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The coating on cash-register receipts is an unlikely source where people may be exposed to BPA and a related substance, BPS.Photo Illustration: Bryan Gee. Source Images: iStock

Rick Smith and Bruce Lourie are leading experts on the health effects of toxic chemicals. The following is adapted from a new edition of their book, Slow Death By Rubber Duck: How the Toxicity of Everyday Life Affects Our Health.

It may turn out that the most damaging aspect of the highly visible plastic pollution that surrounds us (we’re looking at you, Tim Horton’s coffee lids) is the stuff we can’t see.

Plastic, it has recently been discovered, never really disappears. It just gets pounded into smaller and smaller bits by the passage of time, sunlight and the action of waves. These microscopic particles then enter the food chain, air and soil. In the past couple of years, scientists have started to find them in a disturbing range of products, including table salt, honey, shellfish and beer. Virtually all tap water worldwide now contains plastic microparticles. A recent study found plastic particles in the feces of all the people tested. It seems certain that a steady diet of plastic residue is one reason for humanity’s elevated levels of plasticizing chemicals.

The ingestion of plastic is only one delightful way modern contaminants are finding their way into our bodies.

In years past, pollution hit you in the face. The smog of the Industrial Revolution was so thick you could cut it with a knife. The acid rain of the 1980s caused lakes full of dying fish. These days, the truly dangerous pollution is far subtler and more invisible, and more often than not it comes from the most innocuous of sources.

Of the 80,000 or so chemicals that form the building blocks of all the consumer products we surround ourselves with every day, a great many have now been found to be readily absorbed by the human body through what we breathe, eat, drink and apply to our skin. Many of these have been linked to modern epidemics such as diabetes, breast and prostate cancer: A chemical exposure estimated to contribute to health costs that may exceed an astonishing 10 per cent of global gross domestic product (GDP).

A decade ago, the newfound awareness about toxic pollution centred on a hormone-disrupting chemical called bisphenol A (BPA). After an intense public debate, Canada became the first country in the world to ban BPA in baby bottles – something that most countries have now emulated. But the fight to get BPA out of other unlikely corners of our lives continues.

In fact, the BPA story epitomizes much that has gone right – and wrong – with the toxic chemical debate. This fact was brought home to us in the most vivid of terms by Mary Shaw, a Cambridge, Ontario-based health and safety representative for the United Food and Commercial Workers (UFCW) union, one of the largest private-sector unions in the United States and Canada.

In 2017, Ms. Shaw was contacted by one of her members who worked part-time at a grocery store. He was concerned about some research he’d read regarding the exposure of cashiers to BPA and a related substance, BPS (bisphenol S), through an unlikely source: the coatings on cash-register receipts. Receipts are something that UFCW members handle in vast quantities every day.

“This was new information for me and the union,” Ms. Shaw told us. “It turns out that the now standard cash-register receipts are coated on one side with a good quantity of BPA.” When the paper runs through the register, a heat-transfer process creates the numbers on the receipt and allows for inkless printing. Prompted by her member’s concern, Ms. Shaw started looking at some of the recent studies showing that this BPA can come off on people’s hands and be absorbed through the skin.

Ms. Shaw realized the deeply worrisome nature of the situation. “As I read, I became more and more alarmed regarding worker and consumer exposure,” she said. In one study that Ms. Shaw came across, BPA levels in the bodies of cashiers were found to be significantly higher than in the general population because of their constant handling of BPA-coated receipts – many hundreds over the course of typical shift by Ms. Shaw’s calculations.

She quickly understood that the BPA might be carried around on the hands throughout the day. “Anytime we handle thermal receipt paper, the powder comes off on your hand and you transfer that powder to your food and then you ingest it. This should be a huge concern for restaurants,” she said. Though some of the stores where her members work claimed to use “BPA-free” receipts, her research made clear that the main alternative to BPA is the closely related chemical BPS, and “the damaging properties of BPS are very similar to BPA.”

There’s another wrinkle that Ms. Shaw began to worry about. “Wet hands apparently dramatically increase the absorption rate of the BPA. And cashiers often have wet hands, because they’re constantly either using hand sanitizer or handling produce.”

