Understanding Car Air Pollution And Its Impact

Cars, trucks, and buses powered by fossil fuels are major contributors to air pollution. When cars burn gasoline, they emit pollutants such as nitrogen dioxide (NO2), carbon monoxide, and hydrocarbons. These pollutants can cause serious health issues, including respiratory problems, and increase the levels of carbon dioxide and other greenhouse gases in the atmosphere. While it is challenging to determine the exact percentage of air pollution caused by vehicles, the transportation sector is responsible for a significant portion of emissions, particularly in the United States. To address this issue, electric vehicles and clean vehicle technologies are being introduced to reduce emissions and improve air quality.

Electric vehicles reduce air pollution

Cars, trucks, and buses powered by fossil fuels are major contributors to air pollution. Every time a car burns gasoline, it emits pollutants such as nitrogen dioxide (NO2), carbon monoxide, hydrocarbons, and particulate matter. These pollutants have adverse effects on human health, especially for people who live near busy roads. Exposure to these pollutants has been linked to respiratory problems, heart disease, and even cancer.

However, electric vehicles offer a promising solution to reduce air pollution. Electric cars, trucks, and buses are zero-emission vehicles that produce no tailpipe pollution. By switching to electric vehicles, we can eliminate the release of harmful pollutants associated with fossil fuel-powered engines. This includes the reduction of nitrogen oxides, which are formed when nitrogen and oxygen react during the combustion of fossil fuels. Nitrogen dioxide, a component of nitrogen oxides, can irritate the respiratory system and contribute to smog formation when combined with hydrocarbons.

In addition to reducing air pollution, electric vehicles also contribute to the development of clean, renewable electricity. The market for electric trucks and buses is growing, and their widespread adoption has the potential to significantly improve air quality. Electric vehicles are particularly beneficial in urban areas, where motor vehicles are often the largest contributors to ground-level ozone and smog.

To accelerate the transition to electric vehicles, governments and organizations are implementing initiatives and policies. For example, eight states in the US, including New York, have joined an initiative to put 3.3 million zero-emission vehicles on the road by 2025. Additionally, scientific organizations have advocated for the prioritization of electric vehicle deployment in communities that are already breathing the dirtiest air.

By embracing electric vehicles and moving towards a cleaner, more sustainable future, we can effectively reduce air pollution, mitigate health risks, and improve the overall quality of life for people worldwide.

Fossil fuels and vehicle exhausts

Nitrogen dioxide (NO2) is formed when nitrogen and oxygen react during fuel combustion. High concentrations of NO2 in the air can irritate the respiratory system and contribute to smog formation. Vehicles are a significant source of NO2 emissions, along with trucks, buses, power plants, and off-road equipment. The transportation sector is responsible for a significant portion of total NOx emissions.

Vehicle exhausts also release volatile organic compounds (VOCs), which include toxic pollutants such as benzene, acetaldehyde, and 1,3-butadiene. These VOCs react with nitrogen oxides in the presence of sunlight to form ground-level ozone, a key component of smog. Ground-level ozone irritates the respiratory system and is linked to reduced lung capacity.

To address vehicle pollution, the deployment of zero-emission vehicles (ZEVs) is crucial. Electric cars, trucks, and buses can help eliminate tailpipe pollution and promote the development of clean, renewable energy sources. Additionally, technologies like catalytic converters can reduce toxic gases and pollutants in exhaust gases from fossil fuel engines.

It is important to note that air pollution is not solely caused by vehicle exhausts. Other human activities, such as electricity production and heating buildings, also contribute significantly to air pollution. However, transportation, particularly fossil fuel-powered vehicles, remains a major source of air pollution and heat-trapping emissions.

Vehicle emission control programs

Regulatory Framework:

In the United States, the Environmental Protection Agency (EPA) plays a pivotal role in regulating vehicle emissions. The Clean Air Act, first enacted in 1963 and amended multiple times, forms the backbone of vehicle emission regulations. The Act sets stringent standards for acceptable vehicle emissions, including limits on specific pollutants such as hydrocarbons, volatile organic compounds (VOCs), carbon monoxide, nitrogen oxides (NOx), particulate matter (PM), and sulfur oxides (SOx). The EPA's regulations apply to all engines entering the vehicle market, ensuring that manufacturers design vehicles with efficient emission control systems.

