ENVIRONMENTAL HEALTH & ENGINEERING, INC. ASTHMA AND ALLERGY BENEFITS OF USING AIR PURIFIERS

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1 ENVIRONMENTAL HEALTH & ENGINEERING, INC. ASTHMA AND ALLERGY BENEFITS OF USING AIR PURIFIERS SPRING 2012

2 Asthma and Allergy Benefits of Using Air Purifiers Summary Exposures to allergens and indoor pollutants are associated with asthma exacerbations and other respiratory symptoms. Indoor exposures to these agents are important because people spend a majority of their time indoors at home. The use of air purifiers in homes can reduce the levels of asthma triggers in indoor air. Recent studies have found significant reductions in asthma symptoms, unscheduled asthma emergency room visits, and medication usage as well as significant increases in symptom free days in asthmatic children associated with the use of an air purifier. [1-7] Indoor Pollutants Trigger Asthma and Allergy Symptoms The Institutes of Medicine (IOM) has concluded there is an association between asthma exacerbation and exposure to allergens from cats, dogs, cockroaches and dust mites, environmental tobacco smoke (ETS), mold, nitrogen oxides and rhinovirus. [8] Within a subset of these allergens, (cat, cockroach, ETS and dust mite) IOM found that the evidence was compelling enough to find this relationship to be causal. [8] More recently, the U.S. Environmental Protection Agency (EPA) has concluded that a causal relationship is likely to exist between short and long term exposures to fine particulate matter (PM2.5; PM less than 2.5 microns in aerodynamic diameter) and respiratory effects, such as hospitalizations, respiratory emergency room visits, and other respiratory symptoms, including reductions of pulmonary function and increases in inflammation for children with asthma. [9] The first and most important step in controlling allergen-induced asthma is to advise patients to reduce exposure to relevant indoor and outdoor allergens to which the patient is sensitive National Heart, Lung and Blood Institute. Guidelines for the Diagnosis and Management of Asthma (2007) The Importance of Indoor Environments People spend approximately 90% of their time indoors, with roughly 70% of that time indoors at home. [10] Many of the allergens and pollutants associated with asthma and respiratory symptoms have indoor sources, and are therefore found at much higher concentrations indoors than outdoors. This is the case for allergens such as pet allergens, dust mites, and cockroach allergen; respiratory viruses which exacerbate asthma symptoms; and also for pollutants such as environmental tobacco smoke and nitrogen oxides released when using gas appliances. Indoor exposures are not limited to allergens and pollutants from indoor sources but also include asthma triggers that infiltrate homes from outdoor air. Indoor exposures to asthma triggers of outdoor origin such as such as PM2.5 and mold spores, can sometime contribute more to total exposures than exposure that occurs outdoors. Fine particles and particlebound mold spores are generally so small that they can easily move around door and Environmental Health & Engineering 2

3 window frames as well as through small openings in the walls and roofs of homes. [11] Because of the amount of time spent indoors and the easy migration of fine particles indoors, residential indoor concentrations are the primary contributor to personal exposures to PM2.5. [12] Air Purifiers can Limit Indoor Exposures Guidelines for asthma management suggest that allergen avoidance is the ideal way to manage allergic respiratory diseases. [13] In terms of the home environment, this may Use of air purifiers have been shown to reduce indoor levels of allergens generated indoors, such as pet dander, and allergens that infiltrate from outdoors such as mold spores and pollen. be possible for some relevant allergens, such as animal dander, but for other allergens and pollutants, complete avoidance is impractical and in many cases impossible (e.g., fungal spores outdoors and ambient PM2.5). Minimizing exposures to indoor allergens and pollutants can be achieved by removal of the agents from the indoor air. Allergens and most pollutants that trigger respiratory symptoms are particles, and therefore can be easily and effectively removed from the air by filtration. Studies have shown that air purifiers can be an effective way to control exposure to airborne allergens and PM, [14-17] cigarette smoke, [18] cat and dog allergens, [19, 20] and fungal spores and pollen. [21] In studies of homes with pets, the use of air purifiers significantly reduced airborne levels of cat and dog allergens. [19, 20] Cheng and colleagues demonstrated that air purifiers can reduce mold and pollen levels to less than 10% of concentrations prior to operating the air purifiers within one hour. [21] In an urban setting, Brauner showed that the use of air purifiers reduced indoor PM2.5 levels by approximately 60%. [15] Similarly, Allen and colleagues demonstrated that the use of commercially available air purifiers placed in bedrooms and family rooms reduced indoor PM2.5 by approximately the same amount. [14] The ideal way for patients to manage allergic rhinitis is with complete avoidance of all relevant allergens. Because this generally is not possible, patients should be counseled to reduce their exposure to as many relevant allergens as is practical. - J Allergy Clin Immunol 2008;122:S1-84. Environmental Health & Engineering 3

