Dose–response relationships between polycyclic aromatic hydrocarbon exposure and blood cell counts among coke oven workers: a sex-stratified analysis

OBJECTIVES: To explore sex differences and dose–response relationships between nine urinary polycyclic aromatic hydrocarbon (PAH) metabolites and neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) and complete blood counts among coke oven workers. DESIGN AND SETTING: A cross-sectional study with stratified sex was conducted in Shanxi, China. PARTICIPANTS: A total of 458 male workers and 226 female workers were selected. PRIMARY AND SECONDARY OUTCOME MEASURES: General linear models, p values for trend tests and natural cubic spline models were used to explore the dose–response relationships between nine urinary PAH metabolites and NLR, PLR and complete blood counts. RESULT: Compared with male workers, female workers had lower exposure level of PAH (0.95 ng/mL vs 1.38 ng/mL). Only among female workers did we observe that a 1-unit increase in lg(1-OHPyr) was related to a 0.149 (95% CI: 0.055 to 0.242; p for trend=0.041) and 0.103 (95% CI: 0.025 to 0.181; p for trend=0.007) increase in lg(NLR) and lg(PLR), and a 0.116 (95% CI: −0.179 to –0.054; p for trend=0.007) decrease in lg(lymphocyte counts (LYMs)). A 1-unit increase in lg(2-OHNap) was related to a 0.045 (95% CI: 0.003 to 0.086; p for trend=0.037) increase in lg(PLR) and a 0.029 (95% CI: −0.056 to –0.002; p for trend=0.030) and 0.016 (95% CI: −0.029 to –0.003; p for trend=0.010) decrease in lg(white blood cell counts (WBCs)) and lg(haemoglobin (HGB)). CONCLUSION: Female workers’ NLR, PLR, WBCs, HGB and LYMs may be more susceptible than those of male workers when affected by PAH.