Biocides at home: emissions, potential exposure and reduction solutions – BiocidAtHome

The Biocid@Home project brings together multiple disciplines (chemistry, hydrology, modeling, economics and social sciences) to characterize and reduce the health and environmental impacts of biocides. Biocides are contaminants of emerging concern that are widely used at home. Biocidal substances are ubiquitous in the urban habitat; they are used as preservatives in daily products such as cosmetics, detergents, paints or textiles, biocides in building materials, pesticides against insects or mites, etc. These toxic substances pose a double threat on two distinct levels. On the one hand, humans are routinely exposed to biocides at home, which increases health risks, including sensitization, antibiotic resistance or cancers. On the other hand, these biocides may be released into the environment through wastewater or runoff, thus inducing a potential impact on aquatic and terrestrial ecosystems and a deterioration of the resource quality. Despite this alarming situation, the urban/domestic sources of biocides, contrary to the agricultural pesticides, have been overlooked in terms of health and environmental risk assessment. The overall objective of the Biocide@Home project is to identify evidence-based strategies to reduce emissions of urban biocides. To reach this objective, we propose to pursue the following specific aims: (i) to determine biocide emissions by the urban habitat by measuring biocide emissions at the building scale in indoor air, greywater and runoff; (ii) to assess the health and environmental risks related to these emissions by modelling the fluxes, transfer/transformation processes and environmental exposure at the urban scale and by assessing the health and environmental risk linked to these emissions and transfers; and (iii) to compare the efficiency and socio-economic impact of potential solutions designed to reduce exposure. Specifically, we propose to study "at source" solutions, i.e. decentralized treatments (phyto-purification of greywater and infiltration trenches for runoff) and reduction of emissions by changes in practices (consumption, maintenance, etc.). These novel “at source” solutions will be compared to global solutions, i.e. regulation for ban or substitution of substances, and centralized treatments in wastewater treatment plants. The success of this ambitious project is guaranteed by the extensive experience and expertise of the PI and her team, the state-of-the art LEESU facilities in analytical chemistry, and the access to experimental devices in two pilot sites, which are heavily instrumented. The study team assembled (LEESU, ANSES, INERIS, UMTEC) has unique, multidisciplinary expertise with combined experience in biocide studies, environmental sampling and analytical chemistry, modeling, environmental and health risk assessment, sociologic studies of the changes in practices, and socio-economic approach of the different forms of public actions in the mitigation of emerging contaminants. The expected results are the development of novel methods for transformation products with High Resolution Mass Spectrometry (HRMS), indoor analysis and modeling of contaminants transfer from the building scale to the city scale. A public database of biocide concentrations in indoor air, greywater, runoff, groundwater and surface water will be produced. Data on exposure will be linked to health and environmental risks. The efficiency of greywater phytopurification, runoff infiltration and changes in inhabitant practices will be assessed and discussed. Regarding the protection of receiving environments, our project will give key information allowing the prioritization of levers of actions between wastewater and stormwater, and between domestic and building materials sources. By combining our multidisciplinary results, this project will provide vital information to help refining future forms of public actions regarding the control of emerging contaminants and their impact on health and the environment.