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Biomedical subjects

Sukon Kanchanaraksa

Publications and source records attributed to Sukon Kanchanaraksa.

6 recordsLinked to original sources

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

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), NO2, and O3 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 PM10 concentration, 56.5+/-40.7 microg/m3, is 25% higher than the PM2.5 concentration (N=90), 45.1+/-37.5 microg/m3. PM concentrations measured using a nephelometer are consistent and highly correlated with gravimetric estimates. Smoking households' average PM2.5 and PM10 concentrations are 33-54 microg/m3 greater than those of nonsmoking houses, with each cigarette smoked adding 1.0 microm/m3 to indoor PM2.5 and PM10 concentrations. Large percentages of NO2 and O3 samples, 25% and 75%, respectively, were below the limit of detection. The mean NO2 indoor concentration is 31.6+/-40.2 ppb, while the mean indoor O3 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.

Air Pollutants↗

Home environmental intervention in inner-city asthma: a randomized controlled clinical trial.

BACKGROUND: Airborne pollutants and indoor allergens increase asthma morbidity in inner-city children; therefore, reducing exposure, if feasible, should improve asthma morbidity. OBJECTIVE: To conduct a randomized controlled trial of methods to reduce environmental pollutant and allergen exposure in the homes of asthmatic children living in the inner city. METHODS: After the completion of questionnaires, spirometry and allergen skin tests, home inspection, and measurement of home air pollutant and allergen levels, 100 asthmatic children aged 6 to 12 years were randomized to the treatment group (home-based education, cockroach and rodent extermination, mattress and pillow encasings, and high-efficiency particulate air cleaner) or to the control group (treated at the end of the 1-year trial). Outcomes were evaluated by home evaluations at 6 and 12 months, clinic evaluation at 12 months, and multiple telephone interviews. RESULTS: In the treatment group, 84% received cockroach extermination and 75% used the air cleaner. Levels of particulate matter 10 microm or smaller declined by up to 39% in the treatment group but increased in the control group (P < .001). Cockroach allergen levels decreased by 51% in the treatment group. Daytime symptoms increased in the control group and decreased in the treatment group (P = .04). Other measures of morbidity, such as spirometry findings, nighttime symptoms, and emergency department use, were not significantly changed. CONCLUSIONS: A tailored, multifaceted environmental treatment reduced airborne particulate matter and indoor allergen levels in inner-city homes, which, in turn, had a modest effect on morbidity.

Air Pollution, Indoor↗

Methods and issues in conducting a community-based environmental randomized trial.

The environment is suspected to play an important role in the prevalence and severity of asthma in inner-city children. This paper describes the implementation and baseline data of an inner-city community-based participatory research clinical trial designed to test the effectiveness of a pollutant and allergen control strategy on children's asthma morbidity. Participants were 100 elementary-school-aged children with asthma, graduates of a school-based asthma education program in East Baltimore. The intervention for half of the randomly assigned families consisted of environmental control education, allergen-proof encasements, pest extermination, and a HEPA air cleaner at the beginning of the study. Controls received the same at the end of the study. Participants visited a clinic for questionnaires, allergy skin testing, spirometry, and blood sample at baseline and 12 months. Home environments, NO(2), O(3), airborne particulates, and allergens were evaluated at baseline and at 6 and 12 months. Asthma morbidity and adherence was assessed quarterly. Collaboration with the community proved very beneficial in creating a study design and procedures acceptable to an inner-city community.

Air Pollution, Indoor↗

Mouse allergen exposure and mouse skin test sensitivity in suburban, middle-class children with asthma.

