HHI Technical Studies (Research) Project Summaries

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• FY 2002 Advanced Energy; North Carolina
• FY 2002 St. Louis University; Missouri
• FY 2002 University of Medicine and Dentistry of New Jersey; New Jersey
• FY 2001 Air Quality Sciences; Georgia
• FY 2001 Columbia University; New York
• FY 2001 Duke University; North Carolina
• FY 2001 Radiation Monitoring Devices, Inc.;Massachusetts
• FY 2001 Research Triangle Institute; North Carolina
• FY 2001 University of Cincinnati; Ohio
• FY 2000 Healthy Public Housing, Harvard School of Public Health; Massachusetts
• FY 2000 Wisconsin Head Start Healthy Homes Initiative; Wisconsin
• FY 1999 Improving the Lead Dust Final Clean Protocol to Reduce Cockroach Allergen Exposure, Environmental Health Watch; Ohio

Advanced Energy Corporation; North Carolina (2002)

Advanced Energy and its collaborators (Habitat for Humanity, National
Institute of environmental Health Sciences) are investigating the impact of three approaches to low-cost residential construction on indoor environmental quality. The environmental measures of concern include both physical measures (e.g., humidity) and levels of common household allergens (e.g., dust mites) that can be important triggers for asthma and allergies. The researchers will examine the effects of relatively low-cost modifications in basic housing design (e.g., mechanical ventilation and improved moisture control) on these environmental measures, with the objective to determine which construction practices have the largest and most cost-effective impact on indoor environmental quality and ultimately, occupant health.

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Saint Louis University; Missouri (2002)

Researchers at the Saint Louis University School of Public Health are studying the growth and control of common household allergens (dust mites and mold) in carpets. Specifically, they will evaluate the relationship between dust mite and fungal (mold) growth on carpet, screen for effective products to kill and remove both mites and mold in carpets, and conduct experiments that can determine the growth of these organisms on various carpets. The major hypothesis that will be tested is that surface area of a carpet and carpet wear will affect the growth and cleaning of microorganisms and allergens from carpet.

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University of Medicine and Dentistry of New Jersey School of Public Health; New Jersey (2002)

In this study, the Environmental & Occupational Health Sciences Institute (EOHSI) of the University of Medicine and Dentistry of New Jersey, School of Public Health, is testing dry steam cleaning in conjunction with vacuuming as a method of reducing the levels of dust mite allergens, lead, and pesticides in carpets. Researchers will study approximately 50 homes with at least one room with wall-to-wall carpeting and a child with an elevated blood lead level. Each recruited home will be tested with two interventions: dry steam cleaning with regular vacuuming, and regular vacuuming only. Two different types of sampling methods will be used to collect dust samples from the carpets before and after cleaning to assess the effectiveness of the cleaning interventions.

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Air Quality Sciences; Georgia (2001)

The association between conditions of chronic water damage/dampness in homes and the occurrence of allergic respiratory disease is well-known (Dales 1991; Health Canada, 1995). The objective of this project is to provide a database that can serve as an aid in interpreting mycological sampling data collected in homes. Air and dust sampling data collected in a random group of 50 homes (with no water damage or respiratory complaints associated with the residence) in the urban Atlanta metropolitan area in 2001/2002 will provide baseline information on what is the "normal and typical" mold content of homes. This "healthy home" mold database can then be used as a guide for interpreting similar data collected in chronically damp/water damaged homes in Atlanta and other similar climatic regions. This project will fill an important information gap in the currently existing knowledge base, e.g., realistic control data to help the scientific and public health community better understand the role of the indoor environment, specifically moisture problems and resultant mold contamination, in health concerns.

The US Environmental Protection Agency's (USEPA's) Building Assessment and Survey Evaluation (BASE) study of 86 randomly selected, public and private office buildings in the United States has provided baseline environmental data on types and concentrations of fungi normally found in indoor air. This research project will develop a BASE-like pilot study on mycological parameters in randomly selected Atlanta metropolitan area, non-problem homes. The dataset generated in the pilot study will provide investigators with BASE-like information on the normal diversity of fungi found in the Atlanta metropolitan area and, in turn, be useful to investigators interpreting fungal exposure data in problem (e.g., asthmatic) homes.

