Symptoms in Pediatric Asthmatics and Air Pollution: Differences in Effects by Symptom Severity, Anti-Inflammatory Medication Use and Particulate Averaging Time

• Published in: Environmental health perspectives 1998-11, Vol.106 (11), p.751-761
• Main Authors: Delfino, Ralph J., Zeiger, Robert S., Seltzer, James M., Street, Donald H.
• Format: Article
• Language: English
• Subjects: Adolescent; Air pollutants; Air Pollutants - adverse effects; Air pollution; Anti-Asthmatic Agents - therapeutic use; Antiinflammatories; Asthma; Asthma - drug therapy; Asthma - epidemiology; Asthma - etiology; California - epidemiology; Child; Children; Dust - adverse effects; Female; Fungi; Humans; Male; Medications; Ozone - adverse effects; Particulate matter; Pollutants; Severity of Illness Index; Symptoms
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.98106751

Experimental research in humans and animals points to the importance of adverse respiratory effects from short-term particle exposures and to the importance of proinflammatory effects of air pollutants, particularly O3. However, particle averaging time has not been subjected to direct scientific evaluation, and there is a lack of epidemiological research examining both this issue and whether modification of air pollutant effects occurs with differences in asthma severity and anti-inflammatory medication use. The present study examined the relationship of adverse asthma symptoms (bothersome or interfered with daily activities or sleep) to O3 and particles 120 ppb). Longitudinal regression analyses utilized the generalized estimating equations (GEE) model controlling for autocorrelation, day of week, outdoor fungi, and weather. Asthma symptoms were significantly associated with both outdoor O3 and PM10 in single pollutant- and coregressions, with 1-hr and 8-hr maximum PM10 having larger effects than the 24-hr mean. Subgroup analyses showed effects of current day PM10 maximums were strongest in 10 more frequently symptomatic (MS) children: the odds ratios (ORs) for adverse symptoms from 90th percentile increases were 2.24 [95% confidence interval (CI), 1.46-3.46] for 1-hr PM10 (47 μ g/ m3); 1.82 (CI, 1.18-2.81) for 8-hr PM10 (36 μ g/ m3); and 1.50 (CI, 0.80-2.80) for 24-hr PM10 (25 μ g/ m3). Subgroup analyses also showed the effect of current day O3 was strongest in 14 less frequently symptomatic (LS) children: the ORs were 2.15 (CI, 1.04-4.44) for 1-hr O3 (58 ppb) and 1.92 (CI, 0.97-3.80) for 8-hr O3 (46 ppb). Effects of 24-hr PM10 were seen in both groups, particularly with 5-day moving averages (ORs were 1.95 for MS and 4.03 for LS; p