A chemical widely used in plastic food and drink containers may narrow coronary arteries, raising the risk of heart attacks, new research suggests.

High levels of bisphenol-A (BPA) in were seen significantly more often in the urine of patients with severe damage to the arteries supplying blood to the heart.

Scientists analysed data from 591 participants in a UK study looking at the causes of coronary artery disease (CAD).

In all, 385 patients had severely damaged arteries, while 86 were moderately affected and 120 were healthy.

BPA levels were significantly higher in those with severe CAD compared with individuals having normal coronary arteries.

A number of previous studies have already linked the chemical to an increased risk of heart disease. The new study suggests that the specific reason for the association may be narrowing of the arteries.

Lead researcher Professor David Melzer, from the University of Exeter, said: "Our latest study strengthens a growing body of work that suggests that BPA may be adding to known risk factors for heart disease. Full proof will be very difficult to get, as experiments on this in humans are not feasible."

BPA is used in refillable drinks containers, compact discs, plastic eating utensils and many other everyday products.

More than five million tonnes of BPA was manufactured globally in 2008, making it one of the most heavily produced chemicals by volume.

Concerns have previously been raised over the health risks of BPA to babies. In the past two years, the US and EU have banned the chemical from the manufacture of babies' bottles and other feeding equipment.

The new findings are published in the online journal Public Library of Science ONE.

Dr David Mosedale, who chairs the management committee for the Metabonomics and Genomics Coronary Artery Disease (MaGiCAD) study from which the data was drawn, said: "This ... demonstrates the utility of intensively characterised cohorts like MaGiCAD, and highlights the need for further research into the long-term effects of common environmental chemicals such as BPA."