Dumped pesticides persist in Tanzania

Tanzania is facing problems of accumulation of obsolete pesticides, as with many other developing countries. Alcheraus Rwazo reports on existing hazardous stockpiles. He makes recommendations for their disposal and ways to stop similar build-ups in the future.

The main causes of accumulation of pesticide stocks include replacement of outdated formulations by new and more effective ones, importation of excess quantities and uncontrolled foreign aid in the form of pesticides. To make matters worse, the country lacks appropriate disposal facilities. Thus obsolete pesticides have either been dumped indiscriminately in open places or stored indefinitely(1).
In certain cases complaints have been forwarded to the Tropical Pesticides Research Institute (TPRI) and the National Environment Council (NEMC). In these cases short term measures are always recommended which include proper storage away from unauthorised people and animals thereby ensuring that no environmental contamination occurs and re-use after quality assessment.

Magnitude of the problem
The exact quantity of obsolete pesticides in the country is unknown at present. A comprehensive study to determine location, quantities, types and state has never been done. Nevertheless scanty information gathered through surveys and complaints from users is a testimony to the availability of obsolete stocks of pesticides estimated to be more than 90 tonnes.

Table. Preliminary data on obsolete pesticides at Arusha and Tanga, Tanzania*
Trade name	Common name	Quantity
Gesaprim	atrazine	470 litres
Actellic super dust	pirimiphos methyl + permethrin	10 kg
Benlate	benomyl	11 kg
DDT	-	40 tonnes
Thiodan	endosulfan	8 tonnes
DNOC	-	3,000 litres
* Collected by a team of experts formed by NEMC

Stocks of note are:

Unused/obsolete pesticides in private farms, warehouses, and stores of co-operative unions in cotton and coffee growing areas. An inventory conducted in seven regions in October 1989 by NEMC in collaboration with TPRI(2) revealed these stocks. Apart from other products, the stock included about 18 tonnes of DDT and DDT formulations, a product widely banned around the world. No action has been taken to dispose of them.
Unused pesticides received at different times under the Japan International Co-operation Agency (JICA) from 1981 to 1991 by Kilimanjaro Agricultural Development Programme (KADP) in Moshi, Northern Tanzania. The quantity in stock is about 60 kg but unfortunately most of the pesticides have no common names thereby making it difficult to identify their class and chemical make up. In addition some have Japanese labels.
There are about 11,000 litres and 350 kg of the organophosphates Damfin P (methacrifos) and phosphamidon and the fungicide Thiovat (sulphur) lying in the Co-operative and Rural Development Bank (CRDB) warehouse in Mikocheni, in the outskirts of Dar Es Salam city, since 1988.
Around 40,000 litres of expired pesticides are located in cotton growing regions of Mwanza and Shinyanga in the southern part of Lake Victoria(3). The products, which include endosulfan, flumeturon, atrazine, malathion and methidathion and DDT were found during a baseline survey conducted by the Tanzania-Germany Project on Integrated Pest Management in 1993.
Between 15 and 20 tonnes of expired Decis 0.5% (deltamethrin), DDT 75%, Thiodan (endosulfan) and Cottoran 500 (fluometuron) are stored in the Tanzania Cotton Marketing Board warehouses, Eastern zone.
A dump of 50 tonnes at Vikunge farm in the Coast region consists of DDT, aldrin and endrin(4). This is part of a consignment bought as aid through the Ministry of Agriculture from Greece in 1987.

Obsolete stocks pose serious contamination threat says FAO
The UN Food and Agriculture Organisation (FAO) has disposed of 370 tonnes of unused toxic pesticides in Zambia and the Seychelles as part of its ongoing programme to help developing countries clean up obsolete pesticides. Storage sites containing highly dangerous and persistent chemicals like DDT, lindane, dieldrin, atrazine, diazinon, captan, malathion and HCH were shipped to Europe for incineration. Most of the pesticides were unused stocks donated through foreign aid programmes.
    The cost of removal was US $1.3 million. FAO received financial assistance from the Dutch government and the German technical agency GTZ.
    "Obsolete pesticide stocks pose a serious threat to public health and the environment," said FAO Agricultural Officer Alemayehu Wodageneh. "Storage conditions rarely meet international standards." In many countries, pesticide containers are kept in the open where they deteriorate and leak their contents into the soil contaminating the environment.
    According to FAO, donor countries, aid agencies, agrochemical companies and recipient governments are all responsible for the steady accumulation of obsolete pesticides in developing countries.
    FAO estimates that there are more than 100,000 tonnes of obsolete pesticides in developing countries. Of this, 20,000 tonnes are in Africa and 5,000 tonnes are in the Near East countries. Several countries in Asia and Eastern Europe have stocks in excess of 5,000 tonnes each. Due to the absence of environmentally sound disposal facilities stocks are constantly increasing. Some stocks are over 30 years old.
    FAO is seeking the financial support from pesticide companies for pilot disposal operations in Gambia (20 tonnes), Senegal (300 tonnes) and Botswana (200 tonnes).
    Costs of disposing of obsolete pesticides in Africa alone exceeded US $100 million. "A massive global mobilisation of resources is needed to alleviate the situation. Without financial support, this enormous environmental threat cannot be resolved," said Allemayehu. The best way to dispose of pesticides is high temperature incineration, according to the FAO. None of the developing countries, except a few newly industrialised nations, have facilities for the safe and environmentally sound disposal of pesticides.
    The long term solution lies in preventing the accumulation of obsolete pesticides. Stocks should be kept as small as possible and pesticide use should be drastically reduced, according to the FAO.