Fifty participant (non-problem) homes will be selected through a mass mailing (5000 letters) directed at selected urban metro Atlanta zip codes (central city). The selection criteria will be single-family detached houses built since 1945 and located within census tracts listed as a "central city" location and with no known water-damage problem or associated respiratory complaints among occupants. Fifty participant homes will be randomly selected from those who meet the eligibility criteria and express a willingness to participate in the study. To assure that the sample is representative of the larger population of eligible houses, a sample of non-respondent houses will be contacted by phone and interviewed. This group will be compared to the sample group in terms of the selection criteria to determine if there are significant differences.

Following selection of the sample population of houses, two visits (one in heating season, and the second in the cooling season) will be made to each home enrolled. During the initial visit, an assessment of the building will be made to confirm the absence of visible water damage. Sampling will be conducted at each visit, as in the mold portion of the BASE study to allow the results of this study to be compared directly to the mold portion of the USEPA BASE study. Dust samples will be collected, and culturable mold populations will be analyzed from these samples. All culturable molds (rather than only the predominant types) from all samples will be enumerated and identified to the species level where possible. Quantitative results will be summarized with descriptive statistics. Qualitative results will be pooled and compared between seasons by Spearman's rank order statistic.

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Columbia University; New York (2001)

Mold exposure in homes has been associated with respiratory morbidity in children and adults, but the exact nature of the exposure is unclear. In addition, it is unclear how interview surveys and reports of damp and mold spots correlate with exposure to relevant mold components. Because the more objective measures of fungal exposure, utilizing microscopy, can be rather time-consuming and expensive, recent advances in immunoassays for fungal components such as extracellular polysaccharides (EPS) have enabled quantification of mold in house dust in a timely and cost-effective manner. These methods are anticipated to provide a better measure of fungal exposure (Chew et al. In Press; Douwes et al.1996; Douwes et al. 1999). For example, Douwes et al. (1999) found that EPS-Asp/Pen in house dust was positively associated with total culturable mold counts and with respiratory symptoms. Likewise, the use of other types of EPS may further enhance our ability to assess mold exposure.

An ongoing prospective birth cohort study at Columbia University's Mailman School of Public Health provides a unique opportunity to investigate the utility of measuring fungal EPS in house dust and fungal EPS specific IgG in serum of 400 mothers and 100 children in order to identify relationships between mold exposure and respiratory symptoms. The study has already received funding (NIEHS- P50 ES09600 & 5 ROI ES08977-02 and EPA- R 827027-02), to evaluate levels of airborne particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAH), indoor allergens, environmental tobacco smoke (ETS), and pesticides in the home. In addition, the study has been funded to collect nutrition information and measure several biomarkers including cotinine, PAH-DNA adducts, lead, antioxidants, total IgE, specific IgE, lymphocyte proliferation, and T cell cytokines. This study is straight-forward in design and one of the most comprehensive in exposure assessment and clinical evaluation of children. The addition of a novel mold exposure assessment will benefit not only this study, but also future residential and occupational studies where mold exposure is conceivably related to adverse health outcomes.

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Duke University; North Carolina (2001)

A variety of environmental hazards in the home pose individual and aggregate risk to children's health; yet, policy makers, public health officials, and child advocates lack the information required to evaluate children's risk and exposure potential across a broad range of risks. This project aims to use sophisticated information systems technology to develop risk models for evaluating housing-related environmental hazards and illnesses and, thus, focus environmental health and safety control methodologies. Specifically, this research project will develop, validate, and disseminate an aggregate GIS-based predictive model that will characterize a broad range of home environmental health risks to children down to the individual house level. This comprehensive children's environmental health risk model will allow counties across North Carolina and the nation to implement cost-effective approaches to environmental, in-home interventions that protect children before they become sick.

The proposed work will evaluate when and how different environmental exposures can reasonably be incorporated into a single predictive model, as well as when and how preventive intervention programs can be combined. As a result, the predictive model will enable communities to allocate resources most cost-effectively across a range of risks. With the characterization of the housing stock down to the individual tax parcel unit level, communities will be able to implement carefully tailored intervention programs that not only mitigate health effects from exposure, but also prevent adverse effects before exposure occurs.

