Sources include vehicles, factories, electric generating plants, landfills, industrial solvents and many small sources such as gas stations, farm and lawn equipment, etc. Ozone causes significant health and environmental problems at the Earth's surface, where we live. It can irritate the respiratory tract, produce impaired lung function such as inability to take a deep breath, and cause throat irritation, chest pain, cough, lung inflammation and possible susceptibility to lung infection. Smog components may aggravate existing respiratory conditions like asthma. It can also reduce yield of agricultural crops and injure forests and other vegetation.
Ozone is the most injurious pollutant to plant life.
Carbon monoxide Odorless and colorless gas emitted in the exhaust of motor vehicles and other kinds of engines where there is incomplete fossil fuel combustion. Cars, buses, trucks, small engines and some industrial processes. High concentrations can be found in confined spaces like parking garages, poorly ventilated tunnels or along roadsides during heavy traffic. Reduces the ability of blood to deliver oxygen to vital tissues, affecting primarily the cardiovascular and nervous systems. Higher concentrations can cause dizziness, headaches and fatigue.