5&5: News and Science Highlights from March 2012

Science

Transgenerational actions of environmental compounds on reproductive disease. Deliberate study of transgenerational effects of exposure to chemical mixtures, plastics, jet fuel, dioxin and pesticides, finding sperm death and premature female puberty.

Science highlight of the month: Scientists publish review describing regulatory testing as unfit for EDCs. In the largest review to date of studies examining low-dose effects of chemicals, scientists have concluded regulatory testing for chemical safety does not effectively examine the potential health risks of endocrine disruptors. Summaries of the findings in Yale360 and Scientific American.

In an editorial in Environmental Health Perspectives, Linda Birnbaum, Head of the US National Institute of Environmental Health Sciences, says the question is no longer whether nonmonotonic dose responses are real. “Instead, it is which dose–response shapes should be expected for specific environmental chemicals and under what specific circumstances.”

Exposure to Phthalates and Phenols during Pregnancy and Offspring Size at Birth. Consistent with findings of a previous study, observed evidence of an inverse association of 2,5-DCP and a positive association of BP3 with male birth weight.

Effects of Chronic Exposure to an Environmentally Relevant Mixture of BFRs on the thyroid and reproductive systems of adult male rats. Exposure to three commercial brominated diphenyl ethers, formulated to mimic the relative congener levels in house dust, affected liver and thyroid physiology but not male reproductive parameters.

Early breast development in girls after prenatal exposure to non-persistent pesticides. Evidence that prenatal exposure to currently approved pesticides may cause earlier breast development in girls, possibly from aromatisation of androgens.

News

Going to Extreme Lengths to Purge Household Toxins. A subtle and easily misunderstood NYT piece, not about middle-class paranoia, but about how inadequate regulatory control over chemical exposures in consumer goods leads to people to going to almost bizarre lengths to “shop our way to some place which protects us”.

‘Green’ cleaners without cancer-causing ingredients. The Environmental Protection Agency has found that chemicals in household cleaners are three times more likely to cause cancer than air pollution. So what’s the alternative? (And so did the Silent Spring Institute. What, as reported in Forbes, did industry think of the institute’s research? “This study presents a clear example of biased, advocacy-based research,” says William Troy, Ph.D., Scientific Advisor to the International Fragrance Association North America.)

News highlight of the month. What is really making us fat? Man-made chemicals present in homes, schools, offices, cars and food are probably contributing to the sharp rise in obesity and diabetes in western societies, according to a review of scientific literature. The Atlantic recounts various perspectives on the problem and the UK Independent provides a basic overview of the review findings. Download the report here.

Children’s car seat makers to eliminate PVC and halogenated flame-retardants. Britax and Orbit, two major manufacturers of children’s car seats and pushchairs have pledged to eliminate polyvinyl chloride (PVC) and brominated and chlorinated flame retardants from their products.

Campbell’s to end use of BPA in can linings. Campbell’s Soup Co. spokesman Anthony Sanzio said the company has been working on alternatives for five years and will make the transition as soon as “feasible alternatives are available.”

How those pesticides persist even when you wash your fruit and veg. Washing fruit and vegetables does not remove chemical pesticide residues, tests commissioned by Government food watchdogs show.

5&5: News and Science Highlights from January 2012

US FDA advice on food colour safety illustrates divide in how to evaluate bodies of evidence. A detailed explanation of how to determine effects on health of an environmental exposure, in the form of a critique of the US FDA evaluation of the safety of artificial food colours, but of strong general interest. Note the resulting correspondence (FDA defence and author response), which serves as an excellent example of what the author describes as “the wide gulf” between FDA interpretations of weight of evidence, and meaningful action to protect public health, with the “FDA essentially [taking] the position that for a study to be considered as evidence of adverse effects, it must be totally free of uncertainties.”

Breast, ovarian and cervical cancer tumour growth, and the flame retardant Deca-BDE. Study showing that PBDE-209 (deca-BDE) can influence a number of biological pathways involved in breast cancer tumour growth, promoting proliferation of various cancer cells, reducing the effect of some cell suicide mechanisms apoptosis, and up-regulating production of some cancer-related proteins. Deca-BDE is one of the most-common flame retardants found in food.

Pros and cons of oily fish consumption: better lipid profile, but more mercury and inflammatory markers. In a clear example of the pros and cons of eating healthy food, this study finds that although children who eat fish have a significantly improved lipid profile, they also have higher levels of blood mercury. Since the blood mercury levels were associated with markers for systemic inflammation, the authors  conclude it is “impossible [to perform] a risk-benefit analysis of fish consumption”.

Ubiquitous exposure to personal-care phthalates and BPA associated with increased body mass, obesity. A prospective study, in which 97% of the study participants were exposed, finds that children who are more exposed to phthalates typically found in personal care products are heavier. A large, cross-sectional Chinese study finds an association between BPA exposure and abdominal obesity; and Fred vom Saal publishes a paper reviewing how EDC exposure during foetal development causes abnormalities in the homeostatic control systems required for maintaining a normal body weight throughout life.

Serum Vaccine Antibody Concentrations in Children Exposed to Perfluorinated Compounds. JAMA study finding an association between higher exposures to PFCs and reduced humoral immune response to routine childhood immunizations. Nature reported on the study, quoting the lead author as saying: “The effect in PFCs was much stronger than we had seen for PCBs. It’s likely this is going to be a programming effect that is going to stay with these kids for their whole lifetimes.”

