Cumulative Health Risk Assessment: finding new ideas and escaping from the old ones.
Sexton 2014. Human and Ecological Risk Assessment, epub.
In this article, Sexton contrasts effect-based and stressor-based cumulative risk assessment (CRA) approaches, and discusses an alternative vulnerability-based approach (Sexton, 2014). Stressor-based approaches are prospective and useful for chemical regulation, level setting etc, whilst effect-based approaches may come into their own when attempting to explain an observed health effect (retrospectively) and when non-chemical stressors are involved.
The vulnerability-based approach is a hybrid approach with the aim of identifying and evaluating vulnerable or ‘at-risk’ communities/populations. In a phased approach, vulnerability-based CRA would identify vulnerable populations, describe important stressors and identify common receptors and endpoints (phase 1); identify stressors for inclusion in analysis (phase 2); evaluate whether one or several stressors are important (phase 3); quantify a combined effect (phase 4) and consider the possibility of interactions between stressors and effects (phase 5).
This article usefully summarises the purposes and features of CRA approaches, with a slightly US-centric perspective. The difficulties and challenges of CRA are discussed, including data sufficiency, resources, expertise and experience.
MixTox: towards regulatory implementation 