by Ms. Marie Madelaine Gimou and Mr. Dudley Achu Sama

A case study on the management of DDTF and PolyChloro Biphenyls (PCBs) particularly in the populated coastal zone of Cameroon is presented. The selection of DDT and PCB for this case study is because of their presence in vital food chains such as fish are already known to have high concentrations of the said substances, as well is their presence in sediments of mangrove habitats in which most fish species spawn and breed. Because of their persistent, carcinogenic, mutagenic effects on humans, immediate actions must be enlisted to protect human health and ecosystems, particularly in the coastal zone.

Cameroon is located along the end of the West side of West African Coast of the Gulf. of Guinea in the Atlantic Ocean. The portion of the Gulf of Guinea which is under Cameroon’s territorial waters has the most diverse and productive ecosystems. The country's coastline is 402 km long. and extends from the Rio del Rey Estuary at the boundary with the Federal Republic of Nigeria, and to the Kribi coast along the boundaries with Equatorial Guinea and Gabon. It is the major sink for discharge of Pesticides and POPs by inland rivers that drain into the Atlantic Ocean. The zone has the most industrialised areas of the country, high population density, as well as accounting for about 80% of the national annual GDP. Traditional meals in this area includes fish foods. About 39% of the population in this zone have an annual average consumption of 7.02 Kg of fish harvests from the Atlantic ocean

Cameroon is also an importer of PCBs and DDT. The main categories of PCBs imported are: Askarel and Pyralene, from the European market. Data collected from national sources show that, in 1994. PCBs found applications in the power industry (72%), chemical process industry such as PVC, paints and adhesives (22%), aluminium refining (6%).

The major sources (land-based) identified in the framework of this study, are agricultural plantations, soils contaminated due to periodic spraying during malaria-vector control programmes. In the case of PCBs, the two categories still in use in power transformers are Askarel (65% PCBs + 35% Polyclilorinated Benzenes) and Pyralene. Between 1992 total importation of both substances was 14.8 tons for use in Transformers for electricity supply. Data on DDT import is available only for the years between 1982 and 1986. However, DDT is know to be used in malaria-vector control programmes. and in a few cases, in cocoa and coffee plantations, which are major export cash crops. Data on long-range transboundary transport of POPs into Cameroon are not available. According to a study by the FAO for UNEP (1995), 220 Tonnes of POPs listed in UNEP decision 18/32 are found as obsolete stocks in Cameroon.

Industrial wastes in general, and wastes contaminated by PCBs in particular, are not treated before disposal. The known environmental compartments that are contaminated by PCB wastes are the aquatic environment (the coastal estuary), land (via municipal landfills), and the air through open-air incineration of the said wastes. Concentrations of other Pops (such as Lindane, Aldrin and Dieldrin), and heavy metals such as mercury and lead have been identified in coastal aquatic environments. Fore example, 420 mg/Kg of PCBs and 209 mg/Kg of Lidane have been detected in some fish species. Although gaps in data exist for concentrations in point and non-point sources, it is also known that PCBs have contaminated most underground aquifers in a coastal town such as Douala. In another study on the quality of surface and underground waters in Douala town, the average concentration of PCBs was found to be 4.5ug/litre.

Of recent (1995) mineral oils such as UGILEC T and BP (generic names) are progressively used to replace PCBs in power transformers. However, the reasons that have led their use are on the basis of cost and availability from the sources of supply. Because of lack of data, quantities of the substitutes cannot be found at this time. Lidane and Endosulfan are currently used as substitutes to DDT, although they are known to be toxic to aquatic organisms such as fish and crustaceans, as well terrestrial organisms such as honey bees. There is a national committee for registration of agricultural pesticides, however, the process of decision-making in approving importation of pesticides does not include risk assessments, because the technical infrasstructure is not available.

Based on the recommendations of the UNCED, 1992. Cameroon now has institutional and regulatory arrangements for the management of the environment which is based on the principles of sustainable development. The said arrangements derive their structures and expected outputs from the major recommendations of the National Environmental Management Plan (NEMP, 1996) and the framework or outline law on environmental management (law N° 96/12 of 5 August 1996). The Ministry of Environment and Forestry (MINEF) is at the centre of implementation, co-ordination and evaluation of the institutional and legal frameworks. Within the said framework, management of dangerous and toxic chemicals that pose risks to human health and the environment have been addressed. Futhermore, she has elaborated a national profile for sound management of toxic chemicals (1996).

Despite the above achievements. the national capacity for implementation of the aforementioned instruments is still weak; in particular one notes: the absence of comprehensive legislation and capacity for enforcement, low level of public awareness, weak technical infrastructure as well as lack of reliable database. The approach used to monitor the disposal of pollutants in general is based on "command and control", which approach is known to be ineffective and expensive. as well as being media-specific. She has signed and ratified the BAMAKO Convention, but its implementation is quasi-absent. She participated in the negotiations leading to the signature of the BASEL Convention, but she is yet to be party to that convention.

While awaiting implementation of the framework law and the recommendations of the NEMP and the National Profile for Sound Management of Chemicals, she has, within the framework of UNEP GC decisions 18/12 and 18/32 developed a short term (3-5 year) work plan or programme on the management of POPs and other dangerous chemicals