Evidence-based approaches to chemical risk assessment and risk management decision-making

Chemicals policy is designed to protect human and ecological health from the adverse effects that can result from exposure to manufactured chemical substances. It entails a complex process of regulatory chemical risk assessment and risk-management decision-making, drawing expertise from a diverse range of fields including toxicology and environmental health. However, these decision-making processes have come under increased scrutiny in recent years – criticized for bias, lack of transparency, rigor and a failure to identify unacceptable risks before widespread exposure occurs. This has resulted in calls for a more “evidence-based” approach, in which all relevant, available evidence is analyzed in a robust, transparent and reproducible manner. There is thus a growing need to incorporate methodological frameworks capable of facilitating evidence-based approaches to chemical risk assessment and regulatory decision-making. Such frameworks have been successfully developed in the field of medicine, which underwent a similar paradigm shift to that currently shaping chemical risk assessment, in the early 1990s. The gold-standard for evidence-based decision-making championed by the evidence-based medicine movement takes the form of systematic review. Systematic review describes a prescriptive and transparent method for collating, appraising and analyzing all available, relevant evidence in answer to a specific research question. By pooling the results of individual (independent) studies, systematic reviews synthesize conclusions which are not only more precise but are representative of an entire evidence-base. Now well established within clinical decision-making, the application of systematic review to chemical risk assessment is beginning to gain prominence. However, several challenges and barriers threaten to slow the uptake and quality of systematic review for chemical risk assessment. These include the prohibitively narrow focus of systematic reviews, which are at odds w