Bacteria, molds, viruses, and other biological contaminants
Bacteria and molds can breed in stagnant water
that builds up in humidifiers, drain pans, and ducts, or where water collects
on carpet, ceiling tiles, and insulation. Humidifier fever is an illness caused
toxins from microorganisms that grow not only in large heating
and cooling systems in buildings but also in home systems
and humidifiers. Legionella pneumophila is an indoor
bacterium that can cause
Some viruses can survive on household surfaces, such as counters or floors, or they can get spread through the air when an infected person sneezes or coughs. You can help control viruses by:
- Cleaning household surfaces with a disinfectant.
- Having adequate ventilation in your house.
- Having anyone with a viral infection, such as a cold or the flu, cough or sneeze into the bend of the elbow or into a tissue.
Pet dander, pollen,
dust mites, molds, and rat and mouse urine are
allergens that can cause asthma,
allergic rhinitis, and other lung problems. Symptoms
of illness caused by biological contaminants include sneezing, watery eyes,
shortness of breath, lethargy, dizziness, and digestive problems.
Exposure early in
life to indoor allergens such as molds may increase the risk of allergies or asthma.4 Allergies to molds can also make asthma attacks worse
or cause other breathing problems.
Keep your home clean and as free from dust as possible to
help reduce allergens. There are many ways to
control dust and dust mites in your home, such as
washing bedding in hot water to kill dust mites and eliminating furnishings,
such as drapes, that collect dust. Also, there are many steps you can take
animal dander and other pet allergens.
Exhaust fans that vent to the outdoors and are installed in kitchens and
bathrooms can help get rid of moisture that allows microorganisms, including
molds, to grow. When modern building materials get wet, they provide an ideal
place for the growth of molds, which can make asthma attacks worse and
may cause other respiratory symptoms. Ventilating attic and crawl spaces and
keeping humidity levels below 50% can help prevent moisture buildup in building
materials. There are other ways to
control indoor molds, such as preventing leakage,
removing wet materials, storing fireplace wood outside the home, and using a
dehumidifier during humid weather.
Keep humidifiers clean and
refill them daily with fresh water. Frequently clean evaporation trays in air
conditioners, dehumidifiers, and refrigerators. Water-damaged carpets and
building materials can also have molds and bacteria in them. It is difficult to
get rid of bacteria or molds. So, if possible, replace or remove water-damaged
items from your home.
You can also:
- Remove carpets and replace them with
hardwood or tile floor.
- Have sofas with covers that can be removed
- Use blinds instead of drapes, because they collect less
- Have air filters in some rooms, especially in the
For more information, see:
- Allergies: Avoiding Indoor Triggers.