by Michelle McHugh, Ph.D. — Along with increasing creativity and design techniques, new technologies in the modern built environment enable facilities to be more efficient and receptive to occupants’ needs. Although today’s buildings are built with energy efficiency and sustainability in mind, these technologies bring new challenges. One of the biggest challenges faced by FM professionals is maintaining a balance between a building’s functionality and occupant comfort, safety and health. The complexity of managing a facility is highlighted by the competing demands of housekeeping, building maintenance and communication with occupants. When these competing demands converge and a building is not maintained in the manner prescribed by its original design, maintaining a healthy and safe indoor air environment becomes more difficult.
Indoor air quality (IAQ) refers to the environmental conditions inside a building that affects the comfort, work performance and the health of its occupants. In the last 20 years, IAQ has emerged as a leading concern for building managers and owners. According to the U.S. Environmental Protection Agency (EPA), people spend 90 percent of time indoors and the air inside the building can be more polluted than that outside. Indoor air environments are multifaceted and occupants can be exposed to pollutants generated indoors and those that enter from the outside. Contaminant sources that emit particles include tobacco smoke, mold and mildew that grow on damp surfaces, office machines, construction activities and building materials. Gases and fumes also are emitted from building furnishings, consumer products and cleaning products with insects, pollen and outdoor pollutants adding to the already complicated indoor air environment. The health effects of buildings with significant IAQ problems has led to the EPA consistently ranking indoor air pollution among the top five environmental threats to public health.
Buildings are constructed to foster human activity and protect occupants from outside elements; therefore maintaining a healthy indoor air environment is vital. Building performance is measured by how effectively the building supports its occupants’ performance and how efficiently the building operates in order to keep costs manageable. Buildings should foster, not hinder, the work performance of its occupants nor cause discomfort or illness. If a facility’s IAQ is not managed on a daily basis, the consequences for the building owner can surpass the cost of the remediation of the problems and lead to lawsuits. It is important for building owners and facility managers to understand the causes and consequences of poor indoor air quality and how to maintain and manage a healthy indoor air environment.
Causes of poor IAQ
Poor indoor air quality is associated with the increased proliferation of chemicals in consumer and cleaning products; tighter buildings with reduced or improper ventilation; as well as deferred maintenance and other building services due to cost reductions. Indoor air pollutants, climate factors and other stressors from noise and light affect occupant comfort and can be acute or chronic and impact performance. Even modest changes in temperature and relative humidity can lead to lack of concentration and diminished work performance. Some indoor air pollutants cause infectious diseases such as the common cold and influenza; exacerbate allergy or asthma symptoms; and promote eye, ear, nose and throat irritation, cough, wheezing and headaches.
Acute health effects occur within 24 hours after exposure and can lead to headaches from chemicals released by building materials; itchy or watery eyes from mold spores; or respiratory infections that can lead to chronic respiratory conditions. Acute health effects are not long lasting and usually disappear once the exposure ends. Chronic health effects may occur due to a low concentration of certain chemicals over a long period of time or frequently repeated exposures. Indoor air pollutants such as radon, benzene, asbestos and environmental tobacco smoke have been associated with an increased risk of certain types of cancer.
Sick building syndrome (SBS) and building related illness (BRI) are the two most common syndromes or ailments associated with occupant complaints and the rapid rise of IAQ problems. Both occur from indoor air pollutants but differ in terms of the potential causal link to illness. SBS occurs when there is no obvious cause of symptoms and medical tests reveal no particular abnormality, but the symptoms disappear when the occupant leaves the building. SBS complaints include irritation of the eyes, nose and throat; headaches; mental fatigue; lethargy; and skin irritation.
In contrast, BRI is associated directly with a causal contaminant from the building indoor air environment. These contaminants can be chemical (e.g., formaldehyde, pesticides, solvents, lubricants, sealants, dyes) or biological. Biological contaminant sources include cockroaches, dust mites on upholstered furniture, rodents, humidification systems, cooling towers, drain and filter pans, damp duct insulation and other wet surfaces such as water damaged building materials. Legionnaires’ disease, hypersensitivity pneumonia and humidifier fever are examples of BRIs. Although most of these diseases can be treated, some pose serious health effects. Experts from the World Health Organization estimate that more than 30 percent of new buildings and remodeled commercial buildings may have unusually high rates of IAQ-related complaints.
