Environmental risk assessment of low molecule benzotriazoles in urban road rainwaters in Poland

This study aimed to identify and quantify benzotriazoles (BTRs) emissions from road traffic and paved areas in an urban environment. Heterocyclic organic compounds BTRs are an emerging threat, under-recognized and under-analyzed in most environmental and water legislation. They are hazardous, potentially mutagenic, and carcinogenic micropollutants, not susceptible to effective biodegradation, and they move easily through the trophic chain, contaminating the environment and water resources. Traffic activities are a common source of BTR emissions in the urban environment, directly polluting human habitats through the different routes and numerous vehicles circulating in the cities. Using twelve heterogeneous locations scattered over a metropolitan area in Poland as a case study, this research analyzed the presence of BTRs in water samples from runoff produced from rainwater and snowmelt. 1H-BTR, 4Me-BTR, 5Me-BTR and 5Cl-BTR were detected in the tested runoff water. 5Cl-BTR was present in all samples and in the highest concentrations reaching 47,000 ng/L. Risk quotients calculated on the basis of the determined concentrations indicate that the highest environmental risk is associated with the presence of 5Cl-BTR and the sum of 4Me-BTR and 5Me-BTR, and the most sensitive organisms are bacteria and invertebrates. The results indicate that it is possible to associate the occurrence of these contaminants with the type of cover, traffic intensity, and vehicle type.