Less lead, more IQ; more flame retardants, less IQ; BPA and semen quality, plus more / June 2014 Science Digest #1 (human research)June 9, 2014 at 4:15 pm | Posted in Uncategorized | Leave a comment
Tags: behaviour, BPA, chemicals, flame retardants, health, IQ, lead, phthalates, science, semen quality
June 2014 Science Digest #1 // Human Research
IQ, Lead | The possible societal impact of the decrease in U.S. blood lead levels on adult IQ. Given lead’s well-documented neurotoxicity, it should be expected that the dramatic decreases in US blood lead levels since the 1970s would be accompanied by a 4-5-point increase in the mean IQs of Americans. The results of this study suggest this has indeed been the case.
IQ, Flame Retardants | Prenatal Polybrominated Diphenyl Ether Exposures and Neurodevelopment in U.S. Children through 5 Years of Age. Study linking prenatal PBDE exposure to lower IQs and greater hyperactivity in five-year old children: a 10-fold increase in PBDE concentrations in early pregnancy, when the fetal brain is developing, was associated with a 4.5 IQ decrement, comparable with the impact of environmental lead exposure. (“Now we’ve seen this pattern of toxicity with low level environmental chemicals — lead, mercury, now fire retardants — let’s not do it again,” says Prof. Bruce Lanphear.)
Behaviour, Phthalates | Prenatal Phthalate Exposures and Neurobehavioral Development Scores in Boys and Girls at 6–10 Years of Age. In boys, concentrations of monoisobutyl phthalate were associated with higher scores for inattention, rule-breaking behavior, aggression, and conduct problems. The molar sum of di(2-ethylhexyl) phthalate metabolites was associated with higher scores for somatic problems.
Semen Quality, BPA | Urinary Bisphenol A Levels in Young Men: Association with Reproductive Hormones and Semen Quality. This pattern of associations between BPA and reproductive hormones could indicate an antiandrogenic or antiestrogenic effect, or both, of BPA on the hypothalamic–pituitary–gonadal hormone feedback system, possibly through competitive inhibition at the receptor level.
Autistic traits, EDCs | Gestational Exposure to Endocrine-Disrupting Chemicals and Reciprocal Social, Repetitive, and Stereotypic Behaviors in 4- and 5-Year-Old Children. Some EDCs were associated with autistic behaviors in this cohort. The researchers state that modest sample size means chemicals with null associations cannot be excluded as increasing risk of autism. PFOA, β-hexachlorocyclohexane, PCB-178, PBDE-28, PBDE-85, and trans-nonachlor deserve additional scrutiny as factors that may be associated with childhood autistic behaviors.
Study Suggests Long-Term Decline in French Sperm Quality. A new study findings suggest widespread declines in sperm quality in French men between 1989 and 2005, with average sperm counts falling while percentages of abnormally formed sperm rose. These findings are a “serious public health warning,” the authors wrote. Although the average estimated sperm count is still well above the level deemed normal by the World Health Organization, this may increase the proportion of men with fertility problems in the overall population.
Triclosan: Anti-bacterial soaps called useless, potentially dangerous. “Triclosan is what we call a stupid use of a chemical,” said Dr. Sarah Janssen, a physician and senior scientist with the Natural Resources Defense Council, an environmental advocacy group. “It doesn’t work, it’s not safe and it is not being regulated.”
Everyday chemicals ‘pose threat to health’. Excellent NHS Direct coverage of media responses to the WHO EDC report, covering in detail the concerns correctly highlighted (though in a somewhat sensationalist manner) by the Daily Mail, who reported: “Chemicals found in every home may cause breast cancer, asthma, infertility and birth defects, global health chiefs have said.”
Architect describes how US Green Building Council is being attacked to protect interests of a small group of manufacturers of “toxic and obsolete” chemicals. “The war over toxic chemicals and human health is spilling over into places we live and work: our buildings,” says Robin Guenther. “The American Chemical Council (ACC) has launched an expensive and focused attack on the U.S. Green Building Council (USGBC) to protect the status quo of a small set of bad-actor manufacturers of toxic and obsolete chemicals. But innovative companies across the building industries and human health advocates are fighting back.”
