The sex-specific association between maternal paraben exposure and size at birth.

Parabens are a group of esters of parahydroxybenzoic acid and are utilized as antimicrobial preservatives in the majority of personal care products (PCPs). Epidemiological studies regarding the adverse effects of parabens on fetuses are still limited. The aim of this study was to determine the association between maternal paraben exposure and birth outcomes. One hundred and ninety-nine pregnant women were enrolled, and maternal urine was collected in the third trimester. The urine concentrations of four parabens (methyl (MP), ethyl (EP), propyl (PP), and butyl (BP)) were determined by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Generalized additive model-penalized regression splines and a multivariable regression model were employed to determine the association between paraben exposure levels and birth outcomes. A causal mediation analysis was conducted to determine the mediation effect of oxidative stress on birth outcomes. The geometric means of urinary MP, EP, PP, and BP were 51.79, 1.26, 4.21, and 1.25 µg/g cre., respectively. In the penalized regression splines, sex-specific associations between maternal MP levels and birth outcomes were observed; a downward curvature was observed between the MP level and birth weight, length, head circumference, and thoracic circumference among female newborns. Pregnant women in the group with MP levels above the third quartile had neonates with significantly lower body weight (ß = -215.98 g, p value = 0.02) compared to those in the group with MP levels lower than the third quartile. No significant mediation of oxidative stress was observed between maternal MP exposure and female birth weight. The estimated proportion mediated ranged from -6% to 15%. The negative association between maternal paraben exposure and female birth outcomes in relation to child development should be carefully considered.

Associations between prenatal exposure to bisphenol a and neonatal outcomes in a Taiwanese cohort study: Mediated through oxidative stress?

This study determined whether maternal bisphenol A (BPA) exposure influences birth outcomes through oxidative stress and estimated the daily intake of BPA through breast milk for infants. One hundred and eighty-six pregnant women without pregnancy complications were enrolled and maternal urine was collected in the third trimester. Postnatal breast milk was collected in the first and third months after delivery. Concentrations of BPA were determined through ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. Generalized additive model-penalized regression splines and a multivariable regression model were employed to determine the effects of BPA exposure and oxidative stress levels on birth outcomes. A causal mediation analysis was conducted to clarify the mediation effects of oxidative stress due to maternal BPA exposure on birth outcomes. The daily intake of BPA in breast milk was calculated using probabilistic risk assessment methods. The geometric means (geometric standard deviation) of BPA levels for maternal urine and first- and third-month breast milk were 2.19 (2.88) µg/g creatinine., 1.35 (3.53) ng/g, and 3.17 (2.97) ng/g, respectively. No significant mediation existed among maternal BPA exposure, oxidative stress level, and neonatal head circumference. Three percent of 1-monthold babies and 1% of 3-month-old babies exceeded the BPA tolerable daily intake of 4 µg/kg-bw/day proposed by the European Food Safety Authority. This study revealed the BPA exposure profile for pregnant women and infants in northern Taiwan. The marginally significant correlation between maternal BPA exposure and neonatal head circumference should be considered.

Associations between urinary total arsenic levels, fetal development, and neonatal birth outcomes: A cohort study in Taiwan.

BACKGROUND: Arsenic exposure is a global health concern. Several studies have focused on chronic arsenic exposure in adults; however, limited data are available regarding the potential adverse effects of prenatal exposure on fetuses and neonates. OBJECTIVES: To assess which time point maternal arsenic exposure may influence the fetus during pregnancy and birth outcomes. METHODS: In this study, total arsenic concentrations were analyzed in urine samples collected from 130 women with singleton pregnancies (22-45years old) in Taiwan from March to December of 2010. All fetal biometric measurements in each trimester period and birth outcomes at delivery were obtained. We applied a generalized estimating equation model and multivariate regression models to evaluate the associations between maternal urinary total arsenic (UtAs) exposure during pregnancy, fetal biometric measurements, and neonatal birth outcomes. RESULTS: We observed statistically significant correlations between maternal UtAs levels and the fetal biparietal diameter over all three trimesters (ß=-1.046mm, p<0.05). Multiple regression analyses showed a negative association between maternal UtAs levels and chest circumference in the first trimester (ß=-0.721cm, p<0.05), and second-trimester UtAs exposure was associated with decreases in birth weight (ß=-173.26g, p<0.01), head circumference (ß=-0.611cm, p<0.05), and chest circumference (ß=-0.654cm, p<0.05). Dose-response relationships were also observed for maternal UtAs exposure and birth outcomes. CONCLUSIONS: We identified a negative relationship between maternal UtAs levels during pregnancy, fetal development, and neonatal birth outcomes. These findings should be confirmed in future studies with large sample sizes.

