Poor indoor air quality (IAQ) in modern buildings has been implicated in increased employee absenteeism, low morale, and reduced worker productivity.
Those in charge of cleaning, maintenance and housekeeping are responsible for providing breathing air of the best possible quality and ensuring that pollutants do not degrade the indoor air.
As suggested by the U.S. Environmental Protection Agency (EPA), a thorough preventive cleaning and maintenance (PM) program allows building systems to operate at peak performance, and is the most important tool to prevent IAQ problems such as complaints of “sick building syndrome” by building occupants.
With the first energy crisis of the early 1970s, new buildings were designed with sealed outside envelopes, windows that did not open, and centralized control over the indoor climate and outside air exchange.
Significant emphasis was not initially placed on the cleanliness of the air or the quality of recirculated air supplied to building occupants.
However, as air pollutants build up inside a centrally controlled modern building, they need to be diluted with outside air and removed by the HVAC system.
In addition, indoor control of air pollutants is important to prevent the buildup of pollutants originating inside buildings.
Use of modern cleaning equipment (such as true high efficiency particulate air [HEPA] vacuums) and careful selection of less toxic cleaning chemicals, for example, help to decrease levels of airborne dust, volatile organic compounds (VOCs), bacteria, and fungal (mold) colony-forming units inside buildings, resulting in improved IAQ.
EPA-sponsored studies have demonstrated that an organized cleaning program contributes to reductions in particles (particulates), VOCs, and biological pollutants in the range of 50 percent to 90 percent.
Pollutants can be derived from indoor and outdoor sources. Some of the most common indoor contaminants are:
- Bioaerosols — Organisms such as molds, fungi, bacteria and viruses (or parts thereof, such as reproductive mold spores) that can move around the building with air currents. Bioaerosol exposure can trigger reactions in sensitive or allergic individuals. Certain bacteria sometimes found in HVAC and other building systems are potentially dangerous to humans. Viruses are particles that require an animal, bacterium or human host in order to replicate, which can cause maladies such as the common cold, flu and meningitis.
- Organic chemicals — Chemical pollutants include VOCs, which are used in significant quantities in everyday consumer products (such as nail polish remover and in dry cleaning). VOCs are often a problem when they migrate into buildings atop or near environmental spills, such as from contaminated soil or ground-water. Methane is a flammable gas produced in landfills, or also in poorly maintained grease traps or malfunctioning sewer systems. Carbon dioxide (CO2) is a colorless and odorless product of carbon combustion and animal/human metabolic processes. It is measured inside buildings as an indicator of proper air ventilation and circulation. Carbon monoxide (CO) is a colorless, odorless gas resulting from the incomplete oxidation of carbon in combustion processes. Common causes are improperly vented furnaces, malfunctioning gas ranges, or exhausts that are drawn back into buildings. CO causes asphyxiation, meaning it will prevent key parts of the body from receiving oxygen. At high levels, exposure can be fatal.
- Inorganic chemicals — Can include ammonia or chlorine bleach found in some cleaning products. Overuse or improper mixing of cleaning products near occupied areas can result in toxic gases such as chlorine gas. Hydrogen sulfide, which has a characteristic “rotten egg” odor and can be produced when sewers malfunction, is toxic at elevated levels. Inorganic chemicals include metal fumes or vapors (e.g., lead from welding or mercury, such as from industrial usage), paint or ink pigments, silica (from mining or mineral processing), and asbestos.
- Particulates — Include skin flakes, droppings and body parts from humans, insects, rodents or other pests or insects, dust mites and fecal matter, and inert airborne matter such as dusts, asbestos, silica, human skin pieces, and related materials. These are often collectively termed “particulates,” although particulates can include a range of living, non living, active, and inert substances.
Cleaning for better IAQ
According to the EPA, managing good IAQ typically involves three main strategies:
- Removing pollutant sources from the building or isolating them from building occupants.
- Diluting pollutants and removing them from the building through ventilation.
- Using filtration to remove pollutants from the air.
A 2000 study indicated that the performance of simulated office work such as typing, proofreading and addition improved when the air quality was increased through increasing the outdoor air supply rate and decreasing the indoor pollution load.
Perceptions of building cleanliness are also significant.
In 1997 at the Charles Young School in Washington, D.C., significant repairs and improvements were made to the school to correct water damage, mold, bad ventilation, failing air conditioning and problems due to deferred maintenance.
