A Review of the Evidence of the Toxicity of Chemical Substances Included in the European Union Ambient Air Quality and Drinking Water Directives: Perspectives for Health Impact Assessments

Abstract

International audienceThe European Union (EU) Ambient Air QualityDirective (AAQD) and Drinking Water Directive (DWD) are aimedat maintaining and improving air quality and ensuring high standardsfor potable water across the EU. Besides several other indicators, theAAQD and DWD consist of chemical parameters (substances orsubstance groups) that are regulated within this framework. All thesubstances are associated with various health outcomes, and many ofthem are classified as carcinogenic or probably/possibly carcinogenicwith causal links. To quantify the health burden of the chemicalsubstances included in the AAQD and DWD, we need informationregarding population exposure, current baseline mortality/morbidityrates in the populations, and exposure−response functions (ERFs) orunit risks (URs) from previous epidemiological studies. During thisstudy, we analyzed the availability of ERFs or URs and discussed their applicability in health impact assessments (HIAs). From theHIA perspective, ERFsin terms of relative risk (RR), standardized mortality ratio (SMR), odds ratio (OR), or UR datawereavailable for many of the analyzed substances. However, for some substances such as acrylamide, antimony, boron, chlorate andchlorite, copper, microcystin-LR, and selenium, no risk measures could be identified. The aim of this study is to derive ERFs, whichwill allow HIAs for a larger number of chemicals when exposure data and baseline mortality/morbidity data are available. Currently,HIAs have largely focused only on main ambient pollutants such as particulate matter (PM10), fine particulate matter (PM2.5),nitrogen oxides (NOX), and ozone (O3). In contrast, health risks related to exposure to chemicals are much more diverse, and thehealth burdens should be quantified to a much greater extent