Preliminary evidence for an influence of exposure to polycyclic aromatic hydrocarbons on the composition of the gut microbiota and neurodevelopment in three-year-old healthy children.

BACKGROUND: During the second and third year after birth the gut microbiota (GM) is subjected to important development. The polycyclic aromatic hydrocarbon (PAH) exposure could influence the GM in animal and early postnatal exposure is associated with neurodevelopment disorder in children. This study was designed to explore the possible influence of the polycyclic aromatic hydrocarbons (PAHs) on the composition of the gut microbiota (GM) and neurodevelopment in a sample of 38 healthy children at the age of 3 years. METHODS: A brief development (Gesell Development Inventory, GDI) and behavior test (Child Behavior Checklist, CBCL) were completed on 3-yr-olds and stool samples were collected for 16S rRNA V4-V5 sequencing. The PAH-DNA adduct in the umbilical cord blood and the urinary hydroxyl PAHs (OH-PAHs) at the age of 12 months were measured as pre- and postnatal PAH exposure, respectively. RESULTS: The most abundant two phyla were Bacteroidetes (68.6%) and Firmicutes (24.2%). The phyla Firmicutes, Actinobacteria, Proteobacteria, Tenericutes, and Lentisphaerae were positively correlated with most domain behaviors of the GDI, whereas the Bacteroidetes, Cyanobacteria, and Fusobacteria were negatively correlated. Correspondingly, the phyla Bacteroidetes, Actinobacteria, and Fusobacteria showed positive correlations with most CBCL core and broadband syndromes, whereas the Firmicutes, Verrucomicrobia, Synergistetes, Proteobacteria and Tenericules were negatively correlated. The OH-PAH levels were not significantly associated with the Firmicutes phylum whereas the Bacteroidetes, Bacteroidia, and Bacteroidales all showed significant negative association with the OH-PAH levels. CONCLUSION: The current findings suggest that composition of the GM is associated with neurodevelopment of the child. PAHs seem to change the relative abundance of some taxa (some deleted and some recruited) to counteract the negative effects of the PAHs.

[Association of exposure to polycyclic aromatic hydrocarbons during pregnancy with autism spectrum disorder-related behaviors in toddlers: a birth cohort study].

OBJECTIVE: To study the association of exposure to polycyclic aromatic hydrocarbons (PAH) during pregnancy and autism spectrum disorder (ASD)-related behaviors in toddlers. METHODS: A total of 348 toddlers who had accepted the measurement of PAH-DNA adduct in umbilical cord blood and evaluation of behavior problems at the age of 36 months were enrolled in this birth cohort study. Child Behavior Checklist (CBCL) and Autism Behavior Checklist (ABC) were used to evaluate behavior problems at the age of 36 months. The correlation of the concentration of PAH-DNA adduct in umbilical cord blood with CBCL and ABC scores at the age of 36 months were analyzed. RESULTS: The detection rate of PAH-DNA adduct in umbilical cord blood was 52.3%, and the median concentration was 0.68 ng/mL. The median total scores of CBCL and ABC scales were 23 and 8 respectively. In children aged 36 months, the concentration of PAH-DNA adduct was positively correlated with the score of social withdrawal in the CBCL scale (rs=0.205, P<0.05), the total score of the ABC scale (rs=0.412, P<0.05), and the self-care score of the ABC scale (rs=0.355, P<0.05). The concentration of PAH-DNA adduct was closely associated with the total score of the ABC scale in children aged 36 months (ß=0.122, P<0.05). CONCLUSIONS: PAH exposure during pregnancy may be a risk factor for ASD-related behaviors in toddlers. Effective reduction of PAH exposure during pregnancy and detection of PAH-DNA adduct in neonatal umbilical cord blood are of vital importance for early prevention, screening and intervention of ASD.

Levels of polybrominated diphenyl ethers in settled house dust from urban dwellings with resident preschool-aged children in Nanjing, China.

