| Title: | Elucidating Contributions of Anthropogenic Volatile Organic Compounds and Particulate Matter to Ozone Trends over China |
| Author(s): | Li C; Zhu Q; Jin X; Cohen RC; |
| Address: | "Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States. Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, California 94720, United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "In China, emissions of ozone (O(3))-producing pollutants have been targeted for mitigation to reduce O(3) pollution. However, the observed O(3) decrease is slower than/opposite to expectations affecting the health of millions of people. For a better understanding of this failure and its connection with anthropogenic emissions, we quantify the summer O(3) trends that would have occurred had the weather stayed constant by applying a numerical tool that 'de-weathers' observations across 31 urban regions (123 cities and 392 sites) over 8 years. O(3) trends are significant (p < 0.05) over 234 sites after de-weathering, contrary to the directly observed trends (only 39 significant due to high meteorology-induced variability). The de-weathered data allow categorizing cities in China into four different groups regarding O(3) mitigation, with group 1 exhibiting steady O(3) reductions, while group 4 showing significant (p < 0.05) O(3) increases. Analysis of the relationships between de-weathered odd oxygen and nitrogen oxides illustrates how the changes in NO(x), in anthropogenic volatile organic compounds (VOCs), and reductions in fine particulate matter (PM(2.5)) affect the O(3) trends differently in these groups. While this analysis suggests that VOC reductions are the main driver of O(3) decreases in group 1, groups 3 and 4 are primarily affected by decreasing PM(2.5), which results in enhanced O(3) formation. Our analysis demonstrates both the importance of and possibility for isolating emission-driven changes from climate and weather for interpreting short-term air quality observations" |
| Keywords: | *Air Pollutants/analysis *Air Pollution/analysis China Environmental Monitoring/methods Humans Nitrogen Oxides/analysis *Ozone/analysis Particulate Matter/analysis *Volatile Organic Compounds air quality de-weathering of observations environmental policy; |
| Notes: | "MedlineLi, Chi Zhu, Qindan Jin, Xiaomeng Cohen, Ronald C eng Research Support, Non-U.S. Gov't 2022/09/10 Environ Sci Technol. 2022 Sep 20; 56(18):12906-12916. doi: 10.1021/acs.est.2c03315. Epub 2022 Sep 9" |
