Cash register receipts contain BPA.

Cash register receipts and paper money have been found to contain high levels of bisphenol A (BPA), a chemical linked to cancer , obesity and early puberty , a study published on Wednesday says.

Researchers from US nonprofit groups Safer Chemicals , Safer Families and the Washington Toxics Coalition tested till receipts made from thermal paper which they collected from 22 popular retailers and cafes , and found that half of them were coated with large quantities of BPA.

“Since BPA in thermal paper is present in a powdery film , we suspected it could easily travel from those receipts to other objects,” says the study , led by Washington Toxics Coalition scientist Erika Schreder. 

Holding the receipts for just 10 seconds caused up to 2.5 micrograms of BPA to transfer from the paper onto a person’s fingers , and rubbing the receipts increased around 15-fold the amount of BPA transferred from the receipts onto fingers , the study said.

From the fingers , the bisphenol A transferred easily onto dollar bills:the researchers found the chemical on 21 of 22 bills tested, although in much lower levels than on the till receipts.

More than 130 studies over the past decade have linked even low levels of BPA to serious health problems , including breast cancer , obesity and early onset of puberty.

BPA is widely used in plastic water jugs , soft drink cans , hockey helmets , mobile phone housings , computers , car bumpers and other consumer products , and the health impact of the chemical on humans has been disputed.