Mold growth on walls and other surfaces in a home can potentially cause a number of health issues for the occupants. Mold spores are microscopic organisms that float through the indoor and outdoor air continually. When mold spores land on a damp spot indoors that contains organic material, such as drywall, carpet, wood, or dirt, they may begin growing and digesting the material. Molds gradually destroy the things they grow on. There are many types of mold and they can be any color. Toxigenic molds produce mycotoxins that can cause health problems. Mycotoxins are chemicals that are potentially toxic to humans and animals. Mold exposure does not always present a health problem indoors, either because spore counts are low or because the types of mold do not produce toxins. But mold growth on walls and other surfaces can lead to increased exposure to spores, cell fragments, allergens, irritants, and toxins through inhalation, which has the potential to cause ill health effects. Let’s explore in more details what health effects mold growth on walls can cause.
Common Health Effects
Some common health effects that can be caused by mold exposure from contaminated walls and surfaces include:
- Allergic reactions – Inhaling mold spores can cause hay fever-like allergic symptoms such as sneezing, runny nose, red eyes, and skin rash in those allergic to mold.
- Asthma attacks – Mold exposure can trigger asthma attacks in those with asthma or mold allergies.
- Respiratory problems – Mold spores and cell fragments contain irritants that can cause coughing, wheezing, difficulty breathing, sinus congestion, and other respiratory issues.
- Eye irritation – Mold exposure can cause irritated, red, burning, or watery eyes.
The severity of these symptoms depends on the extent of mold growth, the amount of exposure, and an individual’s sensitivity. Those with compromised immune systems or existing respiratory conditions are more vulnerable to the effects of mold.
Rare but Serious Diseases
In rare cases, certain molds can cause more serious diseases in vulnerable individuals with prolonged exposure to high levels of mold:
- Allergic fungal sinusitis – This condition resembles chronic sinusitis and can occur in those with allergies after prolonged mold exposure. It causes nasal congestion, facial pain and headaches.
- Allergic Bronchopulmonary Aspergillosis (ABPA) – This condition can develop in people with asthma after exposure to Aspergillus mold. Symptoms include wheezing, coughing, shortness of breath, fatigue and weight loss.
- Hypersensitivity Pneumonitis – Also called extrinsic allergic alveolitis, this condition may develop after exposure to high levels of mold. Flu-like symptoms occur including fever, chills, body aches, cough, and breathing difficulties.
These conditions require medical diagnosis and treatment but are relatively rare. Those with chronic health problems should see a doctor if mold exposure causes persistent worrisome symptoms.
Toxic Mold Syndrome
Toxic mold syndrome or biotoxin illness is a controversial diagnosis that may result from exposure to mycotoxins from mold. It has not been scientifically proven and is not an officially recognized medical diagnosis. However, some practitioners believe it causes a wide range of symptoms when a person is exposed to dangerous levels of mold, including:
- Headaches, dizziness, nausea
- Breathing difficulties, wheezing, coughing
- Memory problems, concentration and focus issues
- Depression, anxiety, irritability, mood swings
- Fatigue and weakness
- Joint or muscle aches and pains
- Skin irritation or rashes
- Eye redness and blurred vision
- Sore throat, sinus congestion
Many conventional doctors do not diagnose toxic mold syndrome due to lack of research and definitive tests. It should be considered a controversial hypothesis that requires more scientific study for validation.
Vulnerable Groups
Certain people are more vulnerable to the health effects of indoor mold growth:
- Pregnant women – Hormonal changes make them more susceptible to respiratory illnesses.
- Children – Their respiratory systems are still developing.
- Seniors – They may have weaker immune systems and underlying health conditions.
- People with respiratory conditions like allergies, asthma, COPD.
- People with chronic illnesses or suppressed immune systems.
Infants under one year also have developing respiratory systems and immune function, making them more at risk.
Black Mold
Black mold, also known as Stachybotrys chartarum or Stachybotrys atra, is sometimes mentioned as a particularly dangerous mold. It produces mycotoxins that can cause health issues. However, many molds can be black and many non-black molds also produce mycotoxins. The color does not indicate the mold’s ability to cause health problems. This is why identifying the specific type of mold growing is useful to determine potential health risks. Overall mold exposure should be limited, regardless of mold color.
How Much Mold is Dangerous?
There are no governmental standards or exposure limits regarding what levels of airborne mold spores indoors are considered “acceptable” or safe. Any visible mold growth is considered too much because it means there is excess moisture and spores present. The more extensive the mold growth, the higher the spore counts and health risks. Even small amounts of mold should be addressed quickly before growth spreads. Heavy mold contamination carries a higher health risk, especially for those vulnerable to mold issues. Immediate remediation is recommended when mold growth covers over 10 square feet.
Testing for Mold
Several methods can detect indoor mold growth:
- Visual inspection – Carefully examine walls and surfaces for visible mold growth or water damage.
- Odor – Notice musty, earthy smells, which may indicate mold.
- Mold sampling – Surface, air or dust samples can be collected and sent to a lab to identify types of mold present.
- Moisture meter readings – High moisture levels make mold growth more likely.
- Infrared thermal imaging – This technology detects temperature differences caused by moisture in walls.
If sampling is conducted, an outdoor sample is also collected for comparison. Mold types and levels that are higher indoors compared to outdoors indicates indoor mold growth. Consider hiring a professional mold inspector if you are concerned about mold in your home. They can conduct thorough testing and identify all locations of mold growth.
Health Problems from Mold Growth on Drywall
Drywall is a common surface for mold growth because of its cellulose content. Prolonged moisture exposure from flooding, plumbing leaks or humidity can allow mold to colonize drywall. When drywall becomes moldy, some potential health effects include:
- Allergic reactions, asthma exacerbation from mold spores and hyphal fragments
- Respiratory complaints when moldy drywall is disturbed
- Possible mycotoxin exposure depending on the mold species present
- Musty odor from microbial volatile organic compounds (mVOCs)
Moldy drywall is difficult to clean completely. The porous nature of the gypsum material allows mold to penetrate deeply. Replacement of affected drywall is often necessary for remediation.
Is Mold Behind the Wall Dangerous?
Hidden mold contamination behind walls, under materials or in enclosed cavities can still pose a health risk despite not being visible. Spores from hidden mold can migrate to the living space through:
- Wall cavities
- HVAC systems
- Vents
- Electrical outlets
- Cracks and gaps
Moisture and mold issues inside walls, such as behind bathroom tiles or drywall, should not be ignored. Eventually spores can emerge into occupied areas and be inhaled. Addressing water intrusion and moisture problems proactively is important to prevent hidden mold growth.
Can Mold on Walls Make You Sick?
Yes, mold growing on walls and other home surfaces can make you sick. When mold contamination is extensive, the large number of spores and mycotoxins in the indoor air increase the chance of adverse health effects. Symptoms like wheezing, headaches, fatigue, nasal congestion and skin irritation may occur after exposure to high spore levels. Those with mold allergies or compromised immunity are at increased risk when mold is present indoors. Even relatively minor mold growth is unhealthy and should be remediated as soon as possible.
Mold Exposure Limits
Currently no federal government standards set exposure limits or acceptable levels of indoor mold contamination. This makes the health risk posed by different mold levels difficult to quantify. Despite lack of definitive standards, mold contamination should always be minimized with prompt cleanup when found. Here are some general indoor exposure limit guidelines that may indicate increased health risks:
- Greater than 10 square feet of visible mold
- Musty odor present
- Visible moisture damage or high humidity
- Total airborne spore count >10,000 spores/mÂ3
- Indoor levels 10 times higher than outdoor levels
- Presence of Stachybotrys, Aspergillus or other toxigenic mold species
Remediation should be considered when any of these benchmarks are reached, especially for those vulnerable to mold issues. Consulting a mold professional can help interpret test results.
How to Prevent Mold Growth on Walls
Mold needs moisture to grow. Here are some tips to prevent mold growth on walls:
- Quickly fix any water leaks or flooding.
- Use bathroom fans and open windows during showers to reduce humidity.
- Make sure bathrooms are properly ventilated.
- Use dehumidifiers and air conditioners to keep indoor humidity low.
- Increase air circulation with fans or by adjusting vents.
- Allow proper drainage away from the home’s foundation.
- Avoid excess moisture from sprinklers spraying the exterior walls.
- Ensure bathroom caulking and grout is in good condition.
- Insulate cold water pipes to reduce condensation.
Keeping relative humidity below 50% inhibits mold growth. Having proper ventilation and air circulation also helps prevent excess moisture buildup.
Mold Remediation
Mold cleanup process should focus on:
- Fix plumbing leaks or other moisture sources allowing mold to grow
- Dry out affected materials with fans, heaters or dehumidifiers
- Carefully remove moldy materials if possible
- Clean surfaces with detergent solution or disinfectant
- Properly dispose of moldy items in sealed bags
- HEPA vacuum carpeting to remove mold spores and debris
- Make architectural changes like exhaust fan installation to improve ventilation
Protective gear like gloves, goggles and N-95 respirator masks should be worn during remediation to avoid spore inhalation. Extensive mold growth often requires professional remediation. Trying do-it-yourself mold removal without proper containment measures may spread spores to other areas.
Homeowner’s Insurance and Mold
Standard homeowner’s insurance policies do not cover mold damage or remediation costs. Mold is considered a maintenance issue from excessive moisture. Some insurers offer riders or endorsements providing limited mold coverage, which comes with higher premiums. Policyholders should review their policy and discuss mold coverage options with their insurer. Maintaining proper home maintenance helps avoid costly mold problems down the road.
When to Seek Medical Attention
See a doctor if mold exposure causes:
- Persistent flu-like symptoms
- Recurring headaches, dizziness or cognitive issues
- Respiratory complaints like chronic wheezing or coughing
- Repeated sinus congestion, sore throat or runny nose
- Skin rashes and irritation
- Asthma flare-ups with shortness of breath
- Ongoing fatigue, nausea or body aches
Infants, children, pregnant women, seniors and those with chronic illnesses should seek medical help quickly if experiencing above symptoms that may stem from indoor mold exposure. A doctor can provide appropriate treatment and advise on avoiding additional exposure.
Conclusion
Mold growth on damp walls and surfaces releases spores and irritants into indoor air that when inhaled, can cause allergic reactions and respiratory issues. Extensive mold contamination increases health risks, especially for vulnerable individuals with allergies or compromised immunity. Preventing moisture buildup through proper ventilation, humidity control and prompt leak repair prevents mold growth on walls and other materials. Remediation using protective gear removes moldy materials and corrects moisture problems to avoid recurring growth. While government standards do not exist currently regarding safe mold levels indoors, the consensus is that any visible mold is unhealthy and steps should be taken to eliminate it. However, hidden mold behind walls and under materials may also need to be addressed if linked to occupant health complaints. With vigilance and proactive measures taken by homeowners, mold growth indoors can be prevented, protecting health.