This project will characterize the neighborhood housing stock in five North Carolina counties. The counties were chosen to allow for comparisons across regional, climatic, topographic, economic, and cultural zones. The analysis will incorporate three major data layers: a base layer map, consisting of county tax assessor and Census demographic data; an exposures overlay, incorporating data on housing-based environmental hazards; and a children's overlay, indicating the likely presence and characteristics of children.

The proposed project will be carried out in four phases:

• Phase 1: Build the predictive risk model using GIS technology.
• Phase 2: Conduct in-home assessments (via environmental sampling) to evaluate the predictive capability of the Phase I information system.
• Phase 3: Validate the predictive risk models by comparing Phase II data with Phase I spatial models.
• Phase 4: Communicate results and next steps to study participants, local government agencies, and community organizations.

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Radiation Monitoring Devices, Inc.; Massachusetts (2001)

There is a growing concern about the adverse health effects of mold for occupants of damp buildings. Mold spores have been linked to pulmonary hemorrhage, as well as allergic and asthmatic reactions. These health effects are expected to be more severe in infants, children, and immuno-compromised individuals. Therefore, early detection and remediation of mold in homes is expected to improve the quality of the home environment and have a significant positive impact on human health. This project will develop a compact bio-analysis instrument to detect, identify, and quantify the concentration of mold spores in homes. The portable instrument will collect a sample of room air and channel the mold spores through micro-fluidics to analysis chambers. The spore load will be analyzed using antibody reactions and ultra-sensitive optical detection techniques. The instrument will provide onsite analysis capability, enabling spore concentrations to be mapped from room to room and providing a means to identify specific areas of mold infestation for quick remediation.

Several species of mold have been linked to adverse health effects. Although mold species have been linked to adverse health effects, causes of "sick building syndrome" often go unexplained because of the lack of sensitive instruments to evaluate the magnitude of spore load in specific areas of buildings that are susceptible to fungal contamination. There is a critical need for low-cost analytical techniques for the onsite identification of toxigenic bio-aerosols so that the sources may be remediated. An approach to onsite identification and quantification of mold is the utilization of antibodies that specifically recognize fungal spores. The overall goal of this research is three-fold:

1. To demonstrate that the magnitude of total spore load at specific locations within a building can be estimated by subjecting collected bio-aerosols to an immunoassay using a series of polyclonal antibodies, raised against heat-killed condia and soluble extracts from four mold cultures (Penicillium sp., Aspergillus niger, Trichoderma harzianum, and Aureobasidium pullulans);
2. To build a library of monoclonal antibodies to purified spore coat antigens and demonstrate identification to species of a small number of IAQ-related mold fungi by fluorescence-linked immunosorbent assay;
3. To fabricate a low-cost, portable, biochip instrument that will utilize these polyclonal and monoclonal antibodies, and, in combination with fluorescence and light scatter measurements, can effectively evaluate the magnitude of spore load in contaminated buildings and recognize a small range of fungal species.

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Research Triangle Institute; North Carolina (2001)

The adverse health effects resulting from exposure of young children to environmental lead have been a major concern for many years. It is now common knowledge that chronic exposure to even low levels of lead can result in impairment of the central nervous system, mental retardation, and behavioral disorders. Dust containing lead from deteriorating paint and/or tracked in soil is the major source of exposure for children.

This research project will develop a new instrument for the rapid, accurate, low cost measurement of lead (and other metals) in dust using a combination of an efficient Total Dust vacuum and a portable X-ray fluorescence (XRF) instrument. Using a dry or wet vacuum, the Total Dust Vacuum will collect all removeable, residual surface materials (dust) and collect it on a filter for XRF measurement. The project will provide HUD with the research data to illustrate the utility and practicality of this new tool for the collection and analysis of environmental contaminants. It is believed that this new instrument will provide efficient and reproducible sample collection, while yielding immediate sample analysis results. This, in turn, will provide information to make onsite decisions about the presence of risk or requirements for clearance, and will offer significant monetary savings because of the reduced need for laboratory analysis.

