Changes in physicochemical, heavy metals and air quality in life episode of Aplocheilus panchax along Mahanadi industrial belt of India as a function of social lockdowns

Abstract

The COVID-19 induced lockdowns have many positive effects on the environment. However, a preplanned experiment explaining the impacts of such lockdowns on environmental markers and appearance of fish species is lacking. We hypothesize that spotting the fish Aplocheilus panchax along the industrial belt of Mahanadi River near Cuttack in a never seen manner could be due to the regenerated environment. Heavy metals, water quality and air qualities along with spotting A. panchax in up, mid and down stations in Mahanadi River at Jagatpur industrial basins were analysed at pre-lockdown (end of March 2020) and after 60 days of lockdown (last week of May 2020). Here we show that an overall reduction of 45, 61, 79, 100, 97 and 90% of Fe, Cu, Ni, Cd, Pb and Zn, respectively, was recorded in the studied area after lockdowns. Similarly, dissolved oxygen and pH was elevated by 26 and 7%, respectively. Water temperature, conductivity and total dissolved solute levels were reduced by 7, 46 and 15%, respectively. Air NO2, SO2, NH3, PM2.5, PM10 and CO levels were alleviated by 58.75, 80.33, 72.22, 76.28, 77.33 and 80.15%, respectively. Finally, for the first time we documented about 12 numbers of the A. panchax per 100 m shore line in the area. The observed lockdown induced environmental healing at the studied area could contribute to this and therefore a stringent environmental audit is suggested during post-COVID-19 periods to make the regenerated environmental status long lasting at several places of the planet.