3.1 Hair arsenic is associated with the intensity of itch in arsenic-exposed participants
In the cross-sectional study in Shimen, 1,097 participants were recruited, 5 missed key information, and 1,092 eligible cases were included. The mean age was 56.6 ± 12.7 years. A total of 390 (36%) participants reported different intensity of itch (NRS>0). Many of them claimed persistent and generalized pruritus during the interview. The demographic, behavioral, clinical characteristics and internal exposure assessment are presented in supplementary Table S1. The hair arsenic was does-dependently associated with the intensity of itch (P trend=0.001).
The associations of hair arsenic with pruritus are shown in Figure 1. Hair arsenic showed positive associations with NRS and the prevalence of moderate and severe itch. Table 1 shows the effect sizes of hair arsenic. Hair arsenic was identified a risk factor for the intensity of itch, and 1 μg/g increment in hair arsenic was associated with 13% and 12% increased risks of moderate and severe itch, respectively, after adjustments.