The interactions among organophosphate pesticide exposure, oxidative stress, and genetic polymorphisms of dopamine receptor D4 increase the risk of attention deficit/hyperactivity disorder in children.

OBJECTIVE: The aim of this study was to clarify the association between organophosphate pesticides (OPs) and attention-deficit/hyperactivity disorder (ADHD) related to oxidative stress and genetic polymorphisms. METHODS: This case-control study enrolled 93 children with ADHD and 112 control children in north Taiwan. Six dialkyl phosphate (DAP) metabolites of OPs and oxidative stress biomarkers were analyzed. Polymorphisms of the dopamine receptor D4 gene (DRD4) were identified. RESULTS: Children with ADHD had significantly higher dimethylphosphate (DMP, 236.69nmol/g cre. vs. 186.84nmol/g cre., p value = 0.01) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA, 28.95µg/g cre. vs. 16.55µg/g cre., p value<0.01) concentrations than control children. Children who carried DRD4 GA/AA genotypes (rs752306) were less likely than those who carried the DRD4 GG genotype to have ADHD (odds ratio [OR]: 0.45, 95% CI: 0.24-0.84). The estimated value of the AP (attributable proportion due to interaction) was 0.59 (95% CI: 0.13-1.05), indicating that 59% of ADHD cases in DMP-exposed children with the DRD4 GG genotype were due to the gene-environment interaction. After adjustment for other covariates, children who carried the DRD4 GG genotype, had been exposed to high DMP levels (more than the median), and had high HNE-MA levels had a significantly increased risk for developing ADHD (OR = 11.74, 95% CI: 2.12-65.04). CONCLUSION: This study indicated a gene-environment interaction in the risk of ADHD in children. The association between DMP and ADHD in children might relate to the mechanism of lipid peroxidation. Dose-response relationships and the combined effects of OPs, oxidative stress, and genetic polymorphism on ADHD should not be neglected.

Indoor Air Quality in the Metro System in North Taiwan.

Indoor air pollution is an increasing health concern, especially in enclosed environments such as underground subway stations because of increased global usage by urban populations. This study measured the indoor air quality of underground platforms at 10 metro stations of the Taipei Rapid Transit system (TRTS) in Taiwan, including humidity, temperature, carbon monoxide (CO), carbon dioxide (CO2), formaldehyde (HCHO), total volatile organic compounds (TVOCs), ozone (O3), airborne particulate matter (PM10 and PM2.5), bacteria and fungi. Results showed that the CO2, CO and HCHO levels met the stipulated standards as regulated by Taiwan's Indoor Air Quality Management Act (TIAQMA). However, elevated PM10 and PM2.5 levels were measured at most stations. TVOCs and bacterial concentrations at some stations measured in summer were higher than the regulated standards stipulated by Taiwan's Environmental Protection Administration. Further studies should be conducted to reduce particulate matters, TVOCs and bacteria in the air of subway stations.

Quality of Chemical Safety Information in Printing Industry.

