Childhood Asthma and Environmental Interventions
Background: Contaminants encountered in many households, such as environmental tobacco smoke, house dust mite, cockroach, cat and dog dander, and mold, are risk factors in asthma. Young children are a particularly vulnerable subpopulation for environmentally mediated asthma, and the economic burden associated with this disease is substantial. Certain mechanical interventions are effective both in reducing allergen loads in the home and in improving asthmatic children's respiratory health.
Results: Combinations of interventions including the use of dust mite-impermeable bedding covers, improved cleaning practices, high-efficiency particulate air vacuum cleaners, mechanical ventilation, and parental education are associated with both asthma trigger reduction and improved health outcomes for asthmatic children. Compared with valuated health benefits, these combinations of interventions have proven cost effective in studies that have employed them. Education alone has not proven effective in changing parental behaviors such as smoking in the home.
Conclusions: Future research should focus on improving the effectiveness of education on home asthma triggers, and understanding long-term children's health effects of the interventions that have proven effective in reducing asthma triggers.
People in modern societies spend the vast majority of their time–approximately 90%–in indoor environments, including homes, workplaces, schools, and public spaces such as restaurants and malls. Roughly 66% of that indoor time is spent in homes (Leech et al. 2002). Hence, indoor environmental quality in the home has a significant impact on public health and well-being. Indeed, indoor pollution has been ranked by both the U.S. Environmental Protection Agency (EPA) Science Advisory Board and the Centers for Disease Control and Prevention as a high environmental risk (Leung et al. 1997).
Although globally the greatest health risks are associated with particulate pollution from indoor biomass burning that kills an estimated 1.6 million people per year (World Health Organization 2002), the indoor environmental risks that are the focus of this article are related specifically to indoor air quality (IAQ) in higher-income countries. In this setting, indoor chemical contaminants include environmental tobacco smoke (ETS), nitrogen dioxide from space heaters and poorly ventilated furnaces, carbon monoxide, volatile organic compounds (VOCs), phthalates, and pesticides. Biological contaminants include antigens from house dust mites, molds, rodents, cockroaches, and animal dander. Dampness and endotoxins have also been implicated in health risks associated with indoor environments [Institute of Medicine (IOM) 2000, 2004; Thorne 2005].
Indoor air pollutants in the home may lead to the development and/or exacerbation of a variety of diseases and symptoms. Some known and postulated adverse health effects associated with poor indoor air quality are allergies, asthma, infection, hypersensitivity pneumonitis, inhalation fevers, mucosal irritation, central nervous system effects, psychologic effects (including depression), dermatitis, and even some forms of cancer (IOM 2000, 2004).
Asthma and allergic conditions in particular are believed to be associated primarily with exposure to contaminants common in indoor rather than outdoor environments (IOM 2000). The IOM has concluded there is sufficient evidence of a causal relationship between asthma development and exposure to house dust mite (IOM 2000). Substantial evidence indicates that children exposed to indoor air mold in the first years of their lives have a significantly higher probability of developing asthma (Jaakkola et al. 2005). There is sufficient evidence of a causal relationship between asthma exacerbation and exposure to cats, cockroaches, house dust mite, mold, and ETS in preschool-age children (IOM 2000). There is also increasing evidence that pollutants from vehicle traffic infiltrates indoors, adding to the risk of asthma and exacerbations (McConnell et al. 2006).
The number of self-reported asthma cases in the United States increased by 75% between 1980 and 1994 (Mannino et al. 1998). The most dramatic increase–160%–was seen in children younger than 4 years. From 1975 to 1994, the number of office visits for asthma increased from 4.6 million to 10.4 million. Almost 15 million Americans have asthma today (IOM 2000).
From a health-economics standpoint, the loss of quality of life and productivity from an early diagnosis of a lifelong chronic disease such as asthma is enormous–both to the individual and to the society. Moreover, when a child becomes sick, it is often the case that both a school day and a parent's workday are lost. Thus, educational and productivity losses because of adverse health effects from indoor contaminants could be substantial. Individuals with low incomes, particularly in inner cities, are more likely to be living in substandard housing with severe structural problems, with moisture intrusion, poor ventilation, and associated mold and pest-related problems. These families are the least likely to have the means (money and education) by which to remediate such problems (Evans and Kantrowitz 2002; IOM 2004). Often, they also lack access to information regarding the extent of health problems associated with indoor asthma hazards and appropriate remediation responses. Therefore, the group most likely to suffer from indoor environment-induced asthma is children in low-income urban families.
Fortunately, many of the interventions to reduce asthma triggers in home environments are relatively simple. Recently, a 7-year follow-up of a Canadian birth cohort has confirmed previous suggestions that simple environmental interventions directed at the hazards noted above can prevent asthma in high-risk children (Arshad 2003; Chan-Yeung 2005). Intervention measures such as encasing mattresses and pillows with dust mite-impermeable cases, removing carpets, and more frequent cleaning of clothes, floors, and upholstered furniture can reduce exposure of families to potentially harmful contaminants in home environments. In this article we describe costs associated with asthma and suboptimal indoor environments in the United States, evaluate studies that have investigated links between home environmental interventions and reduction of asthma symptoms in children, and address the economic impacts of these interventions and the subsequent health outcomes.
