Mold & damp
The problem is the water, not the species. Fix the moisture and the mold goes with it — and you almost certainly do not need a test.
Draft — not yet medically reviewed
Routine guidance
Here in our region
A dry climate does not mean no mold. It means moisture turns up in particular places rather than everywhere: basements and crawl spaces, plumbing leaks, ice dams at the roof edge, humidifiers, and evaporative or “swamp” coolers, which add moisture by design and need maintaining.
One thing worth being straight about: swamp coolers get blamed a great deal, often by companies selling mold tests. The one pediatric study we could find on it did not find an association with mold or dust mite sensitisation. Maintain them because they are a moisture source, not because they are a proven hazard to your child.
Mold is a water problem
Mold grows wherever water sits long enough — behind a leak, under a window that sweats, in a basement that never quite dries.
Which species it is almost never changes what you should do. The fix is always the same: find the water and stop it. If you clean up mold and leave the moisture, it comes back.
Who is affected most
Children who already have asthma or allergies feel it most — damp housing can make existing asthma noticeably worse. Everyone in a damp home may get more coughing, wheezing and stuffy noses.
Trust your nose and your eyes
A musty smell, visible growth, water stains, bubbling or peeling paint, condensation on windows, or a floor or wall that feels damp. A musty smell with nothing visible usually means water somewhere you cannot see.
Six steps, in this order
- Find and fix the water first. Everything else is temporary until you do.
- Small areas you can do yourself — EPA's rough guide is under about 10 square feet, roughly a 3-by-3-foot patch.
- Skip the bleach. EPA does not recommend bleach or biocides as routine practice for mold clean-up. Detergent and water, and drying thoroughly, does the job.
- Throw out soaked porous things — carpet, ceiling tiles, drywall, upholstered furniture. They cannot be cleaned reliably.
- Keep indoor humidity between 30 and 50%.
- Do not buy a mold test. See the question below.
When to get help
Call in a professional for large areas, anything involving sewage or flood water, or damp inside a heating and cooling system.
Call your child's doctor if their asthma is getting worse, they are wheezing more, or they are having trouble breathing.
And ask us if a landlord is not addressing damp, or if you have been told your child needs testing for mold.
“Should I get the mold tested?” and “What about black mold?”
On testing — almost certainly not. EPA's position is that "in most cases, if visible mold growth is present, sampling is unnecessary." CDC's is blunter: "CDC does not recommend mold testing." The deeper reason is that there are no health-based limits for indoor mold, so a number on a lab report has nothing to be compared against. It cannot tell you whether your home is safe, and it will not change what you should do.
On black mold — this deserves a straight answer, because there is a great deal of frightening material online. It traces back to a cluster of infant lung bleeding investigated in the 1990s. CDC reviewed it and concluded the association was not proven and was not adequately substantiated by the evidence.
What damp housing is well supported to do: more coughing, wheezing, upper respiratory symptoms, and worse asthma in children who already have it. What is not supported: memory loss, "mold toxicity" syndromes, and the more dramatic claims made for toxins.
Resources
No resources are attached to this topic yet.
Show the clinical text of this topic
The short version
- No health-based exposure limit for indoor mold exists. EPA and CDC both confirm no threshold values have been set. Sampling rarely changes management.
- Mold-specific IgE and IgG have a legitimate role in allergy and hypersensitivity pneumonitis work-up — and no role in exposure assessment. That distinction is the one families and attorneys tend to collapse.
- Urine "mycotoxin" testing is unvalidated. ACMT (2025) and AAAAI (2006) agree, nineteen years apart.
- There is no documented evidence for a mold-related toxic encephalopathy.
What is actually actionable
Take a dampness history rather than a mold history: leaks, flooding, visible growth, musty odour, humidification, evaporative cooling, and whether symptoms improve away from home.
Manage the atopy and the asthma in front of you. Direct remediation effort at the moisture source, and document the housing conditions — for a family in substandard rental housing, your note may be the most useful thing you produce that day.
Where the evidence line actually falls
This is worth carrying precisely, because it is the difference between reassuring a family and dismissing them.
IOM 2004 found sufficient evidence of an association with: upper respiratory tract symptoms, cough, wheeze, asthma symptoms in already-sensitised asthmatics, and hypersensitivity pneumonitis in susceptible people.
*On asthma development, the two major reviews differ* — IOM 2004 rated it limited or suggestive; WHO 2009 rated it sufficient. Do not flatten that into a single answer; the honest response to "did our house cause my child's asthma" is that expert bodies disagree.
On mycotoxins, WHO describes the evidence that they matter at indoor concentrations as extremely weak.