Wet deposition of PCDD/Fs in Taiwan

In 2017, the seasonal variations in the wet deposition fluxes of total-PCDD/Fs-WHO₂₀₀₅-TEQ in ambient air were evaluated in Taiwan. The results showed the annual wet deposition fluxes of total-PCDD/Fs-WHO₂₀₀₅-TEQ to be 42.5 pg WHO₂₀₀₅-TEQ m^–2 month^–1, and the seasonal distributions were 53.3, 62.9, 26.7 and 27.1 pg WHO₂₀₀₅-TEQ m^–2 month^–1 in spring, summer, autumn and winter, respectively. The average S_tot of total-PCDD/Fs-WHO₂₀₀₅-TEQ was 12300. There were obvious seasonal variations in S_tot, for which the values were 13840, 6540, 8280 and 20540 in spring, summer, autumn, and winter, respectively. The average concentration of total-PCDD/Fs-WHO₂₀₀₅-TEQ in the rain were 0.453, 0.176, 0.218 and 0.649 pg WHO₂₀₀₅-TEQ L^–1 in spring, summer, autumn and winter, respectively. Atmospheric deposition is the major removal pathway for PCDD/Fs. The results of this study provide an evaluation of the adverse effects of PCDD/Fs exposure on human health, and provide a reason for the government to be concerned and to enact better control on air pollution.