香港有很多污染但主要都是水源污染......

Pollution is the introduction of substances or energy into the environment, resulting in deleterious effects of such a nature as to endanger human health, harm living resources and ecosystems, and impair or interfere with amenities and other legitimate uses of the environment.[1] The major forms of pollution include:

Air pollution, the release of chemicals and particulates into the atmosphere. Common examples include carbon monoxide, sulfur dioxide, chlorofluorocarbons (CFCs), and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight.
Water pollution via surface runoff and leaching to groundwater.
Soil contamination occurs when chemicals are released by spill or underground storage tank leakage. Among the most significant soil contaminants are hydrocarbons, heavy metals, MTBE[2], herbicides, pesticides and chlorinated hydrocarbons.
Radioactive contamination, added in the wake of 20th-century discoveries in atomic physics. (See alpha emitters and actinides in the environment.)
Noise pollution, which encompasses roadway noise, aircraft noise, industrial noise as well as high-intensity sonar.
Light pollution, includes light trespass, over-illumination and astronomical interference.
Visual pollution, which can refer to the presence of overhead power lines, motorway billboards, scarred landforms (as from strip mining), open storage of trash or municipal solid waste.
Thermal Pollution, is a temperature change in natural water bodies caused by human influence.