The determination of adjustment method of urinary mercury in spot urine is one of the important issues in assessing the health risks of mercury workers. But there have been debates about whether creatinine or other forms of correction for urinary concentration are better in reducing the variation of urinary mercury. We evaluated four adjustment methods-specific gravity, creatinine, log creatinine and excretion rate-by correlation between values adjusted by the four methods and individual exposure levels which were the geometric mean of daily air mercury level for 2 or 5 days, and mercury concentrations in 24 hour urine were also investigated to compare the results of spot urine. The correlation between values of spot urine and mercury exposure level was over 0.8 in all adjustment methods for workers who worked over 1 year. All four adjustment methods for urinary mercury were found to be similar in assessing the exposure, log creatinine and excretion rate method however were not practical to use due to lack of reference values, and variable standard values of specific gravity. And the creatinine adjusted values were more sensitive in low mercury exposure level. We therefore recommend the creatinine adjustment method for adjustment of urinary mercury.
Adult ; Air Pollutants, Occupational/*urine ; Female ; Human ; Male ; Mercury/*urine ; Middle Age ; Risk Assessment ; Time Factors

OBJECTIVETo explore the effects of smoking on urinary 10 metabolites of polycyclic aromatic hydrocarbons (PAHs) in the coke oven workers.

METHODSOccupational health examination was performed on 1401 coke oven workers in one coking plant, their urine were collected respectively. The concentrations of the ten monohydroxy polycyclic aromatic hydrocarbons in urine were detected by gas chromatography/mass spectrometry. The 1401 workers were divided into four groups, namely control, adjunct workplaces, bottom and side, top group according to their workplaces and the different concentrations of PAHs in the environment. The concentrations of the ten monohydroxy polycyclic aromatic hydrocarbons between smokers and nonsmokers in each workplace group were compared using analysis of covariance, respectively.

RESULTSThe levels of concentrations of the sixteen polycyclic aromatic hydrocarbons we detected at control were significantly higher than those at other areas (P < 0.05). Comparing the ten monohydroxy polycyclic aromatic hydrocarbons levels between smokers and nonsmokers, the levels of 1-hydroxynaphthalene and 2-hydroxynaphthalene among smokers were higher than nonsmokers with statistically significance in control, adjunct workplaces, bottom and side and top groups (P < 0.05). However, the levels of 1-hydroxypyrene had no statistically significant differences between the four areas.

CONCLUSIONUrinary 1-hydroxynaphthalene and 2-hydroxynaphthalene may be used as biomarkers for the impact of smoking on monohydroxy polycyclic aromatic hydrocarbons in the coke oven workers.

Air Pollutants, Occupational ; urine ; Biomarkers ; urine ; Coke ; Humans ; Male ; Naphthols ; urine ; Occupational Exposure ; analysis ; Polycyclic Aromatic Hydrocarbons ; urine ; Pyrenes ; urine ; Smoking ; urine

OBJECTIVETo explore and provide the possible biological limit of urinary chromium for population occupationally exposure to soluble chromate, as to providing scientific evidences for health monitoring and risk assessment.

METHODSA cross-sectional study was conducted. The studied population contained 83 workers from different processes of the chromate plant, in addition, 10 farmers without exposure to chromate matched with exposed subjects by age, gender and smoking status were identified as a control group. The air chromium concentration for personal exposure during 8-hours shift and the urinary chromium concentration post-shift were determined and their relationship was analyzed statistically. Meanwhile, the literatures of the biological limit of urinary chromium for occupational exposure to soluble chromate were studied.

RESULTSFor the control group, the air chromium concentration had a range from 0.00 microg/m(3) to 0.08 microg/m(3) and the urinary chromium concentration from 0.40 microg/g Cre to 1.02 microg/g Cre. For the exposure group, the air chromium concentration was from 0.10 microg/m(3) to 287.00 microg/m(3) and the urinary chromium concentration was from 1.14 microg/g Cre to 79.07 microg/g Cre. The positive relationship existed in between air chromium concentration and urinary concentration. The urinary chromium concentration was increased depending on the chromate exposed level. The regress equation was that Urinary chromium concentration (microg/g Cre) = 4.16 + 236.86 x air concentration for chromate (mg/m(3)), r = 0.976. The recommendation of ACGIH (USA, 2004) was 65.1 micromol/mol Cre (30 microg/g Cre) with the same TLV-TWA of 0.05 mg/m(3) as our National standard about the air chromate concentration.