OBJECTIVES: Employees in printing industries can be exposed to multiple solvents in their work environment. The objectives of this study were to investigate the critical components of chemical solvents by analyzing the components of the solvents and collecting the Safety data sheets (SDSs), and to evaluate the hazard communication implementation status in printing industries. METHOD: About 152 printing-related industries were recruited by area-stratified random sampling and included 23 plate-making, 102 printing and 27 printing-assistance companies in Taiwan. We analyzed company questionnaires (n = 152), SDSs (n = 180), and solvents (n = 20) collected from this sample of printing-related companies. RESULTS: Analytical results indicated that benzene and ethylbenzene, which were carcinogen and possibly carcinogen, were detectable in the cleaning solvents, and the detection rate were 54.5% (concentrations: <0.011-0.035 wt%) and 63.6% (concentrations: <0.011-6.22 wt%), respectively; however, neither compound was disclosed in the SDS for the solvents. Several other undisclosed components, including methanol, isopropanol and n-butanol, were also identified in the printing inks, fountain solutions and dilution solvents. We noted that, of the companies we surveyed, only 57.2% had a hazard communication program, 61.8% had SDSs on file and 59.9% provided employee safety and health training. We note that hazard communication programs were missing or ineffective in almost half of the 152 printing industries surveyed. CONCLUSIONS: Current safety information of solvents components in printing industries was inadequate, and many hazardous compounds were undisclosed in the SDSs of the solvents or the labels of the containers. The implementation of hazard communications in printing industries was still not enough for protecting the employees' safety and health.

Do the Levels of Maternal Plasma Trace Elements Affect Fetal Nuchal Translucency Thickness?

OBJECTIVE: Fetal nuchal translucency (NT) thickness is an important marker for prenatal screening; however, studies focusing on the correlation between maternal trace element levels and NT thickness are limited. The aim of this study was to evaluate maternal trace element levels during the first trimester and to investigate the association between maternal trace element levels and fetal NT thickness. METHODS: In total, 113 samples were obtained from singleton pregnant women. Maternal plasma samples were collected in the first trimester of gestation. Plasma trace element levels were measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Nuchal translucency thickness was measured using ultrasonography at 10-14 weeks of gestation. RESULTS: We found that maternal plasma potassium (K) levels had a significant negative correlation with both NT (r = -0.230, p < 0.05) and NT Multiples of the Median (NT MoM) (r = -0.206, p < 0.05). After adjustment for potential confounders, log-transformed maternal plasma potassium levels in the first trimester were significantly associated with fetal NT (NT MoM: ß = -0.68, p < 0.05; NT: ß = -1.20, p < 0.01). Although not statistically significant, the As, Hg and Pb levels in maternal plasma were positively correlated with NT, and the Mg, Cu, Zn, Na and Ca levels were negatively correlated with NT. CONCLUSION: Maternal plasma K levels during the first trimester appeared to be associated with NT thickness. The essential elements tended to decrease NT thickness, and non-essential elements tended to increase it.

The critical fetal stage for maternal manganese exposure.

Prenatal exposure and the health effects of that exposure have been intensively studied for a variety of environmental pollutants and trace elements. However, few studies have compared susceptibilities among the three trimesters of gestation. Manganese (Mn) is a naturally occurring and abundant trace element in the environment. Although the effects of Mn on animals are well documented, knowledge of the effects of Mn exposure on pregnant women and fetuses remains limited. A longitudinal study was conducted by collecting blood samples during all three trimesters, and Mn exposure was completely characterized during gestation. The aims of this study were to examine the effects of maternal Mn exposure on neonatal birth outcomes and to explore the critical stage of these effects. In total, 38, 76 and 76 samples were obtained from singleton pregnant women in their first, second and third trimesters, respectively. The cohort of pregnant women was selected at a medical center in northern Taiwan. Erythrocyte samples were collected during the first, second and third trimesters of gestation. Erythrocyte Mn concentrations were measured by inductively coupled plasma mass spectrometry. Neonatal birth outcomes were evaluated immediately after delivery. A multivariate regression model was used to determine the associations between maternal Mn levels in erythrocytes in each trimester and neonatal birth outcomes. The geometric mean concentrations of Mn were 2.93 µg/dL, 3.96 µg/dL and 4.41 µg/dL in the first, second and third trimesters, respectively. After adjusting for potential confounders, a consistently negative association was found between maternal Mn levels throughout the three trimesters and birth outcomes. Log-transformed Mn levels in maternal erythrocytes in the second trimester were significantly associated with neonatal birth weight, head and chest circumferences, respectively (ß=-556.98 g, p=0.038; ß=-1.87 cm, p=0.045; ß=-2.74 cm, p=0.024). Despite the limited sample size in the first trimester, negative effects of maternal Mn levels on birth weight (ß=-1108.95 g, p<0.01) and chest circumference (ß=-4.40 cm, p=0.019) were also observed.

