A Tiered Approach for Assessing Individual and Combined Risk of Pyrethroids Using Human Biomonitoring Data

Area of Science:

• Environmental Health
• Toxicology
• Human Biomonitoring

Background:

• Pyrethroids are widely used insecticides with shared metabolic pathways.
• Urinary metabolites serve as indicators for pyrethroid exposure in human biomonitoring.
• Assessing population-level exposure and risk requires robust methodologies.

Purpose of the Study:

• To evaluate human exposure to pyrethroids using urinary metabolites.
• To implement a tiered risk assessment approach for pyrethroid exposure.
• To determine potential health concerns associated with pyrethroid exposure in European populations.

Main Methods:

• Utilized a tiered risk assessment strategy, starting with screening for 3-phenoxybenzoic acid (3-PBA) metabolites.
• Employed probabilistic approaches and substance-specific metabolites for refined risk estimation.
• Analyzed data from HBM4EU aligned studies (2014-2021) in children and adults across multiple European countries.

Main Results:

• The 95th percentiles of 3-PBA in children exceeded initial screening values across all studied populations.
• Probabilistic refinement indicated a low risk percentage (1-2%) for the most exposed children.
• Substance-specific assessments showed urinary concentrations well below human biomonitoring guidance values (HBM-GVs).

Conclusions:

• Human biomonitoring data suggest a low overall health concern regarding pyrethroid exposure at the population level.
• A potential risk for highly exposed children cannot be entirely ruled out.
• The proposed tiered approach offers a valuable tool for scientific and regulatory risk assessment of pyrethroids.