Connecting the Dots: Why It’s So Hard to Pin Down Environmental Causes of Cancer. A US magazine for cancer patients looks at why it’s hard to find the causes of the range of diseases which is cancer.

Sweden worried by triclosan-treated worktops. Kitchen worktops impregnated with the biocide triclosan could pose a risk to the environment and human health when thrown away, Sweden fears. Regulators in the country are examining the need for new labelling and waste rules.

EPA dioxin limits: will food politics trump science? The US food industry is worried a new Environmental Protection Agency review of safe exposure levels for dioxins could deem the average American diet dangerous. This story is of general importance not only because the EPA dioxin review is likely to have international significance, it seems the level which the EPA will set as safe could be based in politics as much as in science. The NRDC provides a two-art commentary (Part 1 | Part 2) of what has been happening behind the scenes.

Researcher Frederick vom Saal wants bans on BPA, endocrine disruptors. Interesting and comprehensive account of the work of scientist and environmental advocate Frederick vom Saal, about his research on endocrine disrupting chemicals and his conviction that chemicals policy fails to tally with scientific evidence of potential harm.

New conflicts of interest at EU food safety authority. Le Monde: In French, but an important report on findings that an EU expert working group convened to advise the European Food Safety Authority on an initiative to reduce toxicological testing of chemicals is composed almost entirely of researchers with a publishing history favouring the initiative which they are supposed to be evaluating.

5&5: News and science highlights from December 2011

View our full archive of over 1500 news stories and studies at: http://delicious.com/contaminanthealthscience

News

Metastatic Breast Cancer in Pleural Fluid. Picture: Flickr / Ed Uthman

What role does the environment play in cancer risk? In December, two reports were published on the effect which environmental and lifestyle factors might have on overall risk of cancer and on breast cancer specifically. The complexity of the issues presented a stern challenge to media coverage; here we have collated the best articles and commentary.

7 Foods You Should Never Eat. Fox News asks food scientists about what they would completely avoid in their diet. An eye-opening article which is nowhere near as hysterical as it sounds.

Runaway Growth: Forty years into the “War on Cancer,” casualties are mounting. “Most reports on the upcoming 40th anniversary of the War on Cancer will counter disappointment that cancer remains uncured with tidings of new gene-based therapies. You’re unlikely to hear that you have more chance of getting cancer than when the War on Cancer began.” One article in an excellent 4-part series explaining many of the issues facing those concerned with cancer prevention. Other articles are:

• Soft-Pedalling Prevention. “It’s hard to believe we’d need to argue that preventing illness is preferable to trying to cure it. It’s as if we’d abandoned sewage-treatment systems because we have antibiotics for cholera.”
• Gauging the danger posed by carcinogens. “Our environmental regulatory system requires no rigorous toxicological testing of chemicals [before] marketing them. It promulgates legal limits on [individual] chemical releases, largely overlooking that we are all exposed to trace amounts of many contaminants. It is still no one’s job to make sure that the total burden of toxic exposures is not too much for any one of us.”
• Coming Clean: Can we solve the problem of carcinogens in the environment? With cancer now 50 percent more common than when President Nixon launched the US “war on cancer” in 1971, there’s mounting evidence of how such chemicals affect health — and a few ideas what to do about it.

US Tox21 to begin screening 10,000 chemicals. The US NIEHS has formally begun testing the toxicity of 10,000 compounds under its revolutionary ToxCast/Tox21 program, a high-speed robotic screening system. The compounds include consumer products, food additives and industrial chemicals, and will also test mixture toxicity.

Relative Risk, One Result at a Time. American Scientist neatly summarises some of the emerging issues around chemical pollution, including mixture effects, endocrine disruption and the possibility that even very low doses of substances might cause harm.

Science

Immunotoxicity of Perfluorinated Compounds: Recent Developments. Review finding that “risk of immune effects for humans and wildlife exposed to PFCs cannot be discounted, especially when bioaccumulation and exposure to multiple PFCs are considered”.

Visual of the Month: Application of computational systems biology to explore environmental toxicity hazards. Disease–chemical associations network, from a DDT-based case-study investigating the usefulness of computational systems biology in ascertaining links between exposure to an environmental pollutant and adverse health effects.

“The circles represent diseases, with colors representing phenotype categories: red, reproductive disorders; blue, neurodevelopmental-related diseases; green, cancers; gray, other diseases. Rectangles represent the three chemicals studied. The heavier the weight of the connecting lines, the greater the number of proteins linking a chemical to a disease.” (Adouze & Grandjean, 2011) Click to enlarge.

Prenatal Exposure to PCBs and DDE and Birth Weight: A Meta-analysis within 12 European Birth Cohorts. The results of this analysis of grouped data suggest that current exposures to PCBs – while generally lower than 40 years ago – are still harmful to the growing fetus. EHN provides a synopsis here.

Dioxin and polychlorinated biphenyl concentrations in mother’s serum and the timing of pubertal onset in sons. This epidemiological study finds an association between maternal PCB serum concentrations and acceleration in some, but not all, measures of pubertal onset. Animal studies have previously demonstrated that timing of pubertal onset can be altered by prenatal exposure to dioxins and PCBs.

Cancer from foetal exposure to a carcinogen depends on the size and timing of the dose. Animal study finding that the same carcinogen will cause different cancers later in life, depending on the stage of pregnancy when the foetus is exposed and how big the dose is. Synopsis at ScienceDaily.