Accumulation degree and risk assessment of metals in street dust from a developing city in Central Taiwan.

Due to the numerous industrial parks and high traffic density in Miaoli, Taiwan, large amounts of metals may be released into the atmosphere, accumulating in street dust. Therefore, this study aimed to collect street dust in Miaoli to quantify the metals and assess the accumulation degree, sources, and potential risks. The enrichment factor (EF), geological accumulation index (Igeo), ecological risk, and non-carcinogenic and lifetime carcinogenic risk were estimated to assess the accumulation degree and the potential environmental and health risks. Pearson correlation analysis, principal component analysis, and positive matrix factor model were used to clarify the relationship between levels of metals and identify possible sources. The levels of metals in street dust in order were Fe > Zn > Mn > Cu > Cr > Ni > Pb > Sr > Co > Sb. According to Igeo, the level of Ni indicated moderately polluted. The levels of Zn, Cu, and Pb showed moderate to strong pollution, strong pollution, and very strong pollution, respectively. Results of average ecological risk analysis pointed out that Pb and Cu represent a very high risk, while other metals posed low-to moderate-level ecological risks. Excluding the Steel Enterprise area, based on the EF value and source identification, it might be concluded that Co, Sr, Fe, Mn, and Sb were mainly from natural sources, while Cu, Pb, and Zn come from anthropogenic pollution sources. Based on the results of the risk assessments, most metals pose no serious adverse health risk to humans. But, in comparison to Miaoli townships, the health risks of residents living in the Steel Enterprise area were higher. However, given that children and adolescents exposure to Co, Cr, Pb, and Ni together constitute a relatively higher carcinogenic risk (CR > 10-6), more attention needs to be paid to the populations most susceptible.

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate and gas phase from smoldering mosquito coils containing various atomic hydrogen/carbon ratios.

The polycyclic aromatic hydrocarbon emissions in particulate and gas phases generated from smoldering mosquito coils containing various atomic H/C ratios were examined. Five types of mosquito coils were burned in a test chamber with a total airflow rate of 8.0 L/min at a constant relative humidity and temperature. The concentrations of individual PAHs were determined using the GC/MS technique. Among the used mosquito coils, the atomic H/C ratio ranged from 1.23 to 1.57, yielding total mass, gaseous, and particulate PAH emission factors of 28.17-78.72 mg/g, 26,139.80-35,932.98 and 5735.22-13,431.51 ng/g, respectively. The various partitions of PAHs in the gaseous and particulate phases were in the ranges, 70.26-83.70% and 16.30-29.74% for the utilized mosquito coils. The carcinogenic potency of PAH emissions in the particulate phase (203.82-797.76 ng/g) was approximately 6.92-25.08 times higher than that of the gaseous phase (26.27-36.07 ng/g). Based on the analyses of PAH emissions, mosquito coils containing the lowest H/C ratio, a low oxygen level, and additional additives (i.e., CaCO3) are recommended for minimizing the production of total PAH emission factors and carcinogenic potency.

E-cadherin polymorphisms and susceptibility to arsenic-related skin lesions in West Bengal, India.

OBJECTIVES: Although suppression of E-cadherin gene (CDH1) expression and exposure to arsenic have separately been associated with skin lesions, the combined effects of this "gene-environment" interaction have not been explored previously. STUDY DESIGN: A population-based cross-sectional survey. METHOD: This study involved 100 cases with skin lesions and 100 controls who were family members with no lesions. The subjects were recruited from villages and hamlets in northern Nadia Province, West Bengal. Each participant was required to undergo a detailed face-to-face interview; provide spot urine sample; provide saliva sample; and sign a consent form. The type and severity of skin lesions were assessed during a general medical examination of each participant in the field. The following 16 single nucleotide polymorphisms (SNPs) of the CDH1 were measured using DNA extracted from saliva samples: rs16260, rs5030625, rs155364, rs155808, rs155807, rs2303646, rs2059254, rs9925923, rs12919719, rs7188750, rs9989407, rs7196495, rs7196661, rs13689, rs12599393, and rs1862748. RESULTS: The main effects of SNPs on the risk for skin lesions were borderline for rs7196661 (p-value=0.092), rs7196495 (p-value=0.090), and rs12919719 (p-value=0.065); the strongest association was found for rs9989407 (p-value=0.058). Several SNPs, however, showed that the T>T genotype carriers are at higher relative risk for skin lesions compared to carriers of the C>C or C>T genotypes; these results need to be confirmed in a larger study. The main effects of some of the SNPs and genotype frequencies on the severity of skin lesions were found to be relatively weak. CONCLUSIONS: This is the first study that indicates that CDH1 polymorphisms can contribute to the etiology of premalignant skin lesions in people chronically exposed to arsenic in drinking water, and that this gene may be a factor in individual susceptibility to cutaneous diseases.

Characterization of polycyclic aromatic hydrocarbon emissions in the particulate phase from burning incenses with various atomic hydrogen/carbon ratios.

Polycyclic aromatic hydrocarbons in the particulate phase generated from burning various incense was investigated by a gas chromatography/mass spectrometry. Among the used incenses, the atomic H/C ratio ranged from 0.51 to 1.69, yielding the emission factor ranges for total particulate mass and PAHs of 4.19-82.16 mg/g and 1.20-9.50 µg/g, respectively. The atomic H/C ratio of the incense was the key factor affecting particulate mass and the PAHs emission factors. Both the maximum emission factor and the slowest burning rate appear at the H/C ratio of 1.57. The concentrations of the four-ring PAHs predominated and the major species among the 16 PAHs were fluoranthene, phenanthrene, pyrene, and chrysene for most incense types. The benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and dibenzo[a,h]anthracene accounted for 87.08-93.47% of the total toxic equivalency emission factor.

