Reproduced from the The Steamway Cleaning Scene, Fall '94, pages 1,6.

Research Conducted for the United States Environmental Protection Agency
Confirms the Value of Hot Water Extraction Carpet Cleaning In Improving Indoor Air Quality
As Part of a Total Environmental Management And Cleaning System

A recently conducted scientific study performed by the Research Triangle Institute in Chapel Hill North Carolina for the United States Environmental Protection Agency, was recently reported on as part of an effort to study the effect of cleaning on the quality of the indoor air in buildings. This study can be identified as follows:

Indoor Environment Characterization of A Non-Problem Building: Assessment Of Cleaning Effectiveness Prepared For:

United States Environmental Criteria And Assessment Office U.S. Environmental Protection Agency Research Triangle Park, NC 27711

EPA Cooperative Agreement CR-815509-02-1 RTI Project Number 94U-4479-014

Prepared By:

Research Triangle Institute P.O. Box 12194

Research Triangle Park, North Carolina 27709-2194

In some statements, the study is referred to as the Frank Porter Graham (FPG) study because the building used for the study was performed at the Frank Porter Graham Child Development Center at the University of North Carolina in Chapel Hill, North Carolina.

Over the next few issues of the CLEANING SCENE, we will be reprinting, with permission, significant sections of this study. The following, reprinted with permission. is just part of the 202 page report on the findings of this study. The abstract defines the scope and purpose of the study.

ABSTRACT

A study was conducted to characterize the indoor environment of a multi-floor, multiuse, non- problem, non-complaint building through long-term sampling for biological, chemical, and particulate pollutants: and to assess the effects of cleaning on indoor air quality. The study protocol included five months of "baseline" environmental measurements, a rigorous cleaning of the entire building; and, subsequently, seven months of environmental monitoring after implementation of an economically feasible, standard cleaning program. Air, surface, and dust data from monitoring prior to the cleaning program were compared with those obtained while the improved housekeeping program was in place to assess the effectiveness of the cleaning program on the indoor environment. Correlations between pollutants and other environmental factors are also presented. This work involved a collaborative effort by Research Triangle Institute, the U.S. Environmental Protection Agency's Environmental Criteria and Assessment Office, the University of North Carolina at Chapel Hill (UNC), the building service contractor, and commercial cleaning and carpet industries, and their suppliers.

The study concluded that an organized cleaning program based upon environmental management principles and fundamental environmental protection guidelines contributed to improved indoor air quality through reduction of total suspended particles, total volatile organic compounds, and culturable bacteria and fungi. (Page iii in study)

EXECUTIVE SUMMARY

In an earlier study, the Research Triangle Institute (RTI) monitored for bio-aerosols, chemical and particles before and during carpet cleaning in commercial and residential environments (Cole and Foarde, 1992). Non-complaint environments were selected, although problems were found in two of the buildings. In general, the pollutant levels before and during carpet cleaning were related to the extent of routine cleaning in the building. As an extension of the research, the current study was established to better understand and assess the effectiveness of an economically-feasible, standard cleaning program to improve indoor air quality in a building, and to generate an extensive database characterizing anon- problem or "healthy" building environment. This study was planned and conducted with extensive collaboration among personnel from RTI, the U.S. Environmental Protection Agency, lead by the Environmental Criteria and Assessment Office with extensive involvement by the Air and Energy Engineering Research Laboratory, the University of North Carolina at Chapel Hill (UNC), the building service contractor, commercial cleaning and carpet industries, and their suppliers. This study represents an early example (which is being utilized with increasing frequency) of extensive government, not-for-profit organization, and industry collaboration, where industry representatives served on an advisory committee and provided technical guidance in selected areas of key importance to the success of the research.