The association between nonylphenols and sexual hormones levels among pregnant women: a cohort study in Taiwan.

BACKGROUND: Nonylphenol (NP) has been proven as an endocrine disrupter and had the ability to interfere with the endocrine system. Though the health effects of NP on pregnant women and their fetuses are sustained, these negative associations related to the mechanisms of regulation for estrogen during pregnancy need to be further clarified. The objective of this study is to explore the association between maternal NP and hormonal levels, such as estradiol, testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH), and progesterone. METHODS: A pregnant women cohort was established in North Taiwan between March and December 2010. Maternal urine and blood samples from the first, second, and third trimesters of gestation were collected. Urinary NP concentration was measured by high-performance liquid chromatography coupled with fluorescent detection. A mixed-effects model using a generalised estimating equation (GEE) was applied to assess the associations between maternal NP concentration and plasma hormones throughout the three trimesters. RESULTS: In total, 162 singleton pregnant women completed this study through delivery. The geometric mean of creatinine-adjusted urinary NP concentrations were 4.27, 4.21, and 4.10 µg/g cre. in the first, second, and third trimesters respectively. A natural log-transformation of urinary NP concentrations were significantly associated with LH in the GEE model (ß = -0.23 mIU/ml, p<0.01). CONCLUSION: This perspective cohort study demonstrates that negative association occurs between maternal NP exposure and plasma LH levels. The estrogen-mimic effect of NP might influence the negative feedback on LH during pregnancy.

Visualized gene network reveals the novel target transcripts Sox2 and Pax6 of neuronal development in trans-placental exposure to bisphenol A.

BACKGROUND: Bisphenol A (BPA) is a ubiquitous endocrine disrupting chemical in our daily life, and its health effect in response to prenatal exposure is still controversial. Early-life BPA exposure may impact brain development and contribute to childhood neurological disorders. The aim of the present study was to investigate molecular target genes of neuronal development in trans-placental exposure to BPA. METHODOLOGY: A meta-analysis of three public microarray datasets was performed to screen for differentially expressed genes (DEGs) in exposure to BPA. The candidate genes of neuronal development were identified from gene ontology analysis in a reconstructed neuronal sub-network, and their gene expressions were determined using real-time PCR in 20 umbilical cord blood samples dichotomized into high and low BPA level groups upon the median 16.8 nM. PRINCIPAL FINDINGS: Among 36 neuronal transcripts sorted from DAVID ontology clusters of 457 DEGs using the analysis of Bioconductor limma package, we found two neuronal genes, sex determining region Y-box 2 (Sox2) and paired box 6 (Pax6), had preferentially down-regulated expression (Bonferroni correction p-value <10(-4) and log2-transformed fold change ≤-1.2) in response to BPA exposure. Fetal cord blood samples had the obviously attenuated gene expression of Sox2 and Pax6 in high BPA group referred to low BPA group. Visualized gene network of Cytoscape analysis showed that Sox2 and Pax6 which were contributed to neural precursor cell proliferation and neuronal differentiation might be down-regulated through sonic hedgehog (Shh), vascular endothelial growth factor A (VEGFA) and Notch signaling. CONCLUSIONS: These results indicated that trans-placental BPA exposure down-regulated gene expression of Sox2 and Pax6 potentially underlying the adverse effect on childhood neuronal development.

The association between maternal nonylphenol exposure and parity on neonatal birth weight: a cohort study in Taiwan.

