Having an accurate statistic on the percentage of the US population that is allergic to mold can help in
so many ways, including bringing more awareness to mold related problems, supporting calls for more research on what causes mold and how to treat mold infections in humans, and much more. So what is the definitive answer to the question, How many people are allergic to mold in the US?
Several studies indicate that approximately 3-10% of the US population could be allergic to mold. With an estimated population of 336 million in the US, that mean an estimated 10-33 million people in the US could be allergic to mold. 1 2 3
The first thing you will likely notice is that the estimated percentage range is pretty large, and also that this is not an irrefutable statistic. Why is that?
While it would be cleaner to have a definitive number for reporting purposes, the fact of the matter is that it’s difficult to get an accurate sampling of data from a diverse pool of people in the US, and the percentages likely vary by demographics and living situations. So this estimate of 3-10% is about as accurate as we can get.
But Why Did The ACOEM Cite 10%?
We’ve done some extensive research on various sources that estimate the percentage of people allergic go mold, and one statistic we came across frequently – and you likely have too if you’ve done as much research as we have – is that the ACOEM (American College of Occupational and Environmental Medicine) claimed that 10% of the US population is allergic to mold. However, they later came under scrutiny for possible undisclosed conflicts of interests in the team who produced and distributed the report. 4
To clarify, it’s not that the ACOEM’s statement has been definitively proven to be inaccurate, but rather the critique is that stating a single percentage instead of a range can be misleading and is likely not completely accurate, or at best does not give the complete picture.
Geographic Distribution of Mold Allergies
Mold allergies affect people worldwide, but the prevalence varies by region. Factors such as climate, humidity, and local flora can influence the types and concentrations of mold spores present in the environment, leading to differences in sensitization rates.
A study by Twaroch et al. published in the journal Allergy, Asthma & Immunology Research examined the geographic distribution of fungal allergies. They reported that sensitization rates among patients attending allergy clinics range from 5% to 20%, depending on the climate conditions. The authors also noted that fungal sensitization is more prevalent in urban areas compared to rural settings.5
Another study, conducted by the Global Allergy and Asthma European Network (GA2LEN), investigated the prevalence of sensitization to Alternaria alternata and Cladosporium herbarum in 16 European countries. They found an overall sensitization rate of 11.9% for Alternaria alternata and 5.8% for Cladosporium herbarum, with the highest prevalence in the UK, Ireland, and Northern Europe.6
In the United States, the National Health and Nutrition Examination Survey (NHANES) 2005-2006 revealed that approximately 12.9% of the population (aged 6-59 years) had positive skin prick tests to Alternaria alternata. The study also found higher sensitization rates in metropolitan areas compared to rural settings.7
While these studies provide valuable insights into the geographic distribution of mold allergies, it’s important to note that the prevalence data may vary depending on the specific population studied (e.g., patients attending allergy clinics vs. the general population) and the diagnostic methods used (e.g., skin prick tests vs. serum-specific IgE tests).
Sources
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4397360/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8954643/
- https://www.census.gov/popclock/
- https://pubmed.ncbi.nlm.nih.gov/19043916/
- https://pubmed.ncbi.nlm.nih.gov/25840710/
- https://pubmed.ncbi.nlm.nih.gov/19772516/
- https://www.jacionline.org/article/S0091-6749(05)01314-X/fulltext