Impact of Social Restrictions During COVID-19 on the Aquatic Levels of Antimicrobials and Other Drugs in Delhi

TL;DR

The study found that social restrictions during the COVID-19 lockdown in Delhi led to a significant decrease in antimicrobials and other drugs in water resources, but also revealed antibiotic resistance in bacteria.

Contribution

The study compares post-lockdown levels of pharmaceuticals in water to pre-lockdown data and identifies new insights into antimicrobial resistance in coliform bacteria.

Findings

More than 90% of active pharmaceutical ingredients decreased in surface water and aquifers post-lockdown.

Cephalosporin-resistant coliform bacteria were found in surface water and drain samples.

Higher ceftriaxone levels in landfill leachate were linked to coliform resistance and improper medical waste disposal.

Abstract

The relative contribution of factors responsible for the environmental exposure of active pharmaceutical ingredients (APIs) is of interest for appropriate remedial measures. This study was carried out to evaluate the post-lockdown levels of APIs in water resources, in comparison to our previously published study from 2016. The environmental levels of 28 drugs from different classes were analyzed in surface water (Yamuna River), aquifers, and leachate samples collected from 26 locations in Delhi-NCR using the previously validated liquid chromatography-mass spectrometry (LC-MS/MS) methods. In addition, the prevalence of antimicrobial resistance in coliforms isolated from targeted surface water samples was also studied. This study revealed that more than 90% of APIs, including antibiotics, decreased drastically in both surface water and aquifers compared to our previous data. Selected samples subjected to antimicrobial resistance (AMR) analysis revealed the presence of cephalosporin-resistant coliform bacteria. Tracing cephalosporins in the surface and drain water samples revealed the presence of ceftriaxone in the drain and water samples from Yamuna River. Higher levels of ceftriaxone in landfill leachate were also found, which were found to be associated with coliform resistance and indicate the un-segregated disposal of medical waste into landfills. Social restrictions enforced due to COVID-19 resulted in a drastic decrease in antimicrobials and other APIs in aquatic water resources. Increased ceftriaxone and cephalosporin resistance was seen in coliform from surface water and drain, indicating the possibility of hospital waste and treatment-related drugs entering Yamuna River. Enforcement of the regulations for the safe disposal of antibiotics at hospitals and preliminary disinfection of hospital sewage before its inflow into common drains might help minimize the spread of antibiotic resistance in the environment.

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