Association of p-phenylenediamine exposure with alterations of pulmonary function, pruritus and health-related quality of life in hair dye factory workers: a cross-sectional study

P-Phenylenediamine (PPD) is a common component of hair dye, which can cause skin contact allergy and asthma with impaired pulmonary function. However, the adverse effects of occupational exposure to different dose PPD was rarely mentioned. We recruited 124 workers from a hair dye factory to explore the association of occupational PPD exposure on pulmonary function, pruritus and health related quality of life (HRQL). We categorized exposure to PPD into 3 levels: lower exposure group (< 0.00001 mg/m(3)); middle exposure group (0.00001–0.00033 mg/m(3)); higher exposure group (0.00033–0.047 mg/m(3)). The HRQL and subjective pruritus of the workers were assessed by the short form 36 health survey (SF-36) and Visual analogue scale (VAS) of pruritus, respectively. In the high PPD-exposed group, the percentage of FEV1 (FEV1%) was lower in higher exposure group compared with lower exposure group. The FEV1/FVC was also lower in comparison to the higher exposure and middle exposure groups (p < 0.05). PPD levels were negatively correlated with vitality and mental health (p < 0.01). The structural equation model showed the positive effects of PPD on VAS level (β = 0.213, p < 0.001), and indicated partly negtive effects of PPD on total score of SF-36 (β = − 0.465, p = 0.002), respectively. Our results indicate that occupational exposure to PPD might be associated with pulmonary function impairment, poor HRQL, and subjective pruritus of the workers.