Correlation of light transmittance with asthma attack: fine water particles as a possible inducing factor of asthma
- نوع فایل : کتاب
- زبان : انگلیسی
- مؤلف : Kazuo Kanaya Koji Okamoto Shinichiro Shimbo Masayuki Ikeda
- چاپ و سال / کشور: 2010
Description
Background and objectives It has been postulated that air-borne fine water particles (or mist) can induce asthma attacks in asthmatic children. To date, no attempt has been made to quantify the density of air-borne fine water particles with the aim of relating particle density to the etiology of asthma among children. The aim of this study was to investigate the relation of asthma attack frequency and the particle density evaluated in terms of light transmittance. Methods The density of fine water particles was quantified by measuring reductions in light transmittance at 250, 365 and 580 nm at an outdoor location when the surroundings were in darkness. The measurements were made at distances varying from 1 to 3 m from the light sources and performed every morning and evening for 1 year. Each day was separated into two half-day units [i.e., morning (from midnight to noon) and afternoon (from noon to midnight)]. The number of asthma attacks among 121 enrolled asthmatic children was counted for each unit. A possible correlation between the transmittance reduction and frequency of asthma attacks was assessed. Results A significant difference was observed in the extent of reduction in light transmittance at 365 nm between the units with asthma attacks and those without attacks. Furthermore, the reduction in the transmittance was more evident when more asthma attacks were recorded among the patients. No difference was detected in the reduction in light transmittance at 250 or 580 nm. Conclusions These results support the hypothesis that airborne fine water particles are among the etiological factors that induce asthma attacks in asthmatic children
Environ Health Prev Med (2011) 16:44–51 DOI 10.1007/s12199-010-0164-z Received: 19 February 2010 / Accepted: 27 June 2010 / Published online: 15 July 2010
