Establishment of cumulative assessment groups of pesticides for their effects on the nervous system

Abstract

Cumulative assessment groups of pesticides have been established for five effects on the nervous system: brain and/or erythrocyte acetylcholinesterase inhibition, functional alterations of the motor, sensory and autonomic divisions, and histological neuropathological changes in neural tissue. Sources of uncertainties resulting from the methodological approach and from the limitations in available data and scientific knowledge have been identified and considered. This report supports the publication of a scientific report on cumulative risk assessment to pesticides affecting the nervous system, in which all uncertainties identified for either the exposure assessment or the establishment of the cumulative assessment groups are incorporated into a consolidated risk characterisation.

Keywords: acetylcholinesterase inhibition; cumulative assessment groups; cumulative risk assessment; motor division; nervous system; pesticides mixtures.

Figure 1

Distributions quantifying uncertainty about the percentage of substances in each subgroup that cause motor division effects. The vertical axis (probability density) quantifies the experts’ judgement of the likelihood of different proportions of substances causing motor division effects within each subgroup

Figure 2

Distribution quantifying uncertainty about the total number of substances from subgroups 1–7 that cause motor division effects, obtained using Monte Carlo simulation assuming that the elicited distributions for the seven subgroups are independent

Figure 3

Distribution quantifying uncertainty about the total number of substances from subgroups 1–7 that cause motor division effects, obtained using Monte Carlo simulation assuming perfect positive dependence between the elicited distributions for the seven subgroups