Chi Li PhD , Prof Randall V Martin PhD , Aaron van Donkelaar PhD , Prof Jose L Jimenez PhD , Prof Qi Zhang PhD , Prof Jay R Turner DSc , Xuan Liu PhD , Mark Rowe MA , Jun Meng PhD , Wuyue Yu PhD , Prof George D Thurston ScD
{"title":"1998-2022年美国亚微米颗粒物(PM1)浓度估算:利用全国PM2·5成分数据测量PM1","authors":"Chi Li PhD , Prof Randall V Martin PhD , Aaron van Donkelaar PhD , Prof Jose L Jimenez PhD , Prof Qi Zhang PhD , Prof Jay R Turner DSc , Xuan Liu PhD , Mark Rowe MA , Jun Meng PhD , Wuyue Yu PhD , Prof George D Thurston ScD","doi":"10.1016/S2542-5196(25)00094-4","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Excess health risk estimates of exposure per unit mass concentration of fine particulate matter (PM<sub>2·5</sub>) still exhibit a wide range, potentially due to variations in aerosol size and composition. Submicron particulate matter (PM<sub>1</sub>) was recently reported to exert stronger health impacts than PM<sub>2·5</sub> from studies in China, but an absence of long-term PM<sub>1</sub> data in the USA has prohibited such investigations despite a wealth of cohorts. This study aims to fill this data gap and estimate PM<sub>1</sub> concentrations over 1998–2022 across the USA.</div></div><div><h3>Methods</h3><div>We estimated biweekly gapless ambient PM<sub>1</sub> concentrations and their uncertainties at 1 km<sup>2</sup> resolution across the contiguous USA over the 25-year period of 1998–2022, from hybrid estimates of PM<sub>2·5</sub> chemical composition that merged information from satellite retrievals, air quality modelling, and ground-based monitoring. The mass fractions of PM<sub>2·5</sub> components with diameters below 1 μm were constrained by observations for four major components and from established scientific understanding for the other components.</div></div><div><h3>Findings</h3><div>PM<sub>1</sub> concentrations exhibited pronounced spatial variation across the contiguous USA with enhancements observed in the east, major urban and industrial areas, and areas affected by wildfires; low concentrations are prevalent over the arid west. The main components of population-weighted mean (PWM) PM<sub>1</sub> in 2022 (6·1 μg/m<sup>3</sup>) were organic matter (47%), sulphate (22%), nitrate (12%), black carbon (8%), and ammonium (7%). The biweekly PM<sub>1</sub> estimates were highly consistent with independent ground-based PM<sub>1</sub> measurements (slope=0·96, <em>R</em><sup>2</sup>=0·78). The estimated 1-σ uncertainties of annual mean PM<sub>1</sub> for the 25 years over more than 8 million land pixels were less than 20% for 98% of data points, while 0·3% of the population of the contiguous USA was associated with uncertainties of more than 30% due to wildfires. The PWM PM<sub>1</sub> decreased significantly (p<em><</em>0·0001) at a rate of –0·23 μg/m<sup>3</sup> per year during 1998–2022, accounting for 86% of the overall reduction of PWM PM<sub>2·5</sub>; the PWM PM<sub>1</sub>/PM<sub>2·5</sub> ratio experienced simultaneous decrease (–0·0013 per year, p<em><</em>0·0001).</div></div><div><h3>Interpretation</h3><div>The dominance of PM<sub>1</sub> in PM<sub>2·5</sub> reduction and the decreasing PM<sub>1</sub>/PM<sub>2·5</sub> ratio reflect the strong association of PM<sub>1</sub> with fossil fuel and other combustion sources and their responses to air quality regulations during the 25-year study period. The gradual coarsening of PM<sub>2·5</sub> calls for increasing urgency to separately assess health impacts of PM<sub>1</sub> versus PM<sub>2·5</sub>, as supported by the quality of the derived PM<sub>1</sub> estimates. Future particulate matter monitoring programmes, health studies, and regulatory deliberations should consider PM<sub>1</sub> in addition to PM<sub>2·5</sub>.</div></div><div><h3>Funding</h3><div>National Institute of Environmental Health Sciences, National Institutes of Health.