Pesticide occurrence and distribution in fogwater collected at four sites at Strasbourg metropolitan between 2015 and 2021.

The presence of pesticides in fogwater plays a major role in accumulating relatively substantial levels of trace compounds due to their unique physico-chemical characteristics. The radiation wintertime fog in Alsace has been studied in the past few years (between 2015 and 2021) at four sites (Geispolsheim, Erstein, Strasbourg, and Cronenbourg). Fog samples are extracted using the liquid-liquid extraction (LLE) performed on the XTR Chromabond cartridge coupled with gas/liquid chromatography-tandem mass spectrometry (GC-MS/MS and LC-MS/MS). The samples are found to be contaminated by 25 semi- and non-volatile currently-used and previously-banned pesticides (like procymidone) and 16 organochlorine pesticides (OCPs) at notable levels and high detection frequency (DF). The analysis also reveals that Cronenbourg is the most contaminated site (31.5 ± 3.0 µg. L-1), followed by Erstein (23.1 ± 17.0 µg. L-1), Strasbourg (23.0 ± 3.5 µg. L-1), and Geispolsheim (22.8 ± 7.7 µg. L-1). Pearson and principal component analyses (PCA) prove the simultaneous application of fungicides, insecticides, and herbicides, and their atmospheric transport, mainly through west-southern air currents, from highly impacted sites to near-by urban and less impact sites (Strasbourg and Cronenbourg). The levels of OCPs are found at lower concentrations at all sites than other pesticides, of which dichlorodiphenyltrichloroethane (DDT) and its metabolites have the highest contribution (27%), while hexachlorobenzene (HCB) has the least contribution (3%). Ratio analysis indicates the historical emission of DDTs, whereas a recent and local input of lindane and endosulfan has been observed.

Biomonitoring of PAHs and PCBs in industrial, suburban, and rural areas using snails as sentinel organisms.

There is a worldwide concern about the presence of persistent organic pollutants (POPs) in the environment because of their toxicity, bioaccumulation, and resistance to degradation. Various conventional monitoring techniques have been used to assess their presence in diverse environmental compartments. Most currently available methods, however, have limitations with regards to long-term monitoring. In the present work, juvenile Cornu aspersum (O. F. Müller, 1774) snails were tested in field microcosms as biomonitors for two major classes of organic pollutants, namely, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). The study assessed their deployment in one suburban, one rural, and two industrial sites over an 18-week period and monitored for temporal variations of 16 PAHs and 22 PCBs. Sampling was conducted once every 3 weeks. Targeted pollutants were extracted from the caged snails using the QuEChERS extraction procedure and subsequently analyzed using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The results showed that the bioaccumulation of specific pollutants was site dependent; significantly higher levels of PCBs were observed at the industrial sites as compared to the suburban and rural ones. PAHs were bioaccumulated by the snails via ingestion of air and soil whereas PCBs were mainly bioaccumulated via soil contact and ingestion. The findings of this study indicate that C. aspersum is a reliable model organism for the biomonitoring of organic pollutants in air and soil compartments and can be used as part of an integrated environmental assessment.