Cars, Trucks, Buses and Air Pollution

Dirty cars, dirty air

Cars, trucks, and buses powered by fossil fuels are major contributors to air pollution. In fact, transportation emits more than half of nitrogen oxides in our air, and is a major source of heat-trapping emissions in the US. 研究表明，汽车尾气中的污染物对人体几乎每个器官系统都有不利影响. And worse yet, the exposure to pollution is inequitable. The harms fall disproportionately on Latinos, Blacks, and lower-income households.

虽然这种空气污染给人类健康和环境带来了重大风险，但通过 clean vehicle and fuel technologies, we can significantly reduce emissions from our cars and trucks, and help transform transportation.

The ingredients of air pollution

Cars, trucks, and buses produce air pollution throughout their life cycle, including pollution emitted during vehicle operation and fuel production. 额外的排放与燃料的精炼和分配有关，在较小程度上, manufacturing and disposal or recycling of the vehicle.

The following are the major pollutants from motor vehicles:

• Particulate matter (PM). One type of particulate matter is the soot seen in vehicle exhaust. 细小颗粒——直径不到人类头发的十分之一——对人类健康构成严重威胁, as they can penetrate deep into the lungs. PM can be a primary pollutant or a secondary pollutant from hydrocarbons, nitrogen oxides, and sulfur dioxides. Diesel exhaust is a major contributor to PM pollution.
• Volatile Organic Compounds (VOCs). 这些污染物在阳光下与氮氧化物反应，形成地面臭氧, a main ingredient in smog. Though beneficial in the upper atmosphere, at the ground level this gas irritates the respiratory system, causing coughing, choking, and reduced lung capacity. VOCs emitted from cars, trucks and buses — which include the toxic air pollutants benzene, acetaldehyde, and 1,3-butadiene — are linked to different types of cancer.
• Nitrogen oxides (NOx). These pollutants form ground level ozone and particulate matter (secondary). Also harmful as a primary pollutant, 氮氧化物会引起肺部刺激，削弱人体对肺炎和流感等呼吸道感染的防御能力.
• Carbon monoxide (CO). This odorless, colorless, 有毒气体是由汽油等化石燃料燃烧形成的，主要由汽车和卡车排放. When inhaled, CO blocks oxygen from the brain, heart, and other vital organs. 
• Sulfur dioxide (SO2). Power plants and motor vehicles create this pollutant by burning sulfur-containing fuels, especially diesel and coal. Sulfur dioxide can react in the atmosphere to form fine particles and, as other air pollutants, poses the largest health risk to young children and asthmatics.
• Greenhouse gases. Motor vehicles also emit pollutants, predominantly carbon dioxide, that contribute to global climate change. In fact, tailpipe emissions from cars, trucks and buses account for over one-fifth of the United States' total global warming pollution; transportation, which includes airplanes, trains, and ships accounts for around thirty percent of all heat-trapping gas emissions.

The effects of air pollution

Pollutants from vehicle exhaust can affect more than just your lungs. 尾气污染物在生命的每个阶段都对健康构成威胁，甚至可能导致过早死亡. But the impacts of climate change, driven by heat-trapping emissions, also affect people's health and the well-being of entire communities. Climate change is leading to more frequent and intense heat waves—especially risky to children and elderly people—and to sea level rise, flooding, drought, and wildfires that can devastate local communities.

低收入社区和有色人种社区的人们不成比例地暴露在更高水平的空气污染中. Marginalized by urban segregation in US cities, these communities are often located near freight centers and heavily traveled roadways, 并且无法获得适应或远离空气污染和617888九五至尊娱乐相关损害的资源.

Analysis of the emissions from cars, SUVs, trucks, 和公共汽车表明，暴露在有害颗粒物空气污染中是不公平的:亚裔美国人是不公平的, on average, exposed to 34 percent higher PM2.5 concentrations than the average person in the US, and Black people experience concentrations 24 percent higher than average. 拉丁美洲人(定义为西班牙裔或拉丁裔)的暴露率比美国总人口高23%. 白人的平均暴露率比全国平均水平低14%. This means that, on average, Asian American and Black people are exposed to PM2.5 pollution that is 56 and 44 percent higher, respectively, than Whites.

Emissions from heavy-duty vehicles

Trucks and buses play a major role in our lives, hauling goods from manufacturers to stores, picking up our trash, delivering packages, and transporting thousands of people around cities, everyday. But these vehicles also greatly affect public health and global warming

重型车辆只占道路上所有车辆的10%左右，但它们会产生二氧化碳 more than 25 percent 全球变暖排放的45%，氮氧化物排放的45%，以及近60%的直接PM2.5 emissions from on-road vehicles that come from the transportation sector, and significant amounts of air pollution. 港口和州际公路附近的社区——“货运邻近社区”——首当其冲地暴露在这种危险的空气污染中. As the United States moves more and more freight each year, the challenge of reducing emissions from this sector will continue to grow.

解决重型车辆污染问题对于改善全国各地社区的空气质量和减少温室气体排放至关重要. Today, 零排放重型车辆几乎适用于所有应用，而且这些卡车的市场正开始加速发展, but not nearly at the pace needed to adequately affect equitable access to clean air.

Clean air benefits of electric trucks and buses

Just as electric cars are helping to reduce pollution from passenger vehicles, electric trucks and buses could eliminate tailpipe pollution entirely, and increase the development of clean, renewable electricity and hydrogen.

In addition to emitting no harmful tailpipe pollution, 与化石燃料驱动的汽车相比，电动卡车和公共汽车排放的温室气体要少得多. A battery-electric bus on today’s electricity grid is the lowest-carbon option in every part of the country.

Battery- and fuel cell–electric trucks and buses, especially transit buses, are already operating in cities across the United States, and these fleets continue to expand as new models become available. 包括纽约和洛杉矶在内，越来越多的城市承诺在其车队中使用100%零排放的公共汽车, which represent the two largest bus fleets in the country.

Cleaner air is on its way

The right policies and investments from federal, state, 市政府将加快向零排放交通系统的过渡. These include setting targets for electric truck and bus adoption, enacting standards for manufacturers to make more of these types of vehicles, and developing and funding incentive programs to help cities and companies achieve these goals.

这些政策和投资还应确保边缘化社区的工人获得培训和就业机会, 而且，电动汽车的部署优先考虑的是那些已经呼吸着最脏空气的社区.