Groundwater contaminated with manganese linked to cancers in Bihar

Manganese in drinking water and cancer: Is there a connection

Cancer incidences in India are increasing and environmental pollutants have been found to be important risk factors accounting for 80–90 percent of  the cancers, besides general risk factors such as ageing, family history of cancer, tobacco, alcohol, obesity, viral infection, UV exposure etc.

Environmental pollutants can get into the body through food, water and soil. Metallic pollutants such as Arsenic (As), Iron (Fe), Zinc (Zn), Cadmium (Cd) and Manganese (Mn) play an important role in maintaining body homeostasis in smaller concentrations, but can act as carcinogens when consumed in excess amounts.

Manganese (Mn) is one of the essential trace elements and is the 5th most abundant metal on the earth that exists in the form of oxides, carbonates and silicates. It is present in food, water, soil, and rock as a naturally occurring component. While it is useful in bodily functions in small doses, it has been found to be highly toxic in higher doses for human health informs this paper titled 'Manganese pollution in eastern India causing cancer risk' authored by Arun Kumar, Rajiv Kumar, Govind Kumar, Kanhaiya Kumar, Nirmal Kumar Chayal, Siddhant Aryal, Mukesh Kumar, Abhinav Srivastava, Mohammad Ali, Vivek Raj, Akhouri Bishwapriya, Muskan Manjari, Deepak Kumar, Santosh Kumar, Manisha Singh & Ashok Kumar Ghosh published in Nature Scientific Reports.

Bihar (India) has seen a tremendous rise in cancer cases over the last few decades and many parts of the state depend on groundwater for meeting their drinking water needs.

The purpose of this research was to find out if drinking water from handpumps was one of the causes and if manganese contamination of groundwater was related to cancer cases in the state.

Blood samples of all cancer patients registered in Mahavir Cancer Sansthan and Research Centre for the diagnosis and treatment for cancer were collected for the study. Water samples from handpumps were also tested to find traces of manganese for the study.

The study found that:

Maximum numbers of cancer patients were from Patna district

The maximum number of cancer patients with Mn poisoning were from Patna district (116 cases) followed by Vaishali district (60 cases), East Champaran district (57 cases), Saran district (55 cases), Muzaffarpur district (52 cases), Vaishali district (48 cases) and the rest n = 758 from other districts of the state. Low Mn concentration in the blood samples of cancer patients were observed in Kaimur, Sheikhpura and Arwal districts of the state.

The cancer types ranged from breast cancer, hepatobiliary and gastrointestinal cancer, cervical cancer to other types such as oral, nasal, renal, adnexal, penile cancer etc. Cancer types could be categorised broadly as carcinoma, leukemia, lymphoma and sarcoma respectively.

Manganese concentration in drinking water and blood samples of cancer patients was correlated

Long term exposure to manganese was correlated to cancer

The geospatial analysis also revealed that while the water source in these regions had  higher concentrations of Mn, people affected with cancer had been drinking this water for a long time.

Mn poisoning was more among men

The gender wise Mn contamination in blood showed that Mn poisoning was higher in men as compared to women.  

Higher concentrations of Mn were correlated to higher stages of cancer

There was significant correlation observed between Mn contamination in water and higher stages of cancer with stage III and IV having the maximum Mn contamination.

This study is the first of its kind that found that people who were exposed to Mn contamination through drinking water obtained from handpumps were at a higher risk of cancers indicating that long-term Mn exposure could be one of the causes of the cancer incidences in the exposed area. Further studies to assess the extent of the problem, medical Urgent measures to address Mn poisoning in the region and provision of safe drinking water among people is essential.