Parts of Assam and Bihar have witnessed an increase in the spread of the disease due to high arsenic concentrations in groundwater.
A chronic arsenic concentration in drinking water even at low to moderate levels increases the risk factor for gallbladder cancer (GBC), a recent study has established.
The paper published in the Cancer Epidemiology, Biomarkers and Prevention, a journal of the American Association for Cancer Research, describes arsenic an established human carcinogenic element and a natural contaminant of groundwater.
The study was carried out over two years in different parts of Assam and Bihar where GBC cases are high and arsenic concentration in drinking water is high.
The researchers recruited men and women aged 30-69 years from different hospitals who were recently diagnosed with GBC. They collected their long-term residential history, lifestyle factors, family history, socio-demographics, and physical measurements. They determined the average-weighted arsenic concentration in these areas from district-level groundwater monitoring data.
The study found that an arsenic concentration of 1.3-8.9 g/L doubles the risk of GBC and 9.1-448.3 g/L concentration increases the risk by 2.4 times.
A third of the population was found to be exposed to 10 g/L and above concentration of arsenic in water, a level which exceeds the WHO guidelines, the study revealed.
Moreover, 6% of the participants were found to be exposed to arsenic concentration levels of 50 g/L and above.
The participants who consumed tube-well water in the area with the highest level of arsenic contaminants reported more sediments with unsatisfactory colour, odour, and taste as compared to those in the region with low arsenic concentration.
According to another survey, over 18-30 million people in urban and rural India are exposed to arsenic concentrations measuring above 10 g/L and up to 1,500 g/L.
A paper published in 2020 in the European Journal of Cancer Prevention also explored the potential carcinogenic role of arsenic in gallbladder cancer in the USA, India, and Taiwan.