Objectives: Fine particulate matter (PM 2.5) is the principal air pollutant and poses a serious threat to public health. This study explored the effects of PM 2.5 on the action spectrum of ultraviolet radiation for vitamin D production (UV vitD) received by manikin surfaces. Methods: Multi-inclination angle ultraviolet radiation monitoring was conducted with different concentrations of PM 2.5. Combining monitoring data with the PM 2.5 concentration, solar elevation angle (SEA), and inclination angle, a UV vitD exposure model for human body multi-inclined surfaces was constructed through a multiple linear regression analysis. A 3D manikin model was used to examine the PM 2.5 effects on UV vitD received by the manikin surface. Results: When PM 2.5 concentrations ranged from 35 µg/m 3 to 100 µg/m 3 (average concentration of PM 2.5 in this range: 62 µg/m 3), the UV vitD received by the whole body was reduced by approximately 8.45% to 19.82% compared with the UV vitD received when PM 2.5 concentrations ranged from 6 µg/m 3 to 35 µg/m 3 (average concentration of PM 2.5 in this range: 17 µg/m 3) with SEAs between 30 • and 50 •. Moreover, the UV vitD dose was reduced by 11.82% in the above comparisons. When further comparing PM 2.5 concentrations from 100 µg/m 3 to 161 µg/m 3 (average concentration of PM 2.5 in this range: 132 µg/m 3) with those from 6 µg/m 3 to 35 µg/m 3 (average concentration of PM 2.5 in this range: 17 µg/m 3), the UV vitD received by the whole body was reduced by approximately 21.6% to 50.64% at SEAs between 30 • and 50 •. The UV vitD dose was reduced by 30.2%. Conclusions: The occurrence of PM 2.5 obviously reduced the UV vitD received by the manikin surface. INDEX TERMS PM 2.5 , ultraviolet radiation, manikin model, inclination angle, Vitamin D.
