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Background: Severe iodine deficiency or excess during pregnancy can cause congenital hypothyroidism (CH). Iodine deficiency is common in pregnant women in the United States.Objectives: We conducted a nested case-control study in a cohort of ∼2.5 million births in California to determine whether iodine status is related to CH in a US population.Methods: Dried blood spots from 907 newborns with CH identified by newborn screening and 909 unaffected controls matched by month of birth were obtained from the California Newborn Screening Program to measure whole-blood iodine concentration. Iodine status was compared between cases and controls, and logistic regression was used to assess the association between CH status and blood iodine concentrations. Iodine status was also compared between cases and controls among infants treated in a neonatal intensive care unit (NICU) because CH has been reported in infants exposed to high levels of iodine in the NICU.Results: Blood iodine concentrations did not differ significantly between cases (median: 20.0 ng/mL; IQR: 12.1-29.8 ng/mL) and controls (median: 20.3 ng/mL; IQR: 12.5-30.9 ng/mL; P = 0.59). Neither extremely high nor extremely low blood iodine concentrations (1st, 5th, 95th, and 99th percentiles of the distribution) were more common in cases. Among infants treated in NICUs, however, cases had significantly (P = 0.01) higher iodine (median: 22.7 ng/mL; IQR: 16.4-32.1 ng/mL) compared with controls (median: 17.3 ng/mL; IQR: 8.3-26.6 ng/mL).Conclusions: CH cases did not have significantly higher or lower iodine in this population, which is reassuring given that maternal iodine deficiency is common in the United States. Among newborns in the NICU, CH cases had higher blood iodine concentrations compared with controls, suggesting that excess iodine exposure in the NICU could be causing CH. It may be beneficial to monitor iodine exposure from surgical procedures, imaging, and iodine-containing disinfectants and to consider non-iodine alternatives. [ABSTRACT FROM AUTHOR]

Bisphenol A (BPA) is an endocrine disrupting environmental chemical. Urinary concentrations of BPA were measured in samples collected nationwide from Chinese young adults. The geometric mean urinary concentration of BPA in Chinese young adults was 2.23 ng/mL. The estimated daily exposure dose for BPA was 64.8 ng/kg bw/day. Contributions of various BPA sources to exposure in Chinese young adults were estimated. Dietary intake was the primary exposure pathway. The contribution of dietary intake, indoor dust, paper products and personal care products to BPA intake was 72.5 %, 0.74 %, 0.98 %, 0.22 % of the total exposure dose, respectively. This is the first study on the occurrence of BPA in young adults from most provinces and autonomous regions of China. The results can be used to establish a database for BPA exposure assessment for Chinese general population. [ABSTRACT FROM AUTHOR]