</div></div>","PeriodicalId":48548,"journal":{"name":"Lancet Planetary Health","volume":"9 6","pages":"Pages e491-e502"},"PeriodicalIF":24.1000,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Estimates of submicron particulate matter (PM1) concentrations for 1998–2022 across the contiguous USA: leveraging measurements of PM1 with nationwide PM2·5 component data\",\"authors\":\"Chi Li PhD , Prof Randall V Martin PhD , Aaron van Donkelaar PhD , Prof Jose L Jimenez PhD , Prof Qi Zhang PhD , Prof Jay R Turner DSc , Xuan Liu PhD , Mark Rowe MA , Jun Meng PhD , Wuyue Yu PhD , Prof George D Thurston ScD\",\"doi\":\"10.1016/S2542-5196(25)00094-4\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Background</h3><div>Excess health risk estimates of exposure per unit mass concentration of fine particulate matter (PM<sub>2·5</sub>) still exhibit a wide range, potentially due to variations in aerosol size and composition. Submicron particulate matter (PM<sub>1</sub>) was recently reported to exert stronger health impacts than PM<sub>2·5</sub> from studies in China, but an absence of long-term PM<sub>1</sub> data in the USA has prohibited such investigations despite a wealth of cohorts. This study aims to fill this data gap and estimate PM<sub>1</sub> concentrations over 1998–2022 across the USA.</div></div><div><h3>Methods</h3><div>We estimated biweekly gapless ambient PM<sub>1</sub> concentrations and their uncertainties at 1 km<sup>2</sup> resolution across the contiguous USA over the 25-year period of 1998–2022, from hybrid estimates of PM<sub>2·5</sub> chemical composition that merged information from satellite retrievals, air quality modelling, and ground-based monitoring. The mass fractions of PM<sub>2·5</sub> components with diameters below 1 μm were constrained by observations for four major components and from established scientific understanding for the other components.</div></div><div><h3>Findings</h3><div>PM<sub>1</sub> concentrations exhibited pronounced spatial variation across the contiguous USA with enhancements observed in the east, major urban and industrial areas, and areas affected by wildfires; low concentrations are prevalent over the arid west. The main components of population-weighted mean (PWM) PM<sub>1</sub> in 2022 (6·1 μg/m<sup>3</sup>) were organic matter (47%), sulphate (22%), nitrate (12%), black carbon (8%), and ammonium (7%). The biweekly PM<sub>1</sub> estimates were highly consistent with independent ground-based PM<sub>1</sub> measurements (slope=0·96, <em>R</em><sup>2</sup>=0·78). The estimated 1-σ uncertainties of annual mean PM<sub>1</sub> for the 25 years over more than 8 million land pixels were less than 20% for 98% of data points, while 0·3% of the population of the contiguous USA was associated with uncertainties of more than 30% due to wildfires. The PWM PM<sub>1</sub> decreased significantly (p<em><</em>0·0001) at a rate of –0·23 μg/m<sup>3</sup> per year during 1998–2022, accounting for 86% of the overall reduction of PWM PM<sub>2·5</sub>; the PWM PM<sub>1</sub>/PM<sub>2·5</sub> ratio experienced simultaneous decrease (–0·0013 per year, p<em><</em>0·0001).</div></div><div><h3>Interpretation</h3><div>The dominance of PM<sub>1</sub> in PM<sub>2·5</sub> reduction and the decreasing PM<sub>1</sub>/PM<sub>2·5</sub> ratio reflect the strong association of PM<sub>1</sub> with fossil fuel and other combustion sources and their responses to air quality regulations during the 25-year study period. The gradual coarsening of PM<sub>2·5</sub> calls for increasing urgency to separately assess health impacts of PM<sub>1</sub> versus PM<sub>2·5</sub>, as supported by the quality of the derived PM<sub>1</sub> estimates. Future particulate matter monitoring programmes, health studies, and regulatory deliberations should consider PM<sub>1</sub> in addition to PM<sub>2·5</sub>.</div></div><div><h3>Funding</h3><div>National Institute of Environmental Health Sciences, National Institutes of Health.</div></div>\",\"PeriodicalId\":48548,\"journal\":{\"name\":\"Lancet Planetary Health\",\"volume\":\"9 6\",\"pages\":\"Pages e491-e502\"},\"PeriodicalIF\":24.1000,\"publicationDate\":\"2025-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Lancet Planetary Health\",\"FirstCategoryId\":\"3\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2542519625000944\",\"RegionNum\":1,\"RegionCategory\":\"医学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Lancet Planetary Health","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2542519625000944","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Estimates of submicron particulate matter (PM1) concentrations for 1998–2022 across the contiguous USA: leveraging measurements of PM1 with nationwide PM2·5 component data
