Association of improved air quality with lung development in children.
N Engl J Med
; 372(10): 905-13, 2015 Mar 05.
Article
in En
| MEDLINE
| ID: mdl-25738666
ABSTRACT
BACKGROUND:
Air-pollution levels have been trending downward progressively over the past several decades in southern California, as a result of the implementation of air quality-control policies. We assessed whether long-term reductions in pollution were associated with improvements in respiratory health among children.METHODS:
As part of the Children's Health Study, we measured lung function annually in 2120 children from three separate cohorts corresponding to three separate calendar periods 1994-1998, 1997-2001, and 2007-2011. Mean ages of the children within each cohort were 11 years at the beginning of the period and 15 years at the end. Linear-regression models were used to examine the relationship between declining pollution levels over time and lung-function development from 11 to 15 years of age, measured as the increases in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) during that period (referred to as 4-year growth in FEV1 and FVC).RESULTS:
Over the 13 years spanned by the three cohorts, improvements in 4-year growth of both FEV1 and FVC were associated with declining levels of nitrogen dioxide (P<0.001 for FEV1 and FVC) and of particulate matter with an aerodynamic diameter of less than 2.5 µm (P= 0.008 for FEV1 and P<0.001 for FVC) and less than 10 µm (P<0.001 for FEV1 and FVC). These associations persisted after adjustment for several potential confounders. Significant improvements in lung-function development were observed in both boys and girls and in children with asthma and children without asthma. The proportions of children with clinically low FEV1 (defined as <80% of the predicted value) at 15 years of age declined significantly, from 7.9% to 6.3% to 3.6% across the three periods, as the air quality improved (P = 0.001).CONCLUSIONS:
We found that long-term improvements in air quality were associated with statistically and clinically significant positive effects on lung-function growth in children. (Funded by the Health Effects Institute and others.).
Full text:
1
Database:
MEDLINE
Main subject:
Air Pollutants
/
Air Pollution
/
Lung
Type of study:
Prognostic_studies
/
Risk_factors_studies
Limits:
Adolescent
/
Child
/
Female
/
Humans
/
Male
Country/Region as subject:
America do norte
Language:
En
Journal:
N Engl J Med
Year:
2015
Type:
Article