Which substance is not included in the main pollutants contained in automobile exhaust?
2 Answers
Automobile exhaust does not contain carbon dioxide as one of its main pollutants. The primary pollutants emitted from automobile exhaust are as follows: Carbon Monoxide: Automobile exhaust contains carbon monoxide, nitrogen oxides, and other solid particles that have adverse effects on human health, especially leaded gasoline, which poses greater harm to humans. Excess Oxygen: Lead in the exhaust exists in particle form and disperses with the wind. Gasoline mainly consists of carbon and hydrogen. When gasoline burns normally, it produces carbon dioxide, water vapor, excess oxygen, and other substances. Additive Impurities: However, due to the presence of other impurities and additives in the fuel and the fact that the fuel often does not burn completely, some harmful substances are emitted. Automobile Exhaust Composition: The composition of automobile exhaust is extremely complex, with over 100 components. Its main pollutants include carbon monoxide, hydrocarbons, and nitrogen oxides.
As someone who has worked in auto repair for years, I've witnessed firsthand the pollutants in car exhaust: Carbon monoxide (CO) is the most dangerous—colorless, odorless, but it hinders oxygen transport in blood, and increases when engine efficiency is low; Nitrogen oxides (NOx) irritate the respiratory tract and contribute to acid rain; Hydrocarbons (HC) come from fuel leaks, raising cancer risks; Particulate matter (PM), like the black smoke from diesel vehicles, harms lung health. But none of these include water vapor (H2O)—the white smoke during cold starts is mostly condensed water vapor, harmless and completely natural. To reduce these issues, change oil and air filters regularly, ensure the catalytic converter works properly, and maintain complete engine combustion. This not only saves fuel but also protects the environment—a win-win.
