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Background: Perfluoroalkyl substances (PFASs) are a group of fluorinated organic substances that are widely used in consumer products and are often detectable in human tissues. Human studies on prenatal exposure to PFASs and neurodevelopment in children are few and inconsistent.Methods: In the Taiwan Maternal and Infant Cohort Study, we collected serum samples from pregnant women during the third trimester and measured concentrations of 9 PFASs using a high performance liquid chromatography system. A subsample of their children was assessed with full scale intelligence quotient (FSIQ), verbal IQ (VIQ) and performance IQ (PIQ) at both age 5 (n=120) and 8 years (n=120). We used multivariate linear regression models to examine prenatal PFAS exposure in relation to IQ scores at each age period.Results: Prenatal perfluoroundecanoic acid (PFUnDA) concentrations were inversely associated with children's PIQ scores at age 5 years, with an adjusted coefficient (β) of -1.6 (95% confidence interval [CI]: (-3.0, -0.2). When children reached 8 years, most of the prenatal PFASs showed inverse association with children's FSIQ, VIQ and PIQ scores. Among them, prenatal perfluorononanoic acid (PFNA) reached significance. Children with higher prenatal PFNA levels had lower VIQ with an adjusted β of -2.1 (95% CI: -3.9, -0.2).Conclusions: We found two prenatal PFAS exposure, both long-chain PFASs, in association with decreased IQ test scores in children. Our findings suggest more studies on long-chain PFASs and children's neurodevelopment. [ABSTRACT FROM AUTHOR]

Abstract: Pollutant chemicals that are widespread in the environment can affect endocrine function in laboratory experiments and in wildlife. Although human beings are commonly exposed to such pollutant chemicals, the exposures are generally low and clear effects on endocrine function from such exposures have been difficult to demonstrate. Human data including both exposure to the chemical agent and the endocrine outcome are reviewed here, including age at weaning, age at puberty, anogenital distance, and sex ratio at birth, and the strength of the evidence are discussed. Although endocrine disruption in humans by pollutant chemicals remains largely undemonstrated, the underlying science is sound and the potential for such effects is real. [Copyright &y& Elsevier]

Succimer lowers blood lead concentrations in children, and the structure of succimer chelates of lead and cadmium are similar. Using blood samples from a randomized trial of succimer for lead poisoning, however, we found that succimer did not lower blood cadmium in children with background exposure. [Copyright &y& Elsevier]

The effect of feeding method on stress hormone levels in infants is unknown. We studied infants from birth to 1 year and found salivary cortisol 40% higher in breast-fed infants compared with formula-fed infants. The higher cortisol levels among breast-fed children may be involved in the analgesic effect of breastfeeding. [Copyright &y& Elsevier]

Objective: To examine whether succimer, a mercaptan compound known to reduce blood lead concentration in children, reduces blood mercury concentration. Study design: We used samples from a randomized clinical trial of succimer chelation for lead-exposed children. We measured mercury levels in pre-treatment samples from 767 children. We also measured mercury levels in blood samples drawn 1 week after treatment began (n = 768) and in a 20% random sample of the children who received the maximum 3 courses of treatment (n = 67). A bootstrap-based isotonic regression method was used to compare the trend with time in the difference between the adjusted mean mercury concentrations in the succimer group and that in the placebo group. Results: The adjusted mean organic mercury concentration in the succimer group relative to the placebo group fell from 99% at baseline to 82% after 3 courses of treatment (P for trend = .048), but this resulted from the prevention of the age-related increase in the succimer group. Conclusion: Succimer chelation for low level organic mercury exposure in children has limited efficacy. [Copyright &y& Elsevier]