The development of the instrument will be carried out in a series of sequential, logical steps. The Total Dust Vacuum will be further developed to yield efficient collection for all common types of dusts and surfaces. Knowing that some floors are "sticky," a liquid releasing or wetting agent will also be identified or developed, for wet vacuuming. Accordingly, a filter impregnated with an ion-exchange agent to collect any solubilized lead will be developed and tested. The Niton Model XL-703A portable XRF, modified for air filter analysis, will be evaluated with the filter(s) selected for dry and wet vacuuming. Filters will be spiked for this testing. Although lead will be the primary concern in this instrument development, measurement of chromium (Cr), nickel (Ni), arsenic (As), and selenium (Se) will also be investigated. After optimizations, the components will be incorporated into a single vacuum/XRF instrument and the complete, portable system will be evaluated for the analytes listed above. This laboratory evaluation will include the same testing parameters used for the Total Dust Vacuum alone.

After successful engineering, procedure, and protocol development, the instrument will be tested in residences in the Research Triangle area of North Carolina. A total of 10 dwellings undergoing risk assessment or abatement will be evaluated, with 24 samples collected in each residence. Test locations will include difficult-to-sample places like window wells; areas larger than one foot will be sampled and composite samples will be collected. For each vacuum/XRF sample, a wipe (or wipes in the case of composites) will be collected for comparison. Filters and wipe samples collected in the field will then be analyzed in RTI laboratories using inductively coupled plasma atomic emission spectroscopy (ICP-AES) for the analytes measured by XRF in the field. A statistical comparison of the field and laboratory results will be performed to evaluate the applicability of the proposed instrument.

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University of Cincinnati; Ohio (2001)

Fungi - well-known indoor contaminants that grow on moist building materials in homes - produce spores, which become airborne if disseminated from surface sources. About 36-percent of residential houses in the US have mold and moisture problems. These are particularly severe in the Midwest (including the Ohio River Valley region) due to the humid climate and frequent flooding. Mold and moisture are particularly common health hazards in low-income housing. Although the health problems caused by exposure to fungal spores in moldy homes are significant, there is no adequate method available for measuring the source strength for spores, which could adequately identify and assess mold problems in housing.

This project aims to further develop the coinvestigators' new cost-effective methodology for the measurement of fungal spore emissions in residential houses. Conventional indoor air sampling often does not detect high levels of airborne molds, but residents, particularly children, can develop severe health effects associated with exposure to fungal spores. In addition, field protocols require that the air sampling be performed for several intervals over a long time period; this increases the cost of hazard evaluation, but does not ensure that spores released from surfaces into indoor air are properly detected.

The newly-developed portable Fungal Spore Source Strength Tester (FSSST) consists of an inner cup, through which HEPA-filtered air is directed onto the contaminated surface, and an outer cap, through which the released spores are transported to the bio-aerosol sampler. Airflow and heat/vibration stimulate spore emission from moldy surfaces to the sampler. The samples are then analyzed and the spores that may cause adverse health effects are identified and enumerated. The new FSSST estimates the maximum amount of spores that can become airborne under the most favorable conditions. This method allows overcoming the limitations of conventional air sampling methods that cannot account for the fluctuative nature of fungal spore release, and, therefore, often give false negative results when used to sample moldy homes.

The evaluation and field implementation of the new method and protocol will be conducted in homes of low-income families with children under 12. The research provides a unique tool for assessing methods for reducing or eliminating housing-related hazards.

1. First, an in-depth study will be conducted on the factors controlling spore emissions from different building materials.
2. Second, the new method will be evaluated in the laboratory and in the field and then modified and optimized for general use in homes. Several sophisticated techniques for bio-aerosol generation, measurement, and microbial analyses will be employed in the laboratory evaluation phase. The detailed field-testing will be conducted in ten problem and ten non-problem homes, selected from at least 200 housing units owned/rented by low-income families with children. This selection will be based on residents' responses to a survey addressing the housing conditions in these 200 homes and reported respiratory symptoms.
3. Third, the new method will be utilized in ongoing housing intervention projects performed in moldy homes in the Ohio River Valley region. This part of the project will be conducted in collaboration with the City of Cincinnati Environmental Advisory Council and several local agencies, including the Better Housing League and People Working Cooperatively. The use of the newly-developed inexpensive and portable FSSST will allow inspectors, contractors, and residents to adequately assess housing-related mold problems and the effectiveness of interventions in homes.

An external Scientific Advisory Board composed of nationally- and internationally-recognized experts representing exposure assessment, microbial ecology, indoor air quality, building engineering, pulmonary medicine, allergology, and epidemiology will provide technical advice throughout the project.

