Trouble in store
ALEMAYEHU WODAGENEH
describes the crisis of stocks
of obsolete pesticides
building up in developing countries and suggests
how to tackle it
Vast amounts of unused pesticides threaten the environment and public health in developing countries. Without a
concerted international effort and ongoing commitment, the damage to the environment will be irreversible and the
effect on human health catastrophic.
In all, the Food and Agriculture Organization of the United Nations estimates, there are more than 100,000 tonnes of
obsolete pesticides in developing countries, generally left-over pesticides that can no longer be used because they
have deteriorated through prolonged storage, or have been banned while still in store. The stocks include large
amounts of highly persistent organochlorine compounds such as DDT, dieldrin and HCH, as well as highly toxic
organophosphorous compounds. They are now regarded as hazardous waste.
The stocks are gradually increasing because of the lack of environmentally sound disposal facilities in developing
countries. Most are kept in sub-standard stores and are in a deplorable state. Drums are even stored in the open,
exposed to direct sunlight and rain and, as time goes by, containers deteriorate and start leaking.
Leakage, seepage and accidents are both common and widespread. The stocks invariably pose a severe threat to human
health and the environment, particularly when - as most are - they are in urban areas or near water bodies. Ground
water, irrigation water and drinking water are at risk, and humans, livestock and food are in danger of direct
exposure. Disasters can be expected if adequate action is not taken.
The problem is best documented in Africa and the Near East, where there is not a single country unaffected by the
serious environmental hazards associated with obsolete pesticides. There are estimated to be some 20,000 tonnes of
them in Africa alone. Some stocks are over 30 years old, and are kept in poor conditions with few or no safety
precautions.
Action required
The situation in Asia, Latin America and Eastern Europe is not well known, but seems bad in many countries. Several
have obsolete stocks in excess of 5,000 tonnes. The total of obsolete pesticides in non-OECD countries is expected to
be far in excess of 100,000 tonnes. There are in addition
large quantities of heavily contaminated floor material,
soil and empty containers that should also be regarded
as toxic waste.
The most important factors contributing to the accumulation are: banning pesticides while they are still kept in
store; overstocking as a result of poor assessment of requirements or difficulties in forecasting outbreaks of
migratory pests; inappropriate formulations or poor-quality containers; sub-standard stores and poor stock management;
and aggressive sales promotion by the pesticide industry.
A significant part of the stocks, especially in Africa, are left-overs of pesticides obtained under aid agreements.
Excessive donations, ones that arrived too late, and gifts of inappropriate products have all made an important
contribution to the problem.
Urgent action is needed. First, governments should secure their present obsolete stocks to reduce hazards to health
and the environment. This would involve repackaging pesticides in leaking or severely deteriorated containers and
arranging for proper and controlled storage. Second, measures need to be taken to protect pesticides from
deterioration, initially through better planning of requirements and management of stocks. Third, the pesticides
should be disposed of in a
safe and environmentally sound way; this will require international assistance, both technical and financial.
Developing countries do not have the disposal facilities, know-how, or financial resources to tackle this alarming
problem. Disposal is neither cheap nor simple. Costs vary from $3,500 to $5,000 a tonne.
High-temperature incineration in a dedicated hazardous waste incinerator is the best means of disposal. But there
are no safe and environmentally sound hazardous waste incineration facilities in developing countries (with the
exception of some newly industrialized nations). Using mobile incinerators does not appear to be cost effective in 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, by mixing them with the fuel. Experience in using cement kilns in developing countries for this purpose is
still very limited, but some experts believe there may be potential for the future. But most kilns in developing
countries are not suitable and many products are difficult to incinerate safely in this way.
Cleaning up
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 industrialized country willing to accept it - but generally the cost is beyond developing countries'
financial capacities.
The total cost of cleaning up declared obsolete stocks in Africa alone is estimated at $80 to $100 million: FAO is
calling upon the donor community to make a concerted effort to help solve the problem. Its call is supported by new
technical guidelines of the OECD Development Assistance Committee on pest and pesticide management, which give the
issue prominence.
A few aid agencies have helped complete a small number of disposal operations, and it is hoped that their example will
soon be followed by other donors. Assistance should also be sought from agrochemical companies, which often played a
role in excessive or unnecessary pesticide supplies - but so
far remain reluctant to make financial contributions towards the clean-up of old stocks.
FAO is undertaking several activities, with financial assistance from the Government of The Netherlands, to raise
awareness and to enhance a broad involvement of developing countries and aid agencies in addressing the problem. It
has published a series of technical guidelines on managing stocks, on preventing them accumulating, and on disposing
of pesticides in bulk - the latter prepared jointly with UNEP and the World Health Organization. FAO has also
established an ad-hoc technical working group on pesticide disposal to promote the involvement of donors in pesticide
disposal operations and to facilitate coordination and cooperation.
In addition, FAO has already implemented some disposal operations. In March and April 1996 nearly 260 tonnes of
obsolete pesticides - including 70,000 litres of banned dieldrin, and heavily contaminated soil and materials - were
packed and shipped from Yemen to Europe for incineration. Some of the storage sites were in a very bad condition:
thousands of litres had leaked and formed a sticky molasses on the floor of one store. The cost of the operation,
$3,000 to $4,000 per tonne, was met by the Government of The Netherlands, the Government of Germany through
Kreditanstalt für Wiederaufbau and the FAO Technical Cooperation Fund.
Such operations are not easy to organize. International safety standards and regulations on the transport of dangerous
goods are strictly followed to protect the environment and staff involved. FAO has gained valuable experience, through
direct and indirect involvement in disposal operations, which it is now making available to other interested aid
agencies.
Dr. Alemayehu Wodageneh is Coordinator of the Plant Protection Service of the Food and Agriculture Organization of
the United Nations.
