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Indoor Air Quality in the Workplace

Poor indoor air quality (IAQ) can create many health issues for workers. Building occupants could develop breathing problems, cancer, skin issues, headaches, airborne infections and other health concerns. It could contribute to sick building syndrome or building-related illness (BRI) if it affects many workers.

Indoor air quality concerns everyone. As a building manager, you are responsible for providing a safe, healthy and well-maintained building. Your occupants want a safe place to work. Employers want an environment that enhances workplace productivity and reduces liabilities. Meanwhile, your building owners want an attractive location that employers want to rent.

The Occupational Safety and Health Administration (OSHA) also has several standards for indoor air quality. Standard 1910.1000 limits the air contaminants workers can be exposed to, and Standard 1910.94 adds more requirements, regulating workplace ventilation systems to ensure safe breathing air.

Factors That Contribute to Indoor Air Quality

According to the Environmental Protection Agency (EPA), indoor environments often have two to five times higher pollutant concentrations than outdoor environments. When employees complain about an unpleasant smell, breathing problems, headaches or another health issue, you must determine the cause. Many pollutants and circumstances can create indoor air quality concerns.

Outdoor Contamination

Fresh air is crucial to indoor air quality. Often, one of the best solutions for IAQ concerns is to introduce more air from outside. However, when a building has contaminants nearby, they can affect indoor air quality. Many outdoor contaminants can get swept indoors through the ventilation system, including:

  • Dust, pollen and fungal spores.
  • Exhaust from the building or a neighboring building.
  • Industrial pollutants.
  • Exhaust from cars and nearby traffic or loading docks.
  • Odors from dumpsters or unsanitary debris near the outdoor air intake.
  • Soil gas such as radon, underground fuel tank leakage, methane from landfills, pesticides and other leaching contaminants.
  • Moisture and standing water with microbes from rooftops and crawl spaces.

Indoor Contamination

Indoor pollution is one of the most significant factors involved in poor air quality. Contamination from inside a building causes 16% of IAQ issues, according to the National Institute for Occupational Safety and Health (NIOSH). Chemicals, odor and exhaust originating from an indoor space can all create indoor air pollution. Some common offenders are bathrooms, copy rooms, kitchens, smoking lounges, laboratories, exercise rooms, print shops and art rooms, workshops and beauty salons.

Indoor contamination can come from many sources, including:

  • Office equipment emissions like ozone or volatile organic compounds.
  • Supplies like printer toner, solvents and ammonia.
  • Shops, labs and cleaning equipment emissions.
  • Mechanical systems like elevator motors.
  • Carpets, curtains, old furniture and open shelving that collects or releases dust and fibers.
  • Damaged materials that contain asbestos.
  • Soiled or water-damaged furniture harboring bacteria or mold.
  • Furniture or building materials that emit volatile organic compounds (VOCs) or inorganic compounds.
  • Surface condensation that promotes microbial growth.
  • Clogged or poorly designed drains that allow standing water to accumulate.
  • Sewer gas passing through dry traps.

HVAC Systems

Proper temperature, ventilation and humidity levels are crucial for healthy indoor air. Extreme temperatures are a health hazard, and a few degrees in the wrong direction makes a workspace uncomfortable. Humidity also needs to fall within an acceptable window. Low humidity can cause dry skin or nasal passages and eye irritation. Excessive moisture content causes water to condense, encouraging mold and dust mites. Meanwhile, ventilation lets fresh air enter from outside and filters out carbon dioxide from the indoor environment.

Your building’s heating, ventilation and air conditioning (HVAC) system controls all these factors. A well-designed HVAC system ensures a comfortable, safe and productive work environment. Malfunctions with the HVAC can affect the temperature, humidity or ventilation levels. According to NIOSH, inadequate ventilation causes 52% of indoor air quality problems.

The system can also become contaminated. An HVAC system may cause IAQ issues through:

  • Dust and dirt in the air ducts.
  • Mold or bacteria in the drip pans, ductwork, coils or humidifiers.
  • Cleaning compounds, sealants or biocides wafting through the equipment.
  • Leaking refrigerant.

Even a clean HVAC in perfect working order can contribute to IAQ issues. If contaminants from another source are present, the HVAC becomes the vehicle that distributes them around the building.

Human Activity

The employees or residents in your building can also affect indoor air quality. Smoking, cosmetic odors and body odors can all pose air quality concerns.

Sometimes, people’s work-related activities contribute to indoor air quality problems. Some of these activities include:

  • Cleaning procedures.
  • Storing cleaning supplies or trash improperly.
  • Using deodorizers or fragrances.
  • Circulating dust or dirt through sweeping or vacuuming.
  • Releasing dust or fibers during demolition.
  • Using paint, caulk, adhesives and other products that contain VOCs.
  • Spraying pesticides.

Miscellaneous Sources

Some of the other sources for IAQ issues include:

  • Accidental spills.
  • Microbe growth related to floods, roof leaks or piping.
  • Fire damage like soot.
  • Polychlorinated biphenyls from electrical equipment and odors.
  • Emissions from new furniture.
  • Microbes released during demolition or remodeling.

