Contaminated water has affected people in Bangladesh
Scientists say they have identified a link between long-term exposure to arsenic and the accelerated development of atherosclerosis or progressive narrowing and hardening of the arteries leading to the brain.
The findings, published in the Journal of the American Heart Association, strongly point to arsenic and possibly other pollutants, as risk factors for blood vessel disease throughout the body.
The National Taiwan University's Dr Chih-Hao Wang, who carried out the research, said: "More than 100 million people are exposed to underground water with high concentrations of arsenic.
"Chronic arsenic poisoning, called arseniasis, is an emerging epidemic in Asia.
"Our results indicate that long-term exposure may lead to the progression or acceleration of carotid artery disease and most likely generalised artery disease in humans."
The carotid artery carries blood from the heart to the brain and any cholesterol build-up on its inner walls can lead to a stroke.
The researchers studied 199 men and 264 women in an area of south-western Taiwan with a high rate of arseniasis.
Arsenic disease legacy
They found those people with the greatest exposure to arsenic, had three times the risk of atherosclerosis.
Sophisticated water treatment works are able to remove the arsenic from ground water supplies, but they are expensive for developing countries.
World Health Organisation (WHO) toxicologist Dr Antero Aitio said: "We need to make sure people don't drink the water in affected areas."
However he is not convinced by this study.
He said: "There is clearly a problem with arsenic, but the causal relationship has not been demonstrated.
"The link between arsenic and diabetes is much stronger than the link to cardiovascular disease.
"I would view this research with caution, but this is an area which definitely should be studied because cardiovascular diseases are a very important cause of mortality.
"Therefore a very small increase in cardiovascular mortality would affect more people than cancer."
Prolonged exposure to arsenic via drinking water has also been linked to skin diseases, including cancer.
However, the use of contaminated water for washing or bathing is not thought to be dangerous to human health.