The health of tens of millions of Bangladeshi citizens is threatened by contaminated drinking water. Researchers at Norwich University detected high levels of arsenic concentration in it. The effects of climate change, intensifying with each decade, are further exacerbating the situation, worsening the health crisis in the eighth most populous country in the world. Increased risk of cancer or cardiovascular disease is affecting more and more places around the world.
Alarming data from Bangladesh
The findings, published in January of this year in the online journal PLOS One, have stirred up a lot of excitement around the world. A team of U.S. scientists led by Dr. Seth H. Frisbie analyzed the chemical composition of drinking water from Bangladeshi wells and contrasted the results with the expected effects of climate change. It turned out that already high arsenic levels would continue to rise, dramatically increasing the risk of cancer among the population.
The study’s authors recall that Bangladesh is now home to more than 165 million people, 97 percent of whom are in the country. Drinks water from deep wells. In nearly half of the country, arsenic levels in wells exceed the standard set by the World Health Organization (WHO) at 10 μg/l. In some samples, the value was as much as 45 times higher.
In the human body, inorganic arsenic compounds disrupt DNA repair mechanisms and increase the likelihood of chromosomal aberrations. Over time, the toxic element accumulates, leading to keratinization of the surfaces of the feet and hands. Similar changes occur in the lungs and other internal organs, which significantly increases the risk of cancer in the long term.
Where does arsenic in drinking water come from?
The high incidence of cancer in Bangladesh is not new. According to the WHO, the country sees 150,000 new cases every year, with esophageal, oral, breast and lung cancers being the main ones. At the same time, a high incidence of chronic arsenic poisoning has been observed for three decades, which not only increases the risk of cancer, but has also been associated with cardiovascular disease, diabetes and developmental delays in children and adolescents.
The genesis of the problem dates back to the 1970s. of the last century, when Bangladesh was infamously among the countries with the highest infant mortality rates in the world. The cause was contaminated surface water, commonly used for drinking. The United Nations, in cooperation with NGOs, has initiated a program to drill 10 million wells. Mortality rates among the youngest soon declined, but back in the 1990s. The first victims of chronic arsenic poisoning began to be recorded. The problem has grown to such a scale that the WHO has described it as “the largest mass poisoning of a population in history.”
It turned out that Bangladesh’s curse is its location in the delta of the Ganges, Brahmaputra and Meghna rivers. These huge rivers flow down from the Himalayas, carrying with them arsenic-rich alluvial sediments from the Holocene era. Minerals derived from the rocks easily dissolve in groundwater and seep into wells. There, without contact with oxygen, which makes arsenic insoluble and precipitates it out of the water, they act as a poison.
Climate change significantly increases risk of disease
Global warming and related weather extremes will significantly worsen the situation for the people of Bangladesh, according to Norwich scientists. Already today, 21 percent. The country’s surface experiences floods during the monsoon season, which cause a combination of fresh water from rivers and sea water from the Bay of Bengal. In exceptionally stormy years, more than 60 percent are flooded. of the country, whose average altitude is only 8 meters above sea level.
An additional problem is the salt, which increases the solubility of the sediments and causes even more arsenic to seep into the aquifer. In chemistry, this phenomenon is called the salt effect. A warming climate-induced rise in sea levels will make salty floods in Bangladesh more severe. At the same time, scientists expect more frequent and abundant river flooding as cyclones gain strength and glaciers in the Himalayas increase their rate of melting. According to Dr. Frisbie, chemical changes in the aquifer will affect 78 million people, up to 900,000 of them. can die from lung and bladder cancers.
The cancer risk associated with increased arsenic infiltration into groundwater and aquifer under climate change is not limited to Bangladesh. The mechanism of the above-mentioned processes is universal and can also occur in other locations around the world. Already at risk appears to be the Indian state of West Bengal, where geological conditions are similar and well use is widespread.