify both problems and solutions and that gender issues should be considered. 

Risk reduction options
Many of the risk reduction options identified by the case studies apply to chemical management in general. These were highlighted at the October meeting. Emphasis was placed on countries improving basic regulation of imports, including information on types and quantities of pesticides imported, health and safety regulations and inspections at manufacturing and formulation sites, transport regulations, user restrictions, and waste management. Risk reduction options that are general to all stages of a chemicals life cycle were also recommended and included awareness raising and education, training and the promotion of alternatives. 

Conclusions
The problems identified by the country case studies are similar to those experienced by farmers and workers handling pesticides in many parts of the world. Some of these problems appear intractable. The value of this approach lies in helping to bring the problems and solutions into focus, and to increase the capacity of a country to take actions which aim to eliminate the hazards of pesticides. By developing a Guidance Document, other countries can benefit from the experience.

References
1. UN Conference on Environment and Development, 1992. Earth Summit 1992. Chapter 19 calls for increased collaboration between governments, industry and NGOs to exchange information on chemicals and to strengthen risk management activities both nationally and within the UN system.
2. Rotterdam Convention on the PIC Procedure for Certain Hazardous Chemicals and Pesticides in International Trade, 11 September 1998. Joint Secretariat: FAO and UNEP. PIC will give governments information about hazardous chemicals for assessing risks and taking informed decisions.
3. Cameroon also selected the industrial chemical, PCB, for evaluation.

UNITAR is an autonomous body within the United Nations. It is exploring innovative training and capacity building approaches: www.unitar.org/.
    The IFCS is a new mechanism for cooperation among governments for promotion of chemical risk assessment and the environmentally sound management of chemicals. www.who.int/ifcs/

Topsy Jewell is an environmental researcher.

[This article first appeared in Pesticides News No. 46, December 1999, pages 6-8]