Benchmark dose analysis for PAHs hydroxyl metabolites in urine based on mitochondrial damage of peripheral blood leucocytes in coke oven workers in China.

• The mtDNAcn in the PAHs-exposure group was lower than that in the control group. • Dose-response relationship between urinary 1-hydroxypyrene and mtDNA damage. • Dose-response relationship between urinary 3-hydroxyphenanthrene and mtDNA damage. • The biological exposure limit of 1-hydroxypyrene is 0.045 pg/μg creatinine. • The biological exposure limit of 3-hydroxyphenanthrene is 5.142 pg/μg creatinine. The aim was to explore the dose-response relationship between occupational polycyclic aromatic hydrocarbons (PAHs) exposure and mitochondrial damage in coke oven plants workers. 544 workers and 238 healthy people were recruited. The ultra-high performance liquid chromatography was used to determine the level of 1-hydroxypyrene, 1-hydroxynaphthalene, 2-hydroxynaphthalene and 3-hydroxyphenanthrene. The real-time fluorescence quantitative polymerase chain reaction was used to determine the mitochondrial DNA copy number (mtDNAcn). The benchmark dose software was used to analyze the benchmark dose. The mtDNAcn in the exposure group was lower than that in the control group. The concentrations of 1-hydroxypyrene, 1-hydroxynaphthalene, 2-hydroxynaphthalene and 3-hydroxyphenanthrene in the exposure group were higher than those in the control group. There is a dose-response relationship between 1-hydroxypyrene, 3-hydroxyphenanthrene and mitochondrial DNA damage. The benchmark dose lower confidence limit (BMDL) of 1-hydroxypyrene were 0.045, 0.004, and 0.058 pg/μg creatinine in the total, male, and female population, respectively. The BMDL of 3-hydroxyphenanthrene were 5.142, 6.099, and 2.807 pg/μg creatinine in the total, male, and female population, respectively. The BMDL of 1-hydroxypyrene and 3-hydroxyphenanthrene initially explored can provide a reference to establish occupational exposure biological limits. [ABSTRACT FROM AUTHOR]