Silicon carbide production process will produce harmful substances do

Silicon carbide production process will produce harmful substances, harmful substances, but what will it? I have a simple analysis of what, for reference only!
Harmful substances in the production process of silicon carbide are the following categories:
An atmospheric pollutants: dust, smoke, carbon monoxide (small), carbon dioxide (a lot), according to the impurities contained in the abrasive material used may also contain various sulfur dioxide, nitrogen oxides, etc.
2, water pollution: mainly salty higher if near farmland and lakes, while the outside row of the main plant in the form of sewage treatment, the contamination can be imagined.
3, light pollution: the production process requires ignition operations, open burning is the smelting furnace smelting, there is fire, if the neighborhood is a residential area it certainly will affect the residents' daily rest.
But mainly atmospheric pollution, harm far as to see how the wind plant location, this project is now disallowed smelting projects, the State restricted projects.