A preliminary investigation of persistent organic pollutants in ambient air in Hong Kong

Air samples were collected for characterisation of PCDD/Fs and other persistent organic pollutants (POPs) such as aldrin, α-HCH, β-HCH, δ-HCH, γ-HCH, o,p′-DDT, p,p′-DDT, o,p′-DDE, p,p′-DDE, o,p′-DDD, p,p′-DDD, dieldrin, endrin, endosulfan I and II, heptachlor, heptachlor epoxide and hexachlorobenzene during the winter of 2000/2001 at the weather station of the Hong Kong Observatory at Tai Mo Shan (TMS), which is the highest point (not, vert, similar957 m) in Hong Kong, besides the routine monitoring of PCDD/Fs and 200 other toxic air pollutants (TAPs) at two urban TAPs stations at Tsuen Wan and Central & Western. Concentrations of the pollutants detected at TMS station were evaluated and compared to those recorded at the urban stations. Though pesticides including α-HCH, hexachlorobenzene, DDT, DDE, heptachlor, and endosulfan I were detected, these pesticides were found at relatively low concentrations of about 0.02–0.23 ng/m3 and should not have any significant health effects. Concentrations of some of the monitored POPs were found to be higher whilst most of the monitored TAPs were at comparable levels to those measured at the urban stations during the same period.