更清洁的汽车，更清洁的空气

This is a condensed, online version of the report. For all figures, references, and the full text, please download the full report PDF.

California has a long history of poor air quality resulting from transportation 污染 on its roads. 早在1966年, 该州的617888九五至尊娱乐, 地理位置, 大量的车辆导致加州启动了减少乘用车和卡车污染的监管行动. As a result of continuing progress on regulations, 目前在售的新乘用车的空气污染物排放量远低于旧车辆.

Gasoline vehicles result in emissions that both directly and indirectly produce fine particulate matter, 定义为空气中小于2的颗粒.直径5微米. 简称PM_2.5, these particles are small enough to penetrate deeply into the lungs; some can even enter the bloodstream. 慢性暴露于PM_2.5 causes increased death rates attributed to cardiovascular diseases, 包括心脏病发作, and it has been linked to lung cancer and other adverse impacts. 妊娠期和儿童期长期接触也与肺功能发育减慢和哮喘的发展有关, 对健康的其他负面影响.

A Fraction of the Vehicles on California Roads, Older Cars and Trucks Pollute More Than Newer Ones

从2004年开始, 加州对乘用车实施了最新的低排放车辆(LEVII)尾气排放标准，要求大幅减少空气污染排放. 旧车辆(2004年以前)占该州乘用车的19%，行驶里程仅占12%, 然而，它们排放的氮氧化物污染物几乎是2004年及以后所有汽车排放总量的三倍. 汽车排放的氮氧化物占乘用车排放总量的73%，活性有机气体占64%(表1)。. These pollutants can react in the atmosphere to form harmful PM_2.5 污染.

Although older vehicles represent fewer than one-fifth of the cars on California roads, they produce more nitrogen oxides and reactive organics gas emissions than all newer vehicles combined.

Exposure to Harmful Air Pollution from Older Vehicles Is Inequitably Distributed

Using the InMAP air-quality model and data from the California Air Resources Board, 忧思617888九五至尊娱乐家联盟(UCS)和Greenlining研究所(Greenlining)估计了PM的形成和运输_2.5 使用旧乘用车(定义为1976年至2003年车型)和新乘用车(2004年至2021年车型)造成的污染.¹ 结合PM_2.5 污染物浓度与美国人口普查数据, we estimated the exposure of Californians to harmful air 污染 from older cars.

我们的分析表明PM_2.5 在加州，使用2004年以前的车辆的风险在种族和人口群体中分布不均. All of the areas with the highest exposure to PM_2.5 from older vehicles are in the southern half of California and mainly in central Los Angeles. The communities with the highest 污染 burden due to PM_2.5 来自老旧车辆的家庭比例是全州平均水平的两倍多，与没有这些车辆造成空气污染的地区相比，低收入和中等收入家庭的比例更高.

In the parts of the state with the highest exposure to PM _2.5 污染 from older vehicles, over half of households have an income of less than $60,000 a year. 在暴露最少的地区, only 35 percent of households have an income of less than $60,000元/年(图1). On average, higher-income households are exposed to lower concentrations of PM_2.5 所有乘用车造成的污染. Higher-income households also experience significantly less exposure to 污染 from older vehicles.

We also found racial and ethnic disparities in the exposure to air 污染 from passenger vehicles. These disparities, too, are greater for 污染 from older vehicles than for the fleet as a whole. For all passenger cars and trucks, White people are exposed to 17 percent lower concentrations of PM_2.5 低于州平均水平, 而拉丁裔加州人的暴露浓度高出13%，黑人加州人的暴露浓度高出11%.²

只看旧车的污染情况, White Californians are on average exposed to 20 percent lower concentrations of PM _2.5 低于州平均水平. 拉丁美洲人 Californians are exposed to 19 percent higher concentrations, and Black Californians are exposed to 12 percent higher concentrations.

接触PM最多的社区_2.5 这是该州平均水平的两倍多，这里的黑人和拉丁裔人口比例远高于整个州. 在这些暴露率最高的地区, 67 percent of residents are 拉丁美洲人 and 8 percent are Black; the state as a whole is 40 percent 拉丁美洲人 and 5 percent Black. 与此形成鲜明对比的是, those same areas of highest exposure are only 13 percent White; the state is 36 percent White (Figure 2).