BACKGROUND: The aim of this study was to explore the association between NP exposure and parity and their effect on neonatal birth weight. METHODS: A cohort of pregnant women was established in a medical center in North Taiwan. Urinary NP concentration was determined by high-performance liquid chromatography coupled with fluorescent detection and adjusted using creatinine. A multivariable regression model was fit to determine the association between the maternal NP level in each trimester and neonatal birth weight. The odds ratios (ORs) of infant birth weight below the 10th, 25th, and 50th percentiles, comparing pregnant women with the different NP exposure levels, was estimated using a logistic regression. RESULTS: Of the 162 pregnant women in the study, 99 were multiparas and 63 were primiparas. After adjusting for other covariates, the NP level in the second trimester had a significant association with birth weight in the primiparas (ß = -182.49 g, p value = 0.02). The OR of low infant birth weight, comparing pregnant women with different NP levels, was increased by decreasing the cutoff percentile for birth weight (OR = 1.18 for the 50th percentile, 2.12 for the 25th percentile, and 7.81 for the 10th percentile). The odds of primiparas with high NP level having a low neonatal birth weight increased to 3.87, 11.77, and 9.40 for the three different percentiles (p value < 0.05). CONCLUSION: Maternal NP exposure level is associated with an increased risk of low neonatal weight. Primiparas are especially at risk, and the second trimester of pregnancy may be the critical stage of exposure.

Neonatal outcomes of intrauterine nonylphenol exposure--a longitudinal cohort study in Taiwan.

BACKGROUND: Nonylphenol (NP) is an environmental hormone with proven estrogenic effects. Although its adverse effects on animals are well documented, the effects of NP exposure on humans remain unclear, and those on the human foetus are completely unknown. This study explores the effects of intrauterine NP exposure on neonates. METHODS: A cohort of pregnant women was established in a medical centre in northern Taiwan. Urine samples from the first, second, and third trimesters of gestation were collected. Urinary NP concentration was measured by high-performance liquid chromatography coupled with fluorescent detection. Neonatal outcomes were evaluated immediately after delivery. A mixed-effects model using a generalised estimating equation was applied to assess the association between gestational age, maternal body weight, and maternal NP concentration throughout the three trimesters. A multivariable regression model was used to determine the association between maternal NP level in urine in each trimester and neonatal outcomes. RESULTS: In total, 162 singleton pregnant women completed this study through delivery. The geometric mean of creatinine-adjusted urinary NP concentrations were 4.27 µg/g, 4.21 µg/g, and 4.10 µg/g in the first, second, and third trimesters, respectively. Pregnant women whose urinary NP concentrations were above the median in the second trimester had low maternal weight gain (ß=-1.55 kg, p=0.02) and short neonatal body length (ß=-0.47 cm, p=0.04). Women with an above-median urinary NP concentration had an odds ratio of having a small for gestational age (SGA) neonate of 7.81 (p<0.05). CONCLUSIONS: This study indicates that maternal high NP exposure in the second trimester is associated with SGA, decreased foetal body length at birth, and low maternal weight gain. The effects of this endocrine-disrupting substance on pregnant women and foetuses should be a concern during gestation.

The effects of perceived stress and life style leading to breast cancer.

Researchers conducted a study in a Taiwanese medical center from June 2009 to June 2011 to investigate the relations of perceived stress and lifestyle to breast cancer. A total of 157 cases and 314 controls completed a structured questionnaire. Using multiple logistic regression models, high perceived stress (adjusted odds ratio [AOR] = 1.65; 95% confidence interval [CI], 1.10-2.47), less than 1,000 kcal of physical activity expenditure per week (AOR, 2.17; 95% CI, 1.39-3.39), and high intake of fried and stir-fried food (AOR, 1.86; 95% CI, 1.24-2.77) were positively associated with breast cancer. Breast cancer was related to joint interactions between high perceived stress and alcohol intake of 11.0 g or more per day (AOR, 2.91; 95% CI, 1.23-6.86), smoking at least one cigarette per day (AOR, 2.52; 95% CI, 1.16-5.47), intake of less than 100 ml of green tea per day (AOR, 2.47; 95% CI, 1.40-4.38), physical activity of less than 1,000 kcal per week (AOR, 3.36; 95% CI, 1.77-6.36), high fried and stir-fried food intake (AOR, 3.18; 95% CI, 1.79-5.63), and high meat and seafood intake (AOR, 1.89; 95% CI, 1.09-3.27). Perceived stress, when combined with potentially risky lifestyle behaviors, may be a contributing factor to breast cancer.

