Gases (Sulphuric dioxide, Nitrates and Carbon dioxide) are emitted by the combustion of fossil fuels - coal and oil-fired power stations and transport.
Gases are released into the atmosphere
They dissolve into water in cloud forming acids (Sulphuric acid, Nitric acid and Carbonic acid (H2CO3)
Acids fall to the ground in precipitation
This can fall as wet deposition - snow sleet and mist OR as dry deposition - gases, dusts and smog
Dry deposition affects the environment directly and can produce smog and damage buildings by eroding
away limestone and marble. Deposition on farmland and forestry affects plant growth and reduces crop
yields. it can also cause breathing problems in humans and has been linked to asthma
Wet deposition shares the direct effects of dry deposition and has a acidifying effect on lakes, rivers and streams.
This is particularly dangerous as most aquatic life cannot survive in pH of less than 4.5. It also leaches toxic
materials (Cd and Al) which has a direct effect on the respiratory systems of fish, causing their gills to clog up.
The prescence of toxic metals in water supplies presents a health problem to all animal life including humans.
They can enter waterways and kill fish and plants
Acids kill/damage crops, forests and erode buildings
Solutions
Desulphurisation plants are fitted to power stations, which reduce the amount of SO2 in escaping smoke.
Catalytic converters in cars help to remove both NOX and SO2 from car exhaust fumes.