Long-term exposure to diesel engine exhaust induces primary DNA damage: a population-based study.
OBJECTIVE
Diesel engine exhaust (DEE) is a ubiquitous environmental pollutant and is carcinogenic to humans. To seek early and sensitive biomarkers for prediction of adverse health effects, we analysed the components of DEE particles, and examined the genetic and oxidative damages in DEE-exposed workers.


METHODS
101 male diesel engine testing workers who were constantly exposed to DEE and 106 matched controls were enrolled in the present study. The components of DEE were analysed, including fine particulate matter (PM2.5), element carbon (EC), nitrogen dioxide (NO2), sulfur dioxide (SO2) and polycyclic aromatic hydrocarbons (PAHs). Postshift urine samples were collected and analysed for 1-hydroxypyrene (1-OHP), an internal exposure marker for DEE. Levels of DNA strand breaks and oxidised purines, defined as formamidopyrimidine-DNA glycosylase (FPG) sites in leucocytes, were measured by medium throughput Comet assay. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) was also used to determine the level of oxidative stress.


RESULTS
We found higher levels of PM2.5, EC, NO2, SO2 and PAHs in the diesel engine testing workshop and significantly higher urinary 1-OHP concentrations in exposed subjects (p<0.001). Compared with controls, the levels of parameters in normal Comet and FPG-Comet assay were all significantly higher in DEE-exposed workers (p<0.001), and in a dose-dependent and time-dependent manner. There were no significant differences between DEE-exposed workers and controls in regard to leucocyte FPG sensitive sites and urinary 8-OHdG levels.


CONCLUSIONS
These findings suggest that DEE exposure mainly induces DNA damage, which might be used as an early biomarker for risk assessment of DEE exposure.
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Huawei
H
Duan
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Xiaowei
X
Jia
Faculty of Public Health, Weifang Medical University, Weifang, China.
Qingfeng
Q
Zhai
Faculty of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Lu
L
Ma
Faculty of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Shan
S
Wang
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Chuanfeng
C
Huang
Luoyang Center for Disease Control and Prevention, Luoyang, China.
Haisheng
H
Wang
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Yong
Y
Niu
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Xue
X
Li
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Yufei
Y
Dai
Henan Institute of Occupational Medicine, Zhengzhou, Henan, China.
Shanfa
S
Yu
Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, Lubbock, Texas, USA.
Weimin
W
Gao
Faculty of Preventive Medicine, School of Public Health, Sun Yat-sen University, Guangzhou, China.
Wen
W
Chen
Key Laboratory of Chemical Safety and Health, National Institute for Occupational Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing, China.
Yuxin
Y
Zheng
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D015415:Biomarkers / Q000378:metabolism; D002244:Carbon / Q000009:adverse effects / Q000032:analysis; D020552:Comet Assay; D004249:DNA Damage; D043382:DNA-Formamidopyrimidine Glycosylase / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D016273:Occupational Exposure / Q000009:adverse effects*; D018384:Oxidative Stress; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects / Q000032:analysis; D011721:Pyrenes / Q000652:urine*; D012306:Risk; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*; D014937:Work; D055815:Young Adult
D000395:Air Pollutants, Occupational; D015415:Biomarkers; D052638:Particulate Matter; D011084:Polycyclic Aromatic Hydrocarbons; D011721:Pyrenes; D001335:Vehicle Emissions; D013458:Sulfur Dioxide; D002244:Carbon; D000080242:8-Hydroxy-2'-Deoxyguanosine; D043382:DNA-Formamidopyrimidine Glycosylase; D003849:Deoxyguanosine; C033146:1-hydroxypyrene; D009585:Nitrogen Dioxide