Project Abstract

Abstract
Childhood asthma is a common chronic disease that affects millions of children worldwide. There is increasing evidence to suggest that early life exposure to air pollution may play a significant role in the development of childhood asthma. This review aims to summarize the current research on the effects of early life exposure to air pollution on the development of childhood asthma. Multiple studies have demonstrated a clear association between exposure to air pollutants such as particulate matter (PM), nitrogen dioxide (NO2), sulfur dioxide (SO2), and ozone (O3) in early life and an increased risk of developing asthma in childhood. These pollutants are known to induce airway inflammation and oxidative stress, which can lead to respiratory symptoms and exacerbate existing asthma in children. Furthermore, several studies have identified vulnerable populations such as infants, young children, and individuals living in urban areas or near industrial sites, who are at a higher risk of developing asthma due to early life exposure to air pollution. Genetic factors may also interact with environmental exposures to further increase the risk of childhood asthma. It is important to note that the mechanisms underlying the association between early life exposure to air pollution and childhood asthma are complex and multifactorial. Factors such as the timing, duration, and intensity of exposure, as well as individual susceptibility, may influence the development of asthma in children exposed to air pollution early in life. Preventive strategies to reduce childhood asthma related to air pollution exposure include public health interventions aimed at reducing emissions from industrial sources, promoting clean energy technologies, and implementing policies to improve air quality in urban areas. Additionally, early identification of children at risk for asthma through screening programs and targeted interventions may help mitigate the impact of air pollution on childhood asthma development. In conclusion, early life exposure to air pollution is a significant risk factor for the development of childhood asthma. Continued research efforts are needed to further understand the mechanisms underlying this association and to develop effective strategies to prevent and manage asthma in children exposed to air pollution. Addressing air pollution as a modifiable risk factor for childhood asthma is crucial for improving the respiratory health and well-being of children worldwide.

Project Overview

There is increasing recognition of the importance of early environmental exposures in the development of childhood asthma. Outdoor air pollution is a recognized asthma trigger, but it is unclear whether exposure influences incident disease. We investigated the effect of exposure to ambient air pollution in utero and during the first year of life on risk of subsequent asthma diagnosis in a population-based nested case-control study.

METHODS:

We assessed all children born in southwestern British Columbia in 1999 and 2000 (n = 37,401) for incidence of asthma diagnosis up to 34 years of age using outpatient and hospitalization records. Asthma cases were age- and sex-matched to five randomly chosen controls from the eligible cohort. We estimated each individual’s exposure to ambient air pollution for the gestational period and first year of life using high-resolution pollution surfaces derived from regulatory monitoring data as well as land use regression models adjusted for temporal variation. We used logistic regression analyses to estimate effects of carbon monoxide, nitric oxide, nitrogen dioxide, particulate matter RESULTS:

A total of 3,482 children (9%) were classified as asthma cases. We observed a statistically significantly increased risk of asthma diagnosis with increased early life exposure to CO, NO, NO2, PM10, SO2, and black carbon and proximity to point sources. Traffic-related pollutants were associated with the highest risks: adjusted odds ratio = 1.08 (95% confidence interval, 1.041.12) for a 10-microg/m3 increase of NO, 1.12 (1.071.17) for a 10-microg/m3 increase in NO2, and 1.10 (1.061.13) for a 100-microg/m3 increase in CO. These data support the hypothesis that early childhood exposure to air pollutants plays a role in development of asthma.