Bisphenol A

After shopping, you’re paying for your merchandise when the usual question pops up, “Do you want your receipt?” Just say no. Recent research has shown that thermal receipts contain bisphenol A (BPA), the chemical already found in hard plastics and can liners.

Where does BPA lurk?

BPA is a chemical that acts like the perfect criminal. You don’t see it, but it’s there to do its job. An estrogen-mimicking synthetic compound, BPA is heavily used in the manufacturing of epoxy resins and polycarbonate plastics. BPA is often found in

• water bottles
• CDs and DVDs
• electronics
• toys
• resin linings of food and beverage cans
• dental sealants
• medical devices

According to research published in Environmental Science & Technology (2011), a lesser known yet significant BPA exposure source is paper, from thermal receipts to recycled paper products such as some toilet paper and napkins.

How prevalent is BPA?

The worldwide production of BPA is estimated at approximately 8 billion pounds (4 billion kg) a year. According to Statistics Canada, approximately 91 percent of Canadians tested had detectable levels of BPA in their urine, indicating widespread exposure to the chemical. While the half-life of BPA is relatively short—less than six hours—constant exposure through ingestion and skin exposure makes for a persistent presence in the body.

Health dangers

BPA is metabolized in the liver, and contrary to the results of industry-funded studies, independent studies have shown links to long-term health effects such as reproductive effects in males and females, neurobehavioural abnormalities, and increased risk of obesity and heart disease. Recent studies concluded that prenatal exposure to BPA is also associated with increased odds of wheezing and asthma early in life.

Females
Early life exposure was shown to increase adipogenesis (fat storage) in female rats. Another study showed that BPA exposure increases the risk of mammary precancerous lesions in female rats.

Irregular cycles, multiple ovarian cysts, and early onset of sexual maturation are a few of the adverse health effects observed in females following prenatal exposure to BPA. An increased incidence of miscarriage was observed in women following maternal exposure to BPA, even at low doses.

A pioneering study found a connection between BPA exposure and externalizing (aggressive and hyperactive) behaviour in two-year-old girls.

Males
In male offspring of rats, prenatal exposure at doses lower than the established safe exposure level can result in an enlarged prostate in later life.

According to a study published in 2010 in Synapse long-term prenatal exposure to BPA leads to increased anxiety and cognitive deficits in mice. This conclusion is supported by previous research that showed an increase in aggressiveness in male rats following low-dose prenatal BPA exposure.

Human exposure to BPA in the workplace was linked to reduced fertility in male workers by causing reduced daily sperm production, erectile dysfunction, decreased libido, and ejaculation difficulties.

While some might argue that BPA studies on animals have no relevance due to differences in metabolism and physiology between animal models and humans, a recent review showed that knowledge acquired from animal models can be extrapolated to people.

Overexposure

Research indicates that serum BPA levels in humans imply much higher BPA exposure doses than previously thought. The safe exposure dose established by Health Canada is a precautionary 25 micrograms per kilogram (mcg/kg) of body weight per day.

Estimates of BPA exposure in the general Canadian population are between 0.08 to 4.30 mcg/kg of body weight per day, with teenagers having the highest concentrations of BPA of all age groups. Recent studies hypothesize that, given the new evidence of BPA-laden paper, skin exposure, hence total exposure, may be much higher than previously thought.

The paper trail

BPA has been found in paper items ranging from

• thermal paper receipts
• thermal paper and fax paper
• paper cups and food cartons
• magazines and flyers (alive magazine is a BPA-free publication)
• luggage tags, plane boarding passes, and bus tickets
• some recycled paper products such as toilet paper, napkins, and paper towels
• paper currency (contamination appears to come from proximity to paper receipts)
• Thermal paper receipts

These are the worst offenders, since BPA is not chemically bound to the paper but is part of a thermal-sensitive layer. Researchers found that these seemingly innocuous small pieces of paper made up 98 percent of BPA skin exposure through paper.

The consumption of thermal paper in Canada and the US alone is estimated at more than 106,000 tons per year. Approximately 30 percent of all receipts are recycled, contaminating recycled paper with BPA. Receipts are responsible for adding at least 33.5 tons of BPA to the environment in North America each year.

That is low compared to dietary exposure, but in the case of such a powerful estrogen-like compound, small amounts can be threatening, says researcher Kannan Kurunthachalam, PhD, professor at State University of New York at Albany.

How to reduce exposure

According to a recent BPA exposure study, holding a BPA-containing thermal receipt in your hand for five seconds transfers approximately 1 mcg of the endocrine disruptor onto the skin. More BPA is transferred onto the skin if fingers are wet or greasy.

That BPA remains on the skin for almost two hours is good news; it means that thorough handwashing following thermal receipt handling helps eliminate most of the chemical. The bad news is, once it is absorbed, it is impossible to wash away.

Those who are occupationally exposed to handling BPA-laden receipts and money for 10 hours or more a day can absorb up to 71 mcg per day, which is lower than the established tolerable daily intake. However, researchers fear that even if skin exposure ceases after 10 hours, any BPA remaining on the skin will still be absorbed into the body. While with most chemicals a higher concentration produces worse health problems, in the case of BPA, the continuous low-dose exposure causes problems.

Is there a safe alternative to BPA?

Some American producers have replaced BPA with bisphenol S (BPS), which has a very similar structure to BPA. It’s also an endocrine disruptor, albeit less potent than BPA, but more environmentally persistent.

Since BPS comes with its own health threats, replacing BPA with its potentially disruptive relative doesn’t appear to be the answer. As Kurunthachalam says, finding a safe alternative for BPA is the million-dollar unresolved question.

Bottom line

We learn as kids that when saving money every penny counts. The slogan “every little bit counts” applies to BPA too. Governmental environmental reports may estimate that exposures from various sources are too low to matter, but various sources of BPA exposure add up.

Phasing out such a pervasive chemical may seem like a daunting task, but so was the elimination of DDT. Eventually, with awareness and pressure, it happened.

Take action

• Contact your local stores and ask them to reduce the use of thermal paper receipts.
• Ask your MP to pressure Health Canada to begin phasing out BPA in all products.
• Call the manufacturer of your favourite recycled paper products (such as toilet paper) and ask them if their products contain BPA. If it’s not already stated on the package, asking them directly is the only way you’ll know for sure.

Safety tips

• Use care when handling paper currency, as it is usually handled with receipts at the cash register. BPA transfers to currency if they touch.
• Minimize the use of hand cremes or other skin products prior to handling receipts since they can enhance the absorption of BPA
• Don’t store receipts in your wallet or in your pockets. The BPA will rub off onto the fabric and will ultimately be absorbed through skin contact.

How to avoid exposure to BPA