Acute respiratory health effects of air pollution on children with asthma in US inner cities.
BACKGROUND
Children with asthma in inner-city communities may be particularly vulnerable to adverse effects of air pollution because of their airways disease and exposure to relatively high levels of motor vehicle emissions.


OBJECTIVE
To investigate the association between fluctuations in outdoor air pollution and asthma morbidity among inner-city children with asthma.


METHODS
We analyzed data from 861 children with persistent asthma in 7 US urban communities who performed 2-week periods of twice-daily pulmonary function testing every 6 months for 2 years. Asthma symptom data were collected every 2 months. Daily pollution measurements were obtained from the Aerometric Information Retrieval System. The relationship of lung function and symptoms to fluctuations in pollutant concentrations was examined by using mixed models.


RESULTS
Almost all pollutant concentrations measured were below the National Ambient Air Quality Standards. In single-pollutant models, higher 5-day average concentrations of NO2, sulfur dioxide, and particles smaller than 2.5 microm were associated with significantly lower pulmonary function. Higher pollutant levels were independently associated with reduced lung function in a 3-pollutant model. Higher concentrations of NO2 and particles smaller than 2.5 microm were associated with asthma-related missed school days, and higher NO2 concentrations were associated with asthma symptoms.


CONCLUSIONS
Among inner-city children with asthma, short-term increases in air pollutant concentrations below the National Ambient Air Quality Standards were associated with adverse respiratory health effects. The associations with NO2 suggest that motor vehicle emissions may be causing excess morbidity in this population.
O'Connor
George T
GT
Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA. goconnor@bu.edu
Neas
Lucas
L
Vaughn
Benjamin
B
Kattan
Meyer
M
Mitchell
Herman
H
Crain
Ellen F
EF
Evans
Richard
R
Gruchalla
Rebecca
R
Morgan
Wayne
W
Stout
James
J
Adams
G Kenneth
GK
Lippmann
Morton
M
D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis*; D000397:Air Pollution / Q000009:adverse effects*; D001249:Asthma / Q000209:etiology / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D012129:Respiratory Function Tests; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis; D014481:United States; D014504:Urban Health / Q000706:statistics & numerical data; D014505:Urban Population / Q000706:statistics & numerical data; D001335:Vehicle Emissions
D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions; D013458:Sulfur Dioxide; D009585:Nitrogen Dioxide