Tags: chemicals, health, science
PFCs, Allergy | Prenatal exposure to perfluoroalkyl acids and allergic diseases in early childhood. Study suggesting that reducing prenatal exposure to the long-chain PFC PFTrDA may decrease the risk of early childhood eczema in girls.
Pesticides, Thyroid Function | The association between prenatal exposure to organochlorine pesticides and thyroid hormone levels in newborns in Yancheng, China. After adjusting for confounders, the TSH level in cord serum samples was negatively associated with HCB levels (OR=0.535, 95% CI=(0.304-0.941)). The correlation analysis suggested that organochlorine pesticides in maternal blood can transfer through the placenta and affect newborn thyroid hormone levels.
PFCs, Menopause | Polyfluoroalkyl Chemicals and Menopause among Women 20–65 Years of Age (NHANES). Findings suggest a positive association between PFCs and menopause; however, at least part of the association may be due to reverse causation (PFCs were positively associated with rate of hysterectomy, and time since natural menopause was positively associated with serum PFCs). Regardless of underlying cause, women appear to have higher PFC concentrations after menopause.
POPs & Heavy Metals, Neurodevelopment | Domain-Specific Effects of Prenatal Exposure to PCBs, Mercury, and Lead on Infant Cognition: Results from the Environmental Contaminants and Child Development Study in Nunavik. According to this study babies in Arctic Canada are at risk of specific effects on their mental abilities, depending on which contaminants they are exposed to in the womb. Lead, methylmercury and polychlorinated biphenyls are linked to different neurological effects: for example, PCBs seemed to impair the babies’ ability to recognize things they have seen.
VOCs, Exposure | Infant Exposure to Emissions of Volatile Organic Compounds from Crib Mattresses. These results suggest that crib mattresses are an important source of VOCs and infant exposure to VOCs are possibly elevated in their sleep microenvironments. (Synopsis here.)
PFCs, Obesity | Adiposity and Glycemic Control in Children Exposed to Perfluorinated Compounds. Study finding that overweight children who are exposed to higher levels of perfluorinated chemicals tend to show early signs of developing the metabolic syndrome, being more likely to have higher levels of insulin and triglycerides. There was no relationship between PFC exposure and metabolic markers in normal-weight children.
Pesticides (?), Semen Quality | Semen quality trends in French regions are consistent with a global change in environmental exposure. A decrease in sperm concentration and morphology, already shown at the scale of the French metropolitan territory, was observed in most French regions. The strongest decreases and lowest values are consistently observed in 2 proximate regions both highly agricultural and densely populated, suggesting an explanatory role for chemical exposure in the decrease.
Tags: endocrine disrupting chemicals, Julie Girling, precautionary approach, Precautionary Principle
The “junk science
threat” to free trade
In January this year, MEP Julie Girling contributed an opinion piece to the Wall Street Journal (Girling 2014) in which she decried “the EU’s expanding embrace of ‘precautionary’ regulation” of endocrine disrupting chemicals (EDCs), equating this to a “junk science” approach to policy-making.
Since this piece promulgates a number of misconceptions about the legal and scientific underpinnings of precautionary policy-making, which need to be resolved if we are to do as Girling wants and move “toward a common approach to these issues”, it is worth deconstructing some of the points she presents.
Point 1. “The EU’s embrace of precautionary regulation contradicts the established norms of science and risk management.”
This repeats the old canard that a precautionary approach to risk management somehow exists in contradiction to a set of established and therefore superior practices for incorporating science in policy-making and risk management.
Precautionary approaches have gained traction in Europe partly because of difficulties in dealing with uncertainty when we are trying to manage risk/benefit trade-offs. Accurately gauging the benefits and harms from technological innovations is difficult; since information is invariably incomplete it follows that surprises (pleasant or not) can always manifest. Often, determining the extent to which a chemical presents a risk requires observing the amount of damage it does, a knowledge paid for in the lives which are harmed and shortened.
