Pollution Hazards And Human Health

The major pollutants emitted by motor vehicles include CO, NOx, sulphur oxides, (SO), HC, lead (Pb) and suspended particulate matter (SPM). These pollutants have damaging effects on both human health and ecology. The human health effects of air pollution vary in the degree of severity, covering a range of minor effects to serious illness, as well as premature death in certain cases. Most of the conventional air pollutants are believed to directly affect the respiratory and cardio-vascular systems. In particular, high levels of SO2 and SPM are associated with increased mortality, morbidity and impaired pulmonary function, Lead prevents hemoglobin synthesis in red blood cells in bone marrow, impairs liver and kidney function and causes neurological damage.

Pollutants	Effects on Human Health	Effects on the Natural Environment
Carbon monoxide	Can affect the cardio-vascular system, exacer-bating cardiovascular disease symptoms, particularly angina; may also particularly affect foetuses, sickle cell anaemics and young children. Can affect the central nervous system, impairing physical coordination, vision and judgement, creating nausea and headaches, reducing worker productivity and increasing personal discomfort.
Nitrogen oxides (NOX)	Nitrogen dioxide (NO2) can affect the respiratory system. Nitrogen monoxide (NO) and nitrogen dioxide (NO2), where they play a part in photochemical some formation, may contribute indirectly to increased susceptibility to infections, pulmonary disease, impairment of lung function and eye, nose and thread irritations.	NO and NO2 can contribute significantly to acid deposition damaging aquatic eco-systems and other eco-systems such as forests NOx can also have a fertilizing effect on forests.
Sulphur oxides (SO2)	Suphur dioxide (SO2) can affect lung function.	Sulphur oxides can contribute significantly to acid deposition impairing aquatic and forest ecosystems. Sulphates can affect the perception of the environment by reducing visibility even at low concentrations.
Particulate matter (SPM and RPM)	Fine particulate matter may be toxi in itself or may carry toxic (including carcinogenic) trace substance, and can alter the immune system.Fine particulate can penetrate deep into the respiratory system irritating lung tissue and causing long-term disorders.	Fine particulate can significantly reduce visibility. High dust and soot levels are associated with a general perception of dirtiness of the environment.
Lead	Can cause brain damage, encephalopathy in children resulting in lower IQ, death, hyperactivity and reduced ability to concentrate.	Lead