Search

OBJECTIVE: We investigated the association between body mass index (BMI) standard deviation score (SDS) and prenatal exposure to hexachlorobenzene, dichlorodiphenyldichloroethylene (DDE), dioxin-like compounds, and polychlorinated biphenyls (PCBs). METHODS: In this [...]

BACKGROUND: Human carcinogenesis is known to be initiated and/or promoted by exposure to chemicals that occur in the environment. Molecular cancer epidemiology is used to identify human environmental cancer risks [...]

BACKGROUND: Thyroid hormones are important regulators of brain development. During critical periods of development, even transient disorders in thyroid hormone availability may lead to profound neurologic impairment. Animal experiments have shown that certain environmental pollutants, including heavy metals and organochlorine compounds such as polychlorinated biphenyls (PCBs) and dioxins, can interfere with thyroid hormone homeostasis. Whether these contaminants can affect circulating levels of thyroid hormones in humans is unclear, however, because the results of available studies are inconsistent. OBJECTIVES: The aim of the present study is to examine the possible relationships between concentrations of environmental pollutants and thyroid hormone levels in human umbilical cord blood. METHODS: We measured concentrations of environmental pollutants [including selected PCBs, dioxin-like compounds, hexachlorobenzene, p,p'-DDE (dichlorodiphenyldichloroethylene), cadmium, lead] and thyroid hormones in the cord blood of 198 neonates. RESULTS: A statistically significant inverse relationship between concentrations of organochlorine compounds and levels of both free triiodothyronine ([fT.sub.3]) and free thyroxine ([fT.sub.4]), but not thyroid-stimulating hormone, was observed. We found no association between concentrations of heavy metals and thyroid hormone levels. CONCLUSIONS: Our results suggest that environmental chemicals may affect the thyroid system of human neonates. Although the differences in [fT.sub.3] and [fT.sub.4] levels associated with the organochlorine compounds were within the normal range, the observed interferences may still have detrimental effects on the neurologic development of the individual children, given the importance of thyroid hormones in brain development. KEY WORDS: brain, cord blood, development, endocrine disruption, heavy metals, neonates, organo-halogens, PCBs, thyroid. Environ Health Perspect 115:1780-1786 (2007). doi:10.1289/ehp.10486 available via http://dx.doi.org/ [Online 27 September 2007], It is well established that thyroid hormones are important regulators of brain development during the fetal and neonatal periods of life (Bernal et al. 2003). When maternal and/or fetal thyroid [...]

BACKGROUND: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and some related environmental contaminants are aryl hydrocarbon receptor (AhR) ligands that exert reproductive and developmental toxicity in laboratory animals. In humans, fertility-related effects are less documented. [...]

We measured tumor-associated proteins (TAPs) and pollutants in blood, serum, and urine of 200 nonsmoking women 50-65 years of age, residing in the rural municipality of Peer or in Hoboken [...]

BACKGROUND: Ultrafine particles (UFP) may contribute to the cardiovascular effects of particulate air pollution, partly because of their relatively efficient alveolar deposition. OBJECTIVE: In this study, we assessed associations between blood pressure and short-term exposure to air pollution in a population of schoolchildren. METHODS: In 130 children (6-12 years of age), blood pressure was determined during two periods (spring and fall 2011). We used mixed models to study the association between blood pressure and ambient concentrations of particulate matter and ultrafine particles measured in the schools' playground. RESULTS: Independent of sex, age, height, and weight of the child, parental education, neighborhood socioeconomic status, fish consumption, heart rate, school, day of the week, season, wind speed, relative humidity, and temperature on the morning of examination, an interquartile range (860 particles/[cm.sup.3]) increase in nano-sized UFP fraction (20-30 nm) was associated with a 6.35 mmHg (95% CI: 1.56, 11.14; p = 0.01) increase in systolic blood pressure. For the total UFP fraction, systolic blood pressure was 0.79 mmHg (95% CI: 0.07, 1.51; p = 0.03) higher, but no effects on systolic blood pressure were found for the nano-sized fractions with a diameter > 100 nm, nor [PM.sub.2.5], [PM.sub.coarse], and [PM.sub.10]. Diastolic blood pressure was not associated with any of the studied particulate mass fractions. CONCLUSION: Children attending school on days with higher UFP concentrations (diameter < 100 nm) had higher systolic blood pressure. The association was dependent on UFP size, and there was no association with the [PM.sub.2.5] mass concentration. http://dx.doi.org/10.1289/ehp.1408121, Introduction Air pollution is a complex mixture of solid particles and gases. Different size distribution modes can be identified for airborne particles. Coarse mode particles, with diameters > 2.5 [micro]m, [...]