Seasonal Impacts

Indoor Air Quality Changes During the Spring

In March, April and May, temperatures and humidity levels rise. These bring accompanying pollen, dust and mold inside through open windows and doors. Symptoms correspondingly increase, whether individuals expose themselves to these outdoor allergens at work, home or during their commutes.

Though allergies may increase, colds, cases of flu and other respiratory infections tend to decrease due to the extra moisture in the air. While dry air in the winter encourages the spreading of upper respiratory infections, the higher humidity of spring decreases these illnesses.

Tips to Improve Indoor Air Quality During the Spring

When bugs start to appear inside during the spring, choose non-chemical means of keeping them out as much as possible. Close up any gaps in the building and encourage occupants to clean up kitchen areas and avoid leaving out any food. Taking these steps will prevent a buildup of chemicals that some find irritating.

If you have construction or deep cleaning projects occurring in your building, schedule it during times occupation will be at a minimum. Keeping workers out during renovation or cleaning projects reduces their exposure to dust and pollutants produced from these processes. Ensure those engaged in these types of projects remove all debris or garbage before leaving.

To prevent pollen and dust from getting into the ventilation system, schedule regular housekeeping. The main cause of an accumulation of dirt in ventilation systems is a poor quality of cleaning. When temperatures warm enough in the late spring to warrant using the air conditioner, clean off any dust buildup on the coils to ensure the system works well and air quality stays good.

Air Quality Changes Indoors During the Summer

During June, July and August, temperatures increase to their highest levels of the year. Pollen levels drop as flowers produced during the spring begin to turn into fruit or make seeds after pollinating. Mold, dust and humidity also increase with the temperatures, though.

The rising mold and dust levels will also affect those inside the building, especially if you have not had your ventilation system cleaned. Air conditioners can blow dust inside the air ducts throughout the building, irritating those with a sensitivity to dust. The lower humidity inside from an air-conditioned environment compared to outdoor levels can affect those with sinus problems.

Running the air conditioner too often raises electricity bills during the summer. You may try to offset this by integrating more outdoor air into the air conditioner’s intake. Using too much air from outside, however, introduces mold and dust into the indoor air. Finding a balance between outdoor air intake, indoor air quality and electricity costs is one concern for building operators during the summer.

Tips for Improving Summer Indoor Air Quality

When using the air conditioner in the summer, the indoor air can dry out. Too much moisture can contribute to mold growth. Monitor indoor humidity and adjust the air conditioner to keep levels between 30 and 60 percent for the greatest comfort and best air quality.

Additionally, since you will likely use the air conditioner more often during the summer, plan on monthly checks of the system to ensure it does not distribute dust and mold through the building. Before starting the system, have the ducts cleaned out, and the system checked to get the most efficiency and cleanest operation.

Indoor Air Quality During the Fall Season

Extra moisture in the air and vegetation decay lead to the year’s highest levels of outdoor mold. Though mold levels increase in September, October and November, elevated levels may persist through December, depending on weather conditions.

Additionally, some plants will produce pollen during the fall. Those with fall allergies may have reactions to these pollens, depending on the temperature, wind and moisture levels.

Tips to Improve Air Quality Inside During the Fall

While you must pay attention to possible sources of excessive humidity to prevent mold growth throughout the year, autumn poses new concerns. Indoor air quality in fall seasons has a higher likelihood of mold problems due to decaying vegetation. You must ensure your building has proper ventilation to reduce the humidity that encourages indoor mold growth.

Stop any leaks as soon as they happen and ensure bathrooms and other moist environments have adequate ventilation. Repair leaky roofs as soon as possible and remove any walls, ceilings or carpeting materials that sustained water damage from the leak. Leaving these in place encourages mold growth where you cannot see it. It can still affect air quality, though, even hidden behind paint or inside walls.

Changes in Air Quality Indoors During the Winter

In the winter, freezing temperatures prevent the growth of mold spores. Humidity levels plunge to their lowest levels outside and inside. Heating systems inside keep the air even drier than outdoors, which could dry out mucous membranes and cause irritation in the eyes and nose. Respiratory infections spread easily in such dry weather.

In the winter, bringing in outdoor air may reduce heating costs, but too much could cause freezing of ventilation system coils. However, using more humid outdoor air for the heating system’s intake can help improve humidity levels inside. As in the summer, building managers must find a balance between operating their heating systems at a comfortable interior temperature without bringing too many outdoor pollutants inside.

How to Improve Air Quality Inside in the Winter

Just as you should monitor your indoor humidity during the summer, you should do the same in the winter. If your building regularly drops below 30 percent humidity, consider installing a humidifier to add moisture back into the air for comfort and to reduce the spread of upper respiratory infections. When using humidifiers in the winter, check them weekly to ensure they do not have mold growing in them. Clean and disinfect the humidifiers as recommended to ensure they do not contribute negatively to your indoor air quality.

Get professional help to balance outdoor air flowing into your building’s HVAC system and the air quality inside. Taking measurements of temperature and humidity can ensure you have reached a good balance of both.

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