A Time-Series Record during COVID-19 Lockdown Shows the High Resilience of Dissolved Heavy Metals in the Ganga River

Abstract

The world's large rivers have been intensely studied to better understand the impact of climate change and direct human interventions on river water quality and quantity. Of particular importance is the extent to which industrial, domestic, and agricultural discharges are modifying the dissolved inorganic constituents (major elements, trace elements, nutrients, and heavy metals) of large river systems vis-a-vis water quality. The COVID-19 pandemic lockdown provides a rare opportunity to quantify the impact of restricted anthropogenic activities on the water chemistry resilience of large rivers. By analyzing the daily geochemical record of the Ganga River, we demonstrate that reduced industrial discharge during 51 days of mandated nationwide lockdown decreased the dissolved heavy metal concentrations by a minimum of 50%. In contrast, nitrate and phosphate inputs predominantly derived from agricultural runoff and domestic sewage maintained a chemical status quo as these sources were not impacted by the nationwide confinement or their residence time was longer than the characteristic time of the perturbation. We demonstrate the high resilience of dissolved heavy metals and conclude that industrial wastewater minimization programs will substantially improve heavy metal pollution of the Ganga River in a short time span of a few months.

Positive effects of COVID-19 lockdown on river water quality: evidence from River Damodar, India

“…Arif et al 17 reported a significant reduction in Yamuna River water pollution during the lockdown phase compared with the pre-lockdown phase. An assessment on river Ganga revealed that no admixing of urban and industrial effluents has brought positive improvement on river water quality in term of particular parameters at many sites of its course 18 – 25 . A recent study was conducted in an industrial catchment of river Damodar, India and it assesses the impact of lockdown on the change of water quality 10 , 11 .…”

Effects of COVID-19 Lockdown And Unlock On Health of Tropical Large River With Associated Human Health Risk

“…During lockdown, concentration of Pb, Ni, Cr and Fe was lowered down than standard value in all samples. Other study on heavy metals in drinking water at COVID-19 lockdown times also revealed huge reduction of toxic metals load in water resource (Selvam et al, 2020b;Shukla et al, 2021;Chakraborty et al, 2021). Very high positive correlation among those heavy metals and microbial signified that they mixed with river water from possibly common sources i.e., industrial wastes, agricultural runoff or municipal garbage.…”

Aerosol transmission of human pathogens: From miasmata to modern viral pandemics and their preservation potential in the Anthropocene record

“…Among the various immediate environmental impacts of the ongoing COVID-19 pandemic, many are associated with waste generation and disposal. Some of these have been positive, such as the sudden cleansing effect on highly polluted rivers such as the Ganges (Ganga) during the 2020 industrial and touristic shutdown ( Shukla et al, 2021 ). Other impacts in contrast are clearly detrimental, such as the sudden increase in use of personal protective equipment.…”