CONCLUSIONOur findings suggested that the post-shift urinary chromium concentration might be used as an exposed biomarker for chromate. Considering the recommendation of ACGIH (USA, 2004) and the feasibility of the standard performed, we suggest that the biological threshold limit of urinary chromium for occupational exposure to soluble chromate in China should be 65.1 micromol/mol Cre (30 microg/g Cre) (post-shift urine for consecutive 5 work days.).

Air Pollutants, Occupational ; analysis ; Chromates ; Chromium ; urine ; Humans ; Occupational Exposure ; Threshold Limit Values

OBJECTIVETo analyze the relationship between metabolites of polycyclic aromatic hydrocarbons (PAHs) and lung function in coke oven workers, and to provide scientific basis for further exploring the potential mechanism and developing the preventing strategies of the workers' early lung damage.

METHODSWe measured carbon monoxide, sulfur dioxide, benzene soluble matter, particulate matters, and PAHs at different workplaces of a coke oven plant. Detailed information on demography and occupational health condition of 912 workers were collected. We divided these workers into control group and coke oven group according to their workplaces and the different concentrations of COEs in the environment. We detected 10 urinary PAH metabolites and lung function using gas chromatography-mass spectrometry and spirometric tests, respectively.

RESULTSFEV(1.0) (91.12 ± 13.31) and FEV(1.0)/FVC (108.61 ± 20.37) of the coke oven group is significantly lower than the control group (94.16 ± 15.57, 113.45 ± 19.70). In the coke oven group, the hydroxyphenanthrene and 1-hydroxypyrene are negatively correlated with FEV(1.0)/FVC (β = -0.136, β = -0.100), Ptrend < 0.05 for all.

CONCLUSIONThe dose response decrease of lung function is associated with the urinary PAH metabolites in coke oven workers. Indicated that the long exposure to PAHs may cause the early lung damage in coke oven workers, phenanthrene and pyrene may be the main factors.

Adult ; Air Pollutants, Occupational ; urine ; Coke ; Humans ; Lung ; physiopathology ; Male ; Middle Aged ; Occupational Exposure ; analysis ; Phenanthrenes ; urine ; Polycyclic Aromatic Hydrocarbons ; urine ; Pyrenes ; urine ; Respiratory Function Tests

Case reports of indium-related lung disease in workers have raised public concern to the human toxicity of indium (In) and its compounds. However, studies evaluating the exposure or health of workers in In smelting plants are rare. Therefore, in this study, we focused on four In smelting plants, with the main objective of characterizing In in smelter plants in China and discussing the potential exposure biomarkers of In exposure. We recruited 494 subjectsat four In smelting plants in China. Personal air samples, first morning urine and spot blood samples were collected. In concentrations in samples were analyzed using inductively coupled plasma mass spectrometry. In concentrations in air samples did not exceed the permissible concentration-time weighed average, but the smelter workers had a higher internal exposure to In. Positive correlations were observed between the air In and urine In concentrations, and between the air In and blood In concentrations. This study provides basic data for the following In exposure and health risk assessment.
Adult ; Air Pollutants, Occupational ; blood ; urine ; Biomarkers ; blood ; urine ; China ; Environmental Monitoring ; Female ; Humans ; Indium ; blood ; urine ; Male ; Mass Spectrometry ; Metallurgy ; Middle Aged ; Occupational Exposure ; Young Adult

OBJECTIVETo explore the effect of polycyclic aromatic hydrocarbons on the neurobehavioral function of coke oven workers.

METHODS200 healthy adult male coke oven workers were selected from a coke plant of a state-owned steel enterprise in Taiyuan City. 88 controls occupationally unexposed to polycyclic aromatic hydrocarbons (PAHs) were selected from the same enterprise. All the subjects participated in this investigation voluntarily in their consent. Concentration of B(a)P in the working environment was monitored by High Performance Liquid Chromatography (HPLC). Urine samples were sampled immediately after working shifts. The level of urinary 1-hydroxypyrene was determined by HPLC. General information of workers correlated with the investigation was collected in a questionnaire according to the same criteria by well-trained investigators. Neurobehavioral core test battery (NCTB) recommended WHO was performed on coke oven workers and controls to test the neurobehavioral changes and the mood state.

