I-Fang Mao

Exposure assessment of PM2.5 and urinary 8-OHdG for diesel exhaust emission inspector

Animal studies have shown exposure to diesel exhaust particles (DEPs) to induce production of reactive oxygen species (ROSs) and increase levels of 8-hydroxydeoxyquanosine (8-OHdG). Controversial results have been obtained regarding the effects of workplace exposure on urinary 8-OHdG level. This study assessed concentrations of environmental PM(2.5) in DEP (DEP(2.5)), personal DEP(2.5) and urinary 8-OHdG of diesel engine exhaust emission inspector (inspector) at a diesel vehicle emission inspection station (inspection station). The analysis specifically focuses on the factors that influence inspector urinary 8-OHdG. Repeated-measures study design was used to sample for five consecutive days. A total of 25 environmental PM(2.5) measurements were analyzed at 5 different locations by using a dichotomous sampler, and a total of 55 personal PM(2.5) measurements were analyzed from inspectors by using PM(2.5) personal sampler. During the sampling period, a total of 110 pre- and post-work urine samples from inspectors, and 32 samples from the control group were collected. Following age and sex matching between the inspectors and the control group, levels of urinary 8-OHdG were analyzed. Environmental and personal concentrations of DEP(2.5) were 107.25+/-39.76 (mean+/-SD) and 155.96+/-75.70 microg/m(3), respectively. Also, the concentration of urinary 8-OHdG differed significantly between inspector and control non-smokers, averaging 14.05+/-12.71 and 6.58+/-4.39 microg/g creatinine, respectively. Additionally, urinary 8-OHdG concentrations were associated with diesel exposure after controlling for smoking and cooking at home. Compared with the control group, the inspector displayed significantly increased levels of urinary 8-OHdG. Diesel exhaust is the single pollutant involved in the exposure of DEP(2.5) at the inspection station, as confirmed by the final results.

Association between nonylphenol exposure and development of secondary sexual characteristics

Previous studies have reported that p-nonylphenol (NP) can advance the age at vaginal opening in prepubertal rats. A significant exposure levels of NP was found in Taiwanese population even from the prenatal stage. The purposes of this study are to examine the urinary NP concentration of pubertal students in Taiwan and to explore its association with the development of secondary sexual characteristics. 786 pubertal students were recruited. The NP was determined using solid-phase extraction and high-performance liquid chromatography with fluorescent detection. A self-administered questionnaire was used to collect the data on occurrence of secondary sexual characteristics in the subjects. About 30% of the urine samples were positively detected. The NP concentrations ranged from ND to 178.25 microg g(-1) cr. Fifteen percent of the Taiwanese girls between 10.5 and 10.9 years old reported having undergone menarche, which was higher than the white girls (4.6%) and the black girls (8%). There was no significant difference of urinary NP levels between groups of having and not having secondary sexual characteristics because body mass index (BMI) had significant effects on sexual development. After adjusting the effect of age and BMI, the menarcheal age remained inversely correlated with the increase of urinary NP levels. Nonylphenol exposure could disturb pubertal development and the pubertal girls seem more sensitive than pubertal boys to the exposure of endocrine disruption chemicals (EDCs). The effects of early maturation as well as the health implications need further study.

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.

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 (β=-1.55 kg, p=0.02) and short neonatal body length (β=-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 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 (β = -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.

Effects of profuse sweating induced by exercise on urinary uric acid excretion in a hot environment.

In order to determine whether exercise-induced profuse sweating could reduce urinary uric acid excretion, we simulated badminton players training and measured their uric acid in urine, sweat and blood during the training period. Thirteen male volunteers who were well-trained badminton players were recruited in this study. On the first 2 days and the last 2 days of the study period none of the subjects engaged in any intense exercise- or activity-inducing profuse sweat, but they accepted routine training 2 h per day during the middle 3 days. The results show that mean serum urate levels of thirteen volunteers rose significantly on day 4, when the concentrations increased by 18.2% over day 2 (P < 0.05). The mean ten-hour urinary uric acid excretion of seven volunteers on the 3 training days was significantly less at 178.5 micromol/day and 118.3 micromol/day than those on the preceding and subsequent days of the training days, respectively (P < 0.05). Furthermore, for six volunteers, the mean ratio of clearance of uric acid to creatinine was 6.6% on day 2, which significantly decreased to 5.4% on day 4 (P < 0.05). It is concluded profuse sweating exercise results in a decrease of urinary uric acid excretion amounts and leads to increased serum uric acid after the exercise. We suggest that persons who take vigorous exercise or are exposed to hot environments need drinking enough fluids to prevent dehydration and maintain adequate urinary output. People with profuse sweat after rigorous exercise are recommended taking sports drinks containing abundant sodium in order to decrease serum uric acid.

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.

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.

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 (β=-556.98 g, p=0.038; β=-1.87 cm, p=0.045; β=-2.74 cm, p=0.024). Despite the limited sample size in the first trimester, negative effects of maternal Mn levels on birth weight (β=-1108.95 g, p<0.01) and chest circumference (β=-4.40 cm, p=0.019) were also observed.