Impact of the massive effect of the use of disinfectants on anthropized aquatic ecosystems during a pandemic (AUDESSA) – AUDESSA

Since the onset of SARS-CoV-2 (COVID-19), disinfection practices dramatically increased, including in households, to limit disease transmission. These new cleaning routines may continue past the time when COVID-19 is no longer an urgent threat. Many disinfectants are used for inactivation of enveloped viruses including chlorine and quarternary ammonium compounds. Disinfection by-products (DBPs) can form when the chemical disinfectants react with organic matter naturally present in the water; notably, these by-products are a serious threat to the quality of the aquatic ecosystems when they are discharged in the rivers. N-nitrosamines (Nams) have been found to be formed in wastewaters and are considered as one of the major DBPs especially concidering its carcinogenic character. Assessing the levels of organic micropollutants in water is a major concern for consumers, industrialists, scientists, and public authorities.

The first objective of the AUDESSA project is to develop a sensitive and reliable method to analyze nine N-nitrosamines in different aqueous matrices (especially in surface waters but also in the outflows of the wastewater treatment plants) and to evaluate their occurrence at ultra-trace levels (ng/L) in some rivers subject to a high antropogenic pressure, in Hauts-de-France region (e.g., Marque and Yser rivers). In this project, a set of nine chemical compounds will be studied: N-nitrosodimethylamine (NDMA), N-nitrosomorphine (NMOR), N-nitrosodibutylamine (NDBA), N-nitrosodiethylamine (NDEA), N-nitrosomethylamine (NMEA), N-nitrosopiperidine (NPIP), N-nitrosodipropylamine (NDPA), N-nitrosodiphenylamine (NDPHA) and N-nitrosopyrrolidine (NPYR).

The sampling strategies of monitoring campaigns traditionally based on grab sampling do not always allow us to reach a sufficient level of information to characterize the state of the water body as defined by the Water Framework Directive. For this reason, the passive sampling technique, i.e., polar organic chemical integrative samplers (POCIS), will be employed in addition to traditional grab sampling methods in order to take into account discontinuous discharges to the environment. The second objective is therefore to combine advanced chromatographic analytical techniques and passive sampling strategy. This combination does not only allow better integration of the temporal variations of pollution but also offers the possibility to increase the sensitivity of the analyses and thus to reach better detection limits in the waters analyzed without any purification step in the laboratory.

Finally, the challenges of AUDESSA project lie in combined use of high-performance analytical techniques and a new recovery strategy based on passive samplers for monitoring 9 N-nitrosamines in surface water at ultra-trace levels (ng/L) in the Hauts-de-France region.