RESULTSthe concentration of B(a)P at oven bottom,oven side and oven top were 0.0195 microg/m3, 0.186 microg/m3 and 1.624 microg/m3 respectively, that at oven side and oven top being higher than the one stipulated by the occupational hygiene criterion. Urinary 1-hydroxypyrene was significantly different between the exposure group (3.42 +/- 0.98 micromol/mol creatinine) and control group (2.75 +/- 1.09 micromol/mol creatinine). No significant differences were found between exposure group and control group of age, working years, smoking, drinking and unhealthy food consumption; however, compared to the controls, the scores of total digital span, the forward digital span, and right dotting in the coke oven workers were lower, but that of total dotting was higher, with a statistical significance. According to urinary 1-hydroxypyrene concentration, all the subjects were divided into three groups. (<3.10 micromol/mol creatinine, 3.10 micromol/mol creatinine, >3.87 micromol/mol creatinine). Significant differences of the total digital span, the forward digital span, backward digital span, digit symbol and Benton visual retentions existed in different urinary 1-hydroxypyrene concentration groups and showed a dose-response tendency. Results of multiple stepwise regression analysis and correlation analysis showed that the level of urinary 1-hydroxypyrene affected memory and perception of coke oven workers and negative correlations between the level of urinary 1-hydroxypyrene and changes in neurobehavioral function were found.

CONCLUSIONPAHs mainly causes decrease of memory and perception in coke oven workers.

Adult ; Air Pollutants, Occupational ; analysis ; Coke ; Humans ; Male ; Memory ; Neuropsychological Tests ; Occupational Exposure ; Polycyclic Aromatic Hydrocarbons ; urine

OBJECTIVETo establish Biological Limit Value (BLV) for N, N-dimethylacetamide (DMAC).

METHOD201 workers in 3 spandex factories exposed to DMAC were recruited. Air samples were collected using personal air samplers, and urine samples from each works were collected at the end of shift at end of workweek. The urinary metabolite NMAC and air samples of DMAC were determined by gas chromatography (GC). Percentile and relative internal exposure (RIE) were analyzed and proposed a BLV for DMAC.

RESULTSThe number of workers who exposure to DMAC below OELs were 133 (66.2%) among 201 workers monitored. Geometric mean (range) concentration of DMAC in air was 19.4 (0.40 ∼ 300.12) mg/m(3), and that of NMAC in urine was 23.7 (1.30 ∼ 189.42) mg/g Cr. A linear correlation was found between the personal air DMAC and creatinine-adjusted NMAC levels in urine collected at the end of shift at end of workweek (F = 188.872, R(2) = 0.487,P < 0.001). The relationship can be described by the equation Log (NMAC mg/g Cr) = 0.685 + 0.455 log (DMAC mg/m(3)). According to the equation the current China OELs value of 20 mg/m(3) would lead to a mean NMAC concentration of 18.92 mg/g Cr. The 90th percentile biomonitoring result below 20 mg/m(3) 8-hour TWA is 23.9 mg MMAC mg/g Cr, and that of NMAC in urine calculated by relative internal exposure (RIE) was 19.0 mg/g Cr.

CONCLUSIONA BLV of 20 mg/g Cr NMAC in urine at the end of shift at end of workweek for DMAC was recommend by reference to official values from other countries.

Acetamides ; analysis ; urine ; Adult ; Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; Female ; Humans ; Male ; Occupational Exposure ; analysis ; Threshold Limit Values

OBJECTIVETo investigate the role of genetic polymorphisms of epoxide hydrolase 1 (EPHX1) in the metabolism of styrene in vivo.

METHODSFifty-six styrene-exposed workers, who worked in the painting workshop of an enterprise for manufacturing glass fiber-reinforced plastic yachts in Shandong Province, China for over one year and were protected in approximately the same way, were selected as study subjects. The 8-hour time-weighted average concentration (8 h-TWA) of styrene and the concentrations of mandelic acid (MA) and phenyl glyoxylic acid (PGA) as urinary metabolites were measured. The genetic polymorphisms of EPHX1 were detected by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTSThe urinary concentrations of MA and PGA were 177.25±82.36 mg/g Cr and 145.91±69.73 mg/g Cr, respectively, and the 8 h-TWA of styrene was 133.28±95.81 mg/m3. Urinary concentrations of MA and PGA were positively correlated with 8 h-TWA of styrene (R=0.861, P < 0.05; R=0.868, P < 0.05). The subjects were divided into high-exposure group (8 h-TWA >50 mg/m(3)) and low-exposure group (8 h-TWA ≤ 50 mg/m(3), and in the two groups, the urinary concentrations of MA and PGA were significantly higher in the individuals carrying high-activity genotypes of EPHX1 than in those carrying low-activity genotypes of EPHX1 (P < 0.05).

