Regional PM2.5 and asthma morbidity in an agricultural community: A panel study

Abstract

Background Elevated pediatric asthma morbidity has been observed in rural US communities, but the role of the ambient environment in exacerbating rural asthma is poorly understood. Objectives To investigate associations between particulate matter less than 2.5 μm in diameter (PM2.5) and pediatric asthma exacerbations in an agricultural community of Washington State. Methods School-aged children with asthma (n=58) were followed for up to 25 months with repeated measures of respiratory health. Asthma symptoms and quick-relief medication use were assessed biweekly through phone administered surveys (n=2023 interviews). In addition, subjects used home peak flow meters on a daily basis to measure forced expiratory volume in one second (FEV1) (n=7830 measurements). Regional PM2.5 was measured at a single air monitor located centrally in the study region. To assess relationships between PM2.5 and these outcomes we used linear regression with generalized estimating equations, adjusting for meteorological and temporal confounders. Effect modification by atopy was explored as well. Results An interquartile increase (IQR) in weekly PM2.5 of 6.7 μg/m3 was associated with an increase in reported asthma symptoms. Specific symptoms including wheezing, limitation of activities, and nighttime waking displayed the strongest associations. FEV1 as a percent of predicted decreased by 0.9% (95%CI: −1.8, 0.0) for an IQR increase in PM2.5 one day prior, and by 1.4% (95%CI: −2.7, −0.2) when restricted to children with atopic asthma. Conclusions This study provides evidence that PM2.5 in an agricultural setting contributes to elevated asthma morbidity. Further work on identifying and mitigating sources of PM2.5 in the area is warranted.

Acute respiratory effects of livestock related air pollution on a panel of COPD patients

“…A study published in 2015 reported similar associations amongst asthmatic school-aged children in rural Washington State. Both increasing asthma morbidity and decrements in FEV 1 were associated with week average PM 2.5 (Loftus et al, 2015a). Later that year in the same area and cohort, an increase in NH 3 concentration was reported to be associated with decrements in FEV 1 (Loftus et al, 2015b).…”

Retrofitting existing buildings to control indoor PM2.5 concentration on smog days: Initial experience of residential buildings in China

“…where V is the building volume, m 3 . C i and C o are indoor and outdoor PM 2.5 concentration, respectively, mg/m 3 .…”

“…Hwang et al 2 conducted a two-year study of 12-year-old Taiwanese children and concluded that longterm exposure to PM 2.5 may have a detrimental effect on the development of lung function in children. Loftus et al 3 provided evidence that PM 2.5 contributes to elevated asthma morbidity in rural US communities. Choo et al 4 showed through statistical analysis that exposures to poor indoor air quality (IAQ) might increase the risk of developing respiratory symptoms among preschoolers in Malaysia.…”

Acute Effects of Air Pollution and Noise from Road Traffic in a Panel of Young Healthy Subjects

“…The acute effects of air pollutants have been demonstrated repeatedly in respiratory [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] and cardiovascular patients [16][17][18][19][20][21]. Such panel studies have been performed in the elderly [22][23][24][25] and in areas with high air pollution [1,14,[26][27][28][29][30], but less so in young and healthy people in settings with moderate to low air pollution levels [31][32][33][34][35][36][37][38][39].…”