The question, then, is how to strike the right balance between encouraging the sorts of innovations that make life better while preventing the harms that make life worse, particularly when we think we might not be able to accurately anticipate harm? EDC policy cuts to the very core of this because it is based on new research suggesting that we may be greatly underestimating the risks to health posed by chemicals which can interfere in the normal functioning of the hormone system.
To prevent any confusion about exactly what constitutes the Precautionary Principle, it is Principle 15 of the Rio Declaration: “[I]n order to protect the environment, the precautionary approach shall be widely applied by States according to their capability. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation”.
Those advocating precautionary restrictions on EDCs believe they to pose exactly such harms, in particular the irreversible changes to the development of the foetus which may result in increased lifetime risk of cancer, behavioural disorders, allergy and immune disorders and reduced fertility, to name just a few. The real extent of these risks is unclear; what is not wanted is to act on them only after they have become manifest. The Precautionary Principle is the tool for doing that.
Rather than contradicting established norms in risk assessment and risk management, it can be argued that the Precautionary Principle seeks rational ways in which to manage risk by taking action before harm has occurred rather than after. Precautionary approaches use science; what they do not do is wait for certainty of results.
Point 2. “Some public interest groups and an aligned activist scientist movement, parts of the European Commission and many members of the European Parliament are waging an emotion-based campaign for zero risk” which “undermines any attempt to rationally balance risks and benefits”.
Firstly, this list covers so many stakeholders that it hardly seems like the single campaign or niche interest that Girling seems to believe it to be. Enough people seem to be involved that a democratic solution needs to be worked out rather than dismissed as the concerns of an irrational minority.
Secondly, there is no campaign for zero risk: there is not one credible source this writer is aware of which describes itself as such. What is much more likely is that it is a campaign against taking uncalculated and unnecessary risks. The point is not to achieve a zero-risk society but to understand which risks are being taken and for people affected by those risks to have a say in whether they are taken or not.
Thirdly, while a campaign for zero risk would be irrational, precautionary approaches to managing risks posed by chemicals are precisely an attempt to rationally balance risks and benefits when the risks and benefits are unknown or our confidence in our ability as a society to quantify them is limited.
It would not be inconsistent for advocates of precaution to accept, in the case of sufficient information when risks and benefits can be more-or-less fully anticipated, that a risk-based approach to preventing harm would be rational. In the absence of this, however, we need a way of making safer bets. Girling might not think this approach works but it is not obviously irrational.
Point 3. “[…] most things we come into contact with have effects on hormones and therefore could be classified as EDs e.g. sunlight, apples, coffee and soy. So it’s not surprising that a multitude of chemicals would be subject to a ban, even without any evidence of adverse effect on humans.”
This statement contains a number of misunderstandings of the purpose of regulatory control on prospective EDCs, ultimately capturing a position which nobody in fact holds.
The main issue is that sunlight apples and coffee will not be classified as endocrine disruptors and were never intended to be: after EDCs had been discovered as a potential problem for chemical safety assessment and regulation, one of the first issues recognised as needing to be resolved was the distinction between ED effects which society should be regulating vs. the effects it should not.
The original interest was in potential harms caused by exogenous and largely man-made compounds (soya in fact being a recognised “natural” endocrine disruptor for which an argument for restricting exposure can certainly be made). When it became obvious that a simple notion of endocrine disruption failed to distinguish between what society would want to regulate and would not, naturally enough this was sharpened up.
This produced the following generally (though not exclusively, as causal proof is considered by some to be too high a standard for regulatory use) accepted definition of endocrine disruptor: “An exogenous substance or mixture that alters function(s) of the endocrine system and consequently causes adverse effects in an intact organism, or its progeny, or (sub)populations.” (WHO/IPCS 2002).
This is accompanied by the following definition of adverse effect: “A change in morphology, physiology, growth, reproduction, development or lifespan of an organism which results in impairment of functional capacity or impairment of capacity to compensate for additional stress or increased susceptibility to the harmful effects of other environmental influences.”
