A groundbreaking study by the Birbal Sahni Institute of Palaeosciences (BSIP) in Lucknow has revealed alarming levels of heavy metal contamination in the groundwater of Leh district, Ladakh leading to sharp increase in cancer cases in the region over the past decade.
The findings, published in Environmental Geochemistry and Health, suggest a strong correlation between contaminated water and increase in cancer cases.
Dr. Arif Ansari, the lead researcher, highlighted that cancer-related deaths in Ladakh have increased by 27% over the last ten years, rising from 135 in 2013 to 171 in 2022. The study attributes this trend to the presence of toxic heavy metals in groundwater, marking the first such comprehensive analysis in the high-altitude region.
“Ladakh differs from the rest of India, where lung and breast cancer dominate. Here, gastrointestinal cancer accounts for 47% of cases,” Dr. Ansari explained. While past studies linked this to factors like high ultraviolet (UV) radiation, extreme cold, rugged terrain, and the prevalence of the Helicobacter pylori bacterium, the exact cause of the surge has been unclear.
“The new findings point to groundwater contamination as a critical, previously overlooked factor,” the report said..
The research team analyzed water samples from 26 sites across Leh, Nubra, and Indus-Puga regions, including major towns and villages like Leh, Thikshey, Ayu, Shey, Panamik, and Chumathang. Samples collected from hand pumps, bore wells, and government water supplies were tested for heavy metals such as chromium (Cr), arsenic (As), mercury (Hg), and uranium (U).
“Between 46% and 96% of the samples contained heavy metal concentrations exceeding safe limits, with a health hazard index (HI) greater than 1, indicating both carcinogenic and non-carcinogenic risks,” Dr. Ansari said.
Chromium and arsenic—known carcinogens—were found in 46% to 76% of the samples, while mercury and uranium levels raised concerns about kidney damage, neurological disorders, and other health risks.
Changing water practices
Traditionally, Ladakh relied on glacial meltwater, but in recent years, a shift toward groundwater has occurred due to increased development and improved utilities. “Groundwater, available year-round, is now the primary source for drinking, cooking, and irrigation. Unfortunately, this reliance may be inadvertently exposing residents to harmful contaminants leached from the region’s unique geological formations,” Dr. Ansari said.
To assess exposure, researchers interviewed 59 residents across Leh, aged 20 to 84, gathering data on water consumption patterns. Separate analyses for children (2-14 years) and adults (15-84 years) showed that children face higher risks due to their greater water intake relative to body weight. Among adults, long-term exposure was linked to gastrointestinal cancer, kidney disease, and neurological disorders.
Public Health and Policy Implications
The study underscores the urgent need for intervention. “Immediate action is required to identify and mitigate contamination in bore wells and other water sources. Public awareness campaigns must inform residents about the dangers of groundwater consumption and promote alternative water sources,” Dr. Ansari emphasised.
He called for further research, including biological testing of heavy metal levels in the local population and cancer patients. “Understanding the full extent of exposure will help confirm the link between contamination and cancer, guiding effective public health interventions,” he added.
Collaboration between government agencies, healthcare providers, and researchers is essential to address this crisis. “This study is a stark reminder of the connection between environmental health and public health. Protecting water sources is not just environmental conservation—it’s a matter of saving lives,” Dr. Ansari concluded.