Butz and colleagues demonstrated that air purifiers placed in a bedroom and family room significantly reduced airborne particulate levels and increased the number of asthma symptom free days in

4 Butz and colleagues demonstrated that air purifiers placed in a bedroom and family room significantly reduced airborne particulate levels and increased the number of asthma symptom free days in children with asthma. Reducing Indoor Exposures Benefits Respiratory Health Recent studies that are some of the largest, best designed studies investigating this issue have shown a health benefit from reducing indoor exposures. In a double-blinded, randomized trial, investigators from Johns Hopkins University and the Centers for Disease Control and Prevention found that children residing in homes with air purifiers experienced a significant increase in symptom free days. [1] These results are consistent with other controlled trials. [22-24] Lanphear and colleagues found an 18.5% reduction in unscheduled asthma visits due to the use of air purifiers in homes of asthmatic children exposed to second hand smoke. [3] In a multifaceted trial to reduce indoor pollutants that included portable air purifiers, Morgan et al reported a 13.6% reduction in the number of unscheduled visits attributable to asthma and a significant reduction in asthma symptoms. [5] In a trial of multiple environmental interventions that included air purifiers, Eggleston et al reported a significant improvement in asthma symptoms but no difference in unscheduled asthma visits. [2] Studies have shown that PM2.5 exposure is associated with medication use in asthmatics and that the use of air purifiers is associated with decreased medication usage. [6, 7] Taken together, these studies provide evidence that environmental interventions, such as air purifiers, consistently reduce exposures to allergens and pollutants in the home and provide health benefits to children with allergic diseases....based on our review of the literature, there is sufficient evidence that air filtration does reduce indoor levels of ambient particulates that might trigger disease processes themselves. Allergy Clin Immunol 2010;125:32-8. Environmental Health & Engineering 4