The obvious difference between an apple and an endocrine disruptor is that apples are not substances which interfere with the normal functioning of the hormone system and, as a consequence of this interference, cause adverse effects in the consumers of apples or their offspring. The same goes for sunlight: the body responds via hormone signals to maintain homeostasis; what sunlight does not do is interfere with that homeostatic function (it might overwhelm it, but again that is not interference).
The purpose of EDC research and regulation is to determine how chemicals can interfere in the normal functions of the hormone system to harm health, and how to prevent this happening. It is not to try and regulate sunlight or apples.
Point 4. “Any indication that a substance interacts with the body’s endocrine system is proof of potential harm and justification for a ban.”
Part of the issue here is that in an ideal world, all chemicals would have a satisfactory pedigree of safety before being brought to market. The problem is marketing has preceded testing, the result being that we now have on the market an unquantified number of chemicals which need to be removed. The core issue therefore is not the need for bans on existing chemicals (that is a historical contingency brought about by inadequate pre-market testing) but the need for demonstrating safety of chemicals before they are used: bans would not be needed if testing had been done in the first place.
Another part of the issue is a difference in opinion about the amount and quality of evidence required for restrictive action to be taken on a chemical after it has been brought to market. Girling seems to demand a lot of evidence to justify regulatory restrictions and bans; other parties argue for much less (for more detail on how to interpret requirements on evidence before action, see this article in H&E). The compromise on where that threshold for existing chemicals should be set still needs to be worked out.
Point 5. There has been a mainstream community rebellion against the activist attack on current regulatory science: 18 editors of some of Europe’s most prominent scientific journals.
This is a somewhat one-sided account of the debate about the regulatory science. This “mainstream” rebellion has been thoroughly critiqued, with a number of questions being raised including about the accuracy of the concept of endocrine disruption presented by these editors were responding and how EDC policy can possibly be under “activist attack” if the policy framework for EDCs was written by stakeholders including the industry-funded association ECETOC. (For a fuller account of the questions raised, see this article in H&E.)
Point 6. “Let us not jeopardize the huge benefits to be gained from moving toward a common approach to these issues.”
General doubts about chemical safety are indicative of a loss of trust in the regulatory framework around chemicals. Regaining people’s confidence in chemical regulation requires bridges need to be built. One-sided presentations of the debate, with scientists-vs-luddites framing and straw man arguments, is perhaps not the way to reaching the compromise Girling wants.
Endocrine Disruptors, Toxicity Mechanisms | Birnbaum twist on Paracelsus: “Does dose make the poison? A current assessment of nonmonotonicity.” Increasingly, toxicologists in the field of environmental health science, such as Birnbaum, are recognizing that for some compounds, especially hormones and hormone-like chemicals, the reverse may hold true. In these cases, a much smaller dose may have a disproportionate impact on toxicity, while greater doses may actually blunt effects through several antagonistic mechanisms, including the saturation of receptors.
Hazardous Chemicals, Taxation | Sweden proposes hazardous chemical tax on consumer goods. Consumer goods subjected to the tax would be those containing hazardous substances on a list that would be drafted for each product group, according to Kemi. For example, clothing and footwear items containing certain phthalates, allergenic or carcinogenic dyestuffs and antibacterial substances should be taxed.
Flame retardants, Regulation | Calif. law change sparks debate over use of flame retardants in furniture (video). Flame retardants are commonplace in most upholstered furniture to help prevent house fires. But studies have linked the chemicals to cancer and fertility problems, prompting California to change the state’s furniture flammability standards which could have a ripple effect across the country. (Read about how manufacturers are mounting legal challenges to the new law.)
Early Puberty | Trend Towards Early Puberty in Girls Continues, Researchers Ask Why. Obesity alone doesn’t explain the phenomenon. Though girls with a higher body mass index showed the most dramatic changes, even girls with a healthy body weight are developing earlier than in decades past.
Safer Substitutes, Formaldehyde | The ‘No More Tears’ Shampoo, Now With No Formaldehyde. In reformulating some of its iconic products, J&J is navigating a precarious path, investing tens of millions of dollars to remove problem chemicals while at the same time insisting that they are safe – all the while meeting the demand of the marketing department that the new formulations are functionally indistinguishable from the old.