275

Mold and Indoor Air Quality


Mold
Simple things like moisture from laundry and showers, improperly vented dryers, air conditioning that goes off during hot moist months, and standing water can lead to mold growth in the most unlikely places.

Mold destroys materials it grows and feeds on, but the central problem with mold is how it impacts human health. Possible allergic reactions to mold include a runny nose, itchy eyes, nasal and sinus congestion, a cough, a sore throat, or sinus infections. People with chronic respiratory diseases such as asthma may experience difficulty breathing. Those with suppressed immune systems or underlying lung disease will be susceptible to fungal infections when exposed to mold. Some people might develop acute or chronic hypersensitivity pneumonitis, an inflammation of the lung caused by the body’s immune reaction to mold’s small air-borne particles. Mold may even play a part in major illnesses, but researchers have not been able to prove or disprove the theory.

Mold Growth and Elimination
Mold reproduces by sending out tiny, lightweight spores that live and feed on moist surfaces. In order to grow and multiply, mold spores need moisture, a food source, and a suitable surface. Mold can survive long periods of time under adverse conditions until it finds these three conditions. Home basements can be the ideal breeding ground for mold, since they are frequently cold, damp, and prone to water problems.

Mold is easily identified, but not always seen. It shows up as discoloration, watermarks, or stains on walls, floors, and furnishings. It can look velvety, grainy, or leathery. It may be white, gray, green, yellow, black, brown, or even pink. When it can’t be seen, mold can usually be smelled. It has a distinctive dank, musty odor. If mold is seen or smelled, assume a mold problem exists. Remove it and correct the moisture problems that have caused it to grow.

Sometimes finding the source means looking under carpets or flooring or behind wallpaper, sink cabinets, and furniture. Items stored near outside walls or on cold floors should be checked. It might even be necessary to use a more aggressive approach, such as opening up a wall cavity.

Controlling Basement Moisture
Depending on its severity, correcting the source of moisture could end up being a simple job or require outside help. Just using a dehumidifier and line-drying laundry outside may solve a problem with high humidity. Using the air conditioner during warm, moist months is critical for humid-climate homes.

Foundation cracks or perimeter drainage problems resulting in water intrusion call for a contractor just as leaky pipes and pools of standing water require a plumber. A qualified HVAC technician should be able to install proper appliance venting to eliminate moisture buildup from the dryer. Homeowners should always check a firm’s references.

 
 

Controlling Moisture

While flooding is an obvious source of moisture, there are others. They include:

  • Condensation from indoor humidity that is too high or surfaces that are too cold
  • Leaks or absorption through basement walls or floor
  • Plumbing leaks
  • Overflow from tubs, sinks, or toilets
  • Humidifier use
  • Improper venting of combustion appliances
  • Clothes dryer exhaust not vented outdoors
  • Line drying laundry indoors

 
     

Cleanup Must Be Complete
Once the moisture problem is fixed, the homeowner or a remediation professional can cleanup the mold. Again check the firm’s references, confirm its record with the Better Business Bureau, and ask about professional guidelines such as those established by the Environmental Protection Agency for schools and commercial buildings.

Homeowners handling clean-up should be cautious. Disturbed mold releases many particles into the air. To help reduce exposure, homeowners should protect themselves by wearing the following:

  • rubber gloves
  • eye goggles
  • a long-sleeved shirt and pants that can be easily removed and discarded or cleaned
  • a high-efficiency filter dust mask

Anything that has absorbed moisture probably has mold growing on it. That may include wallboard, insulation, plaster, carpet and pad. To protect the rest of the family and home from contamination while cleaning up, separate the work area from the rest of the home with plastic sheeting. Put all moldy materials into plastic bags before they are carried outside and disposed of.

Glass, concrete, metal, and other nonporous materials usually can be cleaned and dried. Disinfection with a bleach solution is recommended so all contamination is removed. Cleaning solutions must be collected and properly discarded. Even dead spores and mold particles can cause health problems if they remain, because dying mold sheds substances that can accumulate in household dust. All surfaces should be vacuumed with a central vac or vacuum equipped with a HEPA filter to prevent spores from becoming airborne.

Control Moisture and Humidity Levels
There is no practical way to eliminate all mold and mold spores indoors. However, with leaks, venting, and other problems eliminated, homeowners should be able to control growth by controlling humidity. A home’s relative humidity should be between 30 and 55 percent. A humidity detector or sensor—typically available for about $8 to $25 at retail stores—will indicate the humidity level present in the home.

Sensors in the basement will help a homeowner gauge potential problems, but beware of different humidity zones. An area of low circulation, like the basement’s cool masonry wall surface, may have a different humidity level than the rest of the basement. If a higher humidity level is indicated, ventilation, air conditioning, or air circulation and dehumidification can help.

If mold does return, the cleaning process has to start again, possibly with a stronger disinfection solution. If mold regrows, it may mean that the material should be removed or that the moisture problem is not yet under control.

Credit: Renovate Your World