Co-contaminant risks in water reuse and biosolids application for agriculture
Laura Carter, Beth Adams, T. Berman, Nririt Cohen, Eddie Cytryn, Felicity Elder, Andrea-Lorena Garduño-Jiménez, Danny Greenwald, Barbara Kasprzyk‐Hordern, Hila Korach-Rechtman, Elma Lahive, Ian Martin, Evyatar Ben Mordechay, Aimee K. Murray, Laura Murray, John Nightingale, Adi Radian, Andrey Ethan Rubin, Brett Sallach, Dalit Sela‐Donenfeld, Olivia J Skilbeck, Harriet Sleight, Thomas H. Stanton, Ines Zucker, Benny Chefetz
Abstract
Agriculture made the shift toward resource reuse years ago, incorporating materials such as treated wastewater and biosolids. Since then, research has documented the widespread presence of contaminants of emerging concern in agricultural systems. Chemicals such as pesticides, pharmaceuticals and poly- and -perfluoroalkyl substances (PFASs); particulate matter such as nanomaterials and microplastics; and biological agents such as antibiotic resistance genes (ARGs) and bacteria (ARB) are inadvertently introduced into arable soils where they can be taken up by crops and introduced to the food-web. Thus, concern about the presence of contaminants in agricultural environments has grown in recent years with evidence emerging linking agricultural exposure and accumulation in crops to ecosystem and human health effects. Our current assessment of risk is siloed by working within disciplines (i.e., chemistry and microbiology) and mostly focused on individual chemical classes. By not acknowledging the fact that contaminants are mostly introduced as a mixture, with the potential for interactions, with each other and with environmental factors, we are limiting our current approach to evaluate the real potential for ecosystem and human health effects. By uniting expertise across disciplines to integrate recent understanding regarding the risks posed by a range of chemically diverse contaminants in resources destined for reuse, this review provides a holistic perspective on the current regulatory challenges to ensure safe and sustainable reuse of wastewater and biosolids to support a sanitation-agriculture circular economy. • Emerging contaminants are present in the environment in co-contaminant mixtures. • Contaminant uptake in crops has been linked to ecosystem and human health effects. • Risks of co-contaminant mixtures across contaminant classes are rarely considered. • Impacts are diverse, and underpinned by the presence of co-contaminants in the environment. • Monitoring underpinned by prioritization is needed to identify co-contaminant hotspots.