Climate Change Worsening Food Contamination by Harmful Mycotoxins, Warns European Environment Agency

Warming temperatures associated with climate change are increasing the risk of human exposure to mycotoxins from food, warned the European Environment Agency (EEA) in a new briefing.

Mycotoxins—formed by fungi in foods like wheat, corn, and barley—pose significant health risks to humans, such as disrupting hormones, weakening the immune system, damaging the liver and kidneys, causing miscarriages and harm to unborn children, and contributing to cancer. People are exposed to mycotoxins through the consumptions of foods like grains, cereals, breads, and pasta, as well as from drinking contaminated water. Mycotoxins are absorbed by plants during growth or after harvest and can remain in food even after washing, cooking or processing.

According to EU chemical human biomonitoring data, 14 percent of the adult European population is exposed to the mycotoxin deoxynivalenol at dangerous levels. Other significant and harmful mycotoxins relevant to human health include aflatoxins, Fumonisin, zearalenone, and ochratoxin A. Recent studies suggest that while approximately 25 percent of crops exceed EU regulatory limits for mycotoxins, with contamination occurring at levels above detectable limits in up to 60–80 percent of crops.

Global climate change is altering fungal behavior and distribution, potentially increasing the risk of exposure to mycotoxins, per EEA. The highest risk of climate-change-induced mycotoxin contamination is expected in developed countries with moderate climates. Extreme weather events, such as heavy rainfall or prolonged droughts, increase the stress that plants are exposed to, making cereals—especially maize—more vulnerable to fungal infections and mycotoxin contamination. Additionally, certain mycotoxins are expected to become more prevalent at higher temperatures in humid conditions, because humidity spurs the growth of fungi that produce them.

Moreover, increased precipitation, flooding, and soil erosion could transfer mycotoxins from soil to rivers and groundwater. This would increase the likelihood of contamination in food and feed, and exacerbate the risk of mycotoxins entering drinking water.

The growing prevalence of fungi-producing mycotoxins may also lead to inadvertent public health and sustainability risks associated with increased fungicide use.

Some “One Health” efforts to understand and mitigate mycotoxin exposure are already underway in the EU; for example, surveillance is already conducted for the impact of environmental factors (e.g., precipitation, sunlight hours, and temperature records) on mycotoxin risk, and could be expanded to include monitoring of food, animal feed, animals, and humans. EEA also suggests other possible future actions to counteract mycotoxin contamination, such as breeding crops that are resistant to fungal infection, adopting good agricultural practices (e.g., adapting to environmental conditions including crop rotation to regenerate soil fertility and minimize the carry-over of mold from one year to year), as well as making use of biological controls and predictive models.