Washington, Dec 11 (IANS): A new study has found that exposure to cadmium metal can accelerate the process of cellular ageing.

People are usually exposed to this toxic metal by inhaling tobacco smoke, eating fruits and vegetables grown in contaminated soil or living near an industrial site.

The exposure leads to significantly shorter telomeres -- bits of DNA at the ends of chromosomes which are associated with cardiovascular disease, diabetes and other old age ailments.

"We looked at heavy metals and found a strong association between exposure to low levels of cadmium and telomere shortening," said Ami Zota, assistant professor of environmental and occupational health at Milken Institute School of Public Health at George Washington University.

The findings suggest that cadmium exposure can cause premature ageing of cells.

"This heavy metal can get into the bloodstream and trigger kidney disease and other health problems," they cautioned.

In this study, Zota and her colleagues looked at blood and urine samples taken from more than 6,700 adults who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002, a nationally representative health survey of the US population.

"People with the highest cadmium exposure had cells that looked on average 11 years older than their chronological age," Zota informed.

For non-smokers, food is generally the largest source of cadmium exposure, said Zota.

Cadmium levels in some foods can be increased due to the application of phosphate fertilizers or sludge which is applied to farm fields.

The World Health Organisation (WHO) calls environmental exposure to cadmium a "major public health concern" and notes that this heavy metal has been associated with cardiovascular disease, respiratory problems, cancer and other serious diseases.

The study was published online in the American Journal of Epidemiology.