Air Pollution And Buses: What's The Connection?

Air pollution is a pressing issue, with 80% of urban residents worldwide breathing in air that does not meet health standards. The transportation sector is the largest contributor to carbon dioxide emissions, and within this sector, personal vehicles are the largest source, responsible for 58% of emissions in 2019. However, commercial trucks and buses are not far behind, contributing 25% of emissions in the same year. Buses alone averaged 0.39 pounds of CO2 per passenger-mile in 2019, with transit buses averaging 0.95 pounds per passenger-mile due to operating below capacity. While bus transportation contributes to air pollution, the move towards more sustainable public transportation options, such as compressed natural gas (CNG) buses, is showing positive results in reducing greenhouse gas emissions and improving air quality.

Buses and trucks made up 25% of transport emissions in 2019

The transportation sector is a major source of air pollution and the largest source of heat-trapping emissions in the United States. Cars, trucks, and buses powered by fossil fuels are the primary contributors to this issue. In 2019, motor vehicles, including personal vehicles and commercial trucks and buses, accounted for 83% of emissions in the transportation sector. Buses and trucks alone made up 25% of transport emissions in 2019.

Commercial trucks and buses play a significant role in our daily lives, from transporting goods and people to providing essential services. However, these heavy-duty vehicles comprise only about 10% of all vehicles on the road, yet they generate a disproportionate amount of emissions. They contribute to global warming emissions, NOx emissions, and direct PM2.5 emissions from on-road vehicles.

The burning of fossil fuels, such as gasoline and diesel, by these vehicles has multiple negative consequences. It produces carbon dioxide and other pollutants that degrade air quality and harm human health. Pollutants from vehicle exhaust have been linked to adverse impacts on nearly every organ system in the body. Exposure to this pollution is inequitable, with Latinos, Blacks, and lower-income households bearing a disproportionate burden.

To address these concerns, efforts have been made to improve fuel efficiency and reduce emissions. The use of electric vehicles and tighter standards for fuel economy are projected to moderately reduce emissions over the next decade. Additionally, initiatives like SmartWay by the EPA help improve supply chain efficiency, reduce greenhouse gases, and save fuel costs for companies. Furthermore, the 2007 Energy Independence and Security Act encourages federal agencies to acquire low-greenhouse gas-emitting vehicles.

Buses emit 0.39 pounds of CO2 per passenger-mile

The transportation sector is the largest source of carbon dioxide (CO2) emissions in the United States, constituting two-fifths of domestic emissions from burning fossil fuels. Within the transportation sector, personal vehicles such as cars, light-duty trucks, and motorcycles are the biggest contributors, responsible for 58% of emissions in 2019. Commercial trucks and buses are the second-largest source of emissions, accounting for 25% of the total.

While bus emissions are a concern, they are generally lower than those of personal vehicles, which averaged 0.47 pounds of CO2 per passenger-mile in 2019. The higher emissions per passenger-mile of personal vehicles are due to the high number of single-occupancy trips. Additionally, personal vehicles contribute to air pollution through the use of antifreeze and other fluids, not just from burning gasoline.

Reducing emissions from transportation is challenging due to the inelastic demand for transportation. Unlike other sectors, such as electric power, changes in prices or taxes do not significantly influence demand for transportation. However, policies such as Low Emission Zones (LEZs) can help improve air quality by charging high-polluting vehicles or restricting access to certain types of vehicles.

Overall, while buses contribute to air pollution, they are more efficient and environmentally friendly than personal vehicles, especially when operating at higher capacities. The use of public transportation, including buses, has been shown to reduce congestion and provide significant environmental benefits, such as reducing greenhouse gas emissions and saving fuel.

Low-income communities are disproportionately affected by bus pollution

Air pollution is a pressing issue that affects people worldwide, and it has been linked to various health issues, including respiratory diseases, heart disease, premature death, and adverse birth outcomes. While air pollution impacts everyone, it is crucial to recognize that low-income communities are disproportionately affected by bus pollution and other sources of transportation pollution. This disparity arises due to several interconnected factors.

Firstly, low-income communities often reside closer to major roads, highways, and urban centers, which results in higher exposure to pollutants from transportation sources, including buses. The proximity of their housing to these busy roadways means that even if they own fewer vehicles and drive less, they still experience higher levels of air pollution. This issue is further exacerbated by the historical placement of transportation arteries in areas with low land values, which were often occupied by low-income and minority populations. The presence of these busy roadways can also hinder the improvement of low-income neighborhoods, trapping them in a cycle of pollution exposure.

Secondly, income inequality plays a significant role in the disproportionate impact of bus pollution on low-income communities. Higher-income individuals and communities tend to have higher rates of car ownership and usage, which reduces their exposure to bus-related pollution. In contrast, low-income individuals are more likely to rely on public transportation, including buses, which exposes them to higher levels of pollution while commuting. This disparity in transportation choices contributes to the inequitable burden of bus pollution on low-income communities.