Both indoor climate and indoor air pollution are key building factors that affect air quality. The indoor thermal environment (temperature, relative humidity and airflow) impacts IAQ and simply adjusting the building’s temperature and relative humidity can mitigate some occupant complaints. Higher building temperatures affect the rate at which chemicals are released from building materials, thus warmer occupants may be exposed to higher pollutant levels. Along with building furnishings and office equipment, occupants and their activities produce indoor air pollution. Well functioning buildings remove pollutants when outdoor air replaces indoor air and when directly exhausted to the outside. Although outside air also may contain contaminants, a good ventilation system will manage this air exchange process. Because air flows from higher to lower areas of atmospheric pressure, ventilation systems can utilize these pathways to draw pollutants away from occupants. Unfortunately, poorly designed or maintained ventilation systems can produce the opposite effect and draw pollutants into occupied areas. Particles settling onto surface and chemicals absorbed by surface are two natural processes of contaminant removal, while incorporating an air filtration device into the ventilation system will further reduce contaminants in the indoor air environment.
To maintain a healthy indoor air environment, the facility manager is responsible for identifying the sources of indoor pollution and taking steps to mitigate and control these sources. To address the pollutants in the indoor air environment, the EPA suggests housekeeping and maintenance use low-emitting products, avoid aerosols and sprays, use high efficiency vacuum bags and filters, clean and store mops to dry, and use exhaust ventilation in storage spaces. Occupant-related sources can be addressed through smoking policies, educational materials for occupants, avoiding paper clutter and using exhaust ventilation with pressure control for major local sources. For print/photocopy shops, dry cleaners, science laboratories, medical offices, hospitals, cafeterias and pet stores, the EPA recommends using exhaust ventilation and pressure control as well as exhaust hoods where appropriate. Building material-related sources such as carpets and carpet adhesives, transformers, upholstered furniture, wet building products, construction adhesives, plywood/compressed wood and remodeling can be addressed by using low-emitting products, keeping material dry before use, air out and ventilate area before installing materials, and increase ventilation rates during and after installation.
Sources of HVAC system contaminants include contaminated filters and duct lining; dirty drain pans and humidifiers; improperly stored lubricants and refrigerants; and unvented combustion appliances. Performing HVAC preventive maintenance, instituting a filter change protocol, using potable water for steam humidification, maintaining a spotless mechanical room and disallowing unvented combustion appliances will mitigate the pollutants associated with the HVAC system. Keeping the building dry and implementing a mold and moisture control protocol will address moisture issues and using exhaust ventilation and maintaining garages under negative pressure in relation to the building will help mitigate and control vehicle-related sources.
Understanding and controlling the sources of indoor contaminants will help building managers prevent the health symptoms and illnesses associated with poor indoor air environments. A host of resources and programs exist to help building managers maintain a healthy indoor air environment. In particular, the EPA created an online learning program to address IAQ in large buildings that can be downloaded from the Internet. The IAQ Building Education and Assessment Model (I-BEAM) is designed to be an updated, state-of-the-art guidance for managing IAQ in commercial buildings (http://www.epa.gov/iaq/largebldgs/i-beam/index.html). Another comprehensive curriculum materials program to address human health and the built environment can be downloaded from the Vital Signs Project administered though the Center for Environmental Design at the University of California-Berkeley (http://arch.ced.berkeley.edu/vitalsigns/res/downloads/rp/iaq/iaq.pdf). Both programs are useful tools to help facility management professionals develop maintenance, housekeeping, renovation and energy efficient programs to protect indoor air quality. FMJ
References/Resources
- Environmental Protection Agency, The Inside Story: A Guide to Indoor Air Quality, http://www.epa.gov/iaq/pubs/insidestory.html#Suspect
- National Institute for Occupational Safety and Health (NIOSH), Work Safety & Health Topics, Indoor Environmental Quality, http://www.cdc.gov/niosh/topics/indoorenv/
- Building Air Quality Action Plan, EPA Publication No. 402-K-98-001, DHSS (NIOSH) Publication No. 98-123, http://www.cdc.gov/niosh/98-123a.html
- Indoor Air Quality Scientific Findings Resource Bank, Lawrence Berkeley National Laboratory, Indoor Environment Department, http://www.iaqscience.lbl.gov
- Environmental Protection Agency, IAQ Building Education and Assessment Model (I-BEAM), http://www.epa.gov/iaq/largebldgs/i-beam/index.html
- The Vital Signs Project, Health and the Built Environment: Indoor Air Quality, http://arch.ced.berkeley.edu/vitalsigns/res/downloads/rp/iaq/iaq.pdf
Michelle McHugh, Ph.D., is a postdoctoral fellow at the University of Texas MD Anderson Cancer Center where her research focuses on occupational and environmental exposures and risk of lung cancer. She earned a doctor of philosophy in public health from the University of Texas Health Science Center at Houston School of Public Health. She can be reached at mkmchugh@mdanderson.org.