The Combined Effect of Elevated Blood Pressure and Occupational Noise Exposure on Bilateral High-Frequency Hearing Loss: Evidence From a Large Sample Cross-sectional Study.

BACKGROUND: Combined effect of elevated blood pressure and occupational noise exposure on hearing loss have rarely been evaluated among Chinese population. METHODS: This cross-sectional study was conducted in 242,811 participants. Logistic regression model was performed to estimate the independent and combined associations. RESULTS: Compared with participants without occupational noise exposure, the risk of bilateral high-frequency hearing loss (BHFHL) was significantly higher for noise exposure 10 years or more (odds ratio [OR] = 1.29, 95% confidence interval [95% CI] = 1.23-1.35). Compared with no hypertension, participants with grade 1 hypertension had higher risk of BHFHL in all age groups (OR, 1.14; 95% CI, 1.09-1.20). As to the combined effect, the highest BHFHL risk was found in males (OR, 1.51; 95% CI, 1.37-1.67), especially among participants with grade 1 hypertension older than 50 years (OR, 1.65; 95% CI, 1.46-1.88). CONCLUSIONS: Elevated blood pressure may synergistically influence hearing loss combined with occupational noise exposure.

[The increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers exposed accumulatively to formaldehyde].

OBJECTIVE: To investigate the effects of occupational exposure to formaldehyde on the micronuclei frequencies in peripheral blood lymphocytes of workers. METHODS: Two hundred thirty six plywood workers were divided into 3 exposure groups (low, middle and high) according to internal exposure biomarker (formaldehyde human serum albumin conjugate, FA-HSA), which was detected by ELISA. The concentrations of formaldehyde (FA) in air of two workshops were measure using the high performance liquid chromatography. Cytokinesis-block micronucleus (CBMN) test was used to detect the micronuclei frequencies of peripheral blood lymphocyte in 236 workers. RESULTS: The average concentrations of FA in the low and high exposure workshops were 0.58 +/- 0.20 and 1.48 +/- 0.61 mg/m3, respectively, there was significant difference (P < 0.01). The average concentrations of serum FA-HAS of workers in two workshops were 69.22 +/- 15.37 and 136.29 +/- 89.49 pg/ml, respectively, there was significant difference (P < 0.01). The results of CBMN test showed that the micronucleus frequencies in low, middle and high exposure groups were 1.94 +/- 1.72, 2.10 +/- 1.92 and 2.10 +/- 1.70 per thousand, respectively, there were no significant differences between groups. However, the micronucleus frequencies in accumulative low, middle and high exposure groups were 1.36 +/- 1.36, 2.31 +/- 1.81 and 2.49 +/- 1.92 per thousand, respectively, there were significant differences between different accumulative exposure groups (P < 0.01). The results of correlation analysis indicated that there was a positive correlation between accumulative exposure levels and micronucleus frequencies (r(s) = 0.321, P < 0.01). The accumulative exposure doses may be a risk factor for high micronucleus frequencies in workers exposed to FA (P(trend) = 0.002). CONCLUSION: FA-HSA levels can serve as an internal exposure biomarker for assessing the exposure level of workers exposed to FA. Accumulative formaldehyde exposure resulted in an increase of micronuclei frequencies of peripheral blood lymphocyte in plywood workers.

[Using the stable HSPA1A promoter-driven luciferase reporter HepG2 cells to assess the overall toxicity of coke oven emissions].

OBJECTIVE: Using the stable HSPA1A (HSP70-1) promoter-driven luciferase reporter HepG2 cells (HepG2/HSPA1A cells) to assess the overall toxicity of coke oven emissions. METHODS: The stable HepG2/HSPA1A cells were treated with different concentrations of coke oven emissions (COEs) collected from the top, side, and bottom of a coke oven battery for 24 h. After the treatments, luciferase activity, cell viability, malondialdehyde (MDA) concentration, Olive tail moment, and micronuclei frequency were determined, respectively. RESULTS: The bottom COEs induced significant increases (P < 0.01) in relative luciferase activity up to 1.4 times the control level at 0.15 µg/L. The low dose of side COEs (0.02 µg/L) led to a significant increase (P < 0.01) in relative luciferase activity that progressively increased to 2.1 times the control level at 65.4 µg/L. The top COEs produced a strong dose-dependent induction of relative luciferase activity up to over 5 times the control level at the highest concentration tested (202 µg/L). In HepG2/HSPA1A cells treated with the bottom COEs, relative luciferase activity was positively correlated with MDA concentration (r = 0.404, P < 0.05). For the three COEs samples, positive correlations were observed between relative luciferase activity and Olive tail moment and micronuclei frequency. CONCLUSION: The relative luciferase activity in HepG2/HSPA1A cells can sensitively reflect the overall toxicity of COEs. The stable HepG2/HSPA1A cells can be used for rapid screening of the overall toxicity of complex air pollutants in the workplace.

[Characteristics of particulate matter pollution in coke oven plant].

OBJECTIVE: To explore the characteristics of particulate matter pollution in coke oven plant, so as to provide scientific data for establishing occupational exposure limits for coke oven emissions. METHODS: Concentrations of CO, SO2, BSM, BTEX (concentrations of benzene, toluene and xylene were determined in this study), PM10, PM2.5, 16 selected PAHs in PM10 and PM2.5 were determined in the work environment of a coke oven plant in Wuhan. The work environment was divided into the adjunct area, the bottom of, the side of and the top of coke oven. RESULTS: The concentrations of CO, SO2, BSM, BETX, PM10, PM2.5, PAHs in PM10 and PM2.5 were significantly related to working environmental categories, respectively, and were increasing as the adjunct area < bottom < side < top (P (trend) < 0.05). PM10 was statistically significantly correlated with CO, SO2, benzene, BTEX and BSM (0.705, 0.823, 0.664, 0.624 and 0.734, respectively). PM2.5 was statistically significantly correlated with CO, SO2, benzene, BTEX and BSM (0.635, 0.916, 0. 680, 0.553 and 0.726, respectively). BSM was statistically significantly correlated with benzene (0.689). The ratios of PM2.5 to PM10 between different work environments were not significantly different in one-way ANOVA (P > 0.05). The distribution of aromatic rings and the concentrations of total benzo[a] pyrene equivalents in PM10 and PM2.5 were not statistically different between work environments. CONCLUSION: The concentrations of particulate matter was related with other contents of coke oven emissions in coke work environment, and the contents and types of PAHs in PM10 and PM2.5 were similar.

[Effects of smoking on the concentrations of urinary 10 metabolites of polycyclic aromatic hydrocarbons in coke oven workers].

OBJECTIVE: To explore the effects of smoking on urinary 10 metabolites of polycyclic aromatic hydrocarbons (PAHs) in the coke oven workers. METHODS: Occupational 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. RESULTS: The 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. CONCLUSION: Urinary 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.