Method development for determining the malodor source and pollution in industrial park.

Malodor pollution emitted from industrial park has become an important environmental issue. However, the difficulty in investigating malodor pollution is in determining the malodor source. The objective of this study was to develop a model for determining the malodor source and pollution in industrial park, via multiple time and site measurements of odor intensity and air pollutants, together with wind direction in different seasons, and the critical environmental factors could be also identified by correlating the odor intensities with meteorological conditions and the concentrations of air pollutants. A high-malodor-polluted industrial park involving metal and petrochemistry processing industries was selected as the study subject, and sampling was performed close to residential districts. Nine sites were selected as sampling points by a chessboard design, with each site measured for 5 days in fall and spring, respectively. Odor intensity (ratings 0-5) and environmental factors, including meteorological condition, PM(10), PM(2.5), total volatile organic compounds (TVOCs), ammonia and reduced sulfides, were evaluated six times daily. The results indicated that the incidences of odor ratings 1-5 were 71.9% and 81.0% in two seasons in the sampling area, and an open ditch for collecting industrial wastewater for feeding to the wastewater treatment plant was identified as the main odor source. Multiple regression analysis showed that the odor rating significantly correlated with TVOC concentration and wind speed (P<0.05); odor intensity increased by 0.001 units on the rating scale for each 1 ppb increase in TVOCs, and decreased by 0.154 units for each 1m/s increase in wind speed. This study developed a method to explore malodor pollution in industrial park, providing a novel thinking to understand and resolve malodor problems.

Polybrominated diphenyl ethers in foodstuffs from Taiwan: level and human dietary exposure assessment.

Polybrominated diphenyl ethers (PBDEs) may contaminate food through bioconcentration and biomagnification. PBDEs often exist in the food chain and are consumed by humans. This study aims to determine the concentrations of PBDEs in food intake and to estimate the daily exposure of Taiwanese citizens to PBDEs. One hundred and eight food samples from nine types of commonly consumed foodstuffs were collected from northern, central, southern, and eastern regions of Taiwan. The samples were analyzed for PBDE level by gas chromatography mass spectrometry. Also, a daily dietary intake survey was conducted of 466 adults (153 men, 313 women) in these four regions of Taiwan. Taiwanese daily dietary intake of PBDE is calculated by means of food PBDEs level and daily dietary intake. The result of this study showed the highest concentration of ΣPBDE was found in butter (890.3±309.0 pg/g wet weight), followed by egg and pork (553.0±185.0 pg/g wet weight and 545.4±181.0 pg/g wet weight). Deca-BDE was found the highest concentration among eight kinds PBDEs. The average daily intake of PBDEs for the 466 subjects was 67.95±23.01 ng/day. There was a significant difference between the daily intake of ΣPBDE in different regions of Taiwan (p<0.05). The highest daily intake of ΣPBDE was in northern Taiwan, which is also the most urbanized area.

Increase of urinary concentrations of 8-hydroxy-2'-deoxyguanosine in diesel exhaust emission inspector exposed to polycyclic aromatic hydrocarbons.

PURPOSE: The objectives of this study were to explore the factors influencing urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in diesel engine exhaust emission inspectors (inspectors), the association between polycyclic aromatic hydrocarbons (PAHs) exposure and fine particulate matter (PM(2.5)) levels in diesel exhaust particles (DEPs), and the PAHs exposure levels in diesel vehicle emission inspection stations (inspection stations). METHODS: Twenty-eight inspectors and a control group of thirty-eight individuals matched by age and gender were recruited for this study. Fifteen ambient air samples and eighty-four personal air samples were monitored during 3-day work periods using a repeated-measures study design in each inspection station. Airborne samples were analyzed with a fluorescence detector and by high-performance liquid chromatography. Urinary 8-OHdG was measured in 168 pre- and post-work urine samples from inspectors, and in 38 urine samples from controls. RESULTS: The concentrations of PAHs in DEP(2.5) (PM(2.5) in DEPs) were significantly and positively related to urinary log(10) 8-OHdG levels after adjusting for smoking status and BMI. Statistically, there was a significant correlation between air log(10) PAHs and air log(10) PM(2.5) concentrations in inspectors. Fifteen PAHs compounds within DEP(2.5) revealed the concentrations ranged from 5.18 to 22.93 ng/m(3) in ambient air monitoring and 1.03 to 12.60 ng/m(3) in personal air monitoring. CONCLUSIONS: This study is the first to indicate an association between occupational PAHs exposure from DEP(2.5) at an inspection station and an increased excretion of urinary 8-OHdG in inspectors. In addition, this study also found smoking is not a confounder in inspectors exposed to PAHs in DEP(2.5).

