Every year, between 1,000 and 2,000 new organic and inorganic chemicals are added to some 100,000 already produced commercially. Though all chemicals are toxic, the vast majority are not provided with toxicity data. Waste which contains potentially toxic chemicals are simply considered hazardous. Toxic chemicals are released into the environment directly or indirectly as wastes from other activities. Once released, many chemicals undergo transformation and some may be carried away by the elements to cause regional or global chemical pollution. Worldwide some 338 million tonnes of hazardous wastes are produced every year, about 80% of which are produced in the USA and Western Europe. Over the years, most hazardous waste has been deposited in landfills or stored in surface impoundments. Leaks from such sites have contaminated groundwater and soil in some cases and as time passes many more are considered potentially dangerous sites. Clean-up costs may involve huge sums of money. The risk to human health and the environment depends on the degree of toxicity and length of exposure. In the last 20 years concern over acute health effects has broadened to include such chronic effects as birth defects, genetic and neurological disorders, and cancer. Hazardous waste management policy, including their export for treatment or disposal, has until recently been chiefly tied to economic considerations. Since the 1980s industrialized countries have tightened their controls over the movement and disposal of hazardous waste as ecological concern and impact increases. As a result, illegal dumping and traffic have increased.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends adopting technical guidelines for the environmentally sound management of hazardous wastes and support for the implementation of regional and international conventions.
The UN Environment Programme (UNEP) addresses the challenges of chemicals in the environment through the International Register of Potentially Toxic Chemicals (IRPTC), the International Programme on Chemical Safety (IPCS) and through its work on agrochemicals. In 1980, the World Health Organization (WHO), UNEP and the International Labour Organization (ILO) set up the IPCS to assess the risks that specific chemicals pose to human health and the environment. In addition to the Environmental Health Criteria documents, IPCS publishes short, non-technical Health and Safety Guides, international Chemical Safety Cards, and Poisons Information Monographs. To help countries without adequate facilities for coping with poisonings, IPCS has set up a computerized poisons information package (INTOX). UNEP adopted, in 1989, the Amended London Guidelines for the Exchange of Information on Chemicals in International Trade to facilitate monitoring and regulating the trade in banned or severely restricted chemicals. In 1989, the UN Food and Agricultural Organization (FAO) International Code of Conduct on the Distribution and Use of Pesticides amended the 1986 version. The FAO, UN Development Programme (UNDP), UNEP, and other organizations are promoting integrated pest management strategies to reduce the use of pesticides. UNEP, FAO and WHO cooperate through the Panel of Experts on Environmental Management of Vector Control (PEEM) to promote alternatives to pesticides in controlling vector-borne diseases. In March 1989, the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and their Disposal was adopted by 116 governments and the European Community. The Convention entered force on 5 May 1992. Its ultimate aim is to cut the generation of hazardous wastes to a minimum. Its immediate target is to impose strict controls on those hazardous wastes which are allowed to cross boundaries and on their disposal.