After extensive protocol development by the many collaborators, the yearlong, environmental monitoring effort was performed at the Frank Porter Graham Child Development Center (FPG) at the University of North Carolina, Chapel Hill, North Carolina. The Center is a multi-disciplinary, research effort led by pediatricians, psychologists, educators, and the health professionals who are studying the development of normal and handicapped preschool children. This 20 year old building has four floors and is approximately 2,700 m2, 66% of which is carpeted. There is a day care facility for 62 children, and 214 adults work with the day care and in the offices and laboratories of the building. Two full-time university housekeeping staffs are assigned to the building.

The environmental monitoring included bioaerosol sampling, non-floor surface biologicals, floor dust samples for mass and biologicals, aerosol particle counts, aerosol dust mass, volatile organic compounds, and comfort factors such as temperature, relative humidity, carbon monoxide, and carbon dioxide. Initially (July 1992), the building was inspected, and an extensive environmental

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Col 2

During the course of the study, several unplanned "occurrences" were environmentally managed. They included a mold contaminated wall in a nursery area, flooding from plumbing and roof leaks, and smoke infiltration from neighborhood fires. When necessary, restoration was rapidly performed and each location was monitored to ensure the bio-pollution did not amplify. Thus, several unplanned "mini-studies" resulted and are described in various sections of the report.

Results of the study are compiled from detailed data in Section 6.0, 7.0, and 8.0 and are presented in Table 1. Key findings, conclusions, and research needs follow Table 1.

 Before Extraction 

After Extraction

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SUMMARY OF MAJOR FINDINGS

Particle Results

• . Airborne dust mass, measures as total suspended particles (TSP), provided the most meaningful particle data and showed a statistically significant reduction with improved cleaning.

• . Immediately after deep cleaning, carpet dust mass was reduced, particularly on floors with the highest dust loads.

• . Soon after deep cleaning, carpet dust mass loads quickly returned to before cleaning levels, confirming carpet as a sink or collector of particles.

• . Airborne dust mass was decreased after deep cleaning and continued lower even though the

• total mass /rom dust in carpets soon returned to original levels. Bio-pollutant Results: Correlations

• . Airborne levels of bio-pollutants correlated with airborne dust mass, and the bacteria correlation is statistically significant.

• . Levels of bacteria and fungi from non-floor surfaces correlated (statistically significant) with

• airborne levels of bacteria and fungi providing evidence that surface pollutants can be reflective of airborne levels and airborne levels can be reflective of surface contamination.

• . Levels of carpet dust bacteria have a statistically significant correlation with airborne bacteria

• indicated a relationship between the two that demonstrates the need for cleaning pollutant removal as an environmental management tool for maintaining acceptable air quality. '  
  

Bio-pollutant Results of Data Comparison

• . A yearlong study of a non-problem building showed that attention to improved housekeeping (in conjunction with proper HVAC operation and maintenance), resulted in sustained reduction of mean levels of:

  • - airborne bacteria (40%) and fungi (61 %), (Andersen sampler),

  • - non-floor surface bacteria (29%) and fungi (25%),

  • - carpet dust bacteria (84%), fungi (93%), and endotoxin (72%).

  • . Deep cleaning resulted in reduction of mean levels of:

  • - airborne bacteria (58%) and fungi (25%), (Andersen sampler) - non-floor surface bacteria (58%) and fungi (15%),

  • - carpet dust bacteria (76%), fungi (99%), and endotoxin (98%).

Overall Results

• . An organized cleaning program based upon environmental management principles and fundamental environmental protection guidelines contributed to indoor air quality through the reduction of total suspended particles (TSP), total volatile organic compounds (TVOC's) and culturable bacteria and fungi.

• . While airborne pollutants increased during deep cleaning, they never reached levels of concern to the researchers, and were shown to decrease rapidly to levels well below the "pre- cleaning" concentrations.

• . The study data suggests the ambient, environmental pollution can be significantly controlled through an effective and managed indoor cleaning program.

• . Routine, non-floor, surface bacterial and fungal sampling can help identify areas for focused cleaning, as well as provide a useful assessment of a building's changing microbial ecology.

(Pages v-x in study)