Shallow wells dug for drinking water in the Amazon basin in order to avoid polluted rivers contain up to 70 times the recommended limit of arsenic, researchers warned Tuesday.
Samples taken from 250 sites along the Amazon — the first systematic analysis of the region’s well water — also revealed hazardous levels of manganese and aluminium, they reported at a conference in Vienna.
“Faced with polluted rivers, many rural communities rely on groundwater as a source of drinking water,” lead researcher Caroline de Meyer, a scientist at the Swiss Federal Institute of Aquatic Science and Technology, told AFP.
“In parts of the Amazon basin, groundwater contains these trace elements in concentrations that are potentially harmful to human health.”
“Contamination should not be underestimated — all our data point in the same direction,” she added.
Levels of manganese were up to 15 times higher than World Health Organization (WHO) limits, while aluminium exceeded WHO standards by up to three-fold.
The elements detected occur naturally, and do not come from industrial pollution, the researchers said.
Chronic exposure to arsenic is linked to cancers of the liver, kidney and bladder, as well as heart disease. It is also thought to contribute to miscarriages, low birth weights and poor cognitive development in children.
In Bangladesh, where arsenic in well water has been a known health hazard for decades, the element is blamed for some 40,000 premature deaths each year.
Manganese poisoning can cause permanent neurological damage, while the impacts of sustained exposure to aluminium are less well understood.
Rural communities in the Amazon basin traditionally rely on rivers and rain to meet freshwater needs.
But with increased pollution from mining, logging and industrial activities, they have also turned to digging wells.