Indoor exposures to air pollutants and allergens in the homes of asthmatic children in inner-city Baltimore

Abstract

This paper presents indoor air pollutant concentrations and allergen levels collected from the homes of 100 Baltimore city asthmatic children participating in an asthma intervention trial. Particulate matter (PM), NO 2, and O 3 samples were collected over 72 h in the child's sleeping room. Time-resolved PM was also assessed using a portable direct-reading nephelometer. Dust allergen samples were collected from the child's bedroom, the family room, and the kitchen. The mean PM 10 concentration, 56.5±40.7 μg/m 3, is 25% higher than the PM 2.5 concentration ( N = 90 ), 45.1±37.5 μg/m 3. PM concentrations measured using a nephelometer are consistent and highly correlated with gravimetric estimates. Smoking households’ average PM 2.5 and PM 10 concentrations are 33–54 μg/m 3 greater than those of nonsmoking houses, with each cigarette smoked adding 1.0 μm/m 3 to indoor PM 2.5 and PM 10 concentrations. Large percentages of NO 2 and O 3 samples, 25% and 75%, respectively, were below the limit of detection. The mean NO 2 indoor concentration is 31.6±40.2 ppb, while the mean indoor O 3 concentration in the ozone season was 3.3±7.7 ppb. The levels of allergens are similar to those found in other inner cities. Results presented in this paper indicate that asthmatic children in Baltimore are exposed to elevated allergens and indoor air pollutants. Understanding this combined insult may help to explain the differential asthma burden between inner-city and non-inner-city children.