Low-level lead exposure causes early deaths from cardiovascular disease - study finds

Lead exposure is linked to high blood pressure and heart disease. Photo / 123RF

Low-level lead exposure may be responsible for around a third of early deaths from cardiovascular disease, a new study has found.

Researchers monitored the lead levels in more than 14,000 people in America over 20 years and found that even low-level lead exposure - between 1-5 micrograms of lead per decilitre of blood - increased the risk of an early death.

The researchers said the study called into question the assumption that there were "safe levels" of lead exposure and suggested that low-level environmental lead exposure was a leading risk factor for premature death, particularly from cardiovascular disease.

University of Otago professor Nick Wilson said the findings were very plausible and high lead levels had likely caused some Kiwis to suffer. However, he thought smoking, poor diet and physical inactivity had a more detrimental impact on New Zealanders.

"It is likely that many New Zealanders have also suffered from heart disease where exposure to lead (especially from lead in petrol) made some contribution.

"This burden was prolonged due to the failure of many New Zealand Governments in the 1970s and 1980s to not act decisively despite good scientific evidence showing that lead levels were lowering the IQ of New Zealand children.

"But even if lead played some role in contributing to heart disease it is unlikely to have been as important over the last 50 years in New Zealand as has smoking, a diet high in saturated fats from meat and dairy products, and physical inactivity.

"Fortunately, heart disease rates are currently declining as New Zealanders quit smoking, consume more healthy fats like olive oil, and also take treatments such as blood pressure lowering drugs and statins."

The international paper from the Simon Fraser University in Canada was published in The Lancet Public Health today.