Effects of Long-Term Exposure to Traffic-Related Air Pollution on Lung Function in Children

Abstract

Lung function in early life has been shown to be an important predictor for peak lung function in adults and later decline. Reduced lung function per se is associated with increased morbidity and mortality. With this review, we aim to summarize the current epidemiological evidence on the effect of traffic-related air pollution on lung function in children and adolescents. We focus in particular on time windows of exposure, small airway involvement, and vulnerable sub-groups in the population. Findings from studies published to date support the notion that exposure over the entire childhood age range seems to be of importance for lung function development. We could not find any conclusive data to support evidence of sup-group effects considering gender, sensitization status, and asthma status, although a possibly stronger effect may be present for children with asthma. The long-term effects into adulthood of exposure to air pollution during childhood remains unknown, but current studies suggest that these deficits may be propagated into later life. In addition, further research on the effect of exposure on small airway function is warranted.

Lung cancer risk by geologic coal deposits: A case–control study of female never‐smokers from Xuanwei and Fuyuan, China

“…Further, the authors found associations between residential traffic exposure at birth and accelerated telomere shortening in the first two decades of life . There have been several longitudinal studies of the influence of traffic‐related air pollution on lung function in early development versus later in life . For example, a study of 2307 children from the Oslo Birth Cohort found that increased early life and lifetime exposure to PM 10 and NO 2 were associated with reduced expiratory flow measurements, with exposure in the first year of life having slightly stronger effects .…”

“…34 There have been several longitudinal studies of the influence of traffic-related air pollution on lung function in early development versus later in life. 35,36 For example, a study of 2307 children from the Oslo Birth Cohort found that increased early life and lifetime exposure to PM 10 and NO 2 were associated with reduced expiratory flow measurements, with exposure in the first year of life having slightly stronger effects. 37 Additionally, there have been efforts to characterize the influence of traffic-related air pollution across the lifecourse on cancer development.…”

Linking COPD epidemiology with pediatric asthma care: Implications for the patient and the physician

“…Traffic‐related pollution at the levels observed in most of Western Europe has yet to be shown to have major deleterious effect on lung function decline in adults . However, its impact on lung growth in children has been reported in numerous studies, which suggest that air pollution has an adverse effect on both FVC and FEV1 …”

Special Considerations in Preschool Age

“…Studies investigating exhaled nitric oxide support that inflammatory processes may partially account for the observed effects of air pollution exposure on childhood wheezing and asthma. Fractional exhaled nitric oxide (FeNO) is an established biomarker of eosinophilic airway inflammation, and several studies show a relation between exposure and increased FeNO levels [67]. Other studies suggest a mixed inflammation response following exposure, including a predominant neutrophil airway inflammation.…”

“…Young children are considered particularly vulnerable since they are more exposed to air pollutants compared to adults relative to their size, due to higher ventilation per minute, and an immature immune system that cannot optimally handle toxic agents. Exposure to traffic-related air pollution has been negatively associated with lung growth and lung function (primarily FEV 1 ) in children in several studies, leading to increased risk of clinically important deficits [67]. In studies from the Swedish BAMSE (Barn/Children Allergy Milieu Stockholm Epidemiology) cohort, conducted in the Stockholm area with air pollution exposure levels well below the current WHO guidelines, exposure during the first year of life seemed to have the largest impact on school age lung function [69].…”