Lagged Influence of Fine Particulate Matter and Geographic Disparities on Clinic Visits for Children’s Asthma in Taiwan

Abstract

Recent studies have revealed the influence of fine particulate matter (PM2.5) on increased medication use, hospital admission, and emergency room visits for asthma attack in children, but the lagged influence of PM2.5 on children’s asthma and geographic disparities of children’s asthma have rarely been discussed simultaneously. This study investigated the documented diagnosis of children’s asthma in clinic visits for children aged less than 15 years old that were associated with PM2.5 in two counties located in west-central Taiwan during 2005–2010. The result shows that PM2.5 had a significant lagged effect on children’s asthma for up to 6 days. A significantly higher relative risk for children’s asthma was more likely to happen at 2-day lag compared to the present day when PM2.5 increased from 36.17 μg/m3 to 81.26 μg/m3. Considering all lagged effects, the highest relative risk for children’s asthma was 1.08 (95% CI = 1.05, 1.11) as PM2.5 increased as high as 64.66 μg/m3. In addition, geographic disparities of children’s asthma were significant, and 47.83% of areas were identified to have children vulnerable to asthma. To sum up, our findings can serve as a valuable reference for the implementation of an early warning to governmental agencies about a susceptible population of children.

Spatial Estimation of PM2.5 Exposure and its Association with Asthma Exacerbation: A Prospective Study in Thai Children

“…Furthermore, the average daily PM 2.5 level exposure at lag day 3 was significantly higher in the group of children with asthma exacerbation than those without any exacerbation. These lag effects of PM 2.5 were previously demonstrated, and explained with regard to the process of inflammation and immune response [26,27,28,29,33]. Therefore, the hazard of PM 2.5 in the sensitive patients could last for at least 3 days before an acute exacerbation occurs.…”

“…Several time-series studies have found lagged effects of PM 2.5 on asthma symptoms (Lag days). The delayed symptoms are because PM 2.5 induces free radical producing, imbalanced intracellular calcium homeostasis which activates inflammation in the lung [26]. The results of Lag days differed from 2 to 7 days [26,27,28,29].…”

PM2.5 concentration forecasting using Long Short-Term Memory Neural Network and Multi-Level Additive Model

“…The general form of multi-level AM can be specified as [33]: Y = ∑gX+α [1] Multi-level AM in this study was modified as follows: Y = ∑βX+∑sX+α [2] Here Y refers to dependent variable, X refers to independent variables, g(X) denotes the fitting function, β(X) denotes linear function, s(X) denotes smoothing function, and α is intercept term.…”

“…Fine particulate matter (particulate matter with an aerodynamic diameter less than or equal to 2.5μm, PM 2.5 ) can increase the risk of occurrence and death of multiple respiratory [1,2], circulatory systemic diseases [3,4]and can increase the morbidity and mortality of tumors [5,6]. In addition, heavy metals carried by PM 2.5 can accumulate in human body and cause chronic hazards.…”

Air pollution, respiratory illness and behavioral adaptation: Evidence from South Korea

“…Since the likelihood of respiratory disease was based on doctor’s visits, there can be a delay in time between exposure to air pollution and the actual visit. This temporal misalignment may be due to an individual’s delay in visiting a doctor, or a delay in the development of respiratory illness [36], which is related to different biological reactions to the particles [37]. The delay is different across types of symptoms, and typically lasts at most 6 days [38–41].…”