Dataset Information

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children.

ABSTRACT: Increased air pollutant concentrations have been linked to several asthma-related outcomes in children, including respiratory symptoms, medication use, and hospital visits. However, few studies have examined effects of ultrafine particles in a pediatric population. Our primary objective was to examine the effects of ambient concentrations of ultrafine particles on asthma exacerbation among urban children and determine whether consistent treatment with inhaled corticosteroids could attenuate these effects. We also explored the relationship between asthma exacerbation and ambient concentrations of accumulation mode particles, fine particles (?2.5 micrograms [?m]; PM2.5), carbon monoxide, sulfur dioxide, and ozone. We hypothesized that increased 1-7 day concentrations of ultrafine particles and other pollutants would be associated with increases in the relative odds of an asthma exacerbation, but that this increase in risk would be attenuated among children receiving school-based corticosteroid therapy.We conducted a pilot study using data from 3 to 10 year-old children participating in the School-Based Asthma Therapy trial. Using a time-stratified case-crossover design and conditional logistic regression, we estimated the relative odds of a pediatric asthma visit treated with prednisone (n=96 visits among 74 children) associated with increased pollutant concentrations in the previous 7 days. We re-ran these analyses separately for children receiving medications through the school-based intervention and children in a usual care control group.Interquartile range increases in ultrafine particles and carbon monoxide concentrations in the previous 7 days were associated with increases in the relative odds of a pediatric asthma visit, with the largest increases observed for 4-day mean ultrafine particles (interquartile range=2088p/cm(3); OR=1.27; 95% CI=0.90-1.79) and 7-day mean carbon monoxide (interquartile range=0.17ppm; OR=1.63; 95% CI=1.03-2.59). Relative odds estimates were larger among children receiving school-based inhaled corticosteroid treatment. We observed no such associations with accumulation mode particles, black carbon, fine particles (?2.5?m), or sulfur dioxide. Ozone concentrations were inversely associated with the relative odds of a pediatric asthma visit.These findings suggest a response to markers of traffic pollution among urban asthmatic children. Effects were strongest among children receiving preventive medications through school, suggesting that this group of children was particularly sensitive to environmental triggers. Medication adherence alone may be insufficient to protect the most vulnerable from environmental asthma triggers. However, further research is necessary to confirm this finding.

SUBMITTER: Evans KA

PROVIDER: S-EPMC3947881 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children.

Evans Kristin A KA Halterman Jill S JS Hopke Philip K PK Fagnano Maria M Rich David Q DQ

Environmental research 20140111

<h4>Objectives</h4>Increased air pollutant concentrations have been linked to several asthma-related outcomes in children, including respiratory symptoms, medication use, and hospital visits. However, few studies have examined effects of ultrafine particles in a pediatric population. Our primary objective was to examine the effects of ambient concentrations of ultrafine particles on asthma exacerbation among urban children and determine whether consistent treatment with inhaled corticosteroids c ...[more]

PMID: 24528997

Similar Datasets

Project description:Background: Air-pollutants containing toxic particulate matters (PM) deposit in the respiratory tract and increases microbial infections. However, the mechanism underline is not well understood. In this study, we evaluated the effect of urban particles (UP) on S. pneumoniae in-vitro biofilm formation, colonization on Human middle ear epithelium cells (HMEECs) and in mouse nasal cavity and transition to middle ear and lungs. Methods: S. pneumoniae in vitro biofilms and planktonic growth was evaluated in metal ion free medium in presence of UP, and biofilms were quantified by CV-microplate assay, cfu counts and resazurin staining. Biofilm structures were analyzed using scanning electron microscope (SEM) and confocal microscopy (CM). Gene expressions of biofilms were evaluated using real time RT-PCR. Effects of UP exposure on S. pneumoniae colonization to HMEECs was evaluated using fluorescent in-situ hybridization (FISH), cell viability was detected by EZcyto kit, apoptosis in HMEECs were evaluated using Annexin-V/PI based cytometry analysis and reactive oxygen species (ROS) production were evaluated using Oxiselect kit. Alteration of HMEECs gene expressions on UP exposure or pneumococci colonization were evaluated using microarray. In vivo colonization of pneumococci in presence of UP and transition to middle ear and lungs were evaluated using intranasal mice colonization model. Results: UP exposure significantly (*p< 0.05) increased pneumococcal in vitro biofilms and planktonic growth. In presence of UP pneumococci formed organized biofilms with matrix, while in absence of UP bacteria was unable to form biofilms. The luxS, ply, lytA, comA, comB and ciaR genes involved in bacterial pathogenesis, biofilms formation and quorum sensing were up-regulated in pneumococci biofilms grown in presence of UP. The HMEECs viability was significantly (p<0.05) decreased and bacteria colonization was significantly (p<0.05) elevated in co-treatment (UP+S. pneumoniae) in compare to single treatment. Similarly, increased apoptosis and ROS produce were detected in HMEECs treated with UP+ pneumococci. The microarray analysis of HMEECs revealed that the genes involve in apoptosis and cell death, inflammation, immune response were up-regulated in co-treatment, those genes were unchanged or expressed in less fold in single treatments of UP or S. pneumoniae. In vivo study showed increased pneumococcal colonization to nasal cavity in presence of UP and higher transition of bacteria to middle ear and lungs in presence of UP.

Dataset Information

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children.

Publications

Increased ultrafine particles and carbon monoxide concentrations are associated with asthma exacerbation among urban children.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets