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Air pollutionChina

An introduction to the traffic rules and road signs of China. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.

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Traffic rules
China

63. Air pollution

Air pollution is the presence of gases, particles or other substances in the air at concentrations that can harm human health, the environment or ecosystems. Road traffic contributes to air pollution through exhaust emissions and through non-exhaust sources such as brake wear, tyre wear and road dust.

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Some pollutants are emitted directly by vehicles, while others can form in the atmosphere through chemical reactions. Vehicle-emission standards, cleaner technologies and traffic-management measures are used to reduce these emissions.

Air pollution
Black smoke emitted from a vehicle exhaust on a road in Kamonyi District. (Rwanda)
Wikimedia.org • Emmanuelkwizera • CC BY-SA
What is air pollution?

Air pollution is the presence of harmful gases, particles or other contaminants in the air. Road transport can contribute through engine emissions, vehicle wear and dust; the sources and pollutants differ by vehicle and conditions.

🔗 epa.gov • US EPA, smog and vehicle emissions

🔗 epa.gov • US EPA, Particulate Matter Basics

🔗 fhwa.dot.gov • US FHWA, particulate matter and road-transport sources

🔗 epa.gov • US EPA, AP-42 section 13.2.1.1, paved-road emissions and dust resuspension

How does road traffic cause air pollution?

Vehicles with combustion engines can emit exhaust pollutants. Road traffic also produces particles through brake, tyre and road-surface wear and can stir up road dust. Vehicles without tailpipe emissions can still contribute to these non-exhaust sources.

🔗 epa.gov • US EPA, smog and vehicle emissions

🔗 epa.gov • US EPA, Particulate Matter Basics

🔗 fhwa.dot.gov • US FHWA, particulate matter and road-transport sources

🔗 epa.gov • US EPA, AP-42 section 13.2.1.1, paved-road emissions and dust resuspension

Which air pollutants are associated with road traffic?

Important traffic-related pollutants include nitrogen oxides, particulate matter, carbon monoxide and volatile organic compounds. Their relative importance depends on the vehicle, fuel and driving conditions.

🔗 epa.gov • US EPA, smog and vehicle emissions

🔗 epa.gov • US EPA, Particulate Matter Basics

🔗 fhwa.dot.gov • US FHWA, particulate matter and road-transport sources

🔗 epa.gov • US EPA, AP-42 section 13.2.1.1, paved-road emissions and dust resuspension

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