We investigated the levels and possible determinants of polybrominated diphenyl ethers (PBDEs) in the settled house-dust (SHD) of urban dwellings with resident preschool-aged children in Nanjing, China. The possible neurodevelopmental effects of house-dust PBDEs were also explored. SHD was collected from 216 urban houses. Levels of 8 PBDEs were measured by gas chromatography-negative chemical ionization mass spectrometry. The Child Behavior Checklist and the Gesell Development Inventory were used to evaluate the child's development. BDE47, BDE99, BDE153, BDE18, and BDE209 were detected in the SHD of >90 % of houses, of which BDE209 predominated. Most PBDEs were found at significantly greater levels in indoor than in outdoor dust (P < 0.05). Levels of BDE28 and BDE154 in houses with solid-wood floors were significantly greater than those in houses with plywood floors (P < 0.05). BDE154 levels in houses with wallpaper were significantly greater than those without wallpaper (P < 0.05). Greater BDE47 concentrations were found in houses with less natural ventilation time (linear trend P < 0.05). After dichotomization at the geometric mean concentration, BDE209 and total BDEs showed significant risks for depressed behavior problems and lower personal social developmental quotients (DQs); BDE99 and BDE153 indicated a risk for lower personal social DQs. In conclusion, PBDEs (especially BDE209) are ubiquitous in urban SHD in Nanjing residences. Natural ventilation and floor materials potentially influence PBDE levels in SHD. The potential adverse effect of postnatal exposure to PBDEs on the behavior and neurodevelopment of preschool-age children requires follow-up in larger studies.

A survey study of factors influencing elevated blood lead levels in donors from Qingdao, China.

BACKGROUND: That lead is harmful to multiple systems of the human body has been known since antiquity and numerous recent studies have shown that blood transfusion may be an important source of exposure to lead in blood recipients. In this study factors influencing elevated lead levels in blood samples from donors in Qingdao, a city in northern China were investigated to provide screening procedures for blood donors and safer blood transfusions for blood recipients. MATERIALS AND METHODS: In 2021, subjects from 15 blood donation sites in Qingdao were selected by stratified random sampling. Blood lead levels (BLL) were analyzed by graphite furnace atomic absorption spectrometry. Multiple linear regression and logistic regression models were used to analyze factors influencing BLL. RESULTS: Of 2,142 blood donors, 1,434 were male and 708 were female, with an average age of 34.8 years. The geometric mean of BLL was 26.03 µg/L (95% confidence interval: 25.52-26.56), and donors in the high blood lead group (≥35 µg/L) accounted for 25.6% of the study population. Multiple linear regression results showed BLL was associated with gender, age, place of residence, duration of residence, and smoking status. Multivariate logistic regression analysis showed that male, increasing age, living in Jimo, duration of residence ≥30 years, and smoking were risk factors for high BLL, with odds ratios (95% confidence intervals) being 2.10 (1.61-2.73), 1.03 (1.01-1.04), 3.89 (1.09-13.86), 1.64 (1.22-2.20), and 1.76 (1.40-2.22), respectively. DISCUSSION: Male, advanced age, living in Jimo, smoking, and duration of residence ≥30 years were associated with higher BLL. Infusion of blood with elevated lead concentration can be reduced by screening out donors presenting one or more of the above risk factors.

Association between maternal allergic rhinitis and asthma on the prevalence of atopic disease in offspring.

BACKGROUND: Asthma is a common co-morbidity of allergic rhinitis (AR). The prevalence of these two allergic diseases has increased in China and has been shown to cluster in families independently. This study evaluated the association between maternal AR (presenting with or without asthma) and the allergic conditions in offspring. METHODS: Women (n = 592) diagnosed with AR were recruited for this study; 379 patients presented with AR and 213 presented with both AR and asthma. Total serum IgE levels and nasal eosinophil counts were analyzed and correlated with disease presentation. RESULTS: The prevalence of allergic conditions in offspring of mothers diagnosed with AR and asthma was significantly higher than the prevalence observed in children born to mothers presenting with AR only. Maternal total serum IgE and eosinophil counts were predictive of atopy in offspring. Children born to mothers presenting with persistent moderate-to-severe AR had the highest risk of developing atopic conditions (OR 6.26, 95% CI 3.26-12.02). Maternal age of 25-30 years at delivery was also associated with a higher risk for the allergic disease in offspring compared to maternal age of 36-40 (OR 2.13, 95% CI 1.31-3.47). CONCLUSIONS: The severity of maternal AR, asthma co-morbidity, elevated serum IgE levels and nasal eosinophilia were all associated with an increased risk of offspring developing allergic conditions. Children born to older mothers were protected against developing atopic disease.

