Pesticide industry, problems with

The recent advances in identifying and utilizing allelochemlcs Involved in host-plant resistance has drawn the attention of the pesticide Industry. A potential problem that may not be recognized, is the effect on insects if analogs of plant protective chemicals are sprayed on agricultural crops. Insects treated with such analogs, could rapidly become tolerant not only to the analog, but also to the natural allelochemlc. 

Neurotoxicity is the result of improper (careless) use, handling, and negligence in the management of chemical substances such as metals, food additives, pesticides, industrial solvents, cosmetics, radiation treatment, and drug therapies. Depending upon route and dose of exposure, the symptoms of neurotoxicity appear immediately after exposure or are delayed. The symptoms include limb weakness or numbness loss of memory, vision, and/or intellect headache cognitive and behavioral problems and sexual dysfunction. Children and workers with certain existing health disorders are more vulnerable to the adverse effects of neurotoxic chemicals. 

Assessment of the risk related to the presence of dangerous chemicals in the environment is both important and difficult. However, accurate assessment of the impact of a chemical is a complex task, for there are many factors involved, and chemical substances are in many cases estimated with a large uncertainty. Further, for most of the currently used industrial chemicals there is no knowledge of their environmental and ecotoxicological properties, and even worse, some chemicals are not commercialized but are present in the environment nevertheless as degradation products or impurities of industrial substances. The more widely studied chemicals are well-known contaminants such as dioxin, and pesticides. Pesticides have been addressed within specific regulations (e.g., European Directive 91/414), so this makes them a good example on how to address the problem with defined protocols. 

Because products of the pesticide industry control the insect, the rodent, the mollusk, and so forth (the vectors), they often are the most effective and sometimes the only practical means for controlling some of the most serious health problems of humankind, especially, but not exclusively, in the underdeveloped countries. Thus, chemicals that control such vectors also are included in the subject matter of this chapter. In this area, and in the area of animal health products. Chapter 25 (on the pharmaceutical industry) overlaps with this chapter to some extent. 

The detection of a potent dioxin impurity in a major herbicide has focused attention on the nature of chlorinated impurities in pesticides, and in a larger sense, impurities in all chlorinated industrial compounds used extensively in man s environment. The present 2,4,5-T controversy is overshadowed by the dioxin problem. Major disagreement still exists on their relative contributions to the teratogenic effects observed in chicks and the validity of interpretation of high dosage rates used to achieve these effects. We have avoided any assessment of the health-related aspects of dioxins but have dealt almost exclusively with dioxins as an environmental entity. 

Chemical pollution From a qualitative point of view, an important common issue is the excess of chemicals (fertilisers and pesticides) associated with agrarian and livestock farming diffuse sources and the point-source discharge of (treated and untreated) sewage water. Industrial point-source pollution is not addressed as a relevant issue, but it is assumed that industries operate following the legal rules and only the incomplete elimination of industrial chemicals in urban wastewater treatment plants is perceived as a problem. 

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