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Healthy Public Housing, Harvard School of Public Health; Massachusetts (2000)

Healthy Public Housing is designed to improve resident health and safety, housing quality, environmental conditions, and energy efficiency using a holistic framework that acknowledges the interconnections between the health of residents, the condition of their housing, and resident involvement in achieving healthier conditions in public housing.

The goals for the program include:

• Documenting the prevalence of environmental, comfort, and health conditions for public housing residents;
• Implementing remedial measures that improve resident health, particularly for asthmatic children;
• Reducing environmental hazards based on measured indicators;
• Quantifying the economic benefits of interventions to be compared with implementation costs in policy frameworks; and
• Developing a collaborative framework that enables the findings from this study to be applied on an ongoing basis to influence public housing policy at the local, state, and federal levels.

The target area for the program is the network of Boston Housing Authority developments and its 14,500 households. Average household income within the developments is $11,250 a year. Asthma and bronchitis are leading causes of hospitalization and three neighborhoods within the target area – Roxbury, North Dorchester, and South Dorchester -- had the highest rates of blood lead poisoning among all Boston neighborhoods in 1997.

Team members will employ three strategies to improve the quality of life for public housing residents:
1. Conduct research to test interventions that improve resident health, safety, and comfort, resulting in physical and economic benefits.
2. Demonstrate the impact of energy improvements and modernization of developments on resident health, comfort, and perceived quality of life.
3. Establish outreach activities with a resident/Boston Housing Authority working group to devise policies, practices, and procedures that incorporate findings on an ongoing basis and bring these to a larger public housing audience.

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Wisconsin Head Start Healthy Homes Initiative; Wisconsin (2000)

The University of Wisconsin's Schools of Pharmacy and Medicine partnered with several public health entities to reduce three health risks for preschool-aged children: asthma, home injury hazards, and lead exposure. The target population is the poverty-level families of 700 preschool children enrolled in Dane County's Head Start program. Twenty-seven percent of the housing stock in Dane County was built before 1950 and 16 percent of the area's 3,522 children enrolled in Head Start have been diagnosed with asthma.

The program will use home visits to the families of the Dane County Parent Council Head Start program to reduce environmental risk factors related to asthma, injury, and lead poisoning. These home visits, by professionals and trained members of Head Start families will employ an extensive environmental survey involving home inspection for allergen, injury hazard, and lead exposure; risk stratification; and targeted home interventions.

The program consists of three one-year cycles. Families will first complete questionnaires to help staff identify children with asthma, children at-risk for home injury hazards, and children at-risk for environmental lead exposure. Families with children meeting the risk criteria will receive home hazard inspections.

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Improving the Lead Dust Final Clean Protocol to Reduce Cockroach Allergen Exposure, Environmental Health Watch; Ohio (1999)

Environmental Health Watch of Cleveland, Ohio is combining advances in testing for cockroach allergen with the established lead final clean protocols to develop an intervention that simultaneously reduces the incidences of lead poisoning and asthma in the area's children. Research indicates that cockroach allergen is one of the most frequent triggers of asthma in inner-city populations. The multi-city National Cooperative Inner-city Asthma (NCICAS) study found that 27 percent of Cleveland's inner-city asthmatic children were highly sensitive to cockroach allergen.

The usual method for assessment of cockroach allergen contamination is a monoclonal analysis of vacuum dust samples. However, researchers at the University of Florida have developed a polyclonal detection assay (swab samples) for cockroach allergens that is less expensive than the traditional method. The lower cost allows many samples to be taken within a housing unit, improving the effectiveness of the cleanup and lowering the overall cost.

The program's target area is family housing with cockroach infestation owned by the Cuyahoga Metropolitan Housing Authority. The program will intensively evaluate the effectiveness of interventions directed at three of the most common and serious residential hazards for children living in this housing: lead dust, cockroach allergen, and household pesticide residue. The program team will recruit 15 households within the Cuyahoga Metropolitan Housing Authority to participate in the study. After confirmation of cockroach infestation and elimination by integrated pest management methods, a HUD standard lead cleanup will be progressively modified to create a multi-hazard cleanup strategy. The goal is to attain levels of cockroach allergen to below reported sensitivity levels. Follow-up testing to assess recontamination in these units will be carried out after the initial cleaning and testing.

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