Differential health effects of short-term exposure to source-specific particles in London, U.K.
There is ample evidence of adverse associations between short-term exposure to ambient particle mass concentrations and health but little is known about the relative contribution from various sources.



We used air particle composition and number networks in London between 2011 and 2012 to derive six source-related factors for PM10and four factors for size distributions of ultrafine particles (NSD). We assessed the associations of these factors, at pre-specified lags, with daily total, cardiovascular (CVD) and respiratory mortality and hospitalizations using Poisson regression. Relative risks and 95% confidence intervals (CI) were expressed as percentage change per interquartile range increment in source-factor mass or number concentration. We evaluated the sensitivity of associations to adjustment for multiple other factors and by season.



We found no evidence of associations between PM10or NSD source-related factors and daily mortality, as the direction of the estimates were variable with 95% CI spanning 0%. Traffic-related PM10and NSD displayed consistent associations with CVD admissions aged 15-64years (1.01% (95%CI: 0.03%, 2.00%) and 1.04% (95%CI: -0.62%, 2.72%) respectively) as did particles from background urban sources (0.36% for PM10and 0.81% for NSD). Most sources were positively associated with pediatric (0-14years) respiratory hospitalizations, with stronger evidence for fuel oil PM10(3.43%, 95%CI: 1.26%, 5.65%). Our results did not suggest associations with cardiovascular admissions in 65+ or respiratory admissions in 15+ age groups. Effect estimates were generally robust to adjustment for other factors and by season.



Our findings are broadly consistent with the growing evidence of the toxicity of traffic and combustion particles, particularly in relation to respiratory morbidity in children and cardiovascular morbidity in younger adults.
Department of Hygiene, Epidemiology and Medical Statistics, Medical school, National and Kapodistrian University of Athens, 75 Mikras Asias Str, 115 27 Athens, Greece. Electronic address: esamoli@med.uoa.gr.
Evangelia
E
Samoli
Population Health Research Institute and MRC-PHE Centre for Environment and Health, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
Richard W
RW
Atkinson
Department of Hygiene, Epidemiology and Medical Statistics, Medical school, National and Kapodistrian University of Athens, 75 Mikras Asias Str, 115 27 Athens, Greece.
Antonis
A
Analitis
MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, UK.
Gary W
GW
Fuller
School of Geography, Earth & Environmental Sciences, Division of Environmental Health & Risk Management, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
David
D
Beddows
MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, UK.
David C
DC
Green
MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, UK.
Ian S
IS
Mudway
School of Geography, Earth & Environmental Sciences, Division of Environmental Health & Risk Management, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK; Department of Environmental Sciences/Center of Excellence in Environmental Studies, King Abdulaziz University, Abdullah Sulayman St, Jeddah, Saudi Arabia.
Roy M
RM
Harrison
Population Health Research Institute and MRC-PHE Centre for Environment and Health, St George's, University of London, Cranmer Terrace, London SW17 0RE, UK; MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, UK.
H Ross
HR
Anderson
MRC-PHE Centre for Environment and Health, King's College London, 150 Stamford Street, London SE1 9NH, UK.
Frank J
FJ
Kelly
D000293:Adolescent; D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008131:London / Q000453:epidemiology; D008875:Middle Aged; D009026:Mortality; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity*; D012140:Respiratory Tract Diseases / Q000175:diagnosis / Q000453:epidemiology; D012306:Risk; D012621:Seasons; D055815:Young Adult
D000393:Air Pollutants; D052638:Particulate Matter
Hospital admissions; Mortality; Particles; Source apportionment; Time series