背景:许多减少交通排放的气候缓解政策具有与环境空气污染相关的公共卫生益处。然而,很少有健康分析考虑替代政策的公平影响。公平可以以许多不同的方式概念化,这些方式可能与社区相关,决策者,和其他利益相关者。
目标:考虑人口暴露减少和多重公平结构,评估整个美国东北部的替代交通减排方案。
方法:我们开发了四个定量指标,这些指标反映了与利益相关者观点一致的公平结构,包括种族/族裔接触不平等,环境正义社区的利益比例,参与国之间的利益分配,和农村/城市的利益分享。我们分析了覆盖东北12个州和哥伦比亚特区的直接排放的细颗粒物(初级PM2.5)的众多运输减排方案。我们使用社区多尺度空气质量模型和解耦直接方法来估计每种情况下人口加权初级PM2.5暴露的减少以及对公平性的影响。
结果:人口加权初级PM2.5暴露量减少幅度更大的方案通常强调城市地区或拥有大型城市中心的州的减排,不同场景的收益差异超过三倍。较高的暴露收益情景通常也会减少种族/族裔暴露不平等,但导致州与州之间或农村/城市之间的不平等。以轻型或重型卡车的统一减排百分比为目标的方案最好地解决了农村/城市的不平等,但导致种族/族裔不平等的减少最小。
结论:权益结构之间存在内在权衡,将资源集中在各州或城市和农村人口之间分配利益可能会以减少种族/族裔接触不平等或环境正义社区的减少为代价。未来的健康效益分析应纳入多个公平指标,以反映不同的利益相关者观点,并阐明潜在的结构和权衡。
BACKGROUND: Many climate mitigation policies to reduce transportation emissions have public health benefits related to ambient air pollution. However, few health analyses consider the equity implications of alternative policies. Equity can be conceptualized in many different ways that may be relevant to communities, decision-makers, and other stakeholders.
OBJECTIVE: To evaluate alternative transportation emissions reduction scenarios across the northeastern United States considering population exposure reductions and multiple equity constructs.
METHODS: We developed four quantitative indicators reflecting equity constructs that aligned with stakeholder perspectives, including racial/ethnic exposure inequities, proportion of benefits in environmental justice communities, distribution of benefits among participating states, and rural/urban share of benefits. We analyzed numerous transportation emissions reduction scenarios for directly emitted fine particulate matter (primary PM2.5) covering 12 Northeast states and the District of Columbia. We used the Community Multiscale Air Quality model with the decoupled direct method to estimate the reduction in population-weighted primary PM2.5 exposure and the impact on equity for each scenario.
RESULTS: Scenarios that yielded greater reductions in population-weighted primary PM2.5 exposure generally emphasized emissions reductions in urban areas or states with large urban centers, with a more than threefold difference in benefits across scenarios. The higher exposure-benefit scenarios typically also had greater reductions in racial/ethnic exposure inequities but led to higher between-state or rural/urban inequality. Scenarios that targeted uniform percentage emission reductions from light or heavy-duty trucks best addressed rural/urban inequalities but led to the smallest reductions in racial/ethnic inequity.
CONCLUSIONS: There are intrinsic tradeoffs among equity constructs, where focusing resources on distributing benefits across states or between urban and rural populations could come at the expense of less reduction in racial/ethnic exposure inequities or in environmental justice communities. Future health benefits analyses should incorporate multiple equity indicators that reflect different stakeholder perspectives and articulate the underlying constructs and tradeoffs.