Evolution of Emission Standards:

Over the years, emission standards have become increasingly stringent. For example, amendments to the Clean Air Act in 1990 further restricted sulfur content in diesel fuel and mandated procedural changes in gasoline formulation to reduce emissions of hydrocarbons, carbon monoxide, nitrogen oxides, and other harmful substances. Regulatory agencies continue to push for even stricter standards, such as the super-ultralow-emission vehicle (SULEV) and Tier 3 standards, to address future emissions challenges.

Emission Control Technologies:

To comply with emission regulations, automotive manufacturers have adopted various emission control technologies. One example is the positive crankcase ventilation (PCV) system, which became standard equipment on vehicles worldwide. The PCV system draws crankcase fumes containing unburned hydrocarbons and burns them in the engine, preventing their release into the atmosphere. Other technologies include catalytic converters, particulate filters, and advanced combustion strategies. The Vehicle Technologies Office (VTO) plays a crucial role in researching and developing these aftertreatment technologies, striving for efficient and cost-effective solutions.

Alternative Propulsion and Zero-Emission Vehicles:

The promotion of alternative propulsion systems, such as hybrid and electric vehicles, is a key component of emission control programs. Electric vehicles, including cars, buses, and trucks, produce zero tailpipe emissions, helping to reduce pollution significantly. As of December 2020, China led the world in the adoption of electric passenger cars, holding 42% of the global stock. However, the transition to zero-emission heavy-duty vehicles needs to accelerate to ensure equitable access to clean air for all communities.

Air pollution from car interiors

Cars are a major contributor to air pollution and the health consequences it causes worldwide. Every time you go for a drive, pollution is emitted directly into the air, which can cause significant risks to your health, especially if you live near busy roads. The air circulating inside your car's cabin may include pollutants from three different types of sources: outdoor air, the vehicle itself, and the occupants.

Outdoor Air

Much of the air pollution in your car enters from outside as you travel, through open windows and air vents. Gasoline and diesel exhaust fumes contain a number of dangerous pollutants, including particulate matter, volatile organic compounds (VOCs), nitrogen oxides, and carbon monoxide. Exposure to traffic emissions on busy roadways with heavy truck traffic is a known health hazard, especially for people with respiratory problems and heart disease.

The Vehicle

Motor vehicles emit several different pollutants, including particulate matter and volatile organic compounds. Particulate matter is a combination of organic material and inorganic substances, including dust, soil, acids, metals, and organic chemicals. Most of this matter is extremely small, and the smaller the particle, the more damaging; particles less than 10 micrometers in diameter are capable of entering the lungs. Nitrogen dioxide (NO2) is produced when fuel burns at high temperatures, and in high concentrations, it can damage your lungs and cause chest pains.

The Occupants

We don't often think of ourselves as a source of indoor air pollution, but many things we bring into a vehicle, our behaviours, and even our breath can result in a pollution problem in a closed environment like a car cabin. Household products frequently contain chemicals that become even more dangerous in enclosed environments. Scented air fresheners and personal care products such as cosmetics and deodorants release VOCs. Food waste, papers, and other clutter can gather dust and may harbour mould, bacteria, and pests. In-cabin smoking, including second-hand smoke from cigarettes and e-cigarettes, contains hundreds of toxic or carcinogenic chemicals, including formaldehyde, benzene, vinyl chloride, arsenic ammonia, and hydrogen cyanide.

How catalytic converters work

Cars, trucks, and buses powered by fossil fuels are major contributors to air pollution. Transportation emits more than half of nitrogen oxides in our air, and is a major source of heat-trapping emissions in the US. When hydrocarbons and nitrogen oxides combine in sunlight, they produce ground-level ozone, a common component of smog.

To reduce air pollution, vehicles are equipped with catalytic converters, which are a part of the car's emissions control system. Catalytic converters treat the exhaust before it leaves the car and removes a lot of the pollution. They do this by reducing toxic gases and pollutants in the exhaust gas from motor vehicle engines into less-toxic pollutants by catalyzing a redox reaction (an oxidation and a reduction reaction).

Catalytic converters are used with gasoline and diesel-powered engines. They can be made more efficient by preheating them, or by injecting a urea solution into the exhaust pipe.

In addition to catalytic converters, electric vehicles are also helping to reduce pollution from passenger vehicles. Electric buses, trucks, and other heavy-duty vehicles could eliminate tailpipe pollution entirely, and increase the development of clean, renewable electricity and hydrogen.

Frequently asked questions