Risks to consumers from the presence of pesticide residues in food are currently estimated substance by substance. However, a number of pesticides have similar effects and their impact on human health could be greater in combination than individually.
EU regulations on pesticides in food and feed stipulate that cumulative and synergistic effects of pesticides should be considered for dietary risk assessment when the appropriate methodologies are available. They also state that residues of pesticides should not have any harmful effects on human health, taking account of known cumulative and synergistic effects.
EFSA has carried out two pilot cumulative risk assessments of pesticide residues: one considering two chronic effects on the thyroid system and another looking at two acute effects on the nervous system.
What were the results of the two assessments?
The overall conclusion for both assessments – taking into account uncertainties – is that consumer risk from dietary cumulative exposure is, with varying degrees of certainty, below the threshold that triggers regulatory action defined by risk managers at the European Commission and in EU Member States.
The pilot assessments were based on the cumulative assessment groups (CAGs) established by EFSA for each of the four effects considered in the pilot assessments. The two CAGs used for the thyroid assessment comprised, respectively, 124 and 18 active substances; the other two CAGs used for the nervous system comprised, respectively, 100 and 47 substances.
For each of the CAGs, two exposure assessments were carried out simultaneously, one by EFSA and another by the Dutch National Institute for Public Health and the Environment (RIVM).
EFSA used the combined (total) margin of exposure concept (MOET). The concept is used commonly in chemical risk assessment, and an MOET of above 100 is generally considered protective of humans. A MOET of 100 at the 99.9th percentile of exposure was established as the threshold (or trigger) for regulatory consideration.