What Causes White Smoke from Car Exhaust in Winter?

[LaCarlos]

White smoke from car exhaust in winter is caused by water vapor adhering to the inner walls of the muffler in the exhaust pipe. Since the exhaust gas coming out of the pipe is at a high temperature, this high-temperature water vapor rapidly cools when expelled from the exhaust pipe, quickly condensing into visible white smoke or small water droplets. Car exhaust poses significant hazards, with major pollutants including carbon monoxide, nitrogen oxides, hydrocarbons, lead, sulfides, and more. The harmful substances emitted while driving damage both the environment and human health: car exhaust pollution primarily manifests as contributing to the greenhouse effect, depleting the ozone layer, and causing phenomena like acid rain and black rain. The harm to human health mainly includes causing various diseases, severely damaging the respiratory system, and having strong carcinogenic properties.