Background
Excess health risk estimates of exposure per unit mass concentration of fine particulate matter (PM2·5) still exhibit a wide range, potentially due to variations in aerosol size and composition. Submicron particulate matter (PM1) was recently reported to exert stronger health impacts than PM2·5 from studies in China, but an absence of long-term PM1 data in the USA has prohibited such investigations despite a wealth of cohorts. This study aims to fill this data gap and estimate PM1 concentrations over 1998–2022 across the USA.
Methods
We estimated biweekly gapless ambient PM1 concentrations and their uncertainties at 1 km2 resolution across the contiguous USA over the 25-year period of 1998–2022, from hybrid estimates of PM2·5 chemical composition that merged information from satellite retrievals, air quality modelling, and ground-based monitoring. The mass fractions of PM2·5 components with diameters below 1 μm were constrained by observations for four major components and from established scientific understanding for the other components.
Findings
PM1 concentrations exhibited pronounced spatial variation across the contiguous USA with enhancements observed in the east, major urban and industrial areas, and areas affected by wildfires; low concentrations are prevalent over the arid west. The main components of population-weighted mean (PWM) PM1 in 2022 (6·1 μg/m3) were organic matter (47%), sulphate (22%), nitrate (12%), black carbon (8%), and ammonium (7%). The biweekly PM1 estimates were highly consistent with independent ground-based PM1 measurements (slope=0·96, R2=0·78). The estimated 1-σ uncertainties of annual mean PM1 for the 25 years over more than 8 million land pixels were less than 20% for 98% of data points, while 0·3% of the population of the contiguous USA was associated with uncertainties of more than 30% due to wildfires. The PWM PM1 decreased significantly (p<0·0001) at a rate of –0·23 μg/m3 per year during 1998–2022, accounting for 86% of the overall reduction of PWM PM2·5; the PWM PM1/PM2·5 ratio experienced simultaneous decrease (–0·0013 per year, p<0·0001).
Interpretation
The dominance of PM1 in PM2·5 reduction and the decreasing PM1/PM2·5 ratio reflect the strong association of PM1 with fossil fuel and other combustion sources and their responses to air quality regulations during the 25-year study period. The gradual coarsening of PM2·5 calls for increasing urgency to separately assess health impacts of PM1 versus PM2·5, as supported by the quality of the derived PM1 estimates. Future particulate matter monitoring programmes, health studies, and regulatory deliberations should consider PM1 in addition to PM2·5.
Funding
National Institute of Environmental Health Sciences, National Institutes of Health.
期刊介绍:
The Lancet Planetary Health is a gold Open Access journal dedicated to investigating and addressing the multifaceted determinants of healthy human civilizations and their impact on natural systems. Positioned as a key player in sustainable development, the journal covers a broad, interdisciplinary scope, encompassing areas such as poverty, nutrition, gender equity, water and sanitation, energy, economic growth, industrialization, inequality, urbanization, human consumption and production, climate change, ocean health, land use, peace, and justice.
With a commitment to publishing high-quality research, comment, and correspondence, it aims to be the leading journal for sustainable development in the face of unprecedented dangers and threats.