High urinary bisphenol A concentrations in workers and possible laboratory abnormalities.

OBJECTIVES: Bisphenol A (BPA) is widely used in epoxy resins in China. There are few reports on the adverse health effects of occupational exposure to BPA. This study examined associations between urinary BPA concentrations in workers and laboratory parameters for health status. METHODS: Spot urine checks at the end shift on Friday were used for cross-sectional analysis of BPA concentrations, and blood or urinary markers of liver function, glucose homeostasis, thyroid function and cardiovascular diseases were measured. The 28 participants were workers in two semiautomatic epoxy resin factories. RESULTS: The average urinary BPA concentration was 55.73±5.48 ng/ml (geometric mean ± geometric SD) (range 5.56-1934.85 ng/ml). After adjusting for urine creatinine (Cr), it was 31.96±4.42 µg/g Cr (geometric mean ± geometric SD) (range 4.61-1253.69 µg/g Cr). BPA feeding operators showed the highest concentrations, over 10 times those of the crushing and packing and office workers. Higher BPA concentrations were associated with clinically abnormal concentrations of FT3, FT4, TT3, TT4, thyroid-stimulating hormone, glutamic-oxaloacetic transaminase and γ-glutamyl transferase. Workers with higher BPA concentrations showed higher FT3 concentrations (linear trend: p<0.001). Bivariate correlation tests for laboratory analytes within normal limits showed FT3 to be positively associated with logged BPA concentrations, r=0.57, p=0.002. FT4 was positively associated with lactate dehydrogenase, r=0.45, p=0.020, and insulin was positively associated with thyroid-stimulating hormone with r=0.57, p=0.009. CONCLUSIONS: Higher occupational BPA exposure, reflected in urinary concentrations of BPA, may be associated with thyroid hormone disruption.

Prevalence of and risk factors for subjective symptoms in urban preschool children without a cause identified by the guardian.

OBJECTIVE: The aim of this study was to explore the prevalence of and the risk factors for subjective symptoms without an identified cause by the guardian (SSWICG) in urban preschool children. METHODS: A questionnaire was used to collect information from 661 urban preschool children. The subjective symptoms were cited from the MM075NA Indoor Environment Quality Investigation Questionnaire. Information about living conditions, kindergarten and outdoor environments was collected, as well as health information from each child. RESULTS: The prevalence of SSWICG reached 31%, among which the prevalence of general symptoms in the central nervous system (CNS) reached 54.6%. Univariate analysis showed that the materials that made indoor furniture, walls and doors, indoor biological factors, outdoor pollution sources near the house and traffic pollution were associated with SSWICG and mucosal, dermal and general symptoms in the CNS subgroups. Multivariate analysis also showed that furniture materials, traffic pollution, kindergarten environment quality and allergies were associated. CONCLUSIONS: The prevalence of SSWICG was relatively high. Possible risk factors include indoor furnishing materials, allergy, traffic pollution and kindergarten environmental pollution.

Bayesian Spatial Modeling for Housing Data in South Africa.

Spatial process models are being increasingly employed for analyzing data available at geocoded locations. In this article, we build a hierarchical framework with multivariate spatial processes, where the outcomes are "mixed" in the sense that some may be continuous, some binary and others may be counts. The underlying idea is to build a joint model by hierarchically building conditional distributions with different spatial processes embedded in each conditional distribution. The idea is simple and the resulting models can be fitted to multivariate spatial data using straightforward Bayesian computing methods such as Markov chain Monte Carlo methods. Bayesian inference is carried out for parameter estimation and spatial interpolation. The proposed models are illustrated using housing data collected in the Walmer district of Port Elizabeth, South Africa. Inferential interest resides in modeling spatial dependencies of dependent outcomes and associations accounting for independent explanatory variables. Comparisons across different models confirm that the selling price of a house in our data set is relatively better modeled by incorporating spatial processes.

Influence of postnatal polycyclic aromatic hydrocarbon exposure on the neurodevelopment of toddlers at the age of 12 months.

