Obsolete pesticides in developing countries

The level of obsolete pesticides in developing countries is increasing. This hazardous waste is often kept in sub-standard conditions which pose a threat to human health and the environment. Alemayehu Wodageneh and Harry van der Wulp recommend urgent action be taken to dispose of obsolete pesticides in a safe and environmentally acceptable manner. A start has been made through the FAO-organised disposal operations in Uganda and the Yemen.

Most developing countries are left with large stocks of obsolete pesticides. Generally, these are excess pesticides that can no longer be used because they have deteriorated as a result of prolonged storage, or because their use has been banned while they were still kept in store. They are now regarded as hazardous waste. Due to lack of environmentally sound disposal facilities in developing countries, the total volume of such stocks is gradually increasing. Most of the stocks are kept in sub-standard stores and are in a deplorable state. Drums are stored in the open, exposed to direct sunlight and rain. As time goes by, containers deteriorate and start leaking. This process is often accelerated by unfavourable climatic conditions. These obsolete stocks invariably pose a severe threat to human health and the environment, particularly if they are located in urban areas or near water bodies, which unfortunately is often the case. Ground water, irrigation water and drinking water are at risk. Direct exposure of human beings, livestock or food is another danger. Disasters caused by obsolete pesticides can be expected if adequate action is not taken to address the present situation.

Quantifying the problem
FAO estimates the total of obsolete pesticide stocks in Africa at 15,000-20,000 tonnes. The situation in Asia and Eastern Europe has not been well documented, but seems bad in many countries. Several countries in these regions have obsolete stocks in excess of 5,000 tonnes each. The total of obsolete pesticides in non-OECD countries is expected to be far in excess of 100,000 tonnes. In addition, there are large quantities of heavily contaminated floor material, soil and empty containers that should also be regarded as toxic waste. The obsolete pesticide stocks include large quantities of organochlorine compounds that are highly persistent in the environment, such as DDT, dieldrin and HCH, as well as highly toxic (WHO Class Ia and Ib) organophosphorus compounds.
    Various factors have contributed to the accumulation of obsolete pesticides in developing countries. The main factors are: banning of pesticides while they are still kept in store; sub-standard stores and poor stock management; overstocking as a result of poor assessment of requirements or difficulties in forecasting outbreaks of migratory pests; inappropriate formulations or poor quality containers; and aggressive sales promotion by the pesticide industry. Particularly in Africa, a significant part of the obsolete pesticide stocks are pesticides that countries obtained under aid arrangements. Excessive donations, donations that arrived too late and donations of inappropriate products made a major contribution to the present stock-piles of obsolete pesticides in Africa.

What governments can do
Urgent action is required to address this alarming situation. First of all, governments should secure their present obsolete stocks to reduce hazards to human health and the environment. This would involve repackaging of pesticides that are presently in leaking or severely deteriorated containers and arranging for proper and controlled storage. Secondly, measures need to be taken to protect pesticides from deterioration. Better planning of requirements and management of stocks would be a first step. Thirdly, the obsolete pesticides should be disposed of in a safe and environmentally sound manner, which will require international assistance, both technically and financially. 

How to dispose safely
At present, the preferred disposal method is high temperature incineration in a dedicated hazardous waste incinerator. With the exception of some newly industrialised countries, there are no safe and environmentally sound hazardous waste incineration facilities in developing countries. The use of mobile incinerators does not appear to be cost effective for the vast majority of situations. In some specific cases it might be possible to use a cement kiln to incinerate limited quantities of liquid pesticides. Adaptations to the kiln can be made to feed in pesticides with the fuel. Co-firing of pesticides and fuel could achieve temperatures and residence times that are sufficient to destroy the pesticides. However, the feasibility of this method depends very much on the type of cement kiln and the type of products. Most cement kilns in developing countries are not suitable for this purpose and many products are difficult to incinerate safely in this way. Experience in using cement kilns in developing countries for this purpose is still very limited, but some experts believe there may be a potential for the future. Small incinerators are generally not suitable for the destruction of bulk quantities of pesticides. New technologies, like plasma pyrolysis (which uses arcing electrical energy to generate extremely high temperatures) are being developed and may offer a solution in the future, but are not yet available on a commercial scale for use in developing countries. In the absence of local incineration facilities, the alternative is to ship the waste to an incinerator in an industrialised country that is willing to accept it for destruction. Generally, the costs of such operations are beyond the financial capacities of developing countries.

