Grantee Research Project Results

2002 Progress Report: The Relationship Of Airborne Pollutants And Allergens To Asthma Morbidity

EPA Grant Number: R826724C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R826724
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for the Study of Childhood Asthma in the Urban Environment
Center Director: Hansel, Nadia
Title: The Relationship Of Airborne Pollutants And Allergens To Asthma Morbidity
Investigators: Eggleston, Peyton A. , Diette, Greg
Institution: The Johns Hopkins University
EPA Project Officer: Callan, Richard
Project Period: January 1, 1998 through January 1, 2002
Project Period Covered by this Report: January 1, 2001 through January 1, 2002
Project Amount: Refer to main center abstract for funding details.
RFA: Centers for Children's Environmental Health and Disease Prevention Research (1998) RFA Text |  Recipients Lists
Research Category: Children's Health , Human Health

Objective:

The long-range goal of the epidemiologic study is to create a research infrastructure for the development and implementation of cost effective community based strategies to reduce asthma morbidity in the urban environment. The main hypothesis to be evaluated is that: in children with asthma, exposure to both air pollutants and allergens results in respiratory morbidity that is greater than expected based on effects from independent exposures to air pollutants and allergens.

The original goals and objectives have been retained. Investigators have made several changes and additions that they think will supplement the original goals and objectives. The current objectives are as follows: (1) to characterize and compare exposure to allergens and air pollutants among inner city children with and without asthma; (2) in a subset of homes, to characterize the within-home temporal variability in air pollution and allergen exposure; (3) to estimate the occurrence of respiratory morbidity among inner city children with asthma; (4) to study environmental and hereditary determinants of childhood asthma; (5) to assess independent and joint effects of exposure to indoor allergens and indoor air pollution on respiratory morbidity in children with asthma; (6) to characterize current use of environmental control practices among inner city children with asthma; (7) to identify barriers through the use of guidelines on environmental control practices among primary care providers caring for inner city children with asthma; (8) to assess the differential impact of indoor and outdoor air pollution among asthmatic and non-asthmatic homes; and (9) to understand the relative contribution of different structural, financial and personal barriers to use of recommended environmental control practices for children with asthma. Changes include the additional of repeated measures of pollutants and antigens in the asthmatic children, and an emphasis on identifying obstacles to the use of environmental control practices at the child/family and health care provider level.

Progress Summary:

Progress has been made in the following areas:

a. Identification and recruitment of asthma and control subjects- through work with the Johns Hopkins Community Physicians, we identified a database of 3,733 children aged 2 to 6 years, of whom 605 are potential asthma subjects and 3,128 are potential control subjects. Investigators have been updating this database every 6 months to identify children who are new to the health system.

b. Identification and recruitment of PrimM Care Physicians: The Primary Care Physicians of the children enrolled in our study are also study subjects. They assess their compliance with national asthma guidelines for use of environmental control practices, as well as identify barriers to their use of these practices. They have identified 19 physicians caring for the 67 children with asthma, of whom I 0 have so far completed the mailed survey.

Preliminary data evaluation:

a. 30 children enrolled. They have performed preliminary analyses on the first. Of the first 10 children with asthma, 50% were male, 100% African-American, 11I% Hispanic and 88% had Medicaid insurance. Symptoms of asthma were frequent in the prior 2 weeks (shortness of breath 55%, wheeze 67%, nocturnal awakening 78% and cough 89%). Approximately 20% bad an ED visit in the prior 3 months, and 67% had a mother who smokes in the home. Similar demographic characteristics were found in the 20 control children (50% male; 95% African-American; 100% Medicaid). Of the homes of children in the study, 87% were row homes and 20% had central air conditioning. The children's bedrooms had evidence of potential environmental problems (moisture or leak 95%, live cockroaches 21%, food 16%, cigarette smell 10%, mildew 10%, and mouse droppings 5%). In settled dust from the bedrooms of children with asthma, the majority had detectable antigens from cat, dog, and mouse, and fewer than 50% had detectable cockroach and dust mite. Survey results suggested that perceptions of violence may lead to greater time indoors, with over 50% of parents of children with asthma reporting that their child stays indoors because of outdoor violence.

b. Preliminary analysis of the physician reported data shows that their adherence is low to environmental control measures recommended by the 1997 NHLBI asthma guidelines. While 80% ask all parents about exposure to tobacco smoke, only 60% ask about pets, 20% about dust mites and 10% about indoor molds. None of the physician routinely order skin testing for allergens, and only 10% advice all of their asthma patients to stay indoors on high ozone days. Barriers to the use of the guidelines, based on a conceptual model of problems with awareness of, agreement with, and ability to use the guidelines were apparent for all studied guideline recommendations. For example, no physicians reported being very or extremely familiar with the NHLBI guidelines, and only 50% had a copy of them. Only 40% agree that children should undergo skin testing to assess sensitivity to seasonal allergens, even though all agree that physicians should help parents to reduce allergen exposure. Citing ability barriers to counseling parents to reduce inhaled allergen exposure for children, 90% reported a lack of time during a patient visit, and 70% a lack of educational materials. Outcomes expectancy was low, too, with only 30% of physicians believing that there would be a modest or large benefit to counseling patients to reduce exposure to pets, dust mites and cockroaches.

Future Activities:

The major activity planned for year 05 is to continue recruitment efforts and to enroll asthma and nonasthma subjects in the study.

Supplemental Keywords:

Children's Health, Disease and Cumulative Effects, Ecological Risk Assessment, Epidemiology, Human Health Risk Assessment, human exposure, cockroaches, dust mites, asthma, allergens., RFA, Health, Air, Scientific Discipline, Susceptibility/Sensitive Population/Genetic Susceptibility, Health Risk Assessment, Risk Assessments, particulate matter, Biology, genetic susceptability, Environmental Chemistry, Epidemiology, tropospheric ozone, Allergens/Asthma, Children's Health, Atmospheric Sciences, air toxics, Genetics, community based, childhood respiratory disease, disease, epidemeology, health effects, Human Health Risk Assessment, air quality, environmental hazard exposures, genetic predisposition, ozone induced inflammation, sensitive populations, human health, inhaled, asthma, airway inflammation, allergen, asthma triggers, stratospheric ozone, community-based studies, biological response, human exposure, community-based, morbidity, genetic susceptibility, children, exposure, particulates, ozone, intervention, environmentally caused disease, toxics, air pollutants, air pollution, human health effects, assessment of exposure, inhalation, airway disease, environmental effects, exposure and effects

Progress and Final Reports:

Original Abstract

1998

1999

2000

Final

Main Center Abstract and Reports:

R826724    Center for the Study of Childhood Asthma in the Urban Environment

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R826724C001 A Randomized, Controlled Trial of Home Exposure Control in Asthma
R826724C002 Mechanisms Of Particulate-Induced Allergic Asthma
R826724C003 Genetic Mechanisms of Susceptibility to Inhaled Pollutants
R826724C004 The Relationship Of Airborne Pollutants And Allergens To Asthma Morbidity