Environmental exposure to low levels of lead hidden in paint, soil and plumbing systems could be responsible for hundreds of premature deaths every year, an international study suggests.

Researchers in the US monitored lead levels in more than 14,000 Americans over 20 years and found that even very low levels – between one to five micrograms of lead per decilitre of blood – increases the risk of premature death.

Compared with people having low levels of lead in their blood, those with high levels of at least 6.7 micrograms were twice as likely to die from ischaemic heart disease, a condition where the heart is starved of blood due to narrowed or block arteries.

Overall cardiovascular death risk was raised by 70 per cent by higher levels of lead exposure, the study found.

Based on the findings, the researchers estimated each year more than 250,000 Americans die from heart disease due to traces of the toxic metal in the environment.

The research, published in The Lancet Public Health journal, contradicts the belief that there is a safe level of lead exposure and has raised concern among Australian experts.

“This work has implications in Australia where we often see lead exposures in a number of inner city areas, for example in Sydney and Melbourne, as well as in mining communities and also nationally through drinking water fixtures and fittings,” said Dr Paul Harvey, a postdoctoral researcher from the Department of Environmental Sciences at Macquarie University.

A similar study would need to be conducted in Australia to confirm the extent of the association between lead exposure and heart disease, Dr Harvey noted.

According to Stuart Khan, a Professor of Civil & Environmental Engineering at the University of New South Wales, lead can enter drinking water from old pipes and other plumbing materials.

“This is particularly common where poor procedures have been used for welding and soldering,” he said.

“Household tap fittings, such as some water filters, can also contain lead-based components, which can leach lead into the water.”

Professor Khan says Australian water quality managers cannot afford to become complacent and believes they should be paying closer attention to school plumping systems.

“I think this is of particular concern when the students come back to school after a long summer break. Under those circumstances, there is potential for water to have sat stagnating, with warm summer temperatures, in the school plumbing system,” said Professor Khan.

“These are ideal conditions for lead to be leached from the pipes to the drinking water,” he warned.

By Sarah Wiedersehn