The Level of Dioxins in Air in Hong Kong
The Level of Dioxins in Air in Hong Kong
The Dioxin Monitoring Results
There are no major dioxin emission sources in Hong Kong. The trace amount of dioxins comes mainly from different types of combustion processes including vehicle engines, incineration facilities, occasional fires and hill fires. Therefore, the level of dioxins in the air has been very low.
The Environmental Protection Department (EPD) has been monitoring the dioxin levels at Central/Western and Tsuen Wan for many years. The monitoring results show that the dioxin levels in Hong Kong are very low and have been decreasing for the past two decades. The annual average in 2024 is 0.015 pg I-TEQ/m3 and is close to the lower detection limit. (See Fig. 1)
Fig. 1 The Annual Trend of Dioxins 1998 - 2024
The 24-hr average levels of dioxins in the past 5 years are much lower than the Japan annual standard (0.6 pg-TEQ/m3) and the Canada 24-hr standard (0.1 pg-TEQ/m3). As the prevailing wind direction differs in winter and summer, the dioxin concentration levels also vary with the seasons. In General, the levels in winter are higher than that in summer.