OBJECTIVES: To investigate the possible influence of polycyclic aromatic hydrocarbons (PAHs) exposure on neurodevelopment of toddlers at the age of 12 months. METHODS: Totally 306 subjects were recruited from the Qingdao Birth Cohort established in 2014. PAH-DNA adducts in toddlers' umbilical cord blood samples, hydroxyl-PAH metabolites in their urine samples and the developmental quotients (DQs) were measured. Sex, gestational age, birth weight, and maternal educational background were adjusted to analyze the influence of the PAH exposure on the neurodevelopment of the toddlers using multivariate linear regression model. RESULTS: Pearson correlation test showed that the logarithmic values of hydroxyl-PAH were negatively correlated with the DQs. Multivariate linear regression analysis indicated that logarithmic concentration of 1(9)- hydroxyphenanthrene was still associated with the DQs of the fine motor behaviors with ß and 95% confidential interval (CI) of -1.137 (-2.053, -0.222), together with PAH-DNA adducts [ß (95% CI): -0.577 (-0.930, -0.225)]. PAH-DNA adducts presented an independently negative influence on the DQs of the gross motor and personal social behaviors with ß (95%CI) of -0.470 (-0.814, -0.126) and -0.526 (-0.859, -0.193), respectively. CONCLUSIONS: The exposure to PAHs in toddlers at 12 months could influence their neurodevelopment. Additionally, prenatal exposure to PAHs should also be considered.

A Genome-Wide Association Study of Age-Related Hearing Impairment in Middle- and Old-Aged Chinese Twins.

BACKGROUND: Age-related hearing impairment (ARHI) is considered an unpreventable disorder. We aimed to detect specific genetic variants that are potentially related to ARHI via genome-wide association study (GWAS). METHODS: A sample of 131 dizygotic twins was genotyped for single-nucleotide polymorphism- (SNP-) based GWAS. Gene-based test was performed using VEGAS2. Pathway enrichment analysis was conducted by PASCAL. RESULTS: The twins are with a median age of 49 years, of which 128 were females and 134 were males. rs6633657 was the only SNP that reached the genome-wide significance level for better ear hearing level (BEHL) at 2.0 kHz (P = 1.19 × 10-8). Totally, 9, 10, 42, 7, 17, and 5 SNPs were suggestive evidence level for (P < 1 × 10-5) BEHLs at 0.5, 1.0, 2.0, 4.0, and 8.0 kHz and pure tone average (PTA), respectively. Several promising genetic regions in chromosomes (near the C20orf196, AQPEP, UBQLN3, OR51B5, OR51I2, OR52D1, GLTP, GIT2, and PARK2) nominally associated with ARHI were identified. Gene-based analysis revealed 165, 173, 77, 178, 170, and 145 genes nominally associated with BEHLs at 0.5, 1.0, 2.0, 4.0, and 8.0 kHz and PTA, respectively (P < 0.05). For BEHLs at 0.5, 1.0, and 2.0 kHz, the main enriched pathways were phosphatidylinositol signaling system, regulation of ornithine decarboxylase, eukaryotic translation initiation factor (EIF) pathway, amine compound solute carrier (SLC) transporters, synthesis of phosphoinositides (PIPS) at the plasma membrane, and phosphatidylinositols (PI) metabolism. CONCLUSIONS: The genetic variations reported herein are significantly involved in functional genes and regulatory domains that mediate ARHI pathogenesis. These findings provide clues for the further unraveling of the molecular physiology of hearing functions and identifying novel diagnostic biomarkers and therapeutic targets of ARHI.

Association between NR3C1 gene polymorphisms and age-related hearing impairment in Qingdao Chinese elderly.