Abstract and Introduction
Abstract
Background: Contaminants encountered in many households, such as environmental tobacco smoke, house dust mite, cockroach, cat and dog dander, and mold, are risk factors in asthma. Young children are a particularly vulnerable subpopulation for environmentally mediated asthma, and the economic burden associated with this disease is substantial. Certain mechanical interventions are effective both in reducing allergen loads in the home and in improving asthmatic children's respiratory health.
Results: Combinations of interventions including the use of dust mite-impermeable bedding covers, improved cleaning practices, high-efficiency particulate air vacuum cleaners, mechanical ventilation, and parental education are associated with both asthma trigger reduction and improved health outcomes for asthmatic children. Compared with valuated health benefits, these combinations of interventions have proven cost effective in studies that have employed them. Education alone has not proven effective in changing parental behaviors such as smoking in the home.
Conclusions: Future research should focus on improving the effectiveness of education on home asthma triggers, and understanding long-term children's health effects of the interventions that have proven effective in reducing asthma triggers.
Introduction
People in modern societies spend the vast majority of their time–approximately 90%–in indoor environments, including homes, workplaces, schools, and public spaces such as restaurants and malls. Roughly 66% of that indoor time is spent in homes (Leech et al. 2002). Hence, indoor environmental quality in the home has a significant impact on public health and well-being. Indeed, indoor pollution has been ranked by both the U.S. Environmental Protection Agency (EPA) Science Advisory Board and the Centers for Disease Control and Prevention as a high environmental risk (Leung et al. 1997).
Although globally the greatest health risks are associated with particulate pollution from indoor biomass burning that kills an estimated 1.6 million people per year (World Health Organization 2002), the indoor environmental risks that are the focus of this article are related specifically to indoor air quality (IAQ) in higher-income countries. In this setting, indoor chemical contaminants include environmental tobacco smoke (ETS), nitrogen dioxide from space heaters and poorly ventilated furnaces, carbon monoxide, volatile organic compounds (VOCs), phthalates, and pesticides. Biological contaminants include antigens from house dust mites, molds, rodents, cockroaches, and animal dander. Dampness and endotoxins have also been implicated in health risks associated with indoor environments [Institute of Medicine (IOM) 2000, 2004; Thorne 2005].
Indoor air pollutants in the home may lead to the development and/or exacerbation of a variety of diseases and symptoms. Some known and postulated adverse health effects associated with poor indoor air quality are allergies, asthma, infection, hypersensitivity pneumonitis, inhalation fevers, mucosal irritation, central nervous system effects, psychologic effects (including depression), dermatitis, and even some forms of cancer (IOM 2000, 2004).
Asthma and allergic conditions in particular are believed to be associated primarily with exposure to contaminants common in indoor rather than outdoor environments (IOM 2000). The IOM has concluded there is sufficient evidence of a causal relationship between asthma development and exposure to house dust mite (IOM 2000). Substantial evidence indicates that children exposed to indoor air mold in the first years of their lives have a significantly higher probability of developing asthma (Jaakkola et al. 2005). There is sufficient evidence of a causal relationship between asthma exacerbation and exposure to cats, cockroaches, house dust mite, mold, and ETS in preschool-age children (IOM 2000). There is also increasing evidence that pollutants from vehicle traffic infiltrates indoors, adding to the risk of asthma and exacerbations (McConnell et al. 2006).
The number of self-reported asthma cases in the United States increased by 75% between 1980 and 1994 (Mannino et al. 1998). The most dramatic increase–160%–was seen in children younger than 4 years. From 1975 to 1994, the number of office visits for asthma increased from 4.6 million to 10.4 million. Almost 15 million Americans have asthma today (IOM 2000).
From a health-economics standpoint, the loss of quality of life and productivity from an early diagnosis of a lifelong chronic disease such as asthma is enormous–both to the individual and to the society. Moreover, when a child becomes sick, it is often the case that both a school day and a parent's workday are lost. Thus, educational and productivity losses because of adverse health effects from indoor contaminants could be substantial. Individuals with low incomes, particularly in inner cities, are more likely to be living in substandard housing with severe structural problems, with moisture intrusion, poor ventilation, and associated mold and pest-related problems. These families are the least likely to have the means (money and education) by which to remediate such problems (Evans and Kantrowitz 2002; IOM 2004). Often, they also lack access to information regarding the extent of health problems associated with indoor asthma hazards and appropriate remediation responses. Therefore, the group most likely to suffer from indoor environment-induced asthma is children in low-income urban families.
Fortunately, many of the interventions to reduce asthma triggers in home environments are relatively simple. Recently, a 7-year follow-up of a Canadian birth cohort has confirmed previous suggestions that simple environmental interventions directed at the hazards noted above can prevent asthma in high-risk children (Arshad 2003; Chan-Yeung 2005). Intervention measures such as encasing mattresses and pillows with dust mite-impermeable cases, removing carpets, and more frequent cleaning of clothes, floors, and upholstered furniture can reduce exposure of families to potentially harmful contaminants in home environments. In this article we describe costs associated with asthma and suboptimal indoor environments in the United States, evaluate studies that have investigated links between home environmental interventions and reduction of asthma symptoms in children, and address the economic impacts of these interventions and the subsequent health outcomes.
Source...