allergies mold

Increased mold levels coming?

Alternaria spores

Can increased levels of atmospheric carbon dioxide (CO2) have an effect on mold spore levels? A new study suggests that increased CO2 will, in fact, lead to a greater number of mold spores outdoors with a resulting effect on allergies. As CO2 levels rise, can we expect to see more allergies to mold?

The article describing the research is titled “Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production” and is found in this month’s Environmental Health Perspectives. The researchers were looking at just one species, Alternaria alternata, so we need to be cautious about drawing big conclusions from such a small study (sorry about the sensationalist blog title!).

The authors found that increased CO2 levels caused the mold to produce nearly three times the number of spores with more than twice the total antigenic protein. Conceivably, as CO2 levels rise in the atmosphere, outdoor molds will produce more allergy triggering spores, making life even more miserable for those with mold allergies.

To read the article in its entirety, please visit: EHP.

By Ian Cull

I'm I.A.N. the Indoor Air Nerd. I'm a speaker and consultant on indoor air quality issues. To learn more about me, click "about" at the top of this page.

3 replies on “Increased mold levels coming?”

Hi Ian, thanks for sharing this article. I wonder to what extent CO2 levels would “amplify” mold spore production. If it’s a miniscule increase, then it might not be a concern. If it affects people greatly, how do you think it will affect the mold inspection and home inspection industry?

The study showed a 3x increase in spore production, but I have a hard time believing the increase in the real world would be that high.

As outdoor counts increase, indoor counts will inevitably rise as well. If mold consultants continue to compare indoor to outdoor numbers, there shouldn’t be much of an effect.

Hello Ian, I’m curious about the inverse of this. Does the presence of mold in an apartment cause increased levels of CO2?

I live in a humid environment where mold is an issue. I have no major visible signs of mold but the apartment has never been treated for mold removal. I have an real-time air quality sensor and my apartment is consistently around 900ppm of CO2 (with the windows closed). There are only three people living in the apartment (1,300sqf) and we have one plant. However, even in the rooms that are rarely occupied our CO2 levels remain 900ppm or above.

I know that 900ppm isn’t anything to be very worried about but I am wondering if the cause of the CO2 could be mold?

My TVOC readings are on average .2-.3ppm so overall very low.

We have babies on the way and I want to make sure the nursery doesn’t have a mold problem (with high CO2 as the indicator).

Any ideas would be very welcome.

Thank you!


Leave a Reply

Your email address will not be published. Required fields are marked *