Climate crisis to increase cancer risk for tens of millions of people in Bangladesh

“Chronic arsenic poisoning from drinking water … is a real problem, not a theoretical exercise,” said the lead researcher, Dr Seth Frisbie, an emeritus professor of chemistry at Norwich University, in a recent presentation of the findings. “I once walked into a village where no one was over 30 years old.”

Arsenic is naturally occurring, and it’s washed down the sediments from the Himalayan uplift,” Frisbie said. “So all the sediments from the Ganges, Brahmaputra, Meghna, Irrawaddy [and] Mekong river basins are rich in naturally occurring arsenic.

“It wasn’t a problem when people drank surface water, because the surface water is in communication with the oxygen in the atmosphere and that makes the arsenic insoluble and removes it from the water. But the deep well water does not communicate as well with the oxygen in the atmosphere. And that’s why all of a sudden giving people access to these deep water wells has been a tremendous public health crisis.”

Chronic arsenic poisoning leads to a buildup of arsenic inside the bodies of those affected. It manifests externally through keratinisation of skin on the palms and the soles of the feet. Similar processes are also under way inside, and deposits gather in their lungs and other internal organs, causing cancers.

“My current estimate is about 78 million Bangladeshis are exposed, and I believe a conservative estimate is that about 900,000 Bangladeshis are expected to die from lung and bladder cancer,” Frisbie said.

Climate breakdown risks making the problem much worse. As sea levels continue to rise, Bangladesh, which sits on one of the world’s biggest river deltas, is expected to be disproportionately affected by flooding, which will change the chemistry of the underlying aquifer through a process known as “reduction” to leach even more arsenic from its sediment.

At the same time, seawater ingress into the aquifer, another result of rising sea levels, will increase its salinity, another chemical change that will increase the rate that arsenic leaches into the water, via a process known as “the salt effect”.

“These changes in aquifer chemistry are expected to increase the release of arsenic into Bangladesh’s drinking well water … [and] this increased exposure to arsenic is expected to increase the rates of death and disease from chronic arsenic poisoning,” write Frisbie and colleagues in their study, published in Plos One.