Applicability of Food Monitoring Data for Assessing Relative Exposure Contributions of Pyrethroids in Retrospective Human Biomonitoring Risk Estimations

Abstract

The use of pyrethroids is very broad and shows increasing trends. Human biomonitoring studies represent the best approach for realistic risk estimations, but their interpretation requires a tiered approach. A previous HBM4EU study indicated levels in European children groups just around the threshold for concern, requiring further refinement. The main difficulty is that several pyrethroids with different toxicity potencies generate the same urinary metabolites. As diet is the main pyrethroid source for the general population, EU food monitoring data reported by EFSA have been used to estimate the relative contribution of each pyrethroid. The main contributors were cypermethrin for DCCA and 3-PBA and lambda-cyhalothrin for CFMP. Urinary levels predicted from food concentration according to the EFSA diets were mostly within the range of measured levels, except 3-PBA and CFMP levels in children, both below measured levels. The predicted lower levels for 3-PBA can be explained by the very low Fue value, initially proposed as conservative, but that seems to be unrealistic. The discrepancies for CFMP are mostly for the highest percentiles and require further assessments. The refined assessments included the revision of the previously proposed human biomonitoring guidance values for the general population, HBM-GV Gen Pop, following recent toxicological reevaluations, and the estimation of hazard quotients (HQs) for each individual pyrethroid and for the combined exposure to all pyrethroids. All HQs were below 1, indicating no immediate concern, but attention is required, particularly for children, with HQs in the range of 0.2-0.3 for the highly exposed group. The application of probabilistic methods offers assessments at the population level, addressing the variability in exposure and risk and providing relevant information for Public Health impact assessments and risk management prioritization.

Keywords: 3PBA; CFMP; CLF3CA; DBCA; DCCA; F3PBA; HBM4EU; pesticide risk; pyrethroids; urinary levels.

Figure 1

Comparison of the distribution of human urine biomonitoring data on pyrethroid metabolites from HBM4EU in adults (solid lines) with the estimations using EFSA PRIMo adult diets based on food monitoring (dotted lines).

Figure 2

Comparison of the distribution of human urine biomonitoring data on pyrethroid metabolites from HBM4EU in children (solid lines) with the estimations using EFSA PRIMo children’s diets based on food monitoring (dotted lines).

Figure 3

Comparison of 50th percentiles molar pyrethroids levels in the different HBM4EU populations estimated from two the selective (DDCA or CFMP) and common (3-PBA) metabolites.

Figure 4

Refined total risk estimations for the aggregate exposure to pyrethroids for the aggregated HBM4EU data.

Figure 5

Estimated contributions of each pyrethroid for the HBM4EU Belgian children group (A) total aggregated and individual HQs. (B) Probabilistic distribution of the measured 3-PBA levels and estimated distributions for each contributing pyrethroid.