Henderson et al., 1993

Henderson, P. T., Brouwer, D. H., Opdam, J. J., Stevenson, H., & Stouten, J. T.; “Risk assessment for worker exposure to agricultural pesticides: review of a workshop;” Annals of Occupational Hygeine, 1993, 37(5), 499-507; DOI: 10.1093/annhyg/37.5.499.


Pesticides are unusual among occupational chemical hazards, because they are designed to injure or to kill living organisms and are intrinsically toxic. Ideally they would be non-injurious to non-target organisms including man, but most are not highly selective. Therefore, their use should be regulated so that the health and safety of agricultural workers are assured. The key question is: “Are actual exposures safe?” The confidence with which this question can be answered depends on the knowledge of the toxicological properties of the pesticide followed by an assessment of the exposure that may be considered safe. Toxicological evaluation derives the ‘no observed-adverse-effect-levels’ (NOAEL) from experimental studies. The actual exposure must also be known. Comparing this with the NOAEL gives an insight to the risks experienced by the workers. There are several ways to estimate or assess exposure of the field worker. For the levels of exposure many factors are important, including physico-chemical properties of the pesticide, agricultural conditions, working procedure and environmental conditions. The central theme of the present Workshop was to achieve consensus about the optimum approach to:
—measurement of exposure of the agricultural worker, in which both ‘external’ and ‘internal’ exposure, in particular the role of biological monitoring, is considered;

—predictive exposure modelling;

—risk assessment and risk management of occupational exposure to pesticides.
Therefore four papers which follow this review were prepared. During the workshop, which was attended by 28 invited experts (see the List of Participants at the end of this review), the manuscripts were presented and each was critically reviewed by two or three invited respondents. This was followed by in-depth discussions. The present review summarizes the workshop discussions on the different subjects. The various recommendations and proposals that were presented, will be considered as starting points for deriving a harmonized approach to exposure and risk assessment.