New Delhi, Oct 23 (IANS): Long-term exposure to arsenic in drinking water may increase the risk of cardiovascular disease even at exposure levels below the regulatory limit, according to a new study on Wednesday.

The study led by researchers at Columbia University in the US is the first to describe exposure-response relationships at concentrations below the current regulatory limit (10 micrograms per litre). It also substantiates that prolonged exposure to arsenic in water contributes to the development of ischemic heart disease.

For the study, published in the journal Environmental Health Perspectives, the team compared various time windows of exposure.

“Our findings further reinforces the importance of considering non-cancer outcomes, and specifically cardiovascular disease, which is the number one cause of death in the US and globally,” said Danielle Medgyesi, a doctoral student in the Department of Environmental Health Sciences at Columbia Mailman School.

To evaluate the relationship between long-term arsenic exposure from community water supplies (CWS) and cardiovascular disease, the researchers analysed 98,250 participants, 6,119 ischemic heart disease cases, and 9,936 CVD cases.

The study found decade-long arsenic exposure up to the time of a cardiovascular disease event was associated with the greatest risk. The findings are consistent with a previous study in Chile finding peak mortality of acute myocardial infarction around a decade after a period of very high arsenic exposure.

The study found a substantial 20 per cent risk at arsenic exposures ranging from 5 to less than 10 micrograms per litre which affected about 3.2 per cent of participants. The results highlight the serious health consequences not only when community water systems do not meet the current standards but also at levels below them.

The study emphasised the need for implementing regulatory standards to protect health.