Fungal toxins easily become airborne, creating potential indoor health risk

June 23, 2017

Washington, DC - June 23, 2017 - Toxins produced by three different species of fungus growing indoors on wallpaper may become aerosolized, and easily inhaled. The findings, which likely have implications for "sick building syndrome," were published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

"We demonstrated that mycotoxins could be transferred from a moldy material to air, under conditions that may be encountered in buildings," said corresponding author Jean-Denis Bailly, DVM, PhD, Professor of Food Hygiene, National Veterinary School of Toulouse, France. "Thus, mycotoxins can be inhaled and should be investigated as parameters of indoor air quality, especially in homes with visible fungal contamination."

The impetus for the study was the dearth of data on the health risk from mycotoxins produced by fungi growing indoors. (image: microscopic view of a sporulating Aspergillus, showing numerous light spores that can be easily aerosolized and inhaled together with mycotoxins. credit: Sylviane Bailly.)

In the study, the investigators built an experimental bench that can simulate an airflow over a piece of contaminated wall paper, controlling speed and direction of the air. Then they analyzed the resulting bioaerosol.

"Most of the airborne toxins are likely to be located on fungal spores, but we also demonstrated that part of the toxic load was found on very small particles -- dust or tiny fragments of wallpaper, that could be easily inhaled," said Bailly..

The researchers used three fungal species in their study: Penicillium brevicompactum, Aspergillus versicolor, and Stachybotrys chartarum. These species, long studied as sources of food contaminants, also "are frequent indoor contaminants," said Bailly. He noted that they produce different mycotoxins, and their mycelia are different from one another, likely leading to differences in the quantity of mycotoxins they loft into the air. (Mycelia are the thread-like projections of fungi that seek nutrition and water from the environment.)

The findings raised two new scientific questions, said Bailly. First, "There is almost no data on toxicity of mycotoxins following inhalation," he said, noting that most research has focused on such toxins as food contaminants.

Second, the different fungal species put different quantities of mycotoxins in the air, "probably related to mycelium organization," but also possibly related to the mechanisms by which mycotoxins from different fungi become airborne -- for example via droplets of exudate versus accumulation in spores. Such knowledge could help in prioritizing those species that may be of real importance in wafting mycotoxins, he said.

Bailly noted that the push for increasingly energy efficient homes may aggravate the problem of mycotoxins indoors. Such homes "are strongly isolated from the outside to save energy," but various water-using appliances such as coffee makers "could lead to favorable conditions for fungal growth," he said.

"The presence of mycotoxins in indoors should be taken into consideration as an important parameter of air quality," Bailly concluded.
-end-
The American Society for Microbiology is the largest single life science society, composed of over 50,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

American Society for Microbiology

Related Air Quality Articles from Brightsurf:

COVID-19: Air quality influences the pandemic
An interdisciplinary team from the University of Geneva and the ETH Z├╝rich spin-off Meteodat investigated possible interactions between acutely elevated levels of fine particulate matter and the virulence of the coronavirus disease.

COVID-19 shutdown effect on air quality mixed
In April 2020, as remote work and social distancing policies were in place in Delaware and a number of other states, there was a sense the skies were clearer and less polluted with fewer people on the road.

School absences correlate to impaired air quality
In Salt Lake City schools, absences rise when the air quality worsens, and it's not just in times of high pollution or ''red'' air quality days--even days following lower levels of pollutions saw increased absences.

Unexpected wildfire emission impacts air quality worldwide
During wildfires, nitrous acid plays a leading role--spiking to levels significantly higher than scientists expected, driving increased ozone pollution and harming air quality, according to a new study led by the University of Colorado Boulder and the Belgian Institute for Space Aeronomy.

Evergreen needles act as air quality monitors
Every tree, even an evergreen, can be an air quality monitor.

Research brief: New insight on the impacts of Earth's biosphere on air quality
A new study provides the first global satellite measurements of one of the most important chemicals affecting Earth's atmosphere.

Extending the coverage of PM2.5 monitoring to help improve air quality
A team of researchers in China has improved the method to obtain mass concentrations of particulate matter from widely measured humidity and visibility data.

Air quality impacts early brain development
Does living close to roadways pose a risk to the developing brain?

COVID-19 lockdowns significantly impacting global air quality
Levels of two major air pollutants have been drastically reduced since lockdowns began in response to the COVID-19 pandemic, but a secondary pollutant -- ground-level ozone -- has increased in China, according to new research.

Can poor air quality make you gain weight?
A new study links air pollution to changes in the human gut microbiome which could fuel diabetes, obesity and inflammatory bowel diseases like colitis and Crohn's disease.

Read More: Air Quality News and Air Quality Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.