The Environment and Asthma in U.S. Inner Cities

School of Medicine, Department of Pediatrics, The Johns Hopkins University, Baltimore, MD 21287-3923, USA.
Environmental Health Perspectives (Impact Factor: 7.98). 07/1999; 107 Suppl 3(Suppl 3):439-50. DOI: 10.1289/ehp.99107s3439
Source: PubMed


The prevalence and severity of asthma has increased in the last 20 years, and the greatest increase has been seen among children and young adults living in U.S. inner cities. The reasons for this increase are obviously complex, but include environmental exposures to allergens and pollutants, changing patterns of medication, and the psychosocial stresses of living in poor inner-city neighborhoods. This paper presents an overview of environmental, immunologic, and genetic factors associated with asthma morbidity and mortality. This overview can be used to provide a framework for designing an interdisciplinary research program to address the complexities of asthma etiology and exacerbation. The strongest epidemiologic association has been found between asthma morbidity and the exposure of immunologically sensitive asthmatic patients to airborne allergens. Our current understanding of the process of sensitization suggests that there is a strong genetic predisposition to form IgE to allergenic proteins on airborne particles. Much of this work has been conducted with animal models, but in a number of instances, specific confirmation has been reported in humans. Sensitized individuals respond to inhaled exposure with immediate mast-cell dependent inflammation that may be augmented by pollutant particles, especially diesel exhaust particles. Relatively little is known about the methods of assessing exposure to airborne pollutants, especially biologically active particulates. However, to examine the relationship of morbidity in genetically predisposed individuals, it will be important to determine the most relevant method of making this assessment.

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    • "Hospitalization and morbidity rates have been shown to be elevated for nonwhites versus whites [3] and in inner-city settings with low-income populations [4]. Multiple recent studies have attempted to explain these disparities by evaluating environmental exposures and housing conditions, racial/ethnic variations, poverty, and social or psychological factors, with no definitive conclusions regarding the dominant factors [1,2,5-9]. "
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    ABSTRACT: Children in urban public housing are at high risk for asthma, given elevated environmental and social exposures and suboptimal medical care. For a multifactorial disease like asthma, design of intervention studies can be influenced by the relative prevalence of key risk factors. To better understand risk factors for asthma morbidity in the context of an environmental intervention study, we conducted a detailed baseline evaluation of 78 children (aged 4-17 years) from three public housing developments in Boston. Asthmatic children and their caregivers were recruited between April 2002 and January 2003. We conducted intake interviews that captured a detailed family and medical history, including questions regarding asthma symptom severity, access to health care, medication usage, and psychological stress. Quality of life was evaluated for both the child and caregiver with an asthma-specific scale. Pulmonary function was measured with a portable spirometer, and allergy testing for common indoor and outdoor allergens was conducted with skin testing using the prick puncture method. Exploratory linear and logistic regression models evaluating predictors of respiratory symptoms, quality of life, and pulmonary function were conducted using SAS. We found high rates of obesity (56%) and allergies to indoor contaminants such as cockroaches (59%) and dust mites (59%). Only 36% of children with persistent asthma reported being prescribed any daily controller medication, and most did not have an asthma action plan or a peak flow meter. One-time lung function measures were poorly correlated with respiratory symptoms or quality of life, which were significantly correlated with each other. In multivariate regression models, household size, body mass index, and environmental tobacco smoke exposure were positively associated with respiratory symptom severity (p < 0.10). Symptom severity was negatively associated with asthma-related quality of life for the child and the caregiver, with caregiver (but not child) quality of life significantly influenced by caregiver stress and whether the child was in the intensive care unit at birth. Given the elevated prevalence of multiple risk factors, coordinated improvements in the social environment, the built environment, and in medical management would likely yield the greatest health benefits in this high-risk population.
    Environmental Health 12/2004; 3(1):13. DOI:10.1186/1476-069X-3-13 · 3.37 Impact Factor
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    ABSTRACT: Evidence suggests that allergy is a significant triggering factor in asthma in children and adults alike. In immunoglobulin (Ig) E-mediated allergic reactions, sensitization occurs when allergen-specific B cells are stimulated and switched to IgE antibody production by interleukin (IL)-4 and IL-13 provided by helper T cells type 2 (Th2). The IgE antibodies act by arming cells bearing either the high-affinity (FcεRI) or low-affinity (FcεRII or CD23) receptor. The subsequent interaction of allergen with IgE-FcεRI complexes on mast cells and basophils causes cross-linking of receptors that triggers the release of a variety of inflammatory mediators, cytokines and chemokines. Therefore, the ability to lower circulating free IgE levels is desirable because most individuals are exposed to multiple allergens to which they are sensitive at any given time. Omalizumab (formerly known as rhuMAb-E25) is a recently developed humanized monoclonal anti-IgE antibody directed at the FcεRI binding domain of human IgE. It inhibits binding of IgE to mast cells without provoking mast cell activation. Preliminary clinical data from randomized controlled trials have shown that the addition of omalizumab to standard asthma therapy reduces asthma exacerbations and decreases inhaled corticosteroid and rescue medication use. The compound is also well tolerated. Omalizumab represents a novel therapeutic approach in the management of asthma.
    American journal of respiratory medicine: drugs, devices, and other interventions 10/2012; 1(5). DOI:10.1007/BF03256629
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    ABSTRACT: Childhood asthma is a growing public health concern in low-income urban communities. Indoor exposure to asthma triggers has emerged as an important cause of asthma exacerbations. We describe indoor environmental conditions related to asthma triggers among a low-income urban population in Seattle/King County, Washington, as well as caregiver knowledge and resources related to control of these triggers. Data are obtained from in-person, structured, closed-end interviews with the caretakers of children aged 4-12 years with persistent asthma living in households with incomes less than 200% of poverty. Additional information is collected during a home inspection. The children and their caregivers are participants in the ongoing Seattle-King County Healthy Homes Project, a randomized controlled trial of an intervention to empower low-income families to reduce exposure to indoor asthma triggers. We report findings on the conditions of the homes prior to this intervention among the first 112 enrolled households. A smoker was present in 37.5% of homes. Mold was visible in 26.8% of homes, water damage was present in 18.6% of homes, and damp conditions occurred in 64.8% of households, while 39.6% of caregivers were aware that excessive moisture can increase exposures to allergens. Dust-trapping reservoirs were common; 76.8% of children's bedrooms had carpeting. Cockroach infestation in the past 3 months was reported by 23.4% of caregivers, while 57.1% were unaware of the association of roaches and asthma. Only 19.8% of the children had allergy-control mattress covers. Many low-income urban children with asthma in King County live in indoor environments that place them at substantial risk of ongoing exposure to asthma triggers. Substandard housing and lack of resources often underlie these exposures. Initiatives involving health educators, outreach workers, medical providers, health care insurers, housing agencies, and elected officials are needed to reduce these exposures.
    Journal of Urban Health 04/2000; 77(1):50-67. DOI:10.1007/BF02350962 · 1.90 Impact Factor
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