Respiratory function declines in children with asthma associated with chemical species of fine particulate matter (PM2.5) in Nagasaki, Japan

Abstract

Background The differential effects of PM2.5 fractions on children’s lung function remain inconclusive. This study aimed to examine whether lung function in asthmatic children was associated with increased PM2.5 fractions in urban areas in Nagasaki prefecture, Japan, where the air pollution level is relatively low but influenced by transboundary air pollution. Methods We conducted a multiyear panel study of 73 asthmatic children (boys, 60.3%; mean age, 8.2 years) spanning spring 2014–2016 in two cities. We collected self-measured peak expiratory flow (PEF) twice a day and daily time-series data for PM2.5 total mass and its chemical species. We fitted a linear mixed effects model to examine short-term associations between PEF and PM2.5, adjusting for individual and time-varying confounders. A generalized linear mixed effects model was also used to estimate the association for worsening asthma defined by severe PEF decline. Back-trajectory and cluster analyses were used to investigate the long-range transboundary PM2.5 in the study areas. Results We found that morning PEFs were adversely associated with higher levels of sulfate (− 1.61 L/min; 95% CI: − 3.07, − 0.15) in Nagasaki city and organic carbon (OC) (− 1.02 L/min; 95% CI: − 1.94, − 0.09) in Isahaya city, per interquartile range (IQR) increase at lag1. In addition, we observed consistent findings for worsening asthma, with higher odds of severe PEF decline in the morning for sulfate (odds ratio (OR) = 2.31; 95% CI: 1.12, 4.77) and ammonium (OR = 1.73; 95% CI: 1.06, 2.84) in Nagasaki city and OC (OR = 1.51; 95% CI: 1.06, 2.15) in Isahaya city, per IQR increase at lag1. The significant chemical species were higher on days that could be largely attributed to the path of Northeast China origin (for sulfate and ammonium) or both the same path and local sources (for OC) than by other clusters. Conclusions This study provides evidence of the differential effects of PM2.5 fractions on lung function among asthmatic children in urban areas, where the Japanese national standards of air quality have been nearly met. Continuous efforts to promote mitigation actions and public awareness of hazardous transboundary air pollution are needed to protect susceptible children with asthma.

Monitoring ambient air pollution and pulmonary function in asthmatic children by mobile applications in COVID-19 pandemic

“…We found that personal exposure to air pollutants reduced lung function in single- and two-way air pollutant models. The association between air pollutants and respiratory function has been explored by several studies ( Kim et al, 2021a ; Gehring et al, 2020 ). Although previous studies also explored other respiratory function parameters such as FEV 1 and FVC, and we only explored PEF, our results were akin to most previous findings ( Kim et al, 2021a ), ( Gehring et al, 2020 ), ( Ye et al, 2021 ).…”

“…The association between air pollutants and respiratory function has been explored by several studies ( Kim et al, 2021a ; Gehring et al, 2020 ). Although previous studies also explored other respiratory function parameters such as FEV 1 and FVC, and we only explored PEF, our results were akin to most previous findings ( Kim et al, 2021a ), ( Gehring et al, 2020 ), ( Ye et al, 2021 ). Such findings may be explained by the oxidative stress produced after exposure to pollutants, which may lead to airway hyper-reactivity and lung injury ( Ghio et al, 2012 ).…”

“…Previous studies have demonstrated that exposure to hazardous air pollutants may decline pulmonary function ( Altman et al, 2023 ). Various studies have provided evidence that sulfate (SO₄ 2 -), ammonium (NH₄⁺), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), particle matter (PM10 and PM2.5), and ozone (O 3 ) exposure in asthmatic patients were associated with decreased PEF levels, ( Edginton et al, 2021 ; Kim et al, 2021a ; Gehring et al, 2020 ). Additionally, the existing biological hazards in air pollutants such as mites have previously been reported to reduce PEF levels because of their allergy sensitization ( Okasha et al, 2021 ).…”

Spatiotemporal distribution, trend, forecast, and influencing factors of transboundary and local air pollutants in Nagasaki Prefecture, Japan

“…Nagasaki air pollution is relatively low but is influenced by transboundary air pollution from Asia and Eurasia 28 , 33 , 34 . Studies conducted in Nagasaki have demonstrated that air pollution has adverse health effects, especially in children 14 , 16 . Moreover, 8.3 and 29.6% of the population in Nagasaki Prefecture are less than or equal to 10 and more than or equal to 65 years of age, respectively.…”

“…However, rarely studies have combined these to generate a more holistic understanding that can help identify health risk areas, influencing factors, pollution trends, and the efficacy (or lack thereof) of policy interventions 11 . For instance, in Nagasaki Prefecture, most of the studies have only focused on either the health impact caused by air pollutants [14][15][16] , the long-range transport of air pollutants from the Asian continent [17][18][19] , or the effects of climatic variables and the spatial and temporal distribution of PM 2.5 20 . Although these studies provide essential information, a multi-method approach is necessary to understand better the distribution, factors, and current and future trends of PM 2.5 and NO 2 pollution in Nagasaki Prefecture.This study used a multi-method approach to analyze PM 2.5 and NO 2 data in Nagasaki Prefecture from 2013 to 2021.…”