Manganese in water is causing cancer in Bihar’s Gangetic plains: Study

Significant association between manganese contamination in blood of cancer patients and their hand pump water, says analysis

Manganese (Mn) contamination of water is causing cancer in the Gangetic plains of Bihar, a study by a team of scientists from Patna-based Mahavir Cancer Sansthan has claimed.

Manganese is a new element of toxicity causing cancer. The presence of high level of Mn in water is a risk factor for cancer, Arun Kumar, a leading scientist of the study team told Down To Earth (DTE).

“The study indicates high Mn contamination in cancer patient blood samples, with 6,022 microgram per litre (µg/L) being the highest level. Moreover, cancer patients’ household hand pump water samples also contained elevated Mn levels. The correlation coefficient study finds significant association between Mn contamination in blood of cancer patients and their hand pump water,” said Kumar.

He further said Bihar has seen a tremendous rise in cancer cases over the last few decades. There may be more than one factor responsible for the development of cancer, but manganese as a trace element is certainly one of them because of the toxicity leading to carcinogenesis.

The study

Researchers obtained blood samples of 1,146 cancer patients for the study from the districts of Patna, Vaishali, East Champaran, Muzaffarpur, Siwan and Saran.

Of the total patients of age ranging from 2 to 92, about 767 were females (67 per cent) and 379 males (33 per cent) respectively.

Of these 1,146 confirmed cancer cases, breast cancer ones were 381 (33.25 per cent), hepatobiliary and gastrointestinal cancer cases were 309 (26.96 per cent), cervical cancer 64 (5.58 per cent) and other cancer types such as oral, nasal, renal, adnexal, penile cancer  were 398 (34.78 per cent).

Further, these cancer types were categorised broadly as carcinoma 972 (84.8 per cent), leukemia 113 (9.86 per cent), lymphoma 35 (3 per cent) and sarcoma 26 (2.27 per cent) respectively.

Of the total patients, 32 (2.8 per cent) were in Stage I of the ailment, 173 (15.1 per cent) in Stage II, 414 (36.1 per cent) in Stage III and 526 (45.9 per cent) in Stage IV.

Their household water samples were also collected for the study. All samples were analysed for Mn contamination using a technique known as Atomic Absorption Spectrophotometer.

Worrying results

The study said manganese concentration showed normal levels?of 15 µg/L in ?blood samples of 235 (20.5 per cent) patients, while 331 (28.8 per cent) had levels between 16 and 50 µg/L, 159 (13.8 per cent) between 51 and 100 µg/L, ?249 (21.7 per cent) between 101 and 500 µg/L, 98 (8.5 per cent) between 501 and 1,000 µg/L and ?48 (4.1 per cent) between 1,001 and 5,000 µg/L respectively. Strikingly, the highest level of Mn observed was 6,022 µg/L in one patient having liver cancer while 56 (4.8 per cent) patients had Mn level below 1 µg/L. The average Mn content in blood was 199?±?10.52 µg/L.

Kumar said the carcinoma group of cancer patients mostly in Stage III & IV had significant Mn contamination in their blood (above World Health Organization/Bureau of Industrial Standards’ permissible limit).

“There has been significant rise in the levels of Mn contamination in blood samples in relation to the cancer stage. The Stage III and IV cancer patients had higher Mn contamination in their blood,” he noted.

Ashok Kumar Ghosh, head of Mahavir Cancer Sansthan’s research centre and a member of the study team said this novel finding is being reported in India for the first time, which correlates cancer with hand pump drinking water and exposed humans. The long-term Mn exposure could be one of the causes of increase in cancer incidences in the affected area.

Kumar said the threat of Mn contamination in water is more in rural areas, with diagnosis being not done or being delayed as a result of ignorance, lack of awareness and healthcare facilities.

This had resulted in a spike in the number of cases, with most patients discovering their illness when they had already reached Stage 3 or 4.

The geospatial analysis of manganese concentration in blood samples of cancer patients showed significant distribution of cases in the middle Gangetic plain region of Bihar. However, high concentration was also found in the southwestern and northeastern parts of the state.

The geo-mapping also showed a significant correlation between Mn concentrations in hand pump household water and Mn in the blood of cancer patients.

The Mn concentration in hand pump water samples was ‘normal’ (BIS-mandated?100 µg/L) in 972 (84.8 per cent) households.

Ninety-seven households (8.4 per cent) had levels between 100 and 200 µg/L, 40 (3.4 per cent) between 200 and 300 µg/L, 30 (2.6 per cent) between 300 and 400 µg/L and 7 (0.6 per cent), above 400 µg/L respectively. The average Mn content in hand pump water was 65.30?±?2.198 µg/L.

Lethal manganese

Manganese is the fifth-most abundant metal on 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.

It is an ‘essential trace element’ which plays a vital role in maintaining body homeostasis but can cause severe toxicity if consumed in excess.

The element has been reported to be toxic in higher doses for human beings. A major source of exposure to Mn is drinking water extracted from groundwater. The cause of water contamination is usually industrial pollution (anthropogenic), or sedimentary or igneous rocks (geogenic) deposits of Mn.

Manganese poisoning is very meagerly reported worldwide. According to the researchers, the first case of manganese poisoning in India was documented in 1957 among a group of manganese miners in Chinchwad, Maharashtra. These miners suffered from a wide range of symptoms, including aches and pains, weakness, clumsiness, anorexia, sleeplessness, emotional instability, and difficulty with gait.

Elevated levels of Mn in Murshidabad and 24 Parganas districts of West Bengal and Tumkur, Karnataka have been detected in groundwater. But such findings have never been reported from Bihar.

Global incidences of high level of Mn in groundwater have been reported in countries such as Nigeria, Bangladesh, China, Greece, Japan and other countries.

Courtesy: Down To Earth

Note: This news is originally published on downtoearth.org.in and is used purely for non-profit/non-commercial purposes, especially for human rights.