Oxidative DNA damage estimated by urinary 8-hydroxy-2'-deoxyguanosine and arsenic in glass production workers.

A total of 130 male glass workers, including 33 administrative workers, 18 batch house workers, 42 craftsmen, and 37 melting process workers, were recruited to investigate the potential DNA damage resulting from toxic element exposure. The occupational exposure to trace elements, including arsenic (As), cadmium (Cd), manganese (Mn), nickel (Ni), lead (Pb), and selenium (Se), was estimated by their urinary levels as internal doses. In addition, all participants filled a self-filled questionnaire indicating their individual information. The average levels of urinary As, Cd, Mn, Ni, Pb, Se, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were 282.3 ± 464.6, 3.07 ± 5.39, 3.81 ± 11.43, 81.48 ± 138.9, 18.23 ± 49.61, 165.2 ± 224.9, and 17.21 ± 26.34 µg/g creatinine, respectively. The urinary levels of 8-OHdG and toxic elements were strongly associated with the work nature of the worker, with an exception of Mn and Pb. In contrast, the levels of toxic element were not influenced by age, smoking behavior, and alcohol consumption. The urinary 8-OHdG was found significantly higher in higher internal exposure groups of As, Cd, Ni, and Se. However, the stepwise multiple regression models showed that urinary 8-OHdG was only associated with urinary As and heat stress but inversely with age.

Internal exposure to trace elements in non-smoking residents living in a northern Taiwan industrial city.

A total of 94 (54 males, 40 females) healthy adult residents living in an industrial city in northern Taiwan were recruited to study their exposure to industrial metals by measuring their blood levels of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W. All participants were non-smokers without obvious direct occupational exposure to these elements, although by working in administrative sectors in industrial facilities their indirect or potential exposure was increased. The average concentrations of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W in blood were 0.30, 1.49, 15.1, 3.84, 2.73, 21.1, 204, 3.2, 0.76, 51.1, and 0.40 ng/mL, respectively. These values were significantly higher than reference values reported for the general population, in some cases exceeding those of occupationally exposed workers. The principal component and correlation analyses among blood element levels suggested that the predominant sources of exposure were glass manufacturing and traffic-related sources. Despite of some limitations, the study demonstrates that the residents in this industrial area may suffer adverse chronic health effects attributable to exposures to these elements.

Inorganic selenium speciation in groundwaters by solid phase extraction on Dowex 1X2.

A Dowex 1X2 resin separation technique followed by analysis with atomic absorption spectroscopy was evaluated for the study of inorganic selenium speciation in groundwaters. After Se(IV) and Se(VI) were retained on the resin column, Se(IV) and Se(VI) were eluted out by 0.1 and 1M nitric acid solutions. The method detection limit was 5.6 ng/L for both Se(IV) and Se(VI). Analysis of synthetic solutions consistently yielded more than 90% recovery of these two selenium forms with negligible cross-contamination. The results of spiked well waters show that this method can be applied at ultra-trace level of Se in groundwater and the interference of chloride ion can be neglected. Water samples collected from the monitoring wells in the Science-based Industrial Park, Hsin-Chu, Taiwan, were analyzed. Average dissolved selenium concentrations were 32.1+/-17.6 ng/L. The proportion of Se(VI) to the total dissolved selenium ranged from 47.6 to 61.2% and an average of 53.8% in water samples analyzed.

Serum selenium in adult Taiwanese.

The levels of serum selenium in 2755 individuals (1424 males, 1331 females) in Taiwan were determined by graphite furnace atomic absorption spectrometry. The average selenium concentration in serum was 110.9 microg/l with a standard deviation of 21.5 microg/l, ranging from 40.5 to 186 microg/l. The observation was higher than those recently reported in European regions but comparable to those observed in the USA or seleniferous regions. Serum selenium level did not vary with the gender, educational levels of the subjects and smoking habits. Serum selenium content seemed drop considerably if one is older than 39 years old. Age and alcohol consumption had statistically significant difference with serum selenium concentration.

Acute toxicity of trivalent thallium compounds to Daphnia magna.

Daphnia magna was used to evaluate the aquatic toxicity of Tl(III) compounds including Tl(III) nitrate, Tl(III) chloride, and Tl(III) acetate. The results clearly show that Tl(III) is extremely toxic to daphnids. The 48-h LC50 values for Tl(III) nitrate, Tl(III) chloride, and Tl(III) acetate are 24, 61, and 203 microg/L, respectively. Tl(III) is much more toxic than Tl(I) and many other metals such as Cd(II), Cu(II), and Ni(II); it is similar to the toxicity that of Hg(II). The formation of Tl(III)-complexes would significantly reduce Tl(III) toxicity.

Aquatic toxicity of nitrogen mustard to Ceriodaphina dubia, Daphnia magna, and Pimephales promelas.

Investigation of toxicity of mustard compounds to aquatic organisms has been limited although their effects on terrestrial mammal species have been well studied. In this study, the 48-h LC50 values of nitrogen mustard (HN2) are reported for two aquatic invertebrate species (Daphnia magna and Ceriodaphnia dubia) and for one fish species (Pimephales promelas). Mean LC50 values to C. dubia, D. magna, and P. promela were 1.12, 2.52, and 98.86 mg/L, respectively. C. dubia was the species most sensitive to HN2. Seven-day lethal and sublethal tests with P. promelas and C. dubia were also conducted. In chronic tests, fathead minnow growth was significantly reduced by 2.50 mg/L HN2, while C. dubia reproduction was significantly affected by 7.81 mug/L HN2. These adverse effects on aquatic organisms caused by lower-level concentrations of HN2 indicate that a possible aquatic ecosystem disaster could occur either after a chemical spill or during chemical warfare.