Analysis

Arsenic not just in drinking water, it has entered our food chain

ARSENIC CONTAMINATION in groundwater is one of the most crippling issues in the drinking water scenario of India. According to the latest report of the Central Ground Water Board (CGWB), 21 states across the country have pockets with arsenic levels higher than the Bureau of Indian Standards’ (BIS) stipulated permissible limit of 0.01 mg/l. The states along the Ganga-BrahmaputraMeghna (GBM) river basin—Uttar Pradesh, Bihar, Jharkhand, West Bengal and Assam—are the worst affected by this human-amplified geogenic occurrence.

In India, arsenic contamination was first officially confirmed in West Bengal in 1983. Close to four decades after its detection, the scenario has worsened. About 9.6 million people in West Bengal, 1.6 million in Assam, 1.2 million in Bihar, 0.5 million in Uttar Pradesh and 0.013 million in Jharkhand are at immediate risk from arsenic contamination in groundwater, says latest data published by the National Rural Drinking Water Programme (NRDWP) of the Ministry of Jal Shakti (MoJS).

The presence of arsenic contamination, as specified by diverse sources for each of the affected states in the GBM river basin presents a perplexing riddle. For instance, in Bihar, the state Public

Health Engineering Department (PHED) data from 2016 claims that 13 districts have arsenic contamination in groundwater. The data published by CGWB in 2018 contradicts PHED’s data and says 18 districts in Bihar are at risk. However, data published by NRDWP

in the same year claims 11 arsenic affected districts. The level of discrepancy in numbers gets worse.

In West Bengal, data published by the West Bengal PHED in 2014 claims 11 districts were facing arsenic contamination. But CGWB’s

2018 data puts the affected districts at eight, while NRDWP’s (2018) data raises it to nine. In Assam, 18 districts are affected according to the NRDWP’s 2018 data. NRDWP’s 2018 data puts the affected districts at eight. The Assam PHED 2017 data says 17 districts are affected by arsenic contamination.

For Uttar Pradesh, CGWB’s 2018 data claims there are 12 affected districts, while NRDWP’s 2018 report puts the figures at 17. Similarly, for

Jharkhand, CGWB’s 2018 data claims two affected districts and NRDWP’s 2018 report raises it to three districts. The state PHED for both Uttar Pradesh and Jharkhand do not have any online published data on the district level presence of arsenic contamination.

Whatever the number, every report only reinforces the fact that arsenic contamination is present in various parts of the country. And these numbers could very well be underestimates. The growing districts with inconsistent data can be termed as “missed districts”. The population in these districts remain oblivious of the arsenic presence in their groundwater.

The gravity of arsenic contamination can be found in NRDWP’s report in 2018, which says that there are 46 districts across these states with arsenic levels between 0.01-0.05 mg/l and 17 districts with levels beyond 0.05 mg/l. This is way above the BIS stipulated permissible limit (between 0.01 mg/l and 0.05 mg/l and beyond 0.05 mg/l). It must be noted here that there are 11 districts (without Bihar districts) in these states that fall in both categories.

CONTAMINATION CHAIN Recent research papers say arsenic contamination in groundwater has penetrated the food chain. That should have woken up governments. Yet the focus remained on drinking water, and the affected regions became the primary stakeholder in the mitigation approach.

MODERN GROUNDWATER-BASED IRRIGATION TECHNIQUES AND A GRADUAL SHIFT FROM A RAINFED CROP TO MULTIPLE IRRIGATED CROPS HAS INCREASED THE ARSENIC CRISIS

The government has only been focussed on drinking water in the affected regions with PHED being the primary stakeholder in the mitigation approach. Mitigation measures are targeted in treatment of groundwater or supply of surface water.

Similarly, government testing of water sources for arsenic contamination has also been restricted to drinking water sources; it has not widened the scope of investigation to water sources used for irrigation. What has aided in this conta