title: [Evaluation of health effect among occupational population exposed to nano-titanium dioxide: a cross-sectional study].
abstract: Objective:To characterize the health effects of nano-titanium dioxide exposure in an occupational cohort.Methods:Eighty-five male employees of a nano-titanium dioxide manufacturing enterprise in Shandong Province were evaluated in September 2014. Forty-four were exposed to nano-titanium dioxide (exposure group), and 41 were not exposed to nano-titanium dioxide (control group). We collected employees' basic information, smoking and drinking history, previous medical history, family history, and occupational history. Differences in blood pressure, hematological parameters, and blood biochemistry between the two groups were analyzed and compared. Multiple linear regression analysis was used to investigate the effect of nano-titanium dioxide exposure on blood pressure, hematological parameters, and blood biochemistry indices after controlling for age, smoking, drinking, and body mass index (BMI). Twenty-five employees from the exposure group and 25 employees from the control group were selected at random for measurement of genetic damage by cytokinesis-block micronucleus assay. Poisson regression analysis was used to investigate the effect of nano-titanium dioxide exposure on micronucleus frequency or micronucleus cell frequency after controlling for age, smoking, drinking, and BMI.Results:The median (P25-P75) surface area concentration of particles deposited in the tracheobronchial region, the surface area concentration of particles deposited in the alveolar region, and particle number concentration in the exposure group were 35.35(24.31-57.42) μ m2/cm3, 173.09(116.27-270.72) μ m2/cm3, and 40 244.00 (17 803.50-78 679.00) /cm3, respectively. These values were significantly higher than those in the control group 33.90 (27.44-43.29) μm2/cm3, 150.50(125.82-192.87)μm2/cm3, and 18 721.00 (12 721.00-51 898.50)/cm3, respectively.Zvalues were 15.47, 15.96, and 14.54, respectively (P<0.001 for all three values). Multiple linear regression analysis showed that exposure to nano-titanium dioxide contributed most to the alteration of mean corpuscular hemoglobin concentration, creatinine, and LDL-C, with standardized regression coefficients of 0.23, -0.51, and 0.30, respectively (P<0.05 for all three values), after adjusting for age, smoking, drinking, and BMI. There were no significant differences in micronucleus frequency and micronucleus cell frequency between the exposure group (3.00‰ (1.50‰-5.00‰) and 3.00‰ (2.00‰-4.00‰), respectively) and control group (2.00‰ (1.00‰-4.50‰) and 2.00‰ (1.00‰-4.00‰), respectively);P>0.05 for all comparisons. Poisson regression analysis showed that after adjusting for age, smoking, drinking, and BMI, there was still no statistically significant correlation between nano-titanium dioxide exposure and micronucleus frequency (OR=1.11, 95%CI:0.81-1.54) or micronucleus cell frequency (OR=1.07, 95%CI:0.75-1.51);P>0.05 for all comparisons.Conclusion:Nano-titanium dioxide particles exerted some health effects on the occupationally-exposed cohort, whose hematological parameters and blood biochemistry were influenced to some degree. However, a potential link between occupational exposure to nano-titanium dioxide and blood pressure or induction of genetic damage or was not found.
authors.affiliation: Department of Occupational and Environmental Health Sciences , School of Public Health, Peking University, Beijing 100191, China.
authors.forename: H D
authors.initials: HD
authors.lastname: Xu
authors.forename: J W
authors.initials: JW
authors.lastname: Zhou
authors.forename: S C
authors.initials: SC
authors.lastname: Tang
authors.forename: F L
authors.initials: FL
authors.lastname: Kong
authors.forename: X W
authors.initials: XW
authors.lastname: Li
authors.forename: Z L
authors.initials: ZL
authors.lastname: Shen
authors.forename: L
authors.initials: L
authors.lastname: Yan
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Chen
authors.forename: L
authors.initials: L
authors.lastname: Zhao
authors.forename: G
authors.initials: G
authors.lastname: Jia
authors.forename: J
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D000428:Alcohol Drinking; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004249:DNA Damage; D006801:Humans; D008297:Male; D015162:Micronucleus Tests; D016273:Occupational Exposure; D012044:Regression Analysis; D012907:Smoking; D014025:Titanium / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood / Q000652:urine
chemical_list: D000395:Air Pollutants, Occupational; C009495:titanium dioxide; D014025:Titanium