Air pollution, airway inflammation, and lung function in a cohort study of Mexico City schoolchildren.
BACKGROUND
The biological mechanisms involved in inflammatory response to air pollution are not clearly understood.


OBJECTIVE
In this study we assessed the association of short-term air pollutant exposure with inflammatory markers and lung function.


METHODS
We studied a cohort of 158 asthmatic and 50 nonasthmatic school-age children, followed an average of 22 weeks. We conducted spirometric tests, measurements of fractional exhaled nitric oxide (Fe(NO)), interleukin-8 (IL-8) in nasal lavage, and pH of exhaled breath condensate every 15 days during follow-up. Data were analyzed using linear mixed-effects models.


RESULTS
An increase of 17.5 microg/m(3) in the 8-hr moving average of PM(2.5) levels (interquartile range) was associated with a 1.08-ppb increase in Fe(NO) [95% confidence interval (CI), 1.01-1.16] and a 1.07-pg/mL increase in IL-8 (95% CI 0.98-1.19) in asthmatic children and a 1.16 pg/ml increase in IL-8 (95% CI, 1.00-1.36) in nonasthmatic children. The 5-day accumulated average of exposure to particulate matter <2.5 microm in aerodynamic diamter (PM(2.5)) was significantly inversely associated with forced expiratory volume in 1 sec (FEV(1)) (p=0.048) and forced vital capacity (FVC) (p=0.012) in asthmatic children and with FVC (p=0.021) in nonasthmatic children. Fe(NO) and FEV(1) were inversely associated (p=0.005) in asthmatic children.


CONCLUSIONS
Exposure to PM(2.5) resulted in acute airway inflammation and decrease in lung function in both asthmatic and nonasthmatic children.
Barraza-Villarreal
Albino
A
Instituto Nacional de Salud Pública, Cuernavaca, México.
Sunyer
Jordi
J
Hernandez-Cadena
Leticia
L
Escamilla-Nuñez
Maria Consuelo
MC
Sienra-Monge
Juan Jose
JJ
Ramírez-Aguilar
Matiana
M
Cortez-Lugo
Marlene
M
Holguin
Fernando
F
Diaz-Sánchez
David
D
Olin
Anna Carin
AC
Romieu
Isabelle
I
D000397:Air Pollution / Q000009:adverse effects / Q000032:analysis*; D000465:Algorithms; D001249:Asthma / Q000209:etiology / Q000503:physiopathology*; D002648:Child; D002947:Cities; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D005843:Geography; D006801:Humans; D016753:Interleukin-10 / Q000032:analysis; D015850:Interleukin-6 / Q000032:analysis; D008297:Male; D008800:Mexico; D017817:Nasal Lavage Fluid / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis; D012129:Respiratory Function Tests; D012574:Schools
D015850:Interleukin-6; D016753:Interleukin-10; D009569:Nitric Oxide