CONCLUSIONGenetic polymorphisms of EPHX1 play an important role in the metabolic process of styrene in vivo.

Adult ; Air Pollutants, Occupational ; pharmacokinetics ; China ; Epoxide Hydrolases ; genetics ; Glyoxylates ; urine ; Humans ; Male ; Mandelic Acids ; urine ; Occupational Exposure ; Polymorphism, Genetic ; Styrene ; pharmacokinetics

OBJECTIVETo explore the hepatic toxicity and the exposure biomarkers of N, N-Dimethylacetamide.

METHODSOne hundred forty five objects were chosen by stratified random sampling method. The investigation was performed using questionnaire and physical examination. The air concentrations of DMAC in the workshops were monitored. The urine samples were collected and analyzed after work everyday or at the weekend. The correlation between the air concentrations of DMAC in the workshops and the concentrations of urinary NMAC wee analyzed by regression.

RESULTSThe air concentration of DMAC in the spinning workshop was higher than others. The morbidity of abnormal hepatic function was 12.4%, 61.1% of workers with abnormal hepatic function appeared in one year after exposure to DMAC in the workshops ( r=0.44, P<0.01).

CONCLUSIONThe abnormal heptic function was found in workers exposed to DMAC for short period. The concentration of urinary NMAC can serve as the exposure biomarker of DMAC.

Acetamides ; toxicity ; urine ; Adolescent ; Adult ; Air Pollutants, Occupational ; analysis ; Biomarkers ; urine ; Environmental Monitoring ; Humans ; Liver Function Tests ; Male ; Middle Aged ; Occupational Exposure ; Surveys and Questionnaires ; Workplace ; Young Adult

OBJECTIVETo investigate the inhalable titanium dioxide exposure level and make an assessment of its oxidative effect on occupational exposed population.

METHODSA total of 7 workers occupationally exposing to inhalable titanium dioxide were recruited into the study. The basic information and occupational history were collected by interview, while their blood sample (10 ml for each subject) were collected before and after the investigation, respectively. Pre- and post-work shift urine samples (60 ml for each subject) were collected for 29 days consecutively. The daily personal titanium dioxide exposure level, temperature and relative humidity were detected too. Urinary 8-hydroxy-deoxyguanosine (8-OHdG) and serum high-sensitivity C-reactive protein (hs-CRP) were detected by ELISA and latex immunoturbidimetric assay, respectively.

RESULTSThe mean concentration of air inhalable titanium dioxide was (1.194 ± 1.015) mg/m(3). Serum hs-CRP level before and after the investigation was (1.13 ± 1.08), (1.33 ± 1.01) mg/L, respectively. No statistical significance was observed between hs-CRP level before and after the investigation (t = -0.848, P = 0.425). Pre- and post-work shift urinary 8-OHdG was (3.51 ± 1.39), (3.65 ± 1.06) µmol/mol Cr, respectively. A positive correlation was found between the concentration of inhalable titanium dioxide and the changes of 8-OHdG level (r = 0.192, t = 2.09, P = 0.039). Linear mixed-effect models, adjusted by work shift, years of employment, age, body mass index, smoking status, temperature and relative humidity, showed no significant exposure-respond trend between the inhalable titanium dioxide concentration and 8-OHdG level (β = 0.288, t = 1.940, P = 0.055).

CONCLUSIONOur findings do not support the potential link between occupationally exposure to inhalable titanium dioxide and high induction of DNA oxidative stress.

Air Pollutants, Occupational ; adverse effects ; C-Reactive Protein ; analysis ; Deoxyguanosine ; analogs & derivatives ; urine ; Humans ; Male ; Middle Aged ; Occupational Exposure ; analysis ; Oxidative Stress ; Titanium ; adverse effects ; blood ; urine