The researchers write in JAMA that bisphenol A -
commonly known as BPA - typically enters the body when people eat
food from a can. But it can also be absorbed through the skin from
receipts, according to the study's lead author.
"It's not the main source of exposure, but it's an additional source
that wasn't previously recognized," Dr. Shelley Ehrlich of the
Cincinnati Children's Hospital Medical Center in Ohio told Reuters
BPA is used in the process of making hard plastics, and has been
banned from use in manufacturing baby bottles. The chemical is also
used in the interior lining of many food cans.
The chemical can leach into foods that are stored in such containers
and eventually end up in the body when people eat the food. More
recent research has found that people can also end up with increased
BPA levels after touching materials containing the chemical.
BPA is in thermal paper, which used to be a mainstay in fax machines
and is still commonly used for receipts.
Thermal paper is coated with a material that turns black when heat
is applied. At the cash register, the printer applies small amounts
of heat to create numbers and letters.
BPA is chemically similar to the hormone estrogen, and is thought to
mimick that hormone's effects in the body, making it a member of a
class of chemicals known as "endocrine disruptors."
In the past, BPA has been linked to a number of health problems,
including reproductive disorders and brain development anomalies
among children exposed in the womb.
Higher levels of BPA in urine have also been tied to an increased
risk of obesity among children (see Reuters Health story of Sep. 18
For the new study, Ehrlich and her colleagues recruited 24 Harvard
School of Public Health students and staff between 2010 and 2011.
The participants were at least 18 years old and not pregnant.
First, the participants were asked to handle receipts for two hours
with their bare hands. After at least one week, they were asked to
handle receipts again while wearing gloves.
[to top of second column]
Before they handled the receipts, the researchers found that 20
of the 24 participants' urine samples had small but measurable
amounts of BPA. After the first experiment, BPA was present in all
urine samples, though at levels that remained within national
The concentration of BPA in the urine samples had increased,
though by an amount equivalent to about a quarter of what would be
expected from eating canned soup, for example.
After waiting a week and having the participants handle receipts for
two hours while wearing gloves, the researchers found no significant
increase in the BPA levels in the participants' urine samples
Ehrlich said the average person should not be alarmed by the
findings, but cashiers and bank tellers who handle receipts
throughout the day may want to take precautions - especially if
they're pregnant or of child-bearing age.
"Handle receipts with care," she said. "They are a source of
exposure to BPA and if people are handling them a lot on a daily
basis . . . they should perhaps consider using gloves for now."
In the current study, the researchers used nitrile gloves. Ehrlich
said additional research would be needed to determine whether latex
or other types of gloves also work.
She also said people may want to wash their hands after handling
"I don't think people should be super alarmed, but they should be
aware," she said.
SOURCE: http://bit.ly/WddS8K JAMA,
online February 25, 2014.
[© 2014 Thomson Reuters. All rights
Copyright 2014 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.