Spatial Investigation of Nilüfer Stream Arsenic Pollution in Previous and Post COVID-19 Pandemic and Evaluation of Health Risks for Adult People

This study was carried out in Nilüfer Stream in Bursa City, where intensiveindustrial, agricultural and mining activities are existed. The temporal andspatial variation of arsenic was evaluated by examining its concentrationsbetween March 2015 and December 2021. Values between March 2015and December 2019 were evaluated as pre-pandemic, and values betweenMarch 2020 and December 2021 were evaluated as post-pandemic. Theresults were compared with national and international standards and thechronic and cancer risks were calculated for adults. When the 7-yeargeneral averages were examined, it was seen that the highest concentrationwas 0.0256 mg/L at the 8th Station, and the lowest concentration was0.0182 mg/L at the 1st Station. The reason why the highest value is atthe 8th station was that the wastewater of Nilüfer and Bursa OrganizedIndustrial Zones was discharged to Bursa West Wastewater TreatmentPlant before this station. After the pandemic the raises in concentrationswere observed at all stations, except for the 3rd Station. This shows thatthe pollution load had increased in general during the pandemic. However,it was estimated that there was a decrease in the pollution load of theindustrial wastewater coming to the 3rd Station, which was located afterthe Eastern Wastewater Treatment Plant of the City. It was observed thatall stations examined were higher than drinking water standards and lowerthan irrigation water standards according to WHO and Turkish NationalStandards. All measuring stations were greater than 1 of the hazardquotient (HQ) values. In terms of human consumption risk, all stations hada chronic and carcinogenic risk according to the values before and afterthe pandemic. After the pandemic conditions, the HQ order of the stationswas 8>10>7>9>2>6>4>1>3. In general, post-pandemic HQ values hadgenerally increased and the risk of cancer had increased.