进一步, 加州人已经面临着来自所有来源的最严重污染，他们还面临着旧车辆排放的首当其冲. 增加接触PM _2.5 污染 from older vehicles correlates with a community's score on CalEnviroScreen 4.0, 一种筛选方法，有助于确定受到多种污染源不成比例负担的社区. 人 in the highest-scoring (most-burdened) census tracts in CalEnviroScreen 4.他们暴露在老旧车辆污染浓度的环境中，是得分最低的人口普查区的两倍.

Estimating Premature Deaths Due to Pollution from Older Vehicles

评估PM对健康的影响_2.5 污染 exposure resulting from older vehicles, we examined two scenarios considering the emissions from engine starts, 蒸发排放, 和驾驶. These scenarios provided a range for the estimated premature deaths in California. One scenario only considered cold-start emissions and assumed those happen where the vehicle is registered. The second scenario assumed that all tailpipe emissions happen where the vehicle is registered. We estimated that older-vehicle emissions led to between 97 and 421 premature deaths per year. The impacts were concentrated in Southern California, especially Los Angeles County.

Rural Areas Have a Higher Proportion Of Older Vehicles

而南加州的城市地区拥有最多的老旧车辆(也暴露在由此产生的污染中), rural areas have higher proportions of older vehicles. 例如, 在摩多克农村, 三一, Sierra县, over 40 percent of vehicles are model year 2003 or older. 与此形成鲜明对比的是, 橙色, 旧金山, 和河滨县, 这些城市都更加城市化, have the lowest percentages of older cars in the state.³

Recommendations: Policies to Reduce Inequitable Exposure to Pollution

Based on the impacts of older cars on local air quality and public health, 因此，加州的相关机构必须优先考虑淘汰和更换老旧车辆. Policymakers should also ensure that programs provide direct, measurable and meaningful benefits to disadvantaged and low-income communities. 此外, 在制定新政策和项目时, California should involve---and in meaningful ways---the communities most impacted by older-vehicle emissions. 这将有助于该州找到减少旧乘用车污染不公平分配的方法.

UCS and Greenlining recommend the following changes in state policies and programs:

• Prioritize incentives 优先考虑拥有旧车的人群. State agencies should integrate programmatic changes to existing incentive programs, such as Clean Cars 4 All and the Clean Vehicle Assistance Program, to prioritize investments in low-income and disadvantaged communities with high concentrations of older cars.

• Engage in intentional, targeted outreach and education to areas with high concentrations of old cars. 州和地方机构应该将有限的推广和教育资金用于旧车密集地区的家庭，而零排放汽车的普及程度却很低.

• Provide transportation solutions that go beyond private passenger vehicles. Even as California attempts to reduce vehicle miles traveled, it continues to invest in vehicle incentive programs that prioritize car ownership. Agencies should consider further funds for programs that promote alternative modes of transportation, 比如公共交通, 走, 汽车共享, 和(e -)骑自行车.

• Evaluate and adjust incentive programs based on changing conditions in the electric vehicle (EV) market. 尽管电动汽车价格不断下降, the pandemic's impact on the supply of EVs has created barriers to the purchase of both new and used EVs. 加州应该继续评估和调整其激励计划，以根据人们的需求最好地帮助他们. While a complete switch to zero-emissions technology will happen in the longer term, the prices and limited supply of electric vehicles can make their purchases more difficult in the near term. 因此, the state should not discourage drivers from switching to other types of cleaner and cheaper-to-fuel vehicles, 即使不是零排放.

结论

A cleaner, safer transportation future for all Californians is possible. To realize it, the state must commit to retiring the dirtiest vehicles on the road. 通过持续投资和有针对性的政策, California can protect its vulnerable communities from harmful air 污染, 节省金钱和生命.

尾注

¹We excluded vehicles older than 1976; our input sources lacked detailed data on vehicles manufactured before 1976. The newest vehicles in the dataset were model year 2021.

² 这份报告使用拉丁裔这个词来描述对美国人口普查问题“这个人是西班牙裔吗?”回答“是”的人, 拉丁美洲人, 或者西班牙血统?" The census collected race data in a separate question. The term White describes persons answering "no" to the Hispanic, 拉丁美洲人, or Spanish ethnicity question and choosing the response "White回答“这个人是什么种族??" The term Black describes persons answering "no" to the Hispanic, 拉丁美洲人, or Spanish question and choosing "Black or African Am.回答“这个人是什么种族??"

³ Maps showing 污染 concentration and vehicle distribution are available online at http://blog.paleorecipescook.com/dave-reichmuth/cleaner-cars-cleaner-air.

This is a condensed, online version of the report. For all figures, references, and the full text, please download the full report PDF.