Water pollution: Lifestyle chemicals among ‘emerging contaminants’ found in Patna groundwater

A total of 73 EOCs were detected within the 51 groundwater samples in the study that has been published in the Environmental Pollution journal.

A recent study on emerging organic contaminants (EOCs) in groundwater in a rapidly developing Patna has pointed to dominance of high concentrations of lifestyle chemicals, besides medical/veterinary, agrochemical, industrial chemicals and antibiotics.

The concentrations of individual compounds, says the study, ranged from below the limit of identification to a maximum of 1.2 mg/L (sucralose). (Representational image)

A total of 73 EOCs were detected within the 51 groundwater samples in the study that has been published in the Environmental Pollution journal and was carried out by experts from the Mahavir Cancer Sansthan and Research Centre (Patna), Department of Earth and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science (University of Manchester), British Geological Survey, Groundwater Hydrology Division, National Institute of Hydrology (Roorkee), National Laboratory Service (Devon) and the School of Geography, Earth and Environmental Sciences (University of Birmingham).

According to the study, the EOCs included compounds in the neonicotinoids (a systemic agricultural insecticide resembling nicotine) insecticides class (compounds on the European Commission 2018 surface water Watch), perfluoroalkylated substances (family of man-made chemicals), certain compounds on the World Health Organization’s highly important antimicrobial list -2018, among other contaminants.

The lifestyle compound sucralos, an artificial sweetener commonly used in yogurt, candy, ice cream and soda that is 600 times sweeter than real sugar with almost no calories and doesn’t leave an aftertaste in mouth, was most frequently detected and at the highest concentration. Sucralose is used as an indicator of “recent” wastewater contamination.

The concentrations of individual compounds, says the study, ranged from below the limit of identification to a maximum of 1.2 mg/L (sucralose).

The detection frequency in groundwater ranged from 2% to 41%, and the highest frequency compounds were sucralose, fluconazole, diuron and carbamazepine. Within a single sample, a wide range of compounds were detected (ranging from 0 to 24 compounds), typically reflecting mixed contributions from medical/veterinary, agrochemical, industrial and lifestyle chemicals.

The maximum concentration (Cmax) of the sum of EOCs was 2.3 mg/L, with lifestyle components usually by far the largest contributor to total concentration. Importantly, 17 detected EOCs have been flagged for priority monitoring and/or regulatory importance.

The study says the total EOC concentration and depth are inversely related, with highest concentrations in shallow groundwaters, although localized elevated concentrations at greater depths are also observed.

The overall profile of EOCs detected has mixed consistency with what has been previously reported in northern India. The EOC profile is generally similar to what has been previously reported in Varanasi.

“A major concern regarding EOCs in groundwater is the potential development of antimicrobial resistance, exacerbated by the presence of low-concentration antimicrobials,” says Prof Ashok Ghosh, chairman of the Bihar State Pollution Control Board and a member of the investigating team that carried the study.