PDF(Pubmed)
Abstract：
Decades of air quality improvements have substantially reduced the motor vehicle emissions of volatile organic compounds (VOCs). Today, volatile chemical products (VCPs) are responsible for half of the petrochemical VOCs emitted in major urban areas. We show that VCP emissions are ubiquitous in US and European cities and scale with population density. We report significant VCP emissions for New York City (NYC), including a monoterpene flux of 14.7 to 24.4 kg ⋅ d-1 ⋅ km-2 from fragranced VCPs and other anthropogenic sources, which is comparable to that of a summertime forest. Photochemical modeling of an extreme heat event, with ozone well in excess of US standards, illustrates the significant impact of VCPs on air quality. In the most populated regions of NYC, ozone was sensitive to anthropogenic VOCs (AVOCs), even in the presence of biogenic sources. Within this VOC-sensitive regime, AVOCs contributed upwards of ∼20 ppb to maximum 8-h average ozone. VCPs accounted for more than 50% of this total AVOC contribution. Emissions from fragranced VCPs, including personal care and cleaning products, account for at least 50% of the ozone attributed to VCPs. We show that model simulations of ozone depend foremost on the magnitude of VCP emissions and that the addition of oxygenated VCP chemistry impacts simulations of key atmospheric oxidation products. NYC is a case study for developed megacities, and the impacts of VCPs on local ozone are likely similar for other major urban regions across North America or Europe.
摘要：
数十年的空气质量改善已大大减少了机动车对挥发性有机化合物（VOC）的排放。今天,挥发性化学产品（VCP）是主要城市地区排放的石化VOCs的一半。我们表明，VCP排放在美国和欧洲城市中无处不在，并随人口密度而变化。我们报告了纽约市(NYC)的大量VCP排放，包括来自芳香VCP和其他人为来源的14.7至24.4kg·d-1·km-2的单萜通量，相当于夏季森林。极端高温事件的光化学模型，臭氧远远超过美国标准，说明了VCP对空气质量的显著影响。在纽约市人口最多的地区，臭氧对人为挥发性有机化合物(AVOCs)敏感，即使存在生物来源。在这种对VOC敏感的制度下，AVOCs对最大8小时平均臭氧的贡献高达20ppb。VCP占AVOC总贡献的50%以上。香味VCP的排放，包括个人护理和清洁产品，至少占归因于VCP的臭氧的50％。我们表明，臭氧的模型模拟主要取决于VCP排放量的大小，并且添加含氧的VCP化学物质会影响关键大气氧化产物的模拟。纽约市是发达特大城市的案例研究，VCP对当地臭氧的影响可能与北美或欧洲其他主要城市地区相似。
