It is well established that individuals in New York City spend 80 to 90 percent of their time indoors, either at the work
place or at home. It has also been established that the indoor air quality may be as poor as the outdoor air. The health risks incurred by merely breathing the air at home can sometimes exceed the general limits set by regulatory agencies. The pollutants found in indoor air are similar to those found outdoors and may, in fact, come from outdoor sources. Some of the more common air quality problems within apartments or townhouses are poor ventilation, odors, insecticides, carbon monoxide, tobacco smoke and formaldehyde, all of which can potentially lead to illness or allergic reaction.
Symptoms of SBS and BRI
Indoor air quality complaints generally begin with building occupants being plagued by one or more symptoms of a non-specific nature, typical of what has been called collectively the Sick Building Syndrome (SBS). Sufferers do not tend to experience symptoms constantly; upon leaving an affected building at night or on a weekend, symptoms subside, only to reappear after reentering the building.
By contrast, a more serious set of diseases, referred to as Building Related Illnesses (BRI), are clinically diagnosable diseases. These diseases are thought to arise from more prolonged exposure than SBS situations. It is quite possible that individuals may suffer from both BRI and SBS.
The Hazards in Your Home
Basically, poor indoor air quality stems from one or more contaminant sources and/or inadequate ventilation. A recent study indicated that the average home contains in excess of 2,000 hazardous chemicals. One of the most familiar indoor air pollutants is cigarette smoke, which mainly consists of organic aerosols and gases. Heating and cooking appliances using combustible fuels such as oil, wood, natural gas, propane and kerosene also emit varying amounts of respirable particles, gases and vapors, as do cooling appliances.
Co-op, condo and townhouse owners and occupants have to pay special attention to emissions of nitrogen dioxide, nitrogen oxides, sulfur dioxide, and particularly carbon monoxide. Carbon monoxide is a colorless, odorless gas which can cause symptoms ranging from headaches to drowsiness. In extreme situations, exposure can result in death.
Nitrogen dioxide, another gas that can cause severe injuries, is also colorless, but can be smelled at relatively low concentrations and has a metallic taste. Sulfur dioxide is also poisonous, however, the characM-teristic rotten egg odor is easily detectable at concentrations well below dangerous levels, thus it has good warning qualities. In high occupancy buildings with poor ventilation, the carbon dioxide which is exhaled as a by-product of breathing may build up to levels which may affect performance and mental acuity.
Chemical indoor pollutants can vary in type and number from consumer and commercial products, building sources, personal sources (such as tobacco smoke) as well as outdoor sources, including automotive emissions, heating furnaces, fireplaces, seasonal blooming or construction work.
Volatile organic compounds (VOC's), which makes up a large family of chemical compounds, are another component of indoor air pollution. These chemical compounds, which can cause acute reactions as well as having c ffb hronic effects, may be given off from many unsuspected sources, including personal care products and cosmetics, automotive and hobby supplies, and clothing and furnishings. Building sources for volatile organics include plastics, adhesives, insulating materials, gas stoves, fireplaces, woodburning stoves, cleaning fluids, pesticides, paints, varnishes, lubricants and paint strippers. VOCs given off by furnishings can create problems for occupants ranging from headaches, drowsiness and fatigue to joint pain, tightness in the chest, blurred vision, and skin irritation.
There are many ways to alleviate vapor emissions, gases and airborne concentrations, thereby reducing the risk of exposure and the incidence of illnesses. By increasing fresh air intake, installing dedicated venM-tilation systems, isolating the materials stored, and/or curtailing the frequency of the use of these products, your building can greatly improve its air quality. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) has released guidelines that suggest that a certain amount of fresh air enter each space on a regular basis, with recommended levels of fresh air being 20 CFM (cubic feet per minute) per person.
One source of indoor air quality problems which is sometimes overlooked is biological contamM-inants. The major source of biological contaminants are pet dander and moisture. Bacteria and fungi grow best and most rapidly in warm, humid environments. Thus, maintaining a comfortable temperature and humidity level in the building is imperative. Bacteria and fungi can grow on any surface, but will proliferate best on porous materials such as ceiling tiles and wall boards.
Pathogens such as bacteria and fungi can cause allergic responses and infections. Infectious agents can enter the indoor environment from outside sources, humans and furnishings. Approximately 13 percent of the respiratory cases associated with the indoor environments are the result of Legionella. This bacteria is ubiquitous in nature and will survive in water at especially high temperatures even for long periods of time. Legionella epidemics usually occur in the summer months and are normally the result of poor maintenance and cleanliness of forced air heating systems, humidifiers, hot tubs, cooling towers and evaporative condensers. However, Legionella infections can also result from construction and dust. Proper maintenance of the cooling towers and humidity control units is essential since these organisms will survive for long periods of time.
Pathogens can also cause allergic asthma, a condition which affects about three percent of the American population. It is characterized by bronchiospasms, edema of the bronchial mucous which will then block the bronchial pathways.
Maintain Building Systems
It is important in any building where a heating, ventilation and air conditioning (HVAC) system operates that the system be well-balanced. An unbalanced system can create indoor air quality problems. Individual occupants should be instructed not to block off the supply or return vents. Blocking off vents in one room will force the additional air out through other vents in the system, causing an imbalance in the system, and some locations of the building will not receive sufficient fresh air.
Another way to counter potential indoor air quality problems is to ensure that the building's HVAC units and the associated duct work are properly maintained. This means regular visual inspections of the filters, heat exchange coils, drip pans and variable air volume control boxes, and regular cleaning and sanitizing of the associated duct work.
The duct work should be vacuumed with High Efficiency Particulate Air (HEPA) vacuums every couple of years and sanitized with a biocide if necessary. For areas where the dust or debris has adhered to the duct surfaces, a more aggressive means may be required to remove the deposits, such as power brushes or air knives.
Regular monitoring for indoor air contam ff7 inants such as VOCs, carbon dioxide and carbon monoxide should be implemented to ensure that contaminants do not exceed recommended levels. Although at this time indoor air quality is not regulated, the Occupational Safety and Health Administration (OSHA) will be coming out with regulations on indoor air environments and promulgating guidelines for acceptable levels. The board should ensure that all units are within the proposed guidelines and that the HVAC system bringing in the fresh air does not contribute any hazards into the indoor air.
Monitor Air Quality
Monitoring for chemical vapors and/or gases can be done by the use of chemical detector tubes, badges or direct reading monitoring devices. Each of these devices can be used to scan for a group of chemicals or for a specific chemical. Some of these monitoring devices are available for continuous monitoring in a given area and can have audible as well as visual warning capability, or can simply record the reading on paper or computer disk.
Building residents should also make sure that chemicals are not stored unnecessarily on the premises. Off-gassing or spills will allow the chemicals to seep into the air supply and may cause air quality problems elsewhere in the building. Chemicals that must be stored on-site should be handled in a safe way and kept at proper temperatures.
Because air quality complaints are complex and varied in nature, it is imperative that properly trained professionals with scientific backgrounds in chemistry, engineering and microbiology perform the testing to identify the source of the problem and develop an effective abatement program. Even if your building's residents have had no cause to complain about the air quality, boards would be wise to follow the precautions outlined here in order to prevent any future problems and ensure the safety of their tenants.
Ms. Toth is vice president of Terra Bio Chem Environmental Services in Andover, New Jersey.