Associations between urinary biomarkers of polycyclic aromatic hydrocarbon exposure and reproductive function during menstrual cycles in women.

Essentially all women are exposed to polycyclic aromatic hydrocarbons (PAHs), formed during incomplete combustion of organic materials, including fossil fuels, wood, foods, and tobacco. PAHs are ovarian toxicants in rodents, and cigarette smoking is associated with reproductive abnormalities in women. Biomonitoring of hydroxylated PAH (OH-PAH) metabolites in urine provides an integrated measure of exposure to PAHs via multiple routes and has been used to characterize exposure to PAHs in humans. We hypothesized that concentrations of OH-PAHs in urine are associated with reproductive function in women. We recruited women 18-44years old, living in Orange County, California to conduct daily measurement of urinary luteinizing hormone (LH) and estrone 3-glucuronide (E13G) using a microelectronic fertility monitor for multiple menstrual cycles; these data were used to calculate endocrine endpoints. Participants also collected urine samples on cycle day 10 for measurement of nine OH-PAHs. Models were constructed for eight endpoints using a Bayesian mixed modeling approach with subject-specific random effects allowing each participant to act as a baseline for her set of measurements. We observed associations between individual OH-PAH concentrations and follicular phase length, follicular phase LH and E13G concentrations, preovulatory LH surge concentrations, and periovulatory E13G slope and concentration. We have demonstrated the feasibility of using urinary reproductive hormone data obtained via fertility monitors to calculate endocrine endpoints for epidemiological studies of ovarian function during multiple menstrual cycles. The results show that environmental exposure to PAHs is associated with changes in endocrine markers of ovarian function in women in a PAH-specific manner.

Environmental Chemicals in an Urban Population of Pregnant Women and Their Newborns from San Francisco.

Exposures to environmental pollutants in utero may increase the risk of adverse health effects. We measured the concentrations of 59 potentially harmful chemicals in 77 maternal and 65 paired umbilical cord blood samples collected in San Francisco during 2010-2011, including polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), hydroxylated PBDEs (OH-PBDEs), and perfluorinated compounds (PFCs) in serum and metals in whole blood. Consistent with previous studies, we found evidence that concentrations of mercury (Hg) and lower-brominated PBDEs were often higher in umbilical cord blood or serum than in maternal samples (median cord:maternal ratio > 1), while for most PFCs and lead (Pb), concentrations in cord blood or serum were generally equal to or lower than their maternal pair (median cord:maternal ratio ≤ 1). In contrast to the conclusions of a recent review, we found evidence that several PCBs and OCPs were also often higher in cord than maternal serum (median cord:maternal ratio > 1) when concentrations are assessed on a lipid-adjusted basis. Our findings suggest that for many chemicals, fetuses may experience higher exposures than their mothers and highlight the need to characterize potential health risks and inform policies aimed at reducing sources of exposure.

Exposures to environmental phenols in Southern California firefighters and findings of elevated urinary benzophenone-3 levels.

Firefighters are at increased risk for exposure to toxic chemicals compared to the general population, but few studies of this occupational group have included biomonitoring. We measured selected phenolic chemicals in urine collected from 101 Southern California firefighters. The analytes included bisphenol A (BPA), triclosan, benzophenone-3 (BP-3), and parabens, which are common ingredients in a range of consumer products. BP-3, BPA, triclosan, and methyl paraben were detected in almost all study subjects (94-100%). The BP-3 geometric mean for firefighters was approximately five times higher than for a comparable National Health and Nutrition Examination Survey (NHANES) subgroup. Demographic and exposure data were collected from medical records and via a questionnaire, and covariates were examined to assess associations with BP-3 levels. BP-3 levels were elevated across all firefighter age groups, with the highest levels observed in the 35 to 39year old group. Body fat percentage had a significant inverse association with BP-3 concentrations. Our results indicate pervasive exposure to BP-3, BPA, triclosan, and methyl paraben in this population of firefighters, consistent with studies of other populations. Further research is needed to investigate possible explanations for the higher observed BP-3 levels, such as occupational or California-specific exposures.

Development and validation of a simple and robust method for arsenic speciation in human urine using HPLC/ICP-MS.

In order to better distinguish the different toxic inorganic and organic forms of arsenic (As) exposure in individuals, we have developed and validated a simple and robust analytical method for determining the following six As species in human urine: arsenous (III) acid (As-III), As (V) acid, monomethylarsonic acid, dimethylarsinic acid, arsenobetaine (AsB), and arsenocholine. In this method, human urine is diluted using a pH 5.8 buffer, separation is performed using an anion exchange column with isocratic HPLC, and detection is achieved using inductively coupled plasma-MS. The method uses a single mobile phase consisting of low concentrations of both phosphate buffer (5 mM) and ammonium nitrate salt (5 mM) at pH 9.0; this minimizes the column equilibration time and overcomes challenges with separation between AsB and As-III. In addition, As-III oxidation is prevented by degassing the sample preparation buffer at pH 5.8, degassing the mobile phase online at pH 9.0, and by the use of low temperature (-70 °C) and flip-cap airtight tubes for long term storage of samples. The method was validated using externally provided reference samples. Results were in agreement with target values at varying concentrations and successfully passed external performance test criteria. Internal QC samples were prepared and repeatedly analyzed to assess the method's long-term precision, and further analyses were completed on anonymous donor urine to assess the quality of the method's baseline separation. Results from analyses of external reference samples agreed with target values at varying concentrations, and results from precision studies yielded absolute CV values of 3-14% and recovery from 82 to 115% for the six As species. Analysis of anonymous donor urine confirmed the well-resolved baseline separation capabilities of the method for real participant samples.