Department of Environmental Health Science, Mailman School of Public Health of Columbia University, New York, New York, United States of America.
Lamont-Doherty Columbia Earth Observatory of Columbia University, Palisades, New York, United States of America.
PLoS One. 2018 Jun 28;13(6):e0199783. doi: 10.1371/journal.pone.0199783. eCollection 2018.
New York City has had a long history of implementing local policies to reduce air pollution. Enacted as a part of PlaNYC, the Clean Heat policies aim to lower wintertime ambient air pollution by phasing out dirty No. 6 heating fuel oil and transitioning to comparatively cleaner No. 4, No. 2, or natural gas. This study evaluates the impacts of policies on ambient air pollution and, given that people spend the majority of their time inside, importantly, indoor air pollution. Using a natural experiment, we evaluate the effects of the policies by measuring average two-week levels of indoor and outdoor black carbon (BC) and fine particulate matter (PM2.5) in 48 upper Manhattan apartments in successive winter heating seasons before and after mandated fuel transition. We failed to observe systematic improvements in indoor BC and PM2.5 concentrations in follow-up. However, outdoor levels of PM2.5 did improve, with statistical differences observed among buildings converting to the cleanest fuels. Non-statistical improvements were observed for outdoor BC. However, when accounting for meteorological differences, apartment characteristics, and behavioral patterns that may have influenced air pollution measurements, these differences were not significant. The study results have important policy and equity implications considering the differential improvements in air quality by conversion to No. 4 oil as compared to the cleaner No. 2 oil and natural gas.
纽约市在减少空气污染方面有着悠久的实施地方政策的历史。作为“大苹果计划”的一部分，清洁热力政策旨在通过逐步淘汰污染严重的 6 号燃料油，转而使用相对清洁的 4 号、2 号燃料油或天然气，来降低冬季的环境空气污染。本研究评估了这些政策对环境空气污染的影响，鉴于人们大部分时间都在室内，因此也评估了对室内空气污染的重要影响。我们通过测量 48 间上曼哈顿公寓在规定燃料转换前后连续冬季供暖季节的两周平均室内和室外黑碳 (BC) 和细颗粒物 (PM2.5) 水平，利用自然实验评估了政策的效果。我们未能观察到后续措施中室内 BC 和 PM2.5 浓度的系统改善。然而，室外 PM2.5 水平确实有所改善，在转换为最清洁燃料的建筑物之间观察到了统计学差异。室外 BC 也观察到了非统计学上的改善。然而，当考虑到可能影响空气污染测量的气象差异、公寓特征和行为模式时，这些差异并不显著。考虑到改用 4 号油与改用更清洁的 2 号油和天然气相比空气质量的差异改善，本研究结果对政策和公平性具有重要意义。