Student academic performance was continually below national averages, although this was also thought to be due to negative socioeconomic conditions in the surrounding neighborhood, such as unemployment, drug use and violence.
In 1997, a major restoration of the school was completed — including replacement of windows, removal of lead paint and repainting to create brighter rooms, repair of roofing and brickwork, removal of moldy and water-damaged materials, repair of leaking steam lines and plumbing, removal of hazardous chemicals, improvement of pest management strategies, removal of bird nests and droppings from the building, replacement of carpeting, and a complete overhaul of the HVAC system.
The carpet industry donated the carpeting, but also insisted on proper maintenance — which was to consist of training, maintenance schedules, effective vacuums, proper carpet cleaning equipment, and other supplies to sustain a healthy condition and inviting appearance of the carpeting.
Certain areas were refurbished with hard floors, which necessitated less intensive maintenance, but cleaning and disinfection nonetheless.
Since the restoration, the school environment has been lauded by teachers and staff and the restoration project has become a model for restoring nine other schools in Washington, D.C.
Attendance at the Charles Young School has risen from 89 percent to 93 percent, and many students who were schooled elsewhere before the restoration returned to the school.
Most telling is the significant increase in math and reading test scores — which suggests a direct link between a healthy school environment and academic performance.
Cleaning and maintenance tips for good IAQ
Some tips that can be followed to help maintain good IAQ in your buildings:
- Develop management and communication protocols that guide re-sponses to all complaints involving the indoor environment and IAQ.
- Identify staff responsible for IAQ issues and ensure they are properly trained.
- Identify and remove or correct existing and potential sources of indoor pollution.
- Choose environmentally friendly cleaners, adhesives, paints, pesticides, solvents, carpeting, equipment and furnishings to reduce fume and vapor production. Consider toxin-free products and read the labels.
- Always mix solutions according to label directions and store in proper containers.
- Provide adequate ventilation for interior painting, use of solvents or other tasks that can affect IAQ.
- Ensure combustion sources are properly vented to the outside.
- Make sure carpeting is thoroughly cleaned and dried to avoid mold growth.
- Check roof for leaks routinely to prevent unwanted moisture intrusion into the building which could promote mold growth.
- Use high-efficiency filters in the HVAC system — provided the system allows them — to remove small particles and develop routine schedules for filter replacement.
- Use preventive measures in pre-1978 schools to minimize lead exposure where paint is chipping or peeling.
- Ensure drain traps contain water to prevent sewer gas passage.
- Reduce classroom clutter and ensure science and art supplies are properly stored.
- Add doormats near building entrances to prevent outdoor dusts and particulates from entering building air.
- Improve ventilation and air filtration to dilute/exhaust indoor pollutants.
- Develop and implement long-term maintenance plans, schedules and recordkeeping and review and update them frequently. Maintain and follow up on all work orders.
- Maintain Material Safety Data Sheets (MSDS) for all on-site chemicals.
- Document compliance with cleaning and maintenance schedules.
- Maintain records as per corporate/governmental requirements.
Modern cleaning techniques and attention to maintenance schedules often result in improved IAQ and a better indoor environment for building occupants.
Management should promptly respond to building occupant complaints about IAQ or other health concerns and ensure that an effective communications program is in place with tenants.
Property managers and cleaning and maintenance personnel who now employ detailed schedules may want to review them to ensure that the procedures in place are in step with good IAQ.
Management, cleaning and maintenance personnel are encouraged to seek additional information — most of which is free through the Internet (See “Information on IAQ readily available” sidebar) — about the prevention and control of indoor air pollution and the protection of IAQ.*
Jeffrey G. Entin is a senior manager with ENVIRON International Corp., a health and environmental sciences consulting firm specializing in environmental, health and safety management, litigation support, due diligence, environmental compliance, indoor air quality, risk assessment, toxicological and epidemiological assessment, brownfield redevelopment, vapor mitigation, nanotechnology, and risk management. He is certified by the Indoor Air Quality Association and American Indoor Air Quality Council as an Indoor Air Quality Manager and Microbial Consultant. Entin is based in Princeton, NJ. He can be reached at firstname.lastname@example.org.
*Entin is not an attorney and nothing presented or discussed in this article is intended to be, nor should be construed as, legal advice. Legal counsel should be contacted in the event additional information on legal aspects of Indoor Air Quality issues is desired. Similarly, all building conditions and problems are specific cases that may require different solutions than those discussed above, and a qualified and competent consultant and/or contractor should be consulted for specific cases.