Article published 13 August 2025
New VALESOR review highlights knowledge gaps in assessing health risks of chemicals regulated in EU air and water directives
A recent scientific review conducted by researchers from several European institutions within the VALESOR project has analysed the evidence of toxicity for chemical substances regulated under the European Union Ambient Air Quality Directive (AAQD) and Drinking Water Directive (DWD). The study emphasises the need for improved data to quantify health burdens from these substances accurately.
The review, published in Environment & Health, examined 35 chemical substances or groups included in the directives. Many of these chemicals are classified as carcinogenic or probably/possibly carcinogenic. While exposure-response functions (ERFs) or unit risks (URs) were available for several substances for health impact assessments (HIAs), no such measures could be identified for chemicals such as acrylamide, antimony, boron, chlorate, chlorite, copper, microcystin-LR, and selenium.
“Current health impact assessments often focus on main air pollutants like particulate matter and nitrogen oxides. However, our findings demonstrate that health risks related to chemicals in air and drinking water are much broader and often overlooked,” says Professor Hans Orru, one of the authors of the study.
“To protect public health, we need better data on exposure levels, and for some chemicals clear exposure-response functions,” says Johan Sommar, Associate Professor at Umeå University and co-author of the review. “Without these, it is not possible to fully assess the health burden from these chemicals.”
Moving towards comprehensive health impact assessments
“The critical importance now is to integrate more chemicals into future health impact assessments,” says Joseph Spadaro, co-author of the review. “We need to prioritise substances with robust causal or likely causal evidence for immediate inclusion, while also improving monitoring and research to establish risk measures for the others.”
They further emphasise that current assessments rarely account for cumulative exposures or combined effects of multiple chemicals, despite people being exposed to complex mixtures daily.
This collaborative work was carried out within the EU-funded VALESOR project, which aims to improve valuation methods for environmental stressors. The authors call for continued efforts to strengthen regulatory frameworks, ensure comprehensive monitoring, and conduct systematic assessments that can inform public health interventions across Europe.
Authors of the review
Hans Orru, Wasif Raza, Francesco Forastiere, Joseph Spadaro, Henrik Olstrup, Nataša Dragic, Ivana Radic, Sanja Harhaji, Sanja Bijelovic, Lars Modig, Mike Holland, Sandrine Andres, Adrien Troise, Antoine Guion, Alicia Gressent, Jörg Schullehner and Johan Nilsson Sommar