BACKGROUND: Age-related hearing impairment (ARHI) has attracted increasing attention recently. It is caused by genetic and environmental factors. A number of ARHI-related genes have been found. This study aimed to detect the potential association between NR3C1 gene polymorphisms and ARHI by means of weighted allele score. METHODS: A total of 861 participants from Qingdao city were selected by means of cluster random sampling. We statistically evaluated the characteristics of individuals and used the Mann-Whitney U test or chi-square test for comparison. The publicly available expression quantitative trait locus (eQTL) was queried on the website of the Genotype-Tissue Expression (GTEx). We used the weighted allele score and logistic regression analysis to explore the association between NR3C1 gene polymorphisms and ARHI. Finally, the prediction model was constructed by logistic regression and receiver operating characteristic (ROC) curve. RESULTS: All individuals over 60 years of age were enrolled in this study. The allele of rs61757411, rs41423247 and rs6877893 were significantly different between the ARHI group and the normal hearing group (P < 0.01). Though eQTL analysis, rs6877893 and rs33388 might affect the occurrence of ARHI by affecting the expression of NR3C1 gene in artery aorta. Then we performed two models: one without adding any covariates into model and the other adjusting for demographic characteristic, smoking and drinking, diet and exercise, and physical conditions. In the multivariate-adjusted model 2, the odds ratio with 95% confidence interval for weighted allele score (NR3C1) was 0.841 (0.710-0.995, P = 0.043). The area under the ROC curve was 0.755, indicating that the model had good predictability. CONCLUSIONS: Our study suggests that NR3C1 gene polymorphisms was significantly associated with ARHI.

Influence of air pollutants on varicella among adults.

Little attention has been paid to the relationship between air pollutants and varicella among adults. We used data collected in Qingdao, China from 2014 to 2019. A combination of quasi-Poisson generalized linear model (GLM) and distributed lag non-linear model (DLNM) was applied to evaluate the association between exposure to air pollutants and varicella. And the effects of exposure to extremely high concentration (at 97.5th percentile) and low concentration (at 2.5th percentile) of air pollutants on varicella were also calculated. The level II of GB3095-2012 was used as the reference. A 10 µg/m3 increase of PM2.5 was significantly associated with an increased risk of varicella (lag day: 4, 5 and 6). The negative associations were found for NO2 per 10 µg/m3 increase from lag 15 to 19 day. The high PM2.5 concentration (135 µg/m3) was significantly associated with the increased risk of varicella (lag day: 6, 7). For NO2, the negative association was found at high concentration (75 µg/m3) on lag 15 to 20 day; and the positive relationship was shown at low concentration (10 µg/m3) on lag 15 to 20 day. Exposure to PM2.5 and NO2 were significantly associated with the risk of varicella among adults.

Long Distance Transmission of SARS-CoV-2 from Contaminated Cold Chain Products to Humans - Qingdao City, Shandong Province, China, September 2020.

What is already known about this topic? Though coronavirus disease 2019 (COVID-19) has largely been controlled in China, several outbreaks of COVID-19 have occurred from importation of cases or of suspected virus-contaminated products. Though several outbreaks have been traced to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) isolated on the outer packaging of cold chain products, live virus has not been obtained. What is added by this report? In September 2020, two dock workers were detected as having asymptomatic SARS-CoV-2 infection using throat swabs during routine screening in Qingdao, China. Epidemiological information showed that the two dock workers were infected after contact with contaminated outer packaging, which was confirmed by genomic sequencing. Compared to the Wuhan reference strain, the sequences from the dock workers and the package materials differed by 12-14 nucleotides. Furthermore, infectious virus from the cold chain products was isolated by cell culture, and typical SARS-CoV-2 particles were observed under electron microscopy. What are the implications for public health practice? The international community should pay close attention to SARS-CoV-2 transmission mode through cold chain, build international cooperative efforts in response, share relevant data, and call on all countries to take effective prevention and control measures to prevent virus contamination in cold-chain food production, marine fishing and processing, transportation, and other operations.

Relationship between indoor chemical concentrations and subjective symptoms associated with sick building syndrome in newly built houses in Japan.

OBJECTIVES: This study explored possible associations between chemical substances and sick building syndrome (SBS)-type symptoms of residents living in new houses in Japan. METHODS: We randomly sampled 5,709 newly built conventional homes. In the end, 1,479 residents in 425 households completed a questionnaire survey and agreed to environmental monitoring for indoor aldehydes and volatile organic compounds (VOCs) to be conducted in their homes. If the residents had complained about at least one SBS-related symptom, they were classified as suffering from SBS. Multiple logistic regression analysis was used to select predictive chemical factors of SBS symptoms. RESULTS: About 14% of the subjects suffered from SBS. Many aldehydes and VOCs were associated factors of optical, nasal, and gular symptoms in univariate analysis. After adjustment for other possible risk factors, formaldehyde dose-dependently showed to be a significant risk factor for SBS. Several chemicals had tendency to be associated with SBS symptoms. CONCLUSIONS: Chemicals detected in Japanese newly built houses tend to increase the risk of subjective symptoms in residents suffering from SBS.

