Association of low dose 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 low dose PPD was rarely mentioned. We recruited 124 workers from a hair dye factory to explore low dose PPD-induced pulmonary dysfunction, pruritus and health-related quality of life (HRQL). The quality of life and subjective pruritus of the workers was assessed by the short form 36 health survey (SF-36) and Visual analogue scale (VAS) of pruritus, respectively. In the high PPD-exposed group, FVC% (percentage of forced vital capacity) was higher, while FEV1/FVC% (ratio percentage of forced expiratory volume) was lower than that in the low PPD-exposed group (P<0.05). In terms of the HRQL, the scores of mental health and vitality in the higher exposure group were the lowest (P<0.05), while the score of VAS was significantly higher than that of other two groups (P<0.001). PPD levels were negatively correlated with vitality and mental health (P<0.01). The structural equation model showed that PPD have positive effects on VAS level (β = 0.213, P <0.001). Then PPD partly lacked total score of SF-36 (β = -0.465, P =0.002). Our results indicate that occupational exposure to low dose PPD might be associated with pulmonary function impairment, poor HRQL, and subjective pruritus of the workers.