What are the harmful gases emitted by cars?
2 Answers
Automobile exhaust contains carbon monoxide, hydrocarbons, nitrogen oxides (NOx), sulfur dioxide, lead, carbon particles, and other impurity dust, which are extremely harmful to humans and the entire ecological environment. Among them, carbon monoxide, hydrocarbons, and nitrogen oxides are the main harmful emissions. The hazards of automobile exhaust are introduced as follows: 1. The harm of automobile exhaust to human health: While consuming a large amount of resources, the exhaust emitted by cars can severely affect human health. Carbon monoxide in automobile exhaust combines with hemoglobin in the blood 250 times faster than oxygen. Therefore, even the inhalation of trace amounts of carbon monoxide can cause terrible hypoxic damage. Mild cases may experience dizziness and headaches, while severe cases can result in permanent damage to brain cells. Nitrogen oxides and hydroxides can cause irritation reactions in susceptible individuals, leading to eye diseases and laryngitis. The benzopyrene contained in the nitrogen-hydrogen compounds in exhaust is a carcinogen. It is a highly dispersed particle that can remain suspended in the air for several days and nights. Once inhaled by the human body, it cannot be expelled and accumulates to a critical concentration, potentially triggering the formation of malignant tumors. 2. The harm of automobile exhaust to the environment: In addition to being one of the main sources of PM2.5 in large cities, motor vehicle exhaust is also one of the main culprits of air pollution in many cities, with photochemical smog being one of its primary effects. Photochemical smog refers to the formation of secondary pollutants such as ozone, aldehydes, ketones, and PAN from hydrocarbons and nitrogen oxides in the atmosphere under the action of sunlight. Its impact on human health is far greater than that of nitrogen oxides and hydrocarbons.
There are several main types of harmful gases emitted by vehicles. Carbon monoxide (CO) is the most common—it's that colorless, odorless gas from exhaust fumes, extremely dangerous as it can cause oxygen deprivation and poisoning if inhaled in large quantities, leading to fainting or worse, especially when idling for long periods in garages. Nitrogen oxides (NOx), like NO and NO2, are also highly toxic, accounting for half of urban pollution. They make the air pungent, harm lungs and eyes, and increase asthma risks. Hydrocarbons (HC) are unburned gasoline byproducts that contribute to smog and ozone formation, damaging respiratory systems. Particulate matter (PM), especially PM2.5, exits vehicle exhaust and penetrates deep into lungs, with long-term exposure linked to heart disease or lung cancer. I maintain my car regularly—changing oil and air filters to ensure efficient combustion—and adopt smooth driving habits (avoiding hard braking/acceleration) to reduce emissions. Many regions now promote electric vehicles, which eliminate tailpipe pollution and are far healthier. Bottom line: never underestimate these gases—protecting yourself and family is key.