Oxidative stress biomarkers and lifestyles in Japanese healthy people.

The urinary concentrations of 8-isoprostane and 8-hydroxy-2'-deoxyguanosine (8-OHdG), which are biomarkers of oxidative stress, were measured in 677 Japanese people without any diseases, and their correlations with lifestyle facotrs, lifestyle-related blood biochemical parameters, and dietary intake of antioxidative vitamins were investigated. The mean urinary concentration of 8-isoprostane and 8-OHdG was 0.58 ng/mg creatinine and 8.43 ng/mg creatinine, respectively. Mean urinary 8-isoprostane was significantly different in terms of age, gender, smoking and alcohol consumption but not different in terms of body mass index (BMI) and exercise. By multiple regression analysis, urinary 8-isoprostane was significantly influenced by smoking and age. On the other hand, mean urinary 8-OHdG showed differences only by age group. Multiple regression analysis revealed that urinary 8-OHdG was significantly influenced by age, smoking, body weight, levels of high-sensitivity C-reactive protein (Hs-CRP) and low density lipoprotein-cholesterol in females, although it was significantly influenced by body weight in males. The present study shows that urinary 8-isoprostane is associated with lipid peroxidation related-lifestyles such as smoking, and urinary 8-OHdG is associated with arteriosclerosis related-factors such as Hs-CRP. Our findings suggest that 8-isoprostane and 8-OHdG appear to be prospective biomarkers for early prediction of lifestyle related-disease risk at the population level.

Effect of Benzo[a]pyrene-DNA Adduct in Cord Blood on the Neurodevelopment of 12-Month-Old Infants in Qingdao City.

INTRODUCTION: The study was designed to explore the possible adverse effects of prenatal polycyclic aromatic hydrocarbons (PAHs) on the neurodevelopment of the infants at the age of 12 months in a birth cohort in Qingdao of China. Benzo[a]pyrene (BaP)-DNA adduct level in umbilical cord blood was measured by enzyme immunoassay. METHODS: Child neurodevelopment was assessed at both 6 months and 12 months of age using the Gesell Development Inventory (GDI). RESULTS: This study results reveal that multivariate linear analysis, cord BaP-DNA adduct level was inversely associated with developmental quotient score in the adaptive domain [ß = -0.08; 95% CI: (-0.16, -0.003); p = 0.04], gross motor domain [ß = -0.10; 95% CI: (-0.20, -0.01); p = 0.02], fine motor domain [ß = -0.15; 95% CI: (-0.25, -0.05); p = 0.01], language domain [ß = -0.12; 95% CI: (-0.21, -0.03); p = 0.02], and personal-social domain [ß = -0.13; 95% CI: (-0.22, -0.04); p<0.01]. Further, multivariate logistic regression analysis showed increased cord BaP-DNA adduct levels associated with increased odds of delayed in language domain. CONCLUSION: In conclusion, the study suggested that prenatal PAH exposure monitored by umbilical cord blood BaP-DNA adducts may adversely affect the neurodevelopment of the infants at 12 months of age.

Symptom definitions for SBS (sick building syndrome) in residential dwellings.

The potential risk factors for sick building syndrome (SBS) in newly built dwellings were investigated. Two different definitions for SBS were used, a narrow definition (symptoms related to home environment and continuously occurring in the last 3 months were regarded as positive) and another relatively broad definition (symptoms related to home environment and either continuously or sporadically occurring in the last 3 months were regarded as positive). With both definitions indoor air chemicals, especially TVOC, and high stress during work were found to be significantly associated with SBS symptoms. Allergic history was more associated with narrow-sense symptoms and odor perception with broad-sense symptoms. The results indicate that the broad definition be preferred to find more potential risk factors.

Association between serum gamma-glutamyltransferase and oxidative stress related factors.

