EPISODES OF ENVIRONMENTAL POISONING WORLDWIDE N J Langford, R E Ferner

The environment is composed of chemical substances, many of which are poisonous if present in large amounts, and some of which are poisonous even in small quantities. Within the industrial ised world, specific concentrations of highly dangerous chemicals may be localised to a certain area, vastly increasing the risk to the local environment. Although highly regulated by legislation such as the Control of Major Accident Hazards Regulations 1999 (COMAH), and agencies such as the Health and Safety Executive (HSE) and the Environment Agency (in England and Wales), or the Scottish Environment Protection Agency (SEPA) (in Scotland), industry has been a common source of environmental contamination. Additionally, as we discuss below, manufacturing of chemicals is not the only industrial process that places the environment at risk. Environmental poisoning can also result from the transport, storage, and secondary uses of the primary product. Small scale releases of toxic chemical substances are common within the industrialised world.1 Their impact is usually limited by effective statutory controls and efficient emergency services, but the combination of system failures can lead to disaster. In limiting the impact of such chemical releases, effective communication is required not only between the operator and emergency serv ices but also from the emergency services to the public. Without such communication, panic may ensue, leading to emergency and hospital services being overwhelmed and prevented from effec tively pursuing their roles. The most serious events usually have an immediate impact. Probably the best known example of this was Bhopal, where 2500 people died. However, chemical disasters can also occur where the release of toxins or contamination of products is insidious. This complicates both the detection of the cause of the poisoning and also the management of the environment and those poisoned. At the extreme, a low level continuing release of products can result in the accumulation of a poison both within the environment and within humans, leading to overt symptoms only decades after exposure to the chemical started. Such problems are becoming increasingly common. The time course of the environmental impact is of major importance in determining environmental damage from chemical incidents. We also distinguish between naturally occurring environmental damage by chemicals; damage from human chemical activity; and poisoning through food and drink, which might be susceptible to legislative control and which requires rather different responses. We com ment briefly on chemical weapons and warfare.