Exposure to a chemical found in plastic containers is linked to heart disease, scientists said recently, confirming earlier findings and adding to pressure to ban its use in bottles and food packaging.
British and US researchers studied the effects of the chemical bisphenol A using data from a US government national nutrition survey in 2006 and found that high levels of it in urine samples were associated with heart disease.
Bisphenol A, known as BPA, is widely used in plastics and has been a growing concern for scientists in countries such as Britain, Canada and the United States, where food and drug regulators are examining its safety.
Research confirms earlier findings
David Melzer, professor of epidemiology and public health at the Peninsula Medical School in Exeter, England, who led the study, said the research confirmed earlier findings of a link between BPA and heart problems.
The analysis also confirmed that BPA plays a role in diabetes and some forms of liver disease, said Melzer's team, who studied data on 1,493 people aged 18 to 74.
"Our latest analysis largely confirms the first analysis, and excludes the possibility that the original report was a statistical blip," they said in a statement.
BPA, used to stiffen plastic bottles and line cans, belongs to a class of compounds sometimes called endocrine disruptors.
The US Endocrine Society called for better studies into BPA and presented research showing the chemical can affect the hearts of women and permanently damage the DNA of mice.
"The risks associated with exposure to BPA may be small, but they are relevant to very large numbers of people. This information is important since it provides a great opportunity for intervention to reduce the risks," said Exeter's Tamara Galloway, who worked on the study published by the Public Library of Science online science journal PLoS One.
US environmental health advocacy groups are urging a federal ban on BPA.
"There's enough research to take definitive action on this chemical to reduce exposures in people and the environment," Dr Anila Jacob of the Environmental Working Group, a non-profit organisation, said in a telephone interview.
The US Food and Drug Administration is considering whether any action needs to be taken.
US government toxicologists at the National Institutes of Health concluded in 2008 that BPA presents concern for harmful effects on development of the prostate and brain, and for behavioural changes in foetuses, infants and children.
Canada's government plans to outlaw plastic baby bottles made with BPA. The charity Breast Cancer UK last month urged the British government to do the same because they said there was "compelling" evidence linking the chemical to breast cancer risk.
Experts estimate BPA is detectable in the bodies of more than 90% of US and European populations. It is one of the world's highest production volume chemicals, with more than 2.2 million tonnes produced annually. - (Kate Kelland/Reuters Health, January 2010)