The toxicological approach is called for, given the lack of hard data on exposure, the number and variety of chemicals involved, and the need to assess potential cumulative effects. Additionally, the toxicological approach addresses, to a limited extent, the potential for future health problems. Each approach has its own strengths and weaknesses, as summarized in Table 6. Dose levels are constant and reliable. Study populations are exposed only to the pesticide formulation of interest.
Study populations are sufficiently large and are homogeneous.
Animal data must be extrapolated to humans. Human reactions may vary markedly from those of test animals. Some toxicity values are derived from very high doses. Humans are rarely exposed to a pesticide active ingredient the way test animals are. Exposure conditions may be unrealistic.