The Great American Baby Bottle Scare

Is your baby’s bottle half empty or half full? Or is it, as the Canadian government believes, leeching potentially dangerous levels of estrogen-like chemicals into his milk?

Canada’s government announced in April that it is holding a consultation on whether to label as toxic Bisphenol-A (BPA), a chemical used in clear plastic containers and also to line tinned foods (1). The Canadian decison was informed by last month’s draft report by the National Toxicology Program (NTP), part of the US government’s Department of Health and Human Services. The NTP reviewed 400 of the most recent studies of BPA. On the basis of limited evidence from animal studies, it noted ‘some concern for neural and behavioral effects in fetuses, infants, and children’ and ‘some concern for exposure in these populations based on effects in the prostate gland, mammary gland, and an earlier age for puberty in females’.

‘Some concern’ in NTP-speak falls far below what scientists would actually consider a risk. In any case, newborns and infants are exposed to BPA at levels nowhere near what might merit concern, let alone constitute a risk. Canadian health minister Tony Clement acknowledged as much, but decided to act anyway, on the basis that ‘it is better to be safe than sorry’.

The reaction was swift and predictable. Within days of the Canadian announcement, WalMart began removing products containing BPA from its shelves. In the US, Senator Charles Schumer of New York announced his intention to sponsor a bill in Congress to ban the use of BPA in food containers, children’s products or products children might put in their mouths. A website called MomsRising.org sent out a panicked email calling on mothers to ‘take a second to take a collective deep breath, and then mobilise for major action’. A Californian woman, Lani Felix-Lozano, announced her intention to sue Nalge Nunc, a manufacturer of Nalgene water bottles, because its website represented BPA as safe. The case is seeking ‘class action’ status.

A plastic panic

The US Food and Drug Administration (FDA) and the NTP rushed to reassure parents. Dr Michael Sheldon of the Center for the Evaluation of Risks to Human Reproduction, who oversaw the NTP report, told the press he did not believe there was ‘anything in it that should lead to alarm’. FDA associate commissioner for science, Norris Alderson, testified in Congress that the NTP report emphasised ‘relatively new data’ with ’emerging or difficult-to-interpret endpoints’ providing ‘limited evidence’ and ‘numerous uncertainties’ . They were ignored.

Worried moms and dads across North America expressed their ‘outrage’, ‘horror’ and ‘disgust’, tossed out their plastic bottles, and rushed to buy BPA-free alternatives – which is no easy task, since plastic labeling is obscure and confusing. Amazingly, Z Recommends, a blog dedicated to finding BPA-free products, set up a free text messaging service, making it possible to check out the chemical composition of sippy cups and baby bottles anywhere in satellite range, 24/7.

An excessive response, no doubt. Yet as Rick Smith of Environmental Canada, an anti BPA group, put it, when a government takes the extraordinary step of banning a substance, ‘no parent in their right mind will be using products made with [BPA]’.

The Canadian ban and the subsequent panic has an almost Orwellian feel for anyone who actually follows scientific discussions of BPA. To appreciate fully the gulf between the public perception of risk and the reality, it is worth knowing something about the discussion of BPA among scientists. Scientists have been studying the chemical intensively for the better part of a decade since it was first suggested it might pose a risk to human health by Frederick vom Saal of the University of Missouri at Columbia. More than 4,000 studies and several major risk assessments later, scientists in the US, Japan and the European Union have exonerated it.

There are a number of points of contention, some to do with dosages and methods of exposure in animal studies of BPA, but the crux of the matter is this: human beings and other primates metabolise BPA much more efficiently than do the rodents used in animal studies.

Of mice and men

Both human beings and rodents metabolise orally ingested BPA in the process of digestion. In human beings, the liver combines BPA with a sugar molecule, transforming it into BPA-glucuronide, BPA’s harmless, water-soluble cousin. Studies in human volunteers show that 100 per cent of BPA ingested is excreted in the urine in about six hours. No BPA at all enters the blood.

In rodents, BPA is metabolised somewhat differently. It passes from the gut to the liver, then back to the gut again in a process known as enterohepatic recirculation. In the course of this process, some of the BPA is absorbed into the bloodstream, where it appears to have ‘estrogenic or toxic potential’.

The animal studies reviewed in the NTP report provide limited evidence that BPA absorbed into the bloodstream can cause neural and behaviour effects in the developing fetuses, infants and young of rodents. In fact, there are still major questions about the animal studies themselves, about their reproducibility and statistical strength. But assuming for the sake of argument that they did prove to be replicable, statistically sound and methodologically robust, it still leaves the question of how much the effects on rodents tell us about possible effects in human beings.