Ms. Shaw is troubled about BPA and BPS on receipts not just for union members but also for consumers. “As a consumer, I’m asked every time I go into a store if I want a receipt. I usually say yes. There’s really no option. This thermal paper is being used not just for cash register receipts but for an increasing number of other things like movie tickets, transit tickets and parking tickets. It’s everywhere.”

Fred vom Saal is probably the first person we spoke to about the science of BPA more than a decade ago. Dr. vom Saal is a professor at the University of Missouri and was the pioneering researcher in the 1990s who first started ringing the alarm bell about BPA’s damaging effects on human health. After 20 years of studying the chemical and more than 70 research papers, he’s more apprehensive about BPA than ever. And he agrees with Ms. Shaw that cash-register receipts are one of our most significant everyday sources of BPA exposure.

“The link between BPA exposure and human disease is much stronger now than it was 10 years ago, when Slow Death was first published. Literally every week now, another new study on BPA crosses my desk,” he told us. “We now have solid evidence for BPA exposure driving things like obesity, diabetes, heart disease and neurobehavioural problems,” he said. “In one recent study, we have evidence of BPA in people causing the deaths of fetuses during in vitro fertilization … BPA exposure results in the ovary producing less estrogen.”

Dr. vom Saal is tracking not only the continuing prevalence and effects of BPA itself, but also the growing problem of “regrettable substitutions.” Incredibly, in Canada, in the United States, and in many countries around the world, when one toxic chemical is banned or phased out, there’s no legal requirement that the replacement be any better. “This is what’s happened with BPA and BPS,” Dr. vom Saal told us.

Ten years ago, one of our very first experiments resulted in a 7.5 times increase in BPA in Rick’s body from eating and drinking out of BPA-plastic containers, including his son’s old baby bottle. After talking to Ms. Shaw, it was clear to us that the obvious – and most important – source of BPA exposure today is cash-register receipts, so we decided to conduct another experiment with the chemical.

We turned to our friends and colleagues at Environmental Defence Canada – the country’s premier pollution fighters – to give us a hand. The organization’s smart young toxic-chemical campaigners Muhannad Malas and Sarah Jamal joined us for our toxic test.

After examining a few recent scientific studies on BPA and BPS in cash-register receipts, we concluded that a necessary first step would be to “detox” from BPA as best we could. In order to show a potential increase in BPA in our bodies, we wanted our levels of BPA to be as low as possible to begin with. To achieve this, we tried to avoid canned food and any handling of cash-register receipts for at least 48 hours in advance of testing day – a task easier said than done!

Because some cash-register receipts are coated with BPA, while others use paper coated with BPS or other substances, we decided to collect receipts from as many different retailers as possible.

With preparations made, we woke on a blustery February morning and prepared to gather at Rick’s house. Before leaving home, each of us collected a urine sample from our first pee of the day and brought it with us. Then we sat down at Rick’s dining-room table to perform possibly the least dramatic toxic experiment in our 10-year history of crazy experiments: passing a bunch of cash-register receipts around the table so that the four of us continually handled them for a 15-minute period.

Because there is some evidence that wet fingers increase BPA/BPS absorption through the skin, Bruce ate greasy French fries and Rick used hand sanitizer prior to the experiment. When 15 minutes had passed, we used our BPA-coated fingers to eat some cheap sushi we had bought at a store down the street.

We waited eight hours to let the BPA and BPS be absorbed by our bodies, and then each of us took a second urine sample. We shipped all the samples to the same lab that we had used for the original Slow Death tests, and awaited the results.

The results of our experiment were stunning. In all cases, the scale of the BPA increase surpassed the levels we were able to achieve with our baby-bottle experiment in Slow Death. All four of us had similar levels of BPA and BPS in our bodies at the outset. All four of us after handling the receipts experienced huge increases in the levels of these chemicals in our bodies. At the high end, Rick’s BPA level was 42 times higher than his starting level. Sarah’s was four times as high. For BPS, Rick’s level increased an incredible 115 times, while Sarah’s was the lowest at eight times. We think that Rick’s impressive increase was due to his use of hand sanitizer before the experiment – a fact that reinforces Ms. Shaw’s concern for the health of her UFCW members.

The game of toxic Whac-A-Mole continues. Consumers demanded – and won – the removal of BPA from baby bottles to make our kids safer. It’s now popped up in unanticipated places, such as cash register receipts, that threaten us all.

Time to change how the game is played once and for all.

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