FAO, 24 July 1997.

Current efforts

The government is now aware of the problem and both short and long term measures are being undertaken to solve it. Some achievements include:

Incineration of DNOC
57,600 litres of dinitro-o-cresol (DNOC) have been incinerated at a cement kiln in the outskirts of Dar Es Salaam with the assistance of the German Technical Agency (GTZ). The consignment was imported in the 1950s for locust control and its use was phased out in the 1970s.

Project on chemical management in Tanzania
The project, funded by the Dutch government at a cost of Dfl 507,381 (US $254,000), is due to be executed throughout the Tanzanian mainland. A team of 12 government experts has been formed and trained(5). The team is expected to assess and document any unusable pesticides and industrial chemicals. Data collected in the exercise will be used by the government to formulate strategies for proper handling, storage and disposal of chemical wastes (including pesticides) in the country(6). The team has already visited some parts of Tanga and Arusha regions in the northern part of Tanzania. Preliminary data (see table) collected on expired pesticides(7) indicate that the exercise will come up with comprehensive information on obsolete stocks including persistent organochlorines such as DDT.

Prevention
Environmental and human health risks associated with accumulation of obsolete pesticides are known. The disposal of pesticides is very expensive and risky.
Thus sound strategies to prevent their accumulation in developing countries including Tanzania remain a viable alternative. The strategies may include:

The creation of awareness among importers and users on potential dangers associated with accumulation of obsolete stocks of pesticides. Thus identification of appropriate target groups is of prime importance. They need to be encouraged to report promptly unused pesticides to concerned parties.
Importers should avoid ordering excessive quantities of pesticides that are above requirements. Pre-planning and assessment of actual quantities needed, though time consuming, needs to be emphasised.
Post-registration activities should be strengthened by amending some legislation and by providing more manpower and resources. These changes will create a better working environment to control imports.
There needs to be a regular inventory of obsolete pesticides. This exercise can be conducted effectively if appropriate experts such as agricultural, environmental and health experts are involved at both district and regional levels.
Pesticide manufacturers have to be involved in disposal. Their role, apart from marketing their products, is to supply information on practical and safe methods of disposal of unused pesticides. They should also be required to re-ship unused and expired products to their countries for disposal.

References
1. UNEP, WHO and FAO, FAO Pesticides Disposal Series 4, Disposal of Bulk Quantities of Obsolete Pesticides in Developing Countries, Provisional technical guidelines, 1996.
2. NEMC, Technical Report on Inventory and Assessment of Pesticide Storage and Waste Dumps in Cotton and Coffee Growing Areas in Tanzania Mainland, 1989.
3. Mallya, G.A., Obsolete Pesticides in Tanzania, A paper presented at the Regional Workshop for Southern and East Africa on Problems of Obsolete Pesticides, Harare, Zimbabwe, December 1996.
4. Rwazo, A.J.M., Chemical Import/Export Monitoring in Tanzania, A consultation final report for Worldwide Fund for Nature, December 1993.
5. The team is drawn from NEMC, the Vice President's office (Department of Environment), the Chief Government Chemist's office, the Ministry of Agriculture and Co-operatives (Plant Protection Division), The Ministry of Industries and Trade, Tropical Pesticides Research Institute (Pesticides Registration and Control Division) and Ministry of Labour and Youth Development (Factory Inspectorate).
6. Daily News, 15 April 1997.
7. Daily News, 1 May 1997.

Alcheraus Rwazo is the Senior Scientific Officer at the TPRI, Arusha, Tanzania.

[This article first appeared in Pesticides News No. 37, September 1997, pages 6-7]