5 REFERENCES 1. Butz A, Matsui E, Breysse P, Curtin-Brosnan J, Eggleston P, Diette G, Williams D, Yuan J, Bernert J, & Rand C. A randomized trial of air cleaners and a health coach to improve indoor air quality for inner-city children with asthma and secondhand smoke exposure. Arch Pediat Adol Med, (8): p Eggleston P, Butz A, Rand C, Curtin-Brosnan J, Kanchanaraksa S, Swartz L, Breysse P, Buckley T, Diette G, Merriman B, & Krishan J. Home environmental intervention in inner-city asthma: a randomized controlled clinical trial. Ann Allergy Asthma Immunol, (6): p Lanphear B, Hornung R, Khoury J, Yolton K, Lierl M, & Kalkbrenner A. Effects of HEPA air cleaners on unscheduled asthma visits and asthma symptoms for children exposed to secondhand tobacco smoke. Pediatrics, (1): p Lanphear B, Kahn R, Bergen O, Auinger P, Bortnick S, & Nahhas R. Contribution of residential exposures to asthma in us children and adolescents. Pediatrics, (6): p. E Morgan W, Crain E, Gruchalla R, O Connor G, Kattan M, Evens R, Stout J, Malinszak G, Smartt E, Plaut M, Walter M, Vaughn B, & Mitchell H. Results of a home-based environmental intervention among urban children with asthma. N Engl J Med, (11): p Verrall B, Muir D, Wilson W, Milner R, Johnston M, & Dolovich J. Laminar flow air cleaner bed attachment: a controlled trial. Annals of Allergy, (2): p Zwemer R, & Karibo J. Use of laminar control device as adjunct to standard environmental control measures in symptomatic asthmatic children. Annals of Allergy, (6): p Institute of Medicine (IOM), Clearing the air: asthma and indoor air exposures. 2000, Washington: National Academy Press. 9. Environmental Protection Agency (EPA), Integrated Science Assessment for Particulate Matter (Final Report). 2009, National Center for Environmental Assessment-RTP Division, Office of Research and Development, U.S. Environmental Protection Agency: Research Triangle Park, NC. 10. Klepeis N, Nelson W, Ott W, Robinson J, Tsang A, Switzer P, Behar J, Hern S, & Engelmann W. The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants. J Exp Sci Environ Epidemiol, (3): p Wilson W, & Suh H, Fine particles and coarse particles: concentration relationships relevant to epidemiologic studies. J Air Waste Manag Assoc, (12): p Sarnat S, Suh H, Coull B, Schwartz J, Stone P, & Gold D. Ambient particulate air pollution and cardiac arrhythmia in a panel of older adults in Steubenville, Ohio. Occup Environ Med, (10): p National Heart Lung and Blood Institute, Guidelines for the Diagnosis and Management of Asthma (EPR-3) Allen R, Carlsten C, Karlen B, Lechie S, van Eedan S, Vedal S, Wong I, & Brauer M. An air filter intervention study of endothelial function among healthy adults in a woodsmokeimpacted community. Am J Respir Crit Care Med, (9): p Brauner E, Forchhammer L, Moller P, Barregard L, Gunnarsenn L, Afshari A, Wahlin P, Glasium M, Dragsted L, Basu S, Raaschou-Nielsen O, & Loft S. Indoor particles affect vascular function in the aged: an air filtration-based intervention study. Am J Respir Crit Care Med, (4): p Environmental Health & Engineering 5

6 16. Hacker D, & Sparrow E. Use of air-cleaning devices to create airborne particle-free spaces intended to alleviate allergic rhinitis and asthma during sleep. Indoor Air, (6): p Xu Y, Raja S, Ferro A, Jaques P, Hopke P, Gressani C, & Wetzel L. Effectiveness of heating, ventilating and air conditioning system with HEPA filter unit on indoor air quality and asthmatic children s health. Building and Environ, (2): p Batterman S, Godwin C, & Jia C. Long duration tests of room air filters in cigarette smokers homes. Environ Sci Technol, (18): p Custovic A, Simpson A, Pahdi H, Green R, Chapman M, & Woodcock A. Distribution, aerodynamic characteristics, and removal of the major cat allergen Fel d 1 in British homes. Thorax, (1): p Green R, Simpson A, Custovic A, Faragher B, Chapman M, & Woodcock A. The effect of air filtration on airborne dog allergen. Allergy, (5): p Cheng Y, Lu J, & Chen T, Efficiency of a portable indoor air cleaner in removing pollens and fungal spores. Aerosol Sci Technol, (2): p van der Heide S, Kauffman H, Dubois A, & de Monchy J. Allergen reduction measures in houses of allergic asthmatic patients: effects of air-cleaners and allergen-impermeable mattress covers. The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology, (6): p van der Heide S, van Aalderen W, Kauffman H, Dubois A, & de Monchy J. Clinical effects of air cleaners in homes of asthmatic children sensitized to pet allergens. J Allergy Clinical Immunol, (2 Pt 1): p Warburton C, Niven R, Pickering C, Flecher A, Hepworth J, & Francis H. Domiciliary air filtration units, symptoms and lung function in atopic asthmatics. Resp Med, (10): p Environmental Health & Engineering 6

Assessing Allergic Sensitivities and Allergen Exposures

Assessing Allergic Sensitivities and Allergen Exposures James A. MacLean, M.D. Partners Asthma Center North Shore Asthma and Allergy Affiliates Massachusetts General Hospital Harvard Medical School Objectives