Diagnosing IAQ Dangers
Wireless instruments and data aggregation systems offer additional advantages for IAQ monitoring.
- By Bobby Sheikhan
- Apr 01, 2013
Poor indoor air quality (IAQ) can threaten the health and lives of the people in that environment, and may require IAQ experts to investigate the source of dangerous air. This article discusses the elements of leading indoor air pollutants and the wireless gas- and radiation-detection instruments for detecting and identifying IAQ threats quickly and efficiently.
Did you know more lives are lost annually to illnesses from indoor air pollution -- such as radon-gas-induced lung cancer -- than lives lost to car accidents related to alcohol in the United States?1 While the very real dangers of poor indoor air quality are not widely known, EPA lists it as the fourth-largest environmental threat in the United States,2 estimating air quality inside homes can be two to five times more polluted than outside air.3 It's an alarming statistic, especially when you consider most people spend more than 95 percent of their time inside a sealed building.
As a result, IAQ has become a greater concern in the past few decades as building materials have improved for energy efficiency and buildings have become more airtight. The drive for greater HVAC efficiency has brought new buildings and renovations with increased insulation, double-paned windows, and tighter seals throughout. At the same time, a degradation of inside air quality can occur. This is primarily attributable to structures with less fresh air, which is required to dilute airborne contaminants. Such pollutants can lead to an increase in sick building syndrome complaints.
Additionally, impure outside air can find its way inside. While indoor air pollution typically comes from sources inside the building, there also is a risk outside air pollutants can enter buildings through opened doors, damaged window seals, plumbing vents, or leaks. Determining the quality of indoor air involves the collection of air samples, performing computer models of airflow inside a building, and monitoring human exposure to pollutants.
Wireless Detection Monitors Improve Safety
Today, there are new methods to detect indoor air pollution, reduce risk, and maintain compliance. Investigators can now remotely monitor inside a room, plant, or building for gas and radiation or aggregate readings from multiple detectors in various locations by wirelessly networking these instruments. This provides environmental experts new ways to remotely collect data in real time and automatically generate reports more quickly and easily than ever before.
While both fixed and portable stand-alone instruments are invaluable tools for isolating and identifying dangerous leaks or other health hazards, wireless instruments and data aggregation systems offer additional advantages for IAQ monitoring. These advantages include portability and easy set-up for monitoring multiple locations in a building and the ability to view readings securely from anywhere at any time over the Internet. Easy-to-use monitoring software captures all of the data for documentation and report generation.
In recent years, a host of updated gas detection instruments and systems that incorporate new, field-proven technologies have been designed to enhance worker, responder, and public safety. New gas-detection tools offer more automated features to capture and store greater data readings than in the past. This allows organizations to accurately document events and exposures in real time for use in potential litigation or remediation.
Photoionization detector (PID) sensors capable of detecting minute levels of contaminants give IAQ investigators a fast and effective way to identify and quantify a problem related to volatile organic compounds, including microbial VOCs. Regardless of whether the instrument is a stand-alone or networked device, multi-gas monitors with a PID sensor provide an ideal tool for detecting VOCs. PID monitors are used for both portable IAQ surveys and permanent IAQ subsystems for a building HVAC system. This gives IAQ consultants, safety & hygiene professionals, and building managers a reliable, affordable, accurate means of directly measuring VOCs in real time so problems can be quickly identified and addressed. The parts-per-billion resolution of PIDs provides immediate insight and diagnosis at a detection sensitivity level required for IAQ surveys.
Leading Indoor Air Pollutants
The following indoor air pollutants can cause a wide range of health issues that include, but are not limited to, infections; allergic symptoms; asthma attacks; skin rashes; health problems such as eye, nose, and throat irritation; and lung cancer. The top indoor air pollutants include:4
- Carbon monoxide
- Combustion pollutants
- Microbial/biological contaminants (mold, dust mites, etc.)
- Secondhand tobacco smoke
- Volatile organic compounds
Indoor air quality monitoring can be employed to detect many of these pollutants so sources can be identified and remediated. VOCs, including formaldehyde, can cause chronic and acute health effects at high concentrations; some are known carcinogens. Combustible materials, such as carbon monoxide, nitrogen dioxide, and particulates, are commonly found indoors from unvented gas heaters, gas and woodstoves, and fireplaces.5 Paint odors also are a common complaint in indoor environments.
A Marker for Bad Air
One of the most common ways to get an early indication of air quality in a building is done by taking an indirect measurement of carbon dioxide (CO2).6 The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) sets standards for CO2 levels as a marker for indoor air quality. Levels of CO2 in excess of 700 ppm over outdoor levels (typically 350 ppm) or greater than 1,000 ppm are an indication of "poor" indoor air quality. High levels of CO2 can indicate air is not being refreshed enough, such that CO2 builds up from the accumulation of exhaled breath of the building’s occupants and other sources of CO2.
While the CO2 is not considered a contaminant in the low levels typically found indoors, elevated levels in the gas are a key indicator of possible contamination by one of the top air pollutants, such as carbon monoxide (CO) or volatile organic compounds (VOCs).
Other hydrocarbon compounds also can contribute to indoor air quality. Carbon monoxide is a common indoor problem where exhaust fumes can infiltrate an HVAC system. Formaldehyde, for instance, has been linked to sick building syndrome and is an indoor pollutant. It is a carcinogenic chemical that, even in small amounts, can pose a risk to human health. It typically can be emitted from building materials and furniture, especially from pressed wood products that use formaldehyde-based adhesives, paints and varnishes. Formaldehyde also gets released in smoke from a lit cigarette,7 along with other VOCs.