Breast cancer among young women increasing. In 1976, 1.53 out of every 100,000 American women 25 to 39 years old was diagnosed with advanced breast cancer, the study found. By 2009, the rate had almost doubled to 2.9 per 100,000 women in that age group — a difference too large to be a chance result. This news comes at the same time as a report faults priorities in breast cancer research, stating that too little of the money the federal government spends on breast cancer research goes toward finding environmental causes of the disease and ways to prevent it.
Persistent Environmental Pollutants and Couple Fecundity: The LIFE Study. This couple-based prospective cohort study with preconception enrollment and quantification of exposures in both female and male partners observed that a subset of persistent environmental chemicals were associated with reduced fecundity.
In Utero and Childhood Polybrominated Diphenyl Ether (PBDE) Exposures and Neurodevelopment in the CHAMACOS Study. Both prenatal and childhood PBDE exposures were associated with poorer attention, fine motor coordination, and cognition in the CHAMACOS cohort of school-age children. This study, the largest to date, contributes to growing evidence suggesting that PBDEs have adverse impacts on child neurobehavioral development. EHP provides a plain-English summary of findings.
Epigenetics and pesticides. In spite of the current limitations, available evidence supports the concept that epigenetics holds substantial potential for furthering our understanding of the molecular mechanisms of pesticides health effects, as well as for predicting health-related risks due to conditions of environmental exposure and individual susceptibility.
Effect of low dose bisphenol A on the early differentiation of human embryonic stem cells into mammary epithelial cells. This in vitro study provides insight into the effects of low doses of BPA on mammary epithelial cells during early stages of differentiation, suggesting that exposure to BPA may make breast cells more likely to become cancerous later in life.
Potential Sources of Bisphenol A in the Neonatal Intensive Care Unit. The authors describe nasal oxygen administration and continuous positive airway pressure as individual sources of higher exposure to BPA. In these circumstances, BPA would pass into circulation in the blood without undergoing first-pass metabolism in the liver, resulting in higher exposure to free, active BPA than if the same amount were to be ingested.
“Probable link” between pregnancy-induced hypertension and PFOA contamination. Explanation of one of the legal “probable-cause” findings which are the scientific basis of determination of DuPont’s liabilities with regard to contaminating a waterway with PFOA.
Obesogens: an environmental link to obesity. Accessible and comprehensive EHP cover feature looking at the mechanisms of action and potential culprits in the obesogen hypothesis.
Cashew nut pesticide linked to blood cancers in Indian children. Report on how a widely-banned pesticide, still extensively used in cashew nut and other cash crop plantations in developing countries, has been found in the bone marrow of children suffering from blood cancers in the areas using the pesticide.
Long-awaited dioxins report released; EPA says low doses risky but most people safe. After 21 years of wrangling over health threats, uncertain science and industry pressure, the U.S. Environmental Protection Agency on Friday released its health assessment of dioxins, concluding there are potentially serious effects even at very low levels of exposure.
Call for new approach on endocrine disruptors. The final version of an EU-commissioned report recommends EDCs be treated as a distinct regulatory category (as for CMRs and PBTs), and cautions that existing, internationally-agreed and validated test protocols capture only a limited range of potential ED effects.
Urinary Bisphenol: A Concentration and Risk of Future Coronary Artery Disease in Apparently Healthy Men and Women. The associations found here between higher BPA exposure and incident CAD show similar trends to cross-sectional findings in the more highly exposed NHANES respondents. Study sponsored by the British Heart Foundation and published in the Journal of the American Heart Association.
Prenatal Exposure to PFOA and Risk of Overweight at 20 Years of Age. Propsective study replicating in humans findings in mice that PFOA exposure increases weight gain and adiposity, with women gestationally exposed to PFOA more likely to be obese at 20 years.
Solvent exposures and Parkinson Disease risk in twins. US epidemiological research finding that exposure to trichloroethylene, the most common organic contaminant in US groundwater, and PERC and CCl4 (also ubiquitous in the environment) may increase risk of PD.
Concentrations and speciation of polybrominated diphenyl ethers in human amniotic fluid. Although PBDE accumulation in humans has been noted since the 1970s, this is the first to date which identifies levels in amniotic fluid. PBDE congeners were identified in all samples.
Birth Weight and Prenatal Exposure to PCBs and DDE: A Meta-analysis within 12 European Birth Cohorts. Low-level exposure to PCB (or correlated exposures) impairs fetal growth, suggests this large meta-analysis, with the effects of PCB 153 exposure on birth weight equivalent to the effects of a pregnant mother smoking 10 cigarettes a day.