How Extensive is Automobile Exhaust Pollution?

[AxelAnn]

Automobile exhaust is mostly concentrated at low levels about one meter above the ground, which is near the human breathing zone, posing significant health hazards. The main pollutants in automobile exhaust are: 1. Carbon Monoxide (CO): In internal combustion engines, CO is a colorless, odorless gas produced during incomplete combustion due to insufficient air or other reasons. Hemoglobin in the lungs binds with CO, leading to oxygen deprivation in the body, causing poisoning symptoms such as headaches, dizziness, vomiting, and in severe cases, death. 2. Hydrocarbons (HC): HC refers to the unburned portion of engine exhaust, including fuel evaporation and leakage from the fuel supply system. HC alone affects human health only when present in relatively high concentrations. 3. Nitrogen Oxides (NOx): NOx is a brown, pungent-smelling exhaust gas produced in large quantities when the engine is under certain loads. When first emitted, the NO present in the gas has relatively low toxicity. 4. Particulate Matter (PM): Particulate matter emitted from the combustion chamber comes from three sources: non-combustible materials, combustible materials that have not undergone combustion, and combustion by-products.