International response
A number of disposal operations has been completed with assistance from a small group of aid agencies (see table 1). FAO is calling upon the donor community to make a concerted effort to help solve this problem for Africa. The total costs of cleaning-up the remaining declared obsolete stocks in Africa is estimated at US$80-100 million. FAO’s call for assistance is supported by new guidelines for aid agencies on pest and pesticide management published by the OECD Development Assistance Committee (DAC) in 1995. The problem of obsolete pesticides in developing countries was given a prominent place in the guidelines. The OECD/DAC also requested aid agencies to provide the necessary technical and financial assistance to help dispose of these stocks. It is hoped that the example set by the aid agencies listed in table 1 will soon be followed by other donors.
    Agrochemical companies, which often played a role in excessive or unnecessary pesticide supplies, so far remain reluctant to make financial contributions towards the clean-up of old stocks.
    With financial assistance of the Netherlands government, FAO is undertaking several activities to raise awareness and to enhance a broad involvement of developing countries and aid agencies in addressing this problem. In 1995, FAO published the Provisional Guidelines in Prevention of Accumulation of Obsolete Pesticide Stocks, which contains a detailed analysis of the causes of accumulation and provides recommendations to governments and aid agencies on how further accumulation of obsolete pesticide stocks can be prevented. Two other FAO publications will follow soon: a pesticide storage and stock control manual and guidelines on the disposal of bulk quantities of obsolete pesticides in developing countries. The latter has been prepared jointly with UNEP and WHO and provides information on available disposal methods. Further, FAO has established an ad-hoc technical working group on pesticide disposal to promote donor involvement in pesticide disposal operations and to facilitate coordination and cooperation.
    FAO has already implemented disposal operations in Uganda and Yemen. A third is being organised in close collaboration with the German agency, GTZ. In each case pesticides were collected, repacked and shipped for incineration in a hazardous waste incinerator in Europe. Such operations are not easy to organise. International safety standards and regulations on the transport of dangerous goods, particularly the International Maritime Dangerous Goods Code, are strictly followed to protect the environment and staff involved in the operation. In practice this means that special packaging materials and protective gear need to be brought in for the operation. Notification procedures as required by the Basel Convention for the transboundary movement and disposal of hazardous waste need to be followed. Through its direct and indirect involvement in disposal operations, FAO has gained valuable experience which it is now making available to other aid agencies which are interested in supporting pesticide disposal operations.

FAO disposal operation in Yemen
In March and April 1996, FAO arranged for the removal of obsolete pesticides from Yemen. Nearly 260 tonnes of obsolete pesticides and heavily contaminated soil and materials were packed and are being shipped to Europe for incineration. The products concerned were mainly old pesticide stocks for locust control and included about 70,000 litres of dieldrin, the use of which was banned for environmental reasons. The pesticides had to be collected from 19 different sites in the country. Some of the storage sites were in a very bad condition. Thousands of litres had leaked in a store near Hodeidah and had formed a thick sticky molasses on the floor of the store. Near Aden, a large quantity of dimethoate had leaked from containers and contaminated the floor and wall of the store. All contaminated material was removed, which involved scraping the floors and collecting contaminated soils.
    Preparations involved a detailed inventory of stocks and sampling and analysis of unidentified products and products that might still be usable. The actual collection, repackaging, shipment and incineration of the obsolete stocks was contracted to a company that specialises in hazardous waste disposal and operates a dedicated hazardous waste incineration plant. The actual field work to repack the pesticides was completed in six weeks. Field activities were facilitated and monitored by FAO. The total costs of the operation worked out between US$ 3,000 and 4,000 per tonne, including preparatory work and monitoring. Funds were provided by the the Netherlands government (DGIS), the German government through Kreditanstalt für Wiederaufbau (KfW) and the FAO Technical Cooperation Fund.

Alemayehu Wodageneh is Coordinator of the FAO Project on Prevention and Disposal of Obsolete Pesticide Stocks in Africa and the Near East.

Harry van der Wulp is an FAO consultant and expert on pesticide disposal

[This article first appeared in Pesticides News No. 32, June 1996, pages 12-13]