Toxicological Priority Index (ToxPi) Prioritization Framework for Pesticide Exposure and Risk Assessments
Abstract
Pesticide exposure assessment in humans involves selecting a set of representative products,
performing a detailed examination of all the label permitted uses, and developing relevant
exposure scenarios. Due to the potentially large number of pesticide application methods and
use sites involved, this process is time-consuming and often requires professional, but subjective,
judgment to triage the information. In this proof-of-concept study, an objective method was
developed to systematically rank pesticide products for human exposure assessment based on a
set of pre-determined criteria. Information employed in this study was obtained from an open
access database for 66 cyfluthrin or β-cyfluthrin containing products. Exposure characterization
of these pesticide products is based on five normalized product profile indices designed to
capture the exposure potential of products, within known exposure settings, through activities
exhibited by different population subgroups. Based on the five normalized indices, Toxicity
Priority Index (ToxPi) software was used to visually rank the exposure potential of the
cyfluthrin/ β-cyfluthrin containing products. The ToxPi-based toxicity predictions were assessed
using Pesticide Illness Surveillance Program database. The utility of the methodology was
discussed in terms of ranking exposure potential of new pesticide products, assisting with future
exposure mitigations and applications to pesticides with a common mode-of-action.
Keywords: pesticide product label; exposure prioritization; ToxPi; β-cyfluthrin/cyfluthrin;
problem formulation; pesticide risk assessment