International safety assessment of pesticides: dithiocarbamate pesticides, ETU, and PTU--a review and update.

For the last 30 years the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) has carried out toxicological evaluations and safety assessments of dithiocarbamate pesticides, continuously adjusting previous appraisals in the light of new data and advances in the understanding of the principles and mechanisms of toxic action of these compounds. The historical narrative of the evaluative process is followed by an account of the present international safety assessment status of the dithiocarbamate pesticides so far examined by the JMPR. They are ferbam, mancozeb, maneb, metiram, nabam, propineb, thiram, zineb, ziram, and the associated substances, ethylenethiourea (ETU) and propylenethiourea (PTU).

Advances in the safety evaluation of food additives. A conceptual and historical overview of the Acceptable Daily Intake (ADI) and Acceptable Daily Intake 'not specified'.

The Acceptable Daily Intake (ADI) is an internationally recognized quantified expression of the acceptability of food additives. It embraces both a concept and a numerical expression. This paper describes the conceptual origin and progression of this instrument of risk assessment and management in the framework of its history which encompasses three sequential stages: developmental, consolidation and contemporary periods. The review narrates in retrospect how the ADI originated, how it developed, and delineates in prospective its future evolution in the light of advances in the safety evaluation of food additives.

The Arjenyattah epidemic. A mass phenomenon: spread and triggering factors.

A massive epidemic of psychogenic aetiology occurred in three districts of the West Bank over two weeks in March-April, 1983. It affected 949 individuals, 727 (77%) of them adolescent females. The symptoms were not accompanied by positive physical signs or by laboratory findings. The epidemiological pattern was pathognomonic of that of a psychogenic disorder. The initial trigger was probably the odour of H2S escaping from a faulty latrine in the schoolyard of the first affected school. Subsequent spread of the disease was due to psychological and extra-medical factors, including publicity by the mass media. Spread was stopped immediately after closure of schools.

The role of the World Health Organization in pesticide research.

For many years the World Health Organization (WHO), a specialized agency of the United Nations, has been involved in activities related to pesticide chemicals such as toxicological evaluation of pesticides used in agriculture, recommendation of limits for pesticide residues in foods, application of pesticides used in public health (including recommending methods and specifications for equipment) and detection of resistance to pesticides. The use of substances toxic to man and to a variety of forms of life comprises an overall health problem, and the participation of WHO at the international level in this area should be regarded as part of its responsibility for promoting the health of all people. During the course of its engagement in these activities the Organization played, and plays, an important role, either by directly sponsoring research projects according to its limited budgetary capabilities or, and mostly, by assisting in the promotion, guidance and coordination of research programmes on a world-wide basis. This paper provides a brief description of the most important activities of WHO and outlines the Organization's involvement in stimulating research in the field of pesticide chemicals. References are made to the "modus operandi" of Expert Committees.

Safety evaluation of chemicals in food: toxicological data profiles for pesticides. 1. Carbamate and organophosphorus insecticides used in agriculture and public health.

The sources of the scientific information used over the past several years by the Joint FAO/WHO Meetings on Pesticide Residues in carrying out toxicological evaluations are classified systematically according to compound and subject for the first time in this paper. It is hoped that those engaged in the toxicological assessment of pesticide chemicals, for the purpose of standardizing pesticide tolerances or for developing criteria of acceptability, will profit from this classification.