August research digest #2: Recent peer-reviewed research into chemical toxicity, risk assessment and risk management

August 13, 2013 at 7:03 pm | Posted in News and Science Bulletins | 1 Comment

See August research digest #1 for human epidemiological research.

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Mixture Effects. Dispelling urban myths about default uncertainty factors in chemical risk assessment — sufficient protection against mixture effects? It is commonly assumed that default uncertainty factors represent worst-case toxicity scenarios and yield conservative estimates of safe exposure levels for humans. An analysis of uncertainty factors, particularly in the context of mixture effects, shows this assumption to be unfounded.

Endocrine Disruption | Science and Policy. Scientifically unfounded precaution drives European Commission’s recommendations on EDC regulation, while defying common sense, well-established science and risk assessment principles. An astonishing attack from editors of various toxicology journals, describing the current EU draft regulatory framework for EDCs as being assembled in “virtually complete ignorance of all well‐established and taught principles of pharmacology and toxicology”. The attack was published alongside an open letter from 81 scientists urging the Chief Scientific Advisor to the President of the European Commission to “listen to the science”. Prof Thomas Zoeller, a biologist at the University of Massachusetts (US) said of the letter’s authors: “They are concerned about their discipline, and concerned about unwarranted regulations, but they don’t seem to be concerned about public health”.

Edocrine Disruption. Potency matters: Thresholds govern endocrine activity. A merely superficially convincing argument: “The ability to discriminate important hormonal signals from background noise can be used to define thresholds for induction of hormonal effects, without which normal physiological functions would be impossible. From such thresholds, safe levels of exposure can be estimated,” say the authors. The counter-point would be that we are unable identify what these thresholds are, so to all practical purposes EDCs are non-threshold substances.

BPA | Exposure. Food is main source of BPA for consumers, thermal paper also potentially significant. EFSA’s scientific experts have provisionally concluded that for all population groups diet is the major source of exposure to bisphenol A (BPA) and exposure is lower than previously estimated by EFSA. (The report is over 300 pages long; critique is needed but has not yet been forthcoming.)

BPA | Obesity. Metabolic disruption in male mice due to fetal exposure to low but not high doses of bisphenol A (BPA): Evidence for effects on body weight, food intake, adipocytes, leptin, adiponectin, insulin and glucose regulation. In this study, pregnant mice were fed BPA at doses spanning 10-fold below the reference dose to 10-fold above the currently predicted NOAEL. At BPA doses below the NOAEL, significant effects were observed in adult male offspring including: an age-related change in food intake, an increase in body weight and abdominal adipocyte mass, and a decrease in glucose tolerance. For most of these outcomes non-monotonic dose-response relationships were observed.

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  1. There is much concern in Cornwall UK, about the mix of toxic particles coming from Imery ‘s Clay Mining and Calciners, now to be burdened by a waste to energy burner to burn all of Cornwall’s waste along with food waste. just beside the clay works. The road to the Incinerator is near completion,so very soon the building of the incinerator will commence. Both local people and people from all over Cornwall have tried to stop the incinerator ,on the precautionary principle, but neither Cornwall Unitary Council, DEFRA, Public Health England or the Appeal courts have listened to our concerns.

    It would be much appreciated if someone knew how to put a stop to this danger.

    Any advice would be welcome.


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