Applicability of the Environmental Relative Moldiness Index for Quantification of Residential Mold Contamination in an Air Pollution Health Effects Study
The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) investigated the impact of exposure to traffic-related air pollution on the respiratory health of asthmatic children in Detroit, Michigan. Since indoor mold exposure may also contribute to asthma, floor dust samples were collected in participants homes () to assess mold contamination using the Environmental Relative Moldiness Index (ERMI). The repeatability of the ERMI over time, as well as ERMI differences between rooms and dust collection methods, was evaluated for insights into the application of the ERMI metric. ERMI values for the standard settled floor dust samples had a mean standard deviation of , indicating high levels of mold contamination. ERMI values for samples collected from the same home 1 to 7 months apart () were consistent and without systematic bias. ERMI values for separate bedroom and living room samples were highly correlated (, ). Vacuum bag dust ERMI values were lower than for floor dust but correlated (, ). These results support the use of the ERMI to evaluate residential mold exposure as a confounder in air pollution health effects studies. 1. Introduction Asthma is the most common chronic disease of children in the United States (US) [1, 2]. Asthma prevalence and related death rates in Detroit are the highest in Michigan and among the highest in the US [3]. Living close to busy roads may be an important risk factor for onset of childhood asthma, and studies have found positive associations between exposure to traffic-related pollution and wheezing in children [4]. In addition, exposure of children in Detroit to ambient air pollutants has been associated with asthma exacerbation [5–7]. Currently, the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) is investigating the impact of exposure to traffic-related air pollutants on the respiratory health of a cohort of children with asthma who live near major roadways in Detroit [8]. However, other exposures may also contribute to asthma-related health outcomes, including cigarette smoke, allergens, and mold [9–13]. An assessment of residential mold contamination was, therefore, included in the NEXUS study design. To standardize the quantification of mold contamination in homes, the Environmental Relative Moldiness Index (ERMI) scale was createdby US EPA researchers in conjunction with the US Department of Housing and Urban Development (HUD) [14]. The standard sample for an ERMI analysis is a composite of bedroom and living room floor dust obtained using the MiTest sampler. This sample is
References
[1]
R. A. Rudd and J. E. Moorman, “Asthma incidence: data from the National Health Interview Survey,” Journal of Asthma, vol. 44, no. 1, pp. 65–70, 2007.
[2]
CDC (Centers for Disease Control and Prevention), “Trends in Asthma Prevalence, Health Care Use, and Mortality in the United States, 2001–2010,” http://www.cdc.gov/nchs/data/databriefs/db94.pdf.
[3]
E. Wasilevich, S. Lyon-Callo, A. Rafferty, and K. Dombkowski, “Detroit—the epicenter of asthma burden,” in Epidemiology of Asthma in Michigan, Michigan Department of Community Health, Lansing, Mich, USA, 2008.
[4]
HEI (Health Effects Institute), “Traffic-related air pollution: a critical review of the literature on emissions, exposure, and health effects,” HEI Special Report 17, Health Effects Institute, Boston, Mass, USA, 2010.
[5]
J. Gallagher, E. Hudgens, A. Williams et al., “Mechanistic Indicators of Childhood Asthma (MICA) study: piloting an integrative design for evaluating environmental health,” BMC Public Health, vol. 11, article 344, 2011.
[6]
S. Li, S. Batterman, E. Wasilevich, H. Elasaad, R. Wahl, and B. Mukherjee, “Asthma exacerbation and proximity of residence to major roads: a population-based matched case-control study among the pediatric Medicaid population in Detroit, Michigan,” Environmental Health, vol. 10, article 34, 2011.
[7]
S. Li, S. Batterman, E. Wasilevich, et al., “Association of daily asthma emergency department visits and hospital admissions with ambient air pollutants among the pediatric Medicaid population in Detroit: time-series and time-stratified case-crossover analyses with threshold effects,” Environmental Research, vol. 111, no. 8, pp. 1137–1147, 2011.
[8]
A. Vette, J. Burke, G. Norris et al., “The Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS): study design and methods,” Science of the Total Environment, vol. 448, pp. 38–47, 2013.
[9]
IOM (Institutes of Medicine) and National Academies of Science, Damp Indoor Spaces and Health, The National Academies Press, 2004.
[10]
WHO (World Health Organization) Europe, WHO Guidelines for Indoor Air Quality: Dampness and Mould, WHO, Copenhagen, Denmark, 2009.
[11]
N. Rabinovitch, L. Silveira, E. W. Gelfand, and M. Strand, “The response of children with asthma to ambient particulate is modified by tobacco smoke exposure,” American Journal of Respiratory and Critical Care Medicine, vol. 184, no. 12, pp. 1350–1357, 2011.
[12]
L. J. Akinbami, B. K. Kit, and A. E. Simon, “Impact of environmental tobacco smoke on children with Asthma, United States, 2003–2010,” Academic Pediatrics, vol. 13, no. 6, pp. 508–516, 2013.
[13]
K.-H. Kim, S. A. Jahan, and E. Kabir, “A review on human health perspective of air pollution with respect to allergies and asthma,” Environment International, vol. 59, pp. 41–52, 2013.
[14]
S. J. Vesper, C. McKinstry, R. A. Haugland, et al., “Development of an environmental relative moldiness index for homes in the U.S,” Journal of Occupational and Environmental Medicine, vol. 49, pp. 987–990, 2007.
[15]
T. Reponen, S. Vesper, L. Levin, et al., “High environmental relative moldiness index during infancy as a predictor of asthma at 7 years of age,” Annals of Allergy, Asthma & Immunology, vol. 107, no. 2, pp. 120–126, 2011.
[16]
T. Reponen, J. Lockey, D. I. Berstein, et al., “Infants exposed to specific molds correlated with age seven asthma,” Journal of Allergy and Clinical Immunology, vol. 130, pp. 639–644, 2012.
[17]
R. A. Haugland, M. Varma, L. J. Wymer, and S. J. Vesper, “Quantitative PCR analysis of selected Aspergillus, Penicillium and Paecilomyces species,” Systematic and Applied Microbiology, vol. 27, no. 2, pp. 198–210, 2004.
[18]
S. Vesper, C. Barnes, C. E. Ciaccio et al., “Higher Environmental Relative Moldiness Index (ERMI) values measured in homes of asthmatic children in Boston, Kansas City, and San Diego,” Journal of Asthma, vol. 50, no. 2, pp. 155–161, 2013.
[19]
D. Johnson, D. Thompson, R. Clinkenbeard, and J. Redus, “Professional judgment and the interpretation of viable mold air sampling data,” Journal of Occupational and Environmental Hygiene, vol. 5, no. 10, pp. 656–663, 2008.
[20]
S. Vesper, “Traditional mould analysis compared to a DNA-based method of mould analysis,” Critical Reviews in Microbiology, vol. 37, no. 1, pp. 15–24, 2011.
[21]
S. Vesper, C. McKinstry, R. Haugland et al., “Higher Environmental Relative Moldiness Index (ERMIsm) values measured in Detroit homes of severely asthmatic children,” Science of the Total Environment, vol. 394, no. 1, pp. 192–196, 2008.
[22]
P. Kaarakainen, H. Rintala, A. Veps？l？inen, A. Hyv？rinen, A. Nevalainen, and T. Meklin, “Microbial content of house dust samples determined with qPCR,” Science of the Total Environment, vol. 407, no. 16, pp. 4673–4680, 2009.
[23]
E. Johansson, T. Reponen, S. Vesper, et al., “Microbial content of household dust associated with exhaled NO in asthmatic children,” Environment International, vol. 59, pp. 141–147, 2013.
