The effects of pollutants on health and environment

i) Poisonous nature of CO
ii) NO2 and SO2 in formation of acid rain and its effects on respiration, buildings and plants.
iii) NO2, CH4 and unburned hydrocarbons in formation of photochemical smog.

Carbon monoxide is colorless and odorless, but very toxic. Carbon monoxide poisoning is the most common type of fatal poisoning in many countries.

Exposures can lead to significant damage to the heart and central nervous system. Carbon monoxide can also have severe effects on the fetus of a pregnant woman.

When in gaseous state, NO2 and SO2 dissolve in rain water to form what we call acid rain.
NO2 + H2O -> NO3H2
SO2 + H2O -> SO3H2
This rain, as its name suggests, has acidic properties. Therefore, when acid rain comes in contact with buildings or surfaces, they will react and resulting in the structures either corroding or being weaker.
When inhaled, the gases will dissolve in the moisture found in our throat or windpipe, resulting in acidic solutions. This will create multiple health problems. As for plants, the concept is similar.

A photochemical smog is the chemical reaction of sunlight, nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere, which leaves airborne particles (called particulate matter) and ground-level ozone.

Nitrogen oxides are released by nitrogen and oxygen in the air reacting together under high temperature such as in the exhaust of fossil fuel-burning engines in cars, trucks, coal power plants, and industrial manufacturing factories.

It can inflame breathing passages, decreasing the lungs' working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body's ability to fight infection, increasing susceptibility to illness.