BPA November Update: Precaution rules in Europe as emerging science casts doubt on BPA safety

December 17, 2010 at 2:18 pm | Posted in Briefing | Leave a comment

2-dimensional structures of BPA (top) and alternatives. BPS is the third molecule down. Click to enlarge.

In a major legislative development during November, BPA was banned from use in baby bottles in Europe. The decision was made by the European Commission under the precautionary principle, which allows a substance to be banned where there is substantial cause for concern about it posing potential harm to health, but where the formal processes of risk assessment have not determined that the degree of harm is certain and substantial enough to force a ban.

Industry group CEFIC was unhappy about the decision, saying it was “astonished” and telling the website ChemicalWatch that it “undermines the systems and processes which ensure the safety of food and food contact materials in the EU”. Environment groups, however, have been arguing the ban needs to go further to eliminate all routes of exposure, citing concerns that prenatal exposure may occur when pregnant women consume tinned food. Several food manufacturers are eliminating the chemical anyway, with Nestle, Heinz and General Mills all announcing plans to end the use of BPA.

Before the Commission’s decision, the WHO published a press release summarising the findings of a joint FAO/WHO expert panel meeting, convened to assess whether or not BPA exposure from food exceeds safe levels. The release said BPA exposure is lower than levels currently considered to be safe, and that research indicating that the safe exposure level should be further reduced is still preliminary and needs confirming. They also concluded that food is the major route of exposure.

The WHO press release (which seems to no longer be available on-line) appeared on 10 November, just over 2 weeks before the European Commission made its decision about the safety of BPA. However, the WHO did not publish its full report until early December; before then it would not comment on specifics as to the report’s content or state who was present on the expert panel. The full report can now be downloaded here.

The WHO position seems to conflict with the Canadian government’s October decision to add BPA to its Toxic Substances List, which allows it to ban the substance from specific uses such as in baby bottles. This classification was greeted with enthusiasm by environment groups and was represented in some media as Health Canada making it “official” that “BPA is a health hazard” (see e.g. canada.com).

In fact, the Canadian position appears to be more nuanced than this: when Health Canada was asked by H&E about the WHO position and how it contrasts with their own, it said the conclusions of the WHO expert meeting “are consistent with the Government of Canada’s position on BPA” but “there is some uncertainty in the science” which is why “the Government of Canada has already taken action to reduce exposure levels in infants and young children”.

This seems to put Health Canada in a position more closely aligned with the precautionary stance taken by the European Commission than it does the bolder statements about the toxicity of BPA that have been presented in the media.

It has not all been plain sailing for advocates of a ban on BPA. A bipartisan bid to ban BPA in the US fell through in November, with the New York Times pointing the finger at industry opposition to the proposed bill. Australia also announced that it has no plans to ban the chemical. Neither development is likely to have been met with approval by BPA researcher Frederick vom Saal, judging by the blistering salvo he launched at the chemicals industry in an interview with Yale Environment 360 website.

New research: New papers have been published suggesting that BPA may increase the chances of chromosome abnormalities by interfering with DNA repair machinery (Allard & Colaiácovo 2010), while other researchers found an association between BPA exposure altered immune parameters (Clayton et al. 2010); more significantly, the study found an association between triclosan exposure and greater odds of being diagnosed with allergies or hayfever.

Of relevance to the WHO conclusion that food is the major exposure route for BPA, a new study found that BPA readily crosses the skin barrier (Zalko et al. 2010). It is currently believed that diet is the only significant source of exposure to BPA and its safety is determined accordingly, with oral exposure being the only route carrying real clout in the risk assessment process.

The amount of BPA in US food was measured for the first time, with chemists detecting BPA in fresh, packaged, and canned food purchased in U.S. supermarkets. Science News observed that it is all well and good avoiding polycarbonate bottles and tinned food, but voiced concern about BPA being a ubiquitous food contaminant: if BPA is detectable even in fresh food, it is questionable how effective overall even a ban on BPA in food packaging is likely to be.

Given that BPA is used in receipts, there is now some speculation that e.g. cashiers might be at elevated risk of harm. In response, a US firm has developed a BPA-free thermal paper. Science News reported that the paper uses diphenyl sulphone (also known as bisphenol-S). BPS is one example of a range of structurally-similar chemicals which could be substituted for BPA but about which we know very little.

