Fossil fuel percent of [its] weighted emissions in 1998. Combustion of fossil fuels also produces other air pollutants, such as nitrogen oxides, sulfur dioxide, volatile organic compounds and heavy metals. According to Environment Canada: "The electricity sector is unique among industrial sectors in its very large contribution to emissions associated with nearly all air issues. Electricity generation produces a large share of Canadian nitrogen oxides and sulphur dioxide emissions, which contribute to smog and acid rain and the formation of fine particulate matter. It is the largest uncontrolled industrial source of mercury emissions in Canada. Fossil fuel-fired electric power plants also emit
Higher sulfur oxides Higher sulfur oxides Higher sulfur oxides are a group of chemical compounds with the formula SO where x lies between 0 and 1. They contain peroxo (O−O) groups and the oxidation state of sulfur is +6 as in SO. Monomeric SO can be isolated at low temperatures (below 78 K) following the reaction of SO and atomic oxygen or photolysis of SO–ozone mixtures. The favoured structure is: Colourless polymeric condensates are formed in the reaction of gaseous SO or SO with O in a silent electric discharge. The structure of the polymers is based on β-SO (one of the three