Arsenic in water of Assam, Bihar adds to gallbladder cancer risk: Study

GUWAHATI: A joint study carried out by Dr Bhubaneswar Borooah Cancer Institute (BBCI), Guwahati, along with some leading institutions, has found chronic arsenic exposure in drinking water, even at low moderate levels, as a potential risk factor for the development of gallbladder cancer (GBC) in arsenic-endemic regions of India. 

BBCI, Guwahati had conducted the research between 2019-2021 along with Public Health Foundation of India (PHFI) and Centre for Chronic Disease Control, New Delhi; Mahavir Cancer Sansthan and Research Centre, Patna; and Indian Institute of Technology, Kharagpur in collaboration with the London School of Hygiene and Tropical Medicine. 

The two-year study was carried out in large tertiary-care hospitals that catered to patients across different parts of Assam and Bihar where both gallbladder cancer and arsenic contamination in drinking water are significant public health problems.

It evaluated the association between arsenic levels in groundwater and gallbladder cancer (GBC) risk in a case-control study of long-term residents (≥10years) in the two states.

Further, it assessed arsenic exposure of the study participants (men and women aged between 30 and 69 years) based on their residential history since childhood and the corresponding average concentration of groundwater arsenic at the district level. 

Long-term residential history, lifestyle factors, family history, socio-demographics and physical measurements were collected.

The research findings have been published in the official journal of the American Association of Cancer Research – Cancer Epidemiology Biomarkers and Prevention.

According to the findings, compared to residents living in regions with arsenic concentration in groundwater less than one microgram per litre, arsenic concentrations ranging from one to eight micrograms per litre in groundwater showed a two-times increased risk of gallbladder cancer, and higher arsenic levels (more than nine micrograms per litre) showed a higher risk of 2.4 times.

It may be mentioned that monitoring of groundwater-sourced drinking water samples collected from tube wells for arsenic and other pollutants has been undertaken by the Ministry of Jal Shakti in 2017-2018.

According to Dr Krithiga Shridhar, Centre for Environmental Health at PHFI and the lead scientist of the study, the findings possibly highlight a modifiable risk factor for gallbladder cancer.

“The study may address the Jal Jeevan Mission-2024, which is completely aligned with Sustainable Development Goals for equitable, clean, and safe drinking water,” Dr Shridhar said.

Dr Manigreeva Krishnatreya, medical officer of BBCI, Guwahati, and a co-investigator of the study said long-term exposure to low levels of arsenic in drinking water could lead to discoloration of the skin, high blood pressure, heart disease, nerve conditions such as numbness, etc.

“Now that arsenic as a possible risk for gallbladder cancer has been established, it is imperative that public health intervention in the form of removing arsenic from drinking water is the need of the hour in endemic regions of Assam and Bihar,” Dr Krishnatreya said.

“Filtration of arsenic and other heavy metals from drinking water has inherent health benefits and could prevent cancer,” he further informed Dr Krishnatreya.

Former director of BBCI, Dr Amal Chandra Kataki also participated in the study as one of the co-investigators. 

“Risk factors for GBC, a rare digestive tract cancer, however, are not fully understood even as data from arsenic-endemic regions of India, with a high incidence of GBC, may offer unique insights. Tackling ‘arsenic pollution’ may help reduce the burden of several health outcomes,” the abstract of the research states.

Notably, evidence linking arsenic in drinking water to digestive tract cancer, is limited.

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