Rising temperatures due to climate change are increasing the risk of human exposure to so-called mycotoxins, naturally occurring toxins produced by fungi found in certain foods, feed and crops according to a European Environment Agency (EEA) briefing published today. These toxins can harm health and preventing the rise of contamination requires joined-up action on European and national levels, on research, policies and practice to effectively reduce risks.
A warmer and more humid climate across European regions is promoting an increased prevalence of mycotoxins coming from fungi, according to the EEA briefing ‘Mycotoxin exposure in a changing European climate’. It explores the associated health concerns around mycotoxins, particularly in relation to their impact on food crops and how a more coordinated European approach can help tackle the spread and prevent contamination.
Health risks
Mycotoxins, harmful naturally-formed compounds produced by fungi, pose significant health risks. The fungi toxins can disrupt hormones, weaken the immune system, damage the liver and kidneys, increase the risk of miscarriage, harm unborn children, and act as carcinogens.
Evidence suggests that certain groups may be at higher risk from exposure to mycotoxins. Young children (1-3 years old) and infants (under 12 months old) are especially vulnerable due to their higher food intake relative to body weight as are pregnant women and workers in the agricultural, food and feed sector.
According to the HBM4EU, European chemical human biomonitoring project, 14% of the adult population in Europe is exposed to the mycotoxin deoxynivalenol (DON) at levels that are considered to be harmful to human health. This particular mycotoxin, DON, is frequently found naturally in wheat, maize and barley in temperate regions.
People are exposed to these toxins by eating contaminated food (particularly grains and cereals, and products which contain them like bread or pasta). Washing and cooking these foods does not necessarily remove the mycotoxins. This is especially a problem since some of the fungi that produce mycotoxins are not visible, or detectable by smell or taste. Another route of exposure is through drinking water contaminated by agricultural runoff. Inhalation and absorption through the skin are other potential exposure routes, for people working with the crops or the food which has been affected.
Climate impacts
Climate change is altering fungal behaviour and distribution, potentially increasing the risk of exposure to these toxins. Increased precipitation, flooding and soil erosion can also transfer these toxins from soil to rivers and groundwater.
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. The concerns do not stop at the level of human health. Increased crop contamination can lead to lower yields, with associated economic losses.
Finally, a growing risk of fungal infections can trigger increased fungicide use by farmers. This may, in the long term, lead to higher risks of antifungal resistance developing, increasing the risk of difficult-to-treat fungal infections in humans.
A ‘One Health’ approach
The case of mycotoxins is a clear example of an issue that has potentially far-reaching consequences for animal, human and ecosystem health, with the environment also playing a key role as a pathway for the spread of contamination.
The European Union is already working across different policy and work areas to understand and develop solutions and mitigation strategies to address the risks from mycotoxins. For example, surveillance already undertaken in the environment (like for precipitation, sunlight hours, temperature records) should also be done to monitor food, animal feed, animals and humans. Other possible future actions to counteract mycotoxin contamination could include breeding crops that are resistant to fungal infection, adopting good agricultural practices, (like adapting to environmental conditions including crop rotation to regenerate soil fertility and minimising the carry-over of mould from one year to the other), as well as making use of biological controls and predictive models.
The European Union’s so-called ‘One Health’ approach can help to coordinate action and research that recognises the complex interconnectedness of human, animal and environmental health, applying solutions that take these different elements into account.
