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Canadian Respiratory Journal
Volume 18, Issue 6, Pages e89-e94
http://dx.doi.org/10.1155/2011/290261
Original Article

The Association between Endotoxin and Lung Function among Children and Adolescents Living in a Rural Area

Joshua A Lawson,1 James A Dosman,1 Donna C Rennie,1 Jeremy Beach,4 Stephen C Newman,5 and Ambikaipakan Senthilselvan6

1Canadian Centre for Health and Safety in Agriculture, Canada
2Department of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
3College of Nursing, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
4Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
5Department of Psychiatry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
6Department of Public Health Sciences, School of Public Health Sciences, University of Alberta, Edmonton, Alberta, Canada

Copyright © 2011 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Increased levels of endotoxin found in rural and agricultural areas are an environmental exposure believed to cause a paradoxical proinflammatory effect on respiratory health that can exacerbate asthma. Previous studies involving adults have demonstrated an association between high endotoxin levels and lower lung function. Apart from occupational settings, however, few studies have investigated the relationship between lung function and endotoxin exposure, such as environmental tobacco smoke, especially in children. This study examined the modifying effects of sex, pre-existing asthma and other environmental exposures, including tobacco smoke, in children living in rural communities in Saskatchewan.

BACKGROUND/OBJECTIVES: Knowledge of the effects of domestic endotoxin on children’s lung function is limited. The association between domestic endotoxin and asthma or wheeze and lung function among school-age children (six to 18 years of age) was examined. The interaction between endotoxin and other personal and environmental characteristics and lung function was also assessed.

METHODS: A case-control study was conducted in and around the rural community of Humboldt, Saskatchewan, between 2005 and 2007. Parents of cases reported either doctor-diagnosed asthma or wheeze in the previous year. Controls were randomly selected from those not reporting these conditions. Data were collected by questionnaire to ascertain symptoms and conditions, while spirometry was used to measure lung function including forced vital capacity and forced expiratory volume in 1 s. Dust collected from the child’s play area floor and the child’s mattress was used to quantify endotoxin, and saliva was collected to quantify cotinine levels and assess tobacco smoke exposure.

RESULTS: There were 102 cases and 207 controls included in the present study. Lower forced expiratory volume in 1 s was associated with higher mattress endotoxin load among female cases (beta=−0.25, SE=0.07 [P<0.01]). There was a trend toward lower forced vital capacity, which was associated with higher play area endotoxin load among cases with high tobacco smoke exposure (beta=−0.17, SE=0.09 [P<0.10]).

CONCLUSIONS: Findings indicated that high endotoxin levels present in common household areas of rural children with asthma or wheeze may also affect their lung function. These associations may be potentiated by tobacco smoke exposure and female sex.