Indoor- and outdoor-generated particles and children with Asthma.In their article "Pulmonary Effects of Indoor- and Outdoor-Generated Particles in Children with Asthma," Koenig et al. (2005) made use of their really interesting model that enables them to discern dis·cern v. dis·cerned, dis·cern·ing, dis·cerns v.tr. 1. To perceive with the eyes or intellect; detect. 2. To recognize or comprehend mentally. 3. exposure from indoor- and outdoor-generated particles. They concluded that The ambient-generated component of P[M.sub.2.5] [particulate matter [less than or equal to] 2.5 [micro]m in aerodynamic diameter] exposure is consistently associated with increases in eNO [exhaled nitric oxide] and the indoor-generated component is less strongly associated with eNO. This finding should not lead to the assumption that particles generated indoors are in general not able to induce endogenous endogenous /en·dog·e·nous/ (en-doj´e-nus) produced within or caused by factors within the organism. en·dog·e·nous adj. 1. Originating or produced within an organism, tissue, or cell. NO production. The authors themselves pointed out one limitation of their study: Children in the Seattle panel study spent an average of 66% of their time indoors at home and 21% indoors away from home (primarily at school) ... (Koenig et al. 2005) However, contribution of indoor sources to PM exposure was only estimated on the basis of measurement data from the subjects' residences. This could have led to uncertainties in the exposure assessment, biasing the effect estimates toward null A character that is all 0 bits. Also written as "NUL," it is the first character in the ASCII and EBCDIC data codes. In hex, it displays and prints as 00; in decimal, it may appear as a single zero in a chart of codes, but displays and prints as a blank space. . I also want to mention the great variability in possible indoor sources of PM. In their article, Koenig et al. (2005) provided no information on the smoking status of household members. If the 19 children under study lived in nonsmoking non·smok·ing adj. 1. Not engaging in the smoking of tobacco: nonsmoking passengers. 2. Designated or reserved for nonsmokers: the nonsmoking section of a restaurant. households, the results might be true for this setting but not for others. Finally, I suggest that time of measurement and exposure should be considered. If the children attend school in the morning, they might go home (maybe in high traffic) at noon or early afternoon for lunch. [NO] samples were collected in the afternoon or early evening at the child's residence. Children were asked to forgo food intake for 1 hr before collection of exhaled breath. If NO production peaks several hours after exposure, it could be possible that the children's exposure on their way home from school was the most influential one (not because of the origin of the particles but because of the study's lag structure). It would be interesting and rather rewarding to study the short-term lag structure between PM exposure and both exhaled NO and lung function [for which Koenig et al. (2005) found an association with exposure due to sources in the residents' homes]. I would expect an increase of exhaled NO to be a rather late reaction to inflammatory stimuli. For example Rolla et al. (2004) reported that after aspirin aspirin, acetyl derivative of salicylic acid (see salicylate) that is used to lower fever, relieve pain, reduce inflammation, and thin the blood. Common conditions treated with aspirin include headache, muscle and joint pain, and the inflammation caused by rheumatic inhalation inhalation /in·ha·la·tion/ (in?hah-la´shun) 1. the drawing of air or other substances into the lungs.inhala´tional 2. the drawing of an aerosolized drug into the lungs with the breath. 3. by subjects with aspirin-inducible asthma, NO increased significantly reaching the peak value 4 hr after bronchoconstriction. The author declares he has no competing financial interests. REFERENCES Koenig JQ, Mar TF, Allen RW, Jansen K, Lumley T, Sullivan JH, et al. 2005. Pulmonary effects of indoor- and outdoor-generated particles in children with asthma. Environ en·vi·ron tr.v. en·vi·roned, en·vi·ron·ing, en·vi·rons To encircle; surround. See Synonyms at surround. [Middle English envirounen, from Old French environner Health Perspect 113:499-503. Rolla G, Di Emanuele A, Dutto L, Marsico P, Nebiolo F, Corradi F, et al. 2004. Effect of inhalation aspirin challenge on exhaled nitric oxide nitric oxide or nitrogen monoxide, a colorless gas formed by the combustion of nitrogen and oxygen as given by the reaction: energy + N2 + O2 → 2NO; m.p. −163.6°C;; b.p. −151.8°C;. in patients with aspirin-inducible asthma. Allergy allergy, hypersensitive reaction of the body tissues of certain individuals to certain substances that, in similar amounts and circumstances, are innocuous to other persons. Allergens, or allergy-causing substances, can be airborne substances (e.g. 59:827-832. Hanns Moshammer Institute of Environmental Health Medical University of Vienna The Medical University of Vienna; Comitted to thriving social development – focused on the challenges of a humane society: The primary mission of the Medical University of Vienna -autonomous since 1 January 2004 - is to serve research and education in the broadest sense. Vienna, Austria E-mail: hanns.moshammer@ meduniwien.ac.at |
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