What are molds?
Molds are microscopic fungi that can grow both indoors and outdoors. They are an integral part of our natural environment and play an important role in the ecosystem. Molds are decomposers. They do the job of breaking down dead organisms and recycling their nutrients. While we require molds in our environment, their growth inside buildings is a matter of concern as they have the potential to cause health problems.
How many different species of fungi exist?
The exact number of species of fungi that exists has not been established. However, there is a general consensus among experts that thousands of fungi species exist. In the United States alone, there are about one thousand mold species.
How do molds grow?
Molds grow from tiny particles called mold spores, which are practically ubiquitous. Mold spores float around in the atmosphere everywhere, outside and inside our homes. Mold spores can grow into mold anywhere where the environment is favorable for their growth. Besides oxygen, molds require the following three things to grow:
- Favorable temperature – Most molds grow well in the same temperature range humans prefer. A few mold species can grow in temperatures as low as 39°F (4°C). However, most mold species do not grow at temperatures below 40°F (4.4°C) or in excess of 100°F (37.8°C). When the temperature is unfavorable, mold spores become dormant. They become active and grow into molds when the temperature becomes favorable. It is only at extreme temperatures that mold spores die.
- Moisture – Mold requires considerable moisture to grow. The moisture requirement is different for different species. Most mold species require water vapor content equivalent to a relative humidity of 70% or more. Humans require less moisture than molds, and so among all the factors that molds need for growth, this is the one we can control most easily.
- Food – Molds can feed on almost any substance that is organic (carbon atoms). Molds can grow on most common home materials such as paper, wood, organic fibers, and carpets. As almost all home materials have the capacity for providing molds the nutrients they require for growing, removing 'mold food' from your home environment completely is virtually impossible.
How do molds enter a building?
Molds enter a building in form of mold spores, which enter your house through the air. When the spores get the right environment, they grow into molds. Inside a building, molds are usually found in areas where moisture content is high.
Which species of molds are most commonly found indoors?
- Alternaria
- Penicillin
- Aspergillus
- Cladosporium
Where do molds grow?
Indoors molds usually grow in: drapes, carpets, leather, upholstery, wood products, clothing, ductwork, ceiling tiles, paper, books, cardboard, rags, household dust, and wallpaper.
How fast can mold grow?
When all the four elements that molds require for growing are present in the environment, molds can germinate within 48 hours. Mold spores can take 1 to 12 days to spread to other areas beyond their initial growth area.
How am I exposed to mold?Mold spores are present in the air. When an area where mold concentration is high is disturbed, the levels of mold spores in the surrounding air rise exponentially. In addition, you can be exposed to molds when you touch moldy items or when you eat food on which molds are present.
Does everyone react to molds in the same way?
Some people are more susceptible to the effects of molds than others. People who are more susceptible to health problems caused by molds have a lower tolerance to them. However, most of us are likely to experience at least some symptoms of mold exposure if we are continuously exposed to high or severly high levels of mold.
People who are more likely to become ill after being exposed to small or moderate levels of mold include:
- Individuals who have asthma or other respiratory problems or those who are genetically predisposed to these conditions
- Individuals who have allergies or have a genetic predisposition to allergies
- Individuals with a weak immune system (such as HIV patients or individuals undergoing chemotherapy)
- Elderly people
- Infants and young children
- Pregnant women
Are all molds harmful?
No, only a few molds can cause health problems in healthy humans. However, people with a history of allergic reactions or with a compromised immune system may be susceptible to all types of mold.
What are the common symptoms associated with mold exposure?The common symptoms of mold exposure are:
- Sinus and nasal congestion
- Difficulty breathing and/or wheezing
- Eye irritation (such as red, watery, or itchy eyes)
- Throat irritation
- Cough
- Headache
- Skin irritation
- Tiredness
- Headache
- Nausea
How can I limit my exposure to mold?Outdoor molds are most likely to be found in damp, shady areas or areas where organic matter, such as leaves, is decomposing. You can limit your exposure to outdoor molds by avoiding such places. You can prevent molds from growing inside your home by ensuring the humidity level of the air inside is less than 70% and by ensuring proper air filtration inside the house.
If mold is present in certain areas of your house, chances are there is some water problem in those areas. To get rid of indoor molds, clean up the areas they are growing and undertake any necessary plumbing work. You can remove molds from hard surfaces, such as sheet metals, using commercial home cleaners.
The use of bleach for removing molds from hard surfaces is not recommended due to the following three reasons:
- It can cause health problems
- It kills molds but does not remove them. In effect, it fails to eliminate the risk of allergic reactions caused by molds completely as dead molds can too trigger allergic reactions
- Commercial home cleaning solutions are effective in removing molds. They are also safer than bleach
If you still decide to use bleach to clean up mold, ensure that you take the following safety measures:
- The concentration of bleach in the bleach water solution should not be more than 10%
- Do not mix bleach with commercial home cleaners or ammonia
- Wear protective eye gear and gloves
- Ensure that the area that is to be cleaned has proper air ventilation
What should I do to prevent molds from growing inside my home?The following steps help you prevent mold growth inside your house:
- Ensure that there is no water leakage inside your house. If there is, fix it right away
- Ensure that air is being properly circulated inside your house. If required, use standing or ceiling fans to ensure proper air circulation in areas where there are no windows.
- Maintain a gap of few inches between your furniture and wall
- Install exhaust fans in the kitchen, laundry rooms, and bathrooms. Switch on the exhaust fan while cooking, doing laundry, or bathing, and keep it running for 30 to 45 minutes afterwards
- Avoid spilling any liquid on carpets, bedding, and clothing. Clean and dry the wet material within a day or two after a spill.
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