The key questions to be answered are: first, whether the capacity of human beings to metabolise orally ingested BPA differs enough between adults, infants and children for them to be adversely affected in the similar way to rats and mice; second, whether it is possible for a fetus to be exposed to BPA via the placenta.

While it is theoretically possible that BPA could be problematic in these circumstances, it is also quite possible that it may not. On balance, many of the NTP’s findings are in line with earlier risk assessments, noting only ‘minimal concern that exposure to bisphenol A in utero causes effects on the prostate’ or ‘accelerates puberty’ and ‘negligible concern’ that it ‘produces birth defects and malformations’. It also expressed ‘minimal concern’ that infants and children exposed to BPA would experience any acceleration in puberty and ‘negligible concern’ about adverse reproductive effects in the general population. It is therefore all the more striking how much the public discussion of the Canadian ban has focused on the worst-case scenario.

Health fears in an age of mistrust

According to Trevor Butterworth and Rebecca Goldin of the research organisation Stats.org: ‘The problem with the coverage of BPA in the media is that the scientific community has been systematically ignored by the press in their rush to report a health scare and an industry-brokered cover up.’ They charge that journalists dismissed studies and risk assessments funded by industry and simply ignored others, like a comprehensive review published in February by NSF International (an independent not-for-profit organisation devoted to consumer affairs) which rejected research claiming a risk to humans from BPA. Instead, journalists have relied on a handful of sources – in particular on Frederick vom Saal, the main proponent of the BPA-as-endocrine-disruptor thesis and someone who believes the Canadian ban will be seen as a vindication of his work.

Among worried parents, the media’s supposition has blossomed into ‘fact’. Donna Norton of MomsRising.org, confuses mice and men when she claims: ‘Growing children are especially at risk to chemicals as they face greater exposure per pound of body weight. Even fetuses are susceptible as chemicals, including BPA, cross the placenta in pregnant women. Over 130 studies suggest that BPA exposure, even at low doses, is linked to many health problems, including early puberty, breast and prostate cancer, obesity, attention and hyperactivity disorder, brain damage, altered immune system, and lower sperm counts.’

In truth, some scientists say they have observed these effects in rodents. It’s a huge leap to suggest that these effects have been observed, let alone studied, in human beings. The health problems BPA supposedly causes are linked by credible evidence to other factors, such as genetic predisposition or lifestyle. Some, like early onset of puberty in girls, are hotly debated. While there is some discussion about whether breast development is occurring earlier in American girls, the average age of puberty – as defined at the onset of menstruation – remains unchanged at 12.75 years.

It is of course very tempting to put these distortions down to journalists’ predisposition for sensation, or perhaps to an environmentalist bias among some parents – but the story’s grip on the public imagination suggests that there’s more going on here. It is not that the facts are unavailable or that parents and journalists are incapable of grasping them. It’s more that it never occurs to them to be critical. They are blinkered by a mistrust of the fruits of modernity and by deep pessimism about the future.

BPA is only the latest invisible worm imagined to be eating away at the heart of modern life. Phthalates in plastic is another. Almost any seemingly innocent household item, from plastic bottles and baby toys to shampoo and paint, can be re-imagined as oozing the insidious toxins that are to blame for ADHD, obesity, chronic disease and especially cancer. And yet, as disturbing as this siege mentality is, the most worrying thing about the panic about BPA is the extent to which fear prevails over science.

Infecting public discussion

The willingness to assume the worst has a debilitating effect on public discussion. When scientists find nothing in claims about BPA, for instance, it is dismissed as the product of chemical industry manipulation rather than genuine and profound weaknesses with the entire thesis. Large, well-designed studies conducted by independently audited contract labs are suspect because they are ‘industry funded’. Apparently even Harvard University’s Center for Risk Assessment is merely a shill for the chemical industry because their 2000 report on BPA was commissioned by the American Plastics Council. In fact, anyone who dares to be critical of the BPA scare is accused of using the tobacco industry’s ‘delaying tactics’.

Most problematically, some now call for ‘independent science’, untainted by any ties to industry. The term is deceptive. Science is science. It stands or falls on its own merits. The notion of ‘independent science’ trivialises the whole notion of objectivity and betrays contempt for the individual men and women involved in scientific research, both in terms of the way they conduct their own work and in the way they review the work of others.

The problem with the BPA scare is not just that individual parents have been frightened out of their wits about a basically benign chemical, or even the potentially huge cost of identifying alternatives and scrapping entirely safe and effective manufacturing processes. The real problem with the BPA scare is the way it elevates fear above dispassionate consideration of the evidence, and makes it into an organising principle for all of society.

Nancy McDermott is a writer and mother-of-two based in New York.

(1) Government of Canada Takes Action on Another Chemical of Concern: Bisphenol A, Health Canada