By: Tim Gates, Green the IU Health Center Intern
On average, Americans spend 90% of their time indoors, and we are beginning to see illnesses related to certain substances we use in constructing buildings and maintaining indoor environments. Pollutant levels are quite often higher indoors than outside, and EPA studies have shown that they can have a serious effect on worker productivity, quality of life, and well-being. A Presidential & Congressional Risk Assessment report highlighted the immediate need to mitigate this issue, and discovered that indoor pollution is responsible for thousands of cancer deaths and hundreds of thousands of respiratory illnesses each year. This has become so common that they have dubbed such illnesses as “Sick Building Syndrome”. So what are the culprits for such pollution and why do we have them in the first place?
Assuming you do not have asbestos, and no one smokes indoors, lets identify the four main toxic sources, their effects, and how they are used:
Volatile Organic Compounds (VOCs): VOCs are one of the largest contributors to indoor pollution due to their near ubiquitous use in building products. They are organic chemical compounds, such as formaldehyde, which are emitted as gases from solids or liquids at room temperature due to high vapor pressure. They are both produced naturally and synthetically, but levels inside buildings can be up to 10 times higher than outdoors. They have been shown to have short-term and long-term health effects, and can be released while both in use, and when stored. There are many products that contain VOCs, but the most common sources for elevated indoor levels are adhesives, sealants, paints, lacquers, aerosols, disinfectants, cleaners, carpets, and certain wood products. High Levels of VOCs are known to cause: headaches; nausea; irritation of eyes, nose, throat; damage to kidney, liver, and central nervous system; allergic reactions, and in some cases has been shown to cause cancer in humans. The extent and nature of possible health impacts vary depending on level of toxicity in compounds and length of exposure. Organic chemical compounds can have varying degrees of health impacts from those known to have highly toxic levels, to those that have no known health effects.
The most effective way to limit exposure to harmful VOCs is to purchase and use products that contain no or low levels of VOCs, and have been certified industry standards such as South Coast Air Quality Management District (SCAQMD), or by a volunteer third-party organizations, such as Green Seal. A list of reputable third-party certification systems can be found here. It is also helpful to use products according to manufacturer’s directions, and to provide plenty of fresh air while products are in use.
Dust, mold, & other particulates: This may seem obvious, but it is something important to point out. If you have a forced-air cooling and heating system, then you have an air filter located in your furnace to directly mitigate these matters, but there are some critical issues. First changing your air filters not only saves on energy, but also ensures proper air filtration as air is recycled throughout the building, and pulled from outdoor air intakes. However there is a catch, the better the air filter, the more energy the furnace needs to force the air through it. Most filters come with Minimum Efficiency Reporting Values (MERV), which balance capacity to remove particles from air stream with resistance to airflow. The simplest technique to keeping dust to a minimum is good housekeeping. Consider damp dusting, high-efficiency vacuum cleaners, and well-maintained rugs at entryways. Health effects vary depending upon the characteristics of the dust/particulates and any associated toxic materials. Dust particles may contain lead, pesticide residues, radon, or other toxic materials. Other particles may be irritants or carcinogens.
Mold on the other hand comes from two main sources: moisture induced growth of mold colonies, and natural sources of dander and pollen. Moisture control is complicated for most buildings and commonly arises from building envelope penetration, plumbing leaks, and condensation buildup from improper ventilation. This issue is most serious for those who suffer from asthma or other respiratory illnesses. If moisture buildup occurs in areas with cellulosic materials (wood, paper, drywall) it is important to dry and vent within 48 hours. If mold is discovered, it is important to clean contaminated areas while wearing respiratory protection, and properly ventilating the area. Mold is always associated with moisture, and maintaining humidity levels below 50% can inhibit its growth. If wanting to test for mold levels in buildings, directions for testing kits can be found here.
Carbon Monoxide & Carbon Dioxide: Carbon Monoxide is one of the most acutely toxic indoor air contaminants. It can cause flu-like symptoms, headaches, dizziness, and nausea. It is a colorless and odorless gas that is the byproduct of incomplete combustion of fossil fuels. The most common sources come from defective central heating furnaces, malfunctioning gas ranges, space heaters using fossil fuel, tobacco smoke, and exhaust fumes drawn back into buildings. The best measure controls for this harmful and sometimes deadly
gas are to properly maintain any combustion appliances, such as furnaces and gas ranges, and make sure air intakes or windows are not directly adjacent to combustion exhaust such as vehicles and chimney flutes. This issue arises more frequently in older buildings, but can occur in any building that uses natural gas. If concerned you can always use a Carbon Monoxide Detectors to make sure you are safe.
Carbon Dioxide is also an odorless colorless gas that is a product of carbon combustion, though it is less dangerous than its single oxygen atom cousin. The largest source in buildings is from the human respiratory process, though it can originate from other sources such as lawnmowers, generators, vehicles, etc. Elevated levels of CO2 have been shown to impair cognition, and are usually a cause for concern in high occupancy rooms such as classrooms, meeting rooms, and auditoriums. Generally HVAC engineers use CO2 censors to regulate airflow in rooms. This can help save on energy by using CO2 levels as an indicator for needed airflow and identifying number of occupants, instead of only using temperature and continuously pumping forced-air when not needed. The detectors are also available for individual purchase, however they are most useful when linked to the ventilation system.
Radon: Is an invisible, odorless, and tasteless radioactive gas that results from the natural decay of uranium in soil and water, and is found underground in various levels throughout the world. This gas is linked to an estimated 20,000 lung cancer deaths each year. Radon is a heavy gas and usually accumulates in basements or floor levels. Building materials can actually be a source of radon, but more usually radon enters buildings through cracks, sump pumps, drains, water pipes, and building joints.
The EPA designates three zones for potential danger levels of Radon. Zone 1 has the highest potential and Zone 3 the lowest, and here in Monroe County we are in Zone 1. Radon test kits are affordable and can be found here. Due to radon having a half-life of 3.8 days, there are simple mitigation techniques such as sealants for floors, cracks, and joints, and increased ventilation.
So what now?
This list is meant to help others become aware of potential health hazards in building indoor environments, not to scare you out of your homes. Since humans consistently spend more time indoors, it is important to know how our current building materials affect our health. Most of these issues have simple mitigation strategies that are effective and not too costly. However, green certified homes and offices are becoming more popular due to health concerns caused by these substances and many other environmental issues. Good luck and healthy living.