Breathing Easier in Seattle: Addressing Asthma Disparities Through Healthier Housing

Abstract

Asthma is the most common chronic condition of childhood, affecting 9.1% of all American children. The prevalence and morbidity of asthma among children in the United States have increased dramatically over the past 3 decades. More than 6 million children currently have asthma, leading to 205,000 pediatric hospitalizations and 697,000 emergency department visits each year (Akinbami et al., Pediatrics 123(Suppl 3):S131–45, 2009). Asthma develops through the interaction of genetic factors with environmental exposures. Strong evidence has linked exposure to dust mites, cockroaches, rodents, mold, and pet dander to the development of sensitization to allergens and subsequent asthma incidence and morbidity (Institute of Medicine, Clearing the air: asthma and indoor air exposures. Washington, DC: National Academy Press, 2000; Institute of Medicine, Damp indoor spaces and health. Washington, DC: National Academy Press, 2004; Platts-Mills et al., J Allergy Clin Immunol 96(4):435–40, 1995; Sporik et al., Thorax 54(8):675–80, 1999; Dales, Am J Epidemiol 134(2):196–203, 1991; Rosenstreich et al., N Engl J Med 336(19):1356–63, 1997; Zock et al., J Allergy Clin Immunol 110(2):285–92, 2002). Exposure to indoor allergens is widespread (Salo et al., Environ Health Perspect 117(3):387–91, 2009). In the United States, disadvantaged and minority populations are disproportionately affected by asthma (Gold and Wright, Annu Rev Public Health 26:89–113, 2005; Asthma and Allergy Foundation of America and National Pharmaceutical Council, Ethnic disparities in the burden and treatment of asthma. Washington, DC, 2005). Relative to wealthier and white populations, they have higher asthma prevalence and experience more serious impacts such as severe attacks leading to emergency department visits and hospitalizations (Aligne et al., Am J Respir Crit Care Med 162: 873–7, 2000; Litonjua et al., Pediatr Pulmonol 28(6):394–401, 1999; Weiss and Gergen, Chest 101(June suppl):362S–7S, 1992; Call et al., J Pediatr 121:862–6, 1992; Lang and Polansky, N Engl J Med 331:1542–6, 1994; Grant et al., Curr Opin Pulm Med 5(1):27–34, 1999; Eggleston, Immunol Allergy Clin North Am 18:75–84, 1998). The current asthma prevalence among blacks is 25% higher than non-Hispanic whites. The emergency department visit rate among blacks is 4.6 times higher than that among whites, the hospitalization rate 3.4 times higher, and the mortality rate 3 times higher (Akinbami, Asthma prevalence, health care use and mortality: United States, 2003–05. http://cdc.gov/nchs/data/hestat/asthma03-05/asthma03-05.htm. Accessed 21 May 2010). Many factors interact to produce these inequities (Eggleston, Immunol Allergy Clin North Am 18:75–84, 1998; Grant et al., Curr Opin Pulm Med 5(1):27–34, 1999). As much as 40% of the excess asthma risk in minority children may be attributable to exposure to residential allergens (Lanphear et al., Pediatrics 107(3):505–11, 2001). Being poor or a person of color is associated with increased rates of sensitization to several asthma-associated allergens found in homes (Christiansen et al., J Allergy Clin Immunol 98(2):288–94, 1996; Willies-Jacobo et al., J Allergy Clin Immunol 92(4):630–2, 1993; Gelber et al., Am Rev Respir Dis 147(3):573–8, 1993; Sarpong et al., J Allergy Clin Immunol 97(6):1393–401, 1996; Lewis et al., J Allergy Clin Immunol 107:615–22, 2001; Strachan, Toxicol Lett 86:199–203, 1996; Huss et al. Ann Allergy 72(2):173–7, 1994; Eggleston, Clin Rev Allergy Immunol 18(3):311–24, 2000). Low-income children and children of color are more likely to live in substandard housing. Living in substandard housing leads to exposure to allergens and higher rates of allergen sensitization (Eggleston, Immunol Allergy Clin North Am 18:75–84, 1998; Huss et al., Ann Allergy 72(2):173–7, 1994; Kitch et al., Environ Health Perspect 108(4):301–7, 2000). Features of substandard housing such as excessive moisture and dampness, poor ventilation, crowding, pest infestations, deteriorated carpeting, and structural deficits are associated with high levels of indoor asthma triggers (Hyndman, Making connections between housing and health. Putting health into place. Syracuse, NY: Syracuse University Press, pp. 191–207, 1998). Exposure to combustion products from unvented stoves can induce asthma symptoms (Eisner et al., Thorax 57:973–8, 2002). A strong parallel thus exists between exposure to asthma triggers and the differential exposure of disadvantaged populations to hazards in the outdoor environment (e.g., toxic waste dumps or freeways) – a hallmark of environmental racism (Northridge and Shepard, Am J Public Health 87(5):730–2, 1997).

J.W. Krieger

Chief, Chronic Disease and Injury Prevention Section, Public Health—Seattle and King County, Clinical Associate Professor of Medicine and Health Services, University of Washington, Seattle, Washington, USA