A real-world example of an IAQ problem is a nail salon business located beneath a law office. Employees and clients of the law office would occasionally smell strong chemical odors emanating from the lower-level salon. A wireless gas-detection monitor was set up in the law office to log data readings over several days. The monitor registered quick, high transient responses shortly after customers arrived at the nail salon, helping the investigator identify nail-polish remover as the source of the odor and recommend ways to improve ventilation.
Indoor Environment Monitoring
Hand-held detection instruments provide continuous-readings with monitors remotely placed in strategic areas of a room, office, or plant to gather indoor air quality data. This provides a data trail for investigators to determine the source of a problem or to confirm no problem exists. In locations where several competing plants operate in refinery clusters, GPS (global positioning satellite) capabilities allow monitor readings to verify responsible parties while keeping workers and the public alerted of potential risks.
The use of stand-alone personal monitors, which alert the user to elevated and unsafe levels of dangerous, toxic, and/or flammable gases in the immediate area, are being augmented with instruments and systems capable of sending alarms and data readings wirelessly to a laptop computer, typically located at a central operations center. These wireless systems provide key advantages, including low installation costs, fast set-up times, and the flexibility to be easily moved or repurposed for uses where toxic-gas monitoring is needed most.
Advances in secure Internet access and the ability to get data onto the Internet from almost anywhere have made these real-time interactions possible. Such access to data has now become an operational advantage to globally distributed safety teams, as well as multinational firms. This provides several advantages; including allowing wireless system users to engage remotely located industrial hygienists, safety experts, or plant managers in the same way doctors working in remote locations can work with medical-center specialists.
Wireless Plant-Wide Monitoring of High-Risk Areas
Wireless-enabled instruments also can be placed in multiple locations or rooms throughout a building or plant for continuous monitoring of selected, high-risk areas. These include copy rooms, art rooms, storage rooms with cleaning products or painting supplies, and areas where malfunctioning equipment can potentially release dangerous emissions.
Monitoring software is used to collect sensor readings in real time and display the data in meaningful ways. The raw data is stored for later analysis or use in legal action or remediation negotiations, and the software can help in generating automated reports based on the collected data.
IAQ investigators can utilize a number of detection technologies to track down contaminants. Wireless IAQ monitors provide investigators with a fast and effective way of identifying and then quantifying a VOC problem, and then wirelessly send the collected data to a portable device. If the PID detects anything, then the investigator knows to look for VOCs. Once a VOC is identified, then the PID can be scaled to that chemical so the on-scene investigator knows the precise compound and its concentration levels in the area. This not only saves time for the IAQ investigator, but also can prevent a small IAQ problem from becoming a major incident.
A good example of this was the cafeteria of a printed circuit board plant. A portable carbon monoxide detector picked up readings of 60 ppm in the cafeteria area with no apparent source or explanation for the presence of the gas. Outside the plant, the CO level on the detector dropped to zero, but a fresh-air calibration was performed anyway. Back inside the plant, the reading again showed 60 ppm. The detector was again recalibrated, but with the same results. Still, investigators did not give up. Because there was no obvious source of CO, a colorimetric tube for CO was used as an inexpensive way to confirm the metered reading was accurate, which it did. By using the CO detector like a Geiger counter, the source was located: a heat-shrink packaging machine was producing 150 ppm of CO in the operator’s breathing zone. The company immediately had the machine repaired.
Indoor Air Quality Resources
- The U.S. Consumer Product Safety Commission makes available a wide range of publications designed to educate consumers on the key risks of contaminated indoor air quality and steps that can be taken to eliminate or reduce dangerous threats. The documents cover biological pollutants in the home in addition to asbestos, carbon monoxide and formaldehyde risks that can make enclosed environments unsafe. http://www.cpsc.gov/cpscpub/pubs/iaq.html
- For an index of indoor air pollutants compiled by the Indoor Air-Health Advisor, visit http://www.indoor-air-health-advisor.com.
- The U.S. National Institute for Occupational Safety and Health (NIOSH) conducts investigations, known as Health Hazard Evaluations, of possible health hazards in the workplace, including those related to indoor air quality. The program also includes a series of reports on indoor air quality. For more information, visit http://www.cdc.gov/niosh/topics/indoorenv.
- The American Society of Heating, Refrigeration and Air Conditioning Engineers publishes a range of materials related to indoor air quality at http://www.ashrae.org.
1. Indoor Air-Health Advisor website: Indoor Air Quality A Global Concern. http://www.indoor-air-health-advisor.com (Retrieved July 17, 2012).
2. American Lung Association of the Mid-Atlantic. http://www.lungusa.org/associations/charters/mid-atlantic/air-quality/indoor-air-quality.html (Retrieved Nov. 14, 2011).
3. Indoor Air-Health Advisor website: Indoor Air Quality A Global Concern. http://www.indoor-air-health-advisor.com/indoor-air-quality.html (Retrieved July 17, 2012).
4. American Lung Association. http://www.lungusa.org/associations/charters/mid-atlantic/air-quality/indoor-air-quality.html (Retrieved Nov. 14, 2011).
5. Environmental Protection Agency (EPA), “Indoor Air Facts No. 4 (revised): Sick Building Syndrome.” http://www.epa.gov/iaq/pubs/sbs.html (Retrieved Feb. 8, 2012).
This article originally appeared in the April 2013 issue of Occupational Health & Safety.