Additionally, the lack of stringent emissions regulations and enforcement in low-income areas further exacerbates the problem. Longstanding violations of air quality standards by large corporations often occur in these communities, subjecting residents to long-term exposure to hazardous pollutants. The combination of inadequate regulations and insufficient enforcement disproportionately affects low-income communities, leading to higher concentrations of pollutants and increased health risks.

The health consequences of bus pollution and air pollution, in general, are more severe for low-income individuals. Studies have shown that low-income communities experience higher rates of respiratory issues, heart disease, and adverse birth outcomes due to air pollution. Moreover, children, pregnant women, and the elderly within these communities are even more vulnerable to the detrimental effects of bus pollution. The cumulative impact of bus pollution on the health and well-being of low-income communities cannot be overstated.

Addressing the disproportionate impact of bus pollution on low-income communities requires a multifaceted approach. It entails stricter enforcement of emissions regulations, the development of cleaner and more efficient public transportation systems, and the implementation of policies that prioritize the relocation of polluting facilities away from low-income neighborhoods. Furthermore, community organizing and political involvement are crucial to ensuring that the voices of low-income communities are heard and that equitable solutions are implemented to mitigate the harmful effects of bus pollution.

Compressed natural gas (CNG) reduces bus emissions

According to the World Health Organization (WHO), 80% of urban residents are breathing air that does not meet health standards, with low- and middle-income countries suffering the highest exposures. Air pollution has been linked to health issues such as heart attacks, premature deaths, delays in early childhood development, asthma, and other serious health issues.

One way to improve air quality is to reduce emissions from buses and other forms of transportation. Compressed natural gas (CNG) buses offer several advantages over traditional diesel or gasoline-powered buses in this regard. Firstly, CNG buses are more environmentally friendly, emitting fewer particles and harmful vapors. The combustion process of natural gas inherently produces lower emissions, including lower levels of nitrous oxide and particulate matter. In fact, CNG buses can achieve a 60% lower NOx emission rate compared to diesel buses, significantly improving air quality, especially in urban areas.

Additionally, CNG buses are more cost-effective than diesel or gasoline alternatives. The price of CNG is lower than diesel, resulting in reduced operational expenses. Furthermore, CNG fuel tanks are stronger and safer, demonstrating better durability in collisions. The use of CNG also eliminates the emission of certain toxins, such as benzene and 1,3-butadiene, commonly associated with diesel engines.

While CNG buses have benefits, there are some challenges to their widespread adoption. The refueling infrastructure for CNG vehicles is not as extensive as that for liquid fuels due to the higher investment costs of building natural gas refueling stations. However, combining CNG refueling stations for city buses with public fueling stations can help increase the efficiency of CNG refueling.

In conclusion, Compressed Natural Gas (CNG) buses offer a more environmentally and economically sustainable option for public transportation. By reducing emissions and providing cost savings, CNG technology plays a crucial role in improving air quality and addressing the health concerns associated with air pollution.

Low Emission Zones (LEZs) reduce bus access in some areas

Low Emission Zones (LEZs) are policies designed to improve air quality by controlling or curbing emission rates from transportation. They work by either charging highly polluting vehicles to enter or by blocking access entirely to certain types of vehicles that do not meet predetermined emissions standards.

LEZs have been implemented in many cities worldwide, including London, Madrid, Barcelona, Amsterdam, The Hague, Oslo, and Hong Kong. These zones aim to reduce emissions from older diesel-engined vehicles, such as lorries, buses, and coaches. For example, the London Low Emission Zone covers almost all of Greater London and targets emissions from diesel-engined buses and coaches, among other vehicles.

The impact of LEZs on bus access varies depending on the specific zone and its regulations. In some cases, buses may be exempt from LEZ restrictions, while in other cases, they may need to meet certain emission standards to enter. For instance, the LEZ in Hong Kong requires franchised bus operators to use buses that meet Euro IV or above emission standards to enter specific zones. Similarly, the London Low Emission Zone has introduced increasingly tougher emissions standards over time, affecting different vehicles, including buses.

While LEZs can reduce bus access in some areas by setting emission standards, they also encourage the adoption of cleaner and more environmentally friendly bus technologies. For example, the PM e-Bus Sewa program aims to introduce 10,000 new electric buses in 169 cities, contributing to the reduction of nitrogen dioxide emissions from road traffic. Additionally, the move from diesel to compressed natural gas (CNG) fuel in buses has resulted in cost savings and environmental benefits, such as reduced greenhouse gas emissions.

Overall, while Low Emission Zones may restrict bus access in certain areas, they play a crucial role in improving air quality, promoting the use of public transportation, and encouraging the adoption of cleaner bus technologies.

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