English: Large amount of construction dust emitted and rising up from a building under rehabilitation on a Saturday afternoon, Treasure Garden, Tai Po, Hong Kong. The scheme is subsidised by the government^[1][2][3] and contract like this can worth up to hundred millions.^[4] People are living inside the building during the whole renovation period, which usually lasts for over a year, and it can be foretold that the residents' exposure to construction dust is more serious than the occupational exposure of the workers. The possible presence of asbestos is also worth worrying. This type of rehabilitation works are very common in districts with older buildings like Kowloon City, Mong Kok, Sham Shui Po, Yao Ma Tei and Tai Po. With such a large amount of dust emitted, it was obvious that neither water was being sprayed nor dust extraction device was in use, which was a violation of the local law^[5]