EPA slow on toxic chemicals; puberty starting earlier; regulatory risk assessments of BPA // Feb 2015 recent news highlights

February 16, 2015 at 3:45 pm | Posted in News and Science Bulletins | Leave a comment
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Recent news highlights (Jan 2015)

Age of onset of puberty | Puberty Comes Earlier and Earlier for Girls. At the turn of the 20th century, the average age for an American girl to get her period was 16 to 17. Today, it is less than 13, according to national data. The trend has been attributed to the epidemic of overweight children and a greater exposure to pollution. (Newsweek)

Chemical regulation | EPA Still Slow to Study Toxic Chemicals, Despite Obama Pledge. An investigation by the Government Accountability Office found that during the Bush administration the White House was delaying the EPA’s efforts to assess whether chemicals posed a public health risk. The agency said it needed to complete 50 assessments a year to do its job properly. Instead, it averaged five a year. The Obama administration promised to fix this. But in the past three years, it has completed fewer assessments of chemicals than at any time in the EPA’s history. (TIME)

New regulatory risk assessments of BPA | FDA Clears BPA In Cans, Again. The federal Food and Drug Administration has quietly reaffirmed its position that Americans are not being harmed by bisphenol A, a synthetic estrogen that is an essential ingredient of the epoxy coating that lines the insides of most food cans made in the U.S. (EWG Blog) BPA plastics chemical poses no health risk, says European watchdog. The chemical bisphenol A, used to stiffen some plastic food containers, poses no health risk to consumers of any age, including unborn children, at current levels of exposure, Europe’s food safety watchdog has said (Reuters).

Epigenetic mechanisms for EDC action; BPA lowers semen quality in rats; and more // Feb 2015 Science Digest #2 (non-human)

February 16, 2015 at 3:30 pm | Posted in News and Science Bulletins | Leave a comment
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February 2015 Science Digest #2:
Non-Human & Policy Research

EDCs, epigenetics | Early-life Exposure to Endocrine Disrupting Chemicals and Later-life Health Outcomes: An Epigenetic Bridge? The purpose of this review is to provide a summary of recent research findings which indicate that exposure to EDCs during in-utero and/or neonatal development can cause long-term health outcomes via mechanisms of epigenetic memory.

BPA, semen quality | Adult exposure to bisphenol A (BPA) in Wistar rats reduces sperm quality with disruption of the hypothalamic-pituitary-testicular axis. In this study, we demonstrated for the first time that adult male exposure to BPA caused a reduction in sperm production and specific functional parameters. The corresponding pattern of gene expression is indicative of an attempt by the pituitary to re-establish normal levels of LH, FSH and testosterone serum concentrations. In conclusion, these data suggest that at dosages previously considered nontoxic to reproductive function, BPA compromises the spermatozoa and disrupts the hypothalamic-pituitary-gonadal axis, causing a state of hypogonadotropic hypogonadism.

BPA, alternatives | A new chapter in the bisphenol A story: bisphenol S and bisphenol F are not safe alternatives to this compound. In this study, the addition of luteinising hormone in the FeTA system considerably enhances BPA minimum effective concentration in mouse and human but not in rat fetal testes. Then, using the FeTA system without LH (the experimental conditions in which mouse and human fetal testes are most sensitive to BPA), we found that, as for BPA, 10 nmol/L BPS or BPF is sufficient to decrease basal testosterone secretion by human fetal testes with often nonmonotonic dose-response curves. This cautions against substitution of BPA with BPF or BPS.

EDCs, mechanism of effect | Effects of the Endocrine-Disrupting Chemical DDT on Self-Renewal and Differentiation of Human Mesenchymal Stem Cells. Human MSCs provide a powerful biological system to investigate and identify the molecular mechanisms underlying the effects of environmental agents on stem cells and human health. MSCs exposed to DDT demonstrated profound alterations in self-renewal, proliferation, differentiation, and gene expression, which may partially explain the homeostatic imbalance and increased cancer incidence among those exposed to long-term EDCs.

BPA and aggressive behaviour; flame retardants and premature birth; and more / Feb 2015 Science Digest #1 (human)

February 10, 2015 at 12:55 pm | Posted in News and Science Bulletins | Leave a comment
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February 2015 Science Digest #1:
Human Research

BPA, behaviour | Prenatal exposure to phthalate esters and behavioral syndromes in children at 8 years of age: Taiwan maternal and infant cohort study. Externalizing problem scores were significantly higher in association with a 1-unit increase in log10-transformed creatinine-corrected concentrations of maternal MBP (β = 4.29; 95% CI: 0.59, 7.99), MEOHP (β = 3.74; 95% CI: 1.33, 6.15), and MEHP (β = 4.28 ; 95% CI: 0.03, 8.26) after adjusting for the child’s sex, intelligence, and family income. Meanwhile, MBP and MEOHP were significantly associated with Delinquent Behavior and Aggressive Behavior scores. The same pattern was found for borderline and/or clinical ranges.

Organophosphates, semen quality | Associations between urinary organophosphate pesticide metabolite levels and reproductive parameters in men from an infertility clinic. Almost all OP pesticides are metabolized to at least one of six possible dialkylphosphates (DAPs). Despite wide use, their potential effects on human reproductive health have not yet been fully characterized. The aim of this study was to evaluate the associations between urinary concentrations of six DAP metabolites and reproductive parameters in men. Sperm concentration and TSC were both significantly inversely associated with DMP, DMDP, DMDTP and ∑DAP in multivariate analysis.

Asthma, environmental exposures | A systematic review of associations between environmental exposures and development of asthma in children aged up to 9 years. There was consistent evidence linking exposures to SHS, inhaled chemicals, mould, ambient air pollutants, some deficiencies in maternal diet and respiratory viruses to an increased risk for asthma (OR typically increased by 1.5-2.0). There was less consistent evidence linking exposures to pets, breast feeding and infant dietary exposures to asthma risk, and although there were consistent associations between exposures to antibiotics and paracetamol in early life, these associations might reflect reverse causation.

POPs, early menopause | Persistent organic pollutants and early menopause in US Women. This study of a representative sample of US women documents an association between EDCs and earlier age at menopause. We identified 15 EDCs that warrant closer evaluation because of their persistence and potential detrimental effects on ovarian function. Earlier menopause can alter the quantity and quality of a woman’s life and has profound implications for fertility, human reproduction, and our global society.

Flame retardants, premature birth | Does exposure to flame retardants increase the risk for preterm birth? Study quantifying PBDE-47, the most common congener in maternal plasma samples, collected at the time of labor from women who subsequently had term or preterm birth (PTB). Women with high (OR=3.8, CI: 1.6, 9.7; P=0.003) or very high PBDE-47 concentrations were at greater odds (OR=5.6, CI: 2.2, 15.2; P<0.001) for PTB than women with very low levels of PBDE-47.

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