Personal endotoxin exposure in a panel study of school children with asthma

Environmental Health

Research

Ralph J Delfino¹  Thomas Tjoa¹  Norbert Staimer¹ 

[1] Department of Epidemiology, School of Medicine, University of California, Irvine (UCI), University of California, Irvine 100 Theory, Suite 100, 92617-7555, Irvine, CA, USA;

关键词: Elemental Carbon;    Personal Exposure;    Quartz Filter;    Endotoxin Exposure;    Small Positive Correlation;   

DOI  :  10.1186/1476-069X-10-69

 received in 2011-04-27, accepted in 2011-08-02,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundEndotoxin exposure has been associated with asthma exacerbations and increased asthma prevalence. However, there is little data regarding personal exposure to endotoxin in children at risk, or the relation of personal endotoxin exposure to residential or ambient airborne endotoxin. The relation between personal endotoxin and personal air pollution exposures is also unknown.MethodsWe characterized personal endotoxin exposures in 45 school children with asthma ages 9-18 years using 376 repeated measurements from a PM2.5 active personal exposure monitor. We also assayed endotoxin in PM2.5 samples collected from ambient regional sites (N = 97 days) and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively) in Riverside and Whittier, California. Endotoxin was measured using the Limulus Amoebocyte Lysate kinetic chromogenic assay. At the same time, we measured personal, home and ambient exposure to PM2.5 mass, elemental carbon (EC), and organic carbon (OC). To assess exposure relations we used both rank correlations and mixed linear regression models, adjusted for personal temperature and relative humidity.ResultsWe found small positive correlations of personal endotoxin with personal PM2.5 EC and OC, but not personal PM2.5 mass or stationary site air pollutant measurements. Outdoor home, indoor home and ambient endotoxin were moderately to strongly correlated with each other. However, in mixed models, personal endotoxin was not associated with indoor home or outdoor home endotoxin, but was associated with ambient endotoxin. Dog and cat ownership were significantly associated with increased personal but not indoor endotoxin.ConclusionsDaily fixed site measurements of endotoxin in the home environment may not predict daily personal exposure, although a larger sample size may be needed to assess this. This conclusion is relevant to short-term exposures involved in the acute exacerbation of asthma.

【 授权许可】

CC BY   
© Delfino et al; licensee BioMed Central Ltd. 2011