What are the main pollutants emitted by vehicle exhaust?
1 Answers
The main pollutants emitted by vehicle exhaust include carbon monoxide, hydrocarbons, nitrogen oxides, and lead. According to statistics, every thousand vehicles emit approximately 3,000 kg of carbon monoxide, 200-400 kg of hydrocarbons, and 50-150 kg of nitrogen oxides daily. In Los Angeles, USA, mobile pollution sources such as vehicles account for 90% of the total atmospheric pollutants. Vehicle exhaust can be considered the 'main culprit' of air pollution. More details are as follows: 1. Carbon monoxide has an affinity for hemoglobin in human red blood cells that is dozens of times stronger than oxygen. After binding, it forms carboxyhemoglobin, weakening the blood's ability to deliver oxygen to various tissues, leading to functional impairments in sensation, reaction, comprehension, and memory. In severe cases, it can harm the circulatory system and even be life-threatening. 2. When vehicles use leaded gasoline, the exhaust contains residual lead. If unleaded gasoline is used, the exhaust produces carbon oxides and nitrogen oxides, which are harmful to human health. The degree of harm from leaded gasoline vehicle exhaust mainly depends on the composition of the gasoline. In the past, tetraethyl lead was commonly used as an anti-knock agent in gasoline, resulting in what was known as leaded gasoline.
