03-GOVERNANCE-01 & 02