BACKGROUND: Exposure to mouse allergen is prevalent in inner-city homes and is associated with an increased risk of mouse skin test sensitivity in inner-city children with asthma. OBJECTIVE: To determine the distribution of mouse allergen and its relationship to mouse skin test sensitivity in a primarily suburban, middle-class population of asthmatic children. METHODS: Children with asthma, 6 to 17 years old, were recruited from 3 pediatric practices located in counties surrounding the city of Baltimore and from 1 practice located within the city limits. Participants underwent skin prick testing and completed a baseline questionnaire. Their homes were inspected, and settled dust samples were collected for allergen analysis. RESULTS: Two hundred fifty-seven of 335 (76.7%) participants resided outside the city, and 53.7% had annual incomes >$50,000. Mouse allergen was detected in 74.9% of bedrooms, and 13.1% were sensitized to mouse. Lower maternal education (odds ratio [OR], 2.17; 95% CI, 1.28-3.67), city residence (OR, 5.39; 95% CI, 2.23-13.02), and higher bedroom cockroach allergen levels (OR, 9.61; 95% CI, 1.17-79.03) were independent predictors of high bedroom mouse allergen. The risk of mouse skin test sensitivity increased with increasing bedroom Mus m 1 exposure (OR, 1.43; 95% CI, 1.04-1.96, with each increase in quartile), and dog skin test sensitivity was a strong independent predictor of mouse skin test sensitivity (OR, 7.23; 95% CI, 3.03-17.22). CONCLUSION: Mouse allergen exposure is common among suburban, middle-class asthmatic children. Increasing bedroom levels of Mus m 1 and dog skin test sensitivity are risk factors for mouse skin test sensitivity.

Adolescent↗

Knowledge and practice of dust mite control by specialty care.

BACKGROUND: Dust mites are the primary indoor allergen risk for increasing asthma attacks and morbidity. Adherence to allergen avoidance recommendations decreases bronchial reactivity and asthma morbidity. OBJECTIVE: This study compared the knowledge and practice of environmental control advice of families of children with asthma seen by an allergist or a pediatrician. Studies suggest that knowledge and practice of environmental control recommendations is inconsistent. METHODS: Subjects were aged 6 to 17 years, diagnosed with asthma, and had positive skin test to dust mites. There were 114 eligible pediatric patients, and 69 had also seen an allergist before the study. An in-home evaluation was completed during which parents were asked about environmental control knowledge and practice. An environmental technician then completed a walk-through evaluation to observe which recommendations were implemented in the home. RESULTS: Families who saw an allergist demonstrated significantly greater awareness of environmental control recommendations for dust mite allergens than those who had not. Knowledge and placement of allergen-proof mattress and pillow covers was significantly higher in these families. However, 30% of families who saw an allergist reported no knowledge of any environmental control recommendations for dust mites. Less than half of the allergist families (48%) who were advised to use mattress encasements actually had encasements on their children's beds. CONCLUSIONS: The parents of dust mite-sensitive, asthmatic children who saw an allergist were more aware of dust mite allergen control recommendations and made more indoor environmental changes.

Adolescent↗

Cockroach allergen exposure and sensitization in suburban middle-class children with asthma.

BACKGROUND: Exposure to cockroach allergen is prevalent in inner-city homes and is associated with an increased risk of cockroach sensitization. OBJECTIVE: We sought to determine the prevalence of cockroach allergen exposure in suburban middle-class homes and to study its relationship to cockroach sensitization. METHODS: Children with asthma, 6 to 17 years of age, were recruited from 3 pediatric practices located in counties surrounding Baltimore city and from 1 practice located within Baltimore city limits. Participants underwent skin prick testing and completed baseline questionnaires. In addition, their homes were inspected, and settled dust samples were collected for allergen analysis. RESULTS: Forty-one percent of the total study population (n = 339) had kitchen Bla g 1 levels of greater than 1 U/g. Forty-nine percent were white, 53% had annual incomes of greater than US dollars 50000, and 48% of mothers had college degrees. Seventy-seven percent of the study population resided in a suburban or rural location, and 30% of kitchens in these homes had Bla g 1 levels of greater than 1 U/g. Among the suburban-rural subgroup, 21% were sensitized to cockroach compared with 35% of the city group. In multivariate analysis, exposure to kitchen Bla g 1 levels of greater than 1 U/g was associated with cockroach sensitization for both the total study population (odds ratio, 2.29; 95% CI, 1.28-4.11) and the suburban-rural subgroup (odds ratio, 2.37; 95% CI, 1.23-4.57). CONCLUSIONS: Cockroach allergen exposure might be more common in suburban middle-class homes of asthmatic children than previously thought. Moreover, the data suggest that low-level cockroach exposure is a risk factor for cockroach sensitization.

Adolescent↗