Health Canada’s response to the WHO expert panel report, in full:

  • Canada continues to be a world leader in addressing any potential risks related to exposure to bisphenol A.
  • The conclusions of the WHO expert meeting are consistent with the Government of Canada’s position on BPA.
  • The experts at the WHO/FAO meetings concluded that it would be premature to indicate any human health concern, but that ongoing studies will help to clarify the extent of human health concern for this chemical.
  • This aligns with Health Canada’s conclusions that while exposure levels to BPA are below those that could cause health effects for Canadians, there is some uncertainty within the science.
  • This uncertainty is why the Government of Canada has already taken action to reduce exposure levels in infants and young children even further (for example, by introducing a prohibition on the importation, sale and advertising of polycarbonate baby bottles containing BPA), and why we continue to conduct research on the safety of BPA.

Obtained via the Health Canada press office, telephone +1 613 946 4250

Californian Medical Association backs moves to limit BPA exposure, and other BPA developments in October.

November 6, 2010 at 7:24 pm | Posted in Briefing | 3 Comments

Sperm and EggOctober was a busy month for BPA. The Californian Medical Association passed a resolution “recogniz[ing] a public health concern for Bisphenol A (BPA), a known endocrine disruptor, and endors[ing] efforts to reduce towards elimination of BPA in consumer products”. (CMA Resolution 116a-10, PDF)

The government of Canada formally declared bisphenol A, to be a toxic substance, while the Danish Minister of Food said Denmark will not be rescinding its precautionary ban on BPA. The European Food Safety Authority’s recent statement that it has no reason to change the tolerable daily intake level for BPA is becoming increasingly controversial.

The progress of the debate is well summarised by John Hendel of The Atlantic. Hendel charts the emergence of the controversy over the use of the substance, with researcher Fred vom Saal as a central character in the story, and includes an explanation of why toxicology needs to be reformed.

Bryan Walsh, a TIME magazine journalist who has covered BPA in detail adds his two cents to recent developments, offering his opinion on the direction in which things are going. In general, knowledge about and awareness of BPA seems much higher in the US than in Europe.

While Walsh speculates about regulation, USA Today and The Independent (UK) both covered a story about how investment advisory firms are rating companies on issues such as how quickly they are eliminating problem chemicals such as BPA from their products.

Moves toward more BPA-free products than just baby bottles were given added impetus by research showing that pregnant women who eat canned vegetables are unwittingly exposing their infants during fetal development. A second paper suggests that BPA levels in humans are too high to be accounted for by dietary exposure alone (Taylor et al. 2010).

Further research into the effects of BPA on fertility was published, with a new study funded by US healthcare provider Kaiser Permanente (picked up by USA Today) finding that Chinese workers who are highly exposed to BPA have reduced semen quality (Li et al. 2010).

In the spirit of constructive criticism the conservative website Junk Science slammed the research, saying that rather than being published in the journal of Fertility and Sterility, the study “may as well have been published in the journal of Futility and Stupidity”.

The Kaiser Permanente study hardly came out of nowhere: there is a small body of research which suggests that BPA harms fertility, with low levels of BPA having been found to reduce semen quality in rats (Herath et al. 2004) and fish (Lahnsteiner et al. 2005).

Evidence of harm to fertility from BPA in human studies is mixed. Mendiola et al. 2010 recently found that although urinary BPA concentrations have been associated with altered levels of sex hormones, researchers could only find evidence of small resulting changes to reproductive function which are of “uncertain clinical significance”.

In contrast, Meeker et al. 2010 did find an association between BPA concentration and lower semen quality in men, a finding which has been corroborated by the new study. A new review in Reproductive Toxicology summarises the currently available data (Salian et al. 2010).

Meanwhile, an updated review has been published which discusses BPA’s role as both an endocrine active compound, its ability to make epigenetic changes through DNA methylation, and its reported effects of BPA on brain and behaviour (Wolstenholme et al. 2010).

New research has found that rats exposed neonatally to BPA were more likely as adults to develop pre-cancerous lesions on the prostate gland (Prins et al 2010). The research was heavily criticised by a cancer charity; we point out some of the more positive aspects of the paper here.

Neutrophils, DEHP and immune dysfunction

October 21, 2010 at 2:34 pm | Posted in Briefing | Leave a comment

Although classified as a CMR and banned in toys, DEHP is still widely-used in medical devices. DEHP is already believed to pose problems with reproductive health.

This month, we look at mounting evidence that DEHP may also present an immediate threat to neonatal health by potentially compromising normal immune response.

Below is footage of a neutrophil absorbing a bacterium. If neutrophils become activated at the wrong time, they can exacerbate inflammation and increase the risk of developing a range of health problems.

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