BACKGROUND/AIMS: To investigate the main factors correlated with the serum gamma-glutamyltransferase activity. METHODOLOGY: We measured serum gamma-glutamyltransferase activity in 248 healthy Japanese people and determined its correlations with serum antioxidants, other plasma or serum factors, urinary 8-hydroxydeoxyguanine, and lifestyle factors. RESULTS: The mean serum gamma-glutamyltransferase activity was 29 IU/L. Gamma-glutamyltransferase activities of males and persons older than 45 years were significantly higher than each counterpart. Gamma-glutamyltransferase levels increased significantly with the number of cigarettes smoked per day and the frequency of alcohol consumption except for the persons who did not take alcohol. Additionally, gamma-glutamyltransferase significantly correlated with urinary 8-hydroxydeoxyguanine, and with more blood factors including serum tocopherols, carotenoids, antioxidative enzymes, lipid peroxide, and free fatty acids than urinary 8-hydroxydeoxyguanine did. In multiple regression analyses, gamma-glutamyltransferase had significant associations with retinol, 8-hydroxydeoxyguanine, docosahexaenoic acid, and cigarette smoking. CONCLUSIONS: Our present findings support the hypothesis that gamma-glutamyltransferase can be used as a marker related with oxidative stress.

Effects of mask fitness and worker education on the prevention of occupational dust exposure.

To decrease the incidence of pneumoconiosis, we examined dust protective mask performance and its relation to pulmonary function as well as the effects of worker education on the proper wearing of masks. One hundred and seventy-eight workers from 15 factories subject to dust exposure participated in this study. All participants were interviewed to obtain relevant personal information and underwent both a mask leakage and a pulmonary function test. The mask leakage was expressed as a percentage, with under 10% leakage indicating that the dust protective mask worked efficiently. In addition, 23 workers from 2 factories were educated on how to wear masks properly. The average mask leakage was 24.3%, and 58% of workers wore ineffective masks. Though pulmonary function was almost normal, the percent vital capacity (%VC) tended to be lower depending on the mask leakage. Mask education, which was very easy and took only a short time, dramatically decreased average mask leakage from 32.1% to 10.5% (p0.001). Educating workers to wear masks properly might prevent the worsening of pulmonary function in response to dust exposure. Appropriate mask fitness by education could be useful in preventing the development of pneumoconiosis.

Cytotoxicity of lawsone and cytoprotective activity of antioxidants in catalase mutant Escherichia coli.

Lawsone is an active naphthoquinone derivative isolated from henna (Lawsonia inermis L.), a widely used hair dye. Previous study on the toxicity of lawsone remains unclear since the involvement of oxidative stress and the kind of ROS (reactive oxygen species) involved have not been fully resolved yet. This present study reports the cytotoxic effects of lawsone and henna. We carried out CAT assay (a zone of inhibition test of bacterial growth and colony-forming efficiency test of transformant Escherichia coli strains that express mammalian catalase gene derived from normal catalase mice (Cs(a)) and catalase-deficient mutant mice (Cs(b))), Ames mutagenicity assay and H(2)O(2) generation assay. Lawsone generated H(2)O(2) slightly in phosphate buffer system and was not mutagenic in Ames assay using TA 98, TA 100 and TA 102, both in the absence and presence of metabolic activation. Lawsone exposure inhibited the growth of both Cs(a) and Cs(b) strains in a dose-dependent manner. Mean zone diameter for Cs(a) was 9.75+/-0.96 mm and 12.75+/-1.5 mm for Cs(b). Natural henna leaves did not show toxic effects, whereas two out of four samples of marketed henna products were shown toxicity effects. Catalase abolished zone of inhibition (ZOI) of marketed henna products, eliminated ZOI of lawsone in a dose-dependent manner and low concentration of exogenous MnSOD and Cu/ZnSOD eliminated the toxicity. Histidine and DTPA, the metal chelator; BHA and low concentration of capsaicin, the inducer of NADH-quinone reductase, effectively protected Cs(a) and Cs(b) against lawsone in this study. We suggest that lawsone cytotoxicity is probably mediated, at least in part, by the release of O(2)(-), H(2)O(2) and OH(-).