Effects of polybrominated diphenyl ethers on steroidogenesis in rat Leydig cells.

BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants that have been defined as major environmental pollutants. While previous studies have found that PBDEs may enhance the levels of sex-steroid hormones, their effects on testosterone secretion from rat Leydig cells are unclear. This study investigated the effects and mechanisms of PBDE-710, a mixture of tetra- and penta-PBDEs, on testosterone biosynthesis in rat Leydig cells. METHODS: Leydig cells from adult male rats were challenged with different concentrations of PBDE-710 (0.5-15 ng/ml) to evaluate the effects on testosterone steroidogenesis. Concentrations of testosterone and of cAMP and pregnenolone in medium were measured by radioimmunoassay (RIA) and by enzyme-linked immunosorbent assay, respectively. Nuclear translocation of protein kinase A α (PKAα) was determined by immunofluorence assay and western blot assay, and the mRNA expression of steroidogenic acute regulatory protein (StAR) was analyzed by quantitative real-time polymerase chain reaction. RESULTS: In this in vitro study, PBDE-710 (5 or 15 ng/ml) increased basal testosterone secretion and cAMP production by 3- and 2-fold, respectively. The stimulatory effect was abolished by adenylyl cyclase inhibitor. Enzyme activity of CYP11A1, as determined by the pregnenolone concentration, was stimulated by PBDE-710 treatment. Furthermore, nuclear translocation of PKAα was increased by 20% and StAR gene expression was elevated by 4-fold after PBDE-710 treatment. CONCLUSIONS: These results suggest that low concentrations of PBDE-710 could stimulate testosterone secretion by acting directly on Leydig cells to activate the cAMP pathway and increase expression of StAR.

Trajectory of depression symptoms and related factors in later life--a population based study.

BACKGROUND: A number of studies of elderly depression have examined the association between depression and its related factors; however, they did not observe how the development of related factors influenced elderly depression over time. This study aims to understand the rising trajectory of depressive symptoms found in elderly male and female, and whether the causation of depression due to related factors would be heterogeneous between male and female over a decade from 1993 to 2003. METHOD: This study uses the data from the "Survey of Health and Living Status of the Elderly in Taiwan". A total of 1017 elderly Taiwanese, aged 60 and over, completed four survey modules. The latent growth curve model and general growth mixture model were used to identify the trajectories of depression symptoms, and to assess their related factors in the elderly male and female in Taiwan during the 10 year survey study. RESULT: The results showed that a rising trajectory of depressive symptoms came about for both Taiwan elderly male and female over ten years. We also found that in the trajectories of depressive symptoms between elderly male and female across four waves of data, the results were heterogeneous. The trajectory of depressive symptoms in males was affected by perceived health and disability; the trajectory of depressive symptoms in females was influenced by disability and social support. CONCLUSION: These findings demonstrated that the final depressive symptoms of the elderly would differ from the elderly with developmentally different depressive related factors. The findings also highlighted the developmental trajectories of depressive symptom in terms of their related factors in the elderly.

Urinary 8-hydroxydeoxyguanosine as a biomarker of oxidative DNA damage in workers exposed to ethylbenzene.

This study assessed the relationships between ethylbenzene exposure and levels of 8-hydroxydeoxyguanosine (8-OHdG) among spray painters. Sixty-four male workers employed at a large shipyard were recruited for this investigation. Fifteen spray painters exposed to paint, together with two non-exposed groups, namely 19 sandblasting workers and 30 office staffs were selected as the subjects. Personal exposure to xylene and ethylbenzene in air were collected using diffusive samplers. Urine samples of the spray painters were collected after a month-long holiday leave and during the pre- and post-workshifts. Urine samples of sandblasting workers and office staffs were gathered after their shift. Urinary mandelic acid and methyl hippuric acid were used as biological indices of dose of ethylbenzene and xylene, respectively. Urinary 8-OHdG was used as biomarker of oxidative DNA damage. The post-workshift concentration of urinary 8-OHdG for 10 spray painters (30.3 ± 9.28 µg g(-1) creatinine) significantly exceeded that of holiday leave (7.20 ± 1.08 µg g(-1) creatinine; P = 0.001). The post-workshift concentration of urinary 8-OHdG was higher among 15 spray painters (29.0 ± 6.52 µg g(-1) creatinine) than sandblasting workers (9.14 ± 2.05 µg g(-1) creatinine; P = 0.01) and office staffs (8.35 ± 0.84 µg g(-1) creatinine; P = 0.007). A stepwise regression model revealed an 8.11 µg g(-1) creatinine increase per 1 p.p.m. increase in ethylbenzene [95% confidence interval (CI) 4.13-12.1]. A stepwise regression model revealed an increase of 6.04 µg g(-1) creatinine (95% CI 2.23-9.84) per 1 p.p.m. in ethylbenzene after adjustment of age (95% CI 2.23-9.84). This pilot study suggests that occupational exposure to paint increases oxidative DNA injury. Moreover, urinary 8-OHdG levels displayed greater DNA damage in spray painters compared to other unexposed groups and their holiday leave samples. A significant correlation was found between urinary 8-OHdG and the exposure to ethylbenzene. The ethylbenzene exposure could not explain all urinary 8-OHdG measured. Other components of paint deserve further investigation.

Sulfur-rich geothermal emissions elevate acid aerosol levels in metropolitan Taipei.

Several studies have demonstrated that millions of people globally are potentially exposed to volcanic gases. Hydrogen sulfide is a typical gas in volcanic and geothermal areas. The gas is toxic at high concentrations that predominantly affects the nervous, cardiovascular, and respiratory systems. The WHO air quality guideline for hydrogen sulfide is 150 microg m(-3) (105 ppb). The northwest part of Taipei is surrounded by sulfur-rich geothermal and hot springs. Active fumaroles and bubbling springs around the geothermal area emit acidic gases. In combination with automobile emissions, the pollution of acid aerosols is characteristic of the metropolis. This study considered sulfur-rich geothermal, suburban and downtown locations of this metropolis to evaluate geothermally emitted acid aerosol and H(2)S pollution. Acid aerosols were collected using a honeycomb denuder filter pack sampling system (HDS), and then analyzed by ion chromatography (IC). Results indicated that long-term geothermal emissions, automobile emissions and photochemical reactions have led to significant variations in air pollution among regions of metropolitan Taipei. The highest H(2)S concentration was 1705 ppb in the geothermal area with low traffic density and the mean concentration was 404.06 ppb, which was higher than WHO guideline and might cause eye irritation. The SO(2) concentrations were relatively low (mean concentration was 3.9 ppb) in this area. It may partially result from the chemical reduction reaction in the geothermal emission, which converted the SO(2) gas into SO(4)(2-) and H(2)S. Consequently, very high sulfate concentrations (mean concentration higher than 25.0 microg m(-3)) were also observed in the area. The geothermal areas also emitted relatively high levels of aerosol acidity, Cl(-), F(-), PO(4)(3-), and N-containing aerosols. As a result, concentrations of HNO(3), NO(2)(-), PO(4)(3-), and SO(4)(2-) in metropolitan Taipei are significantly higher than those in other urban areas considered in other studies. These results provide evidence that geothermal emissions represent a significant source of acid aerosols in metropolitan Taipei. Therefore, in this metropolitan area, the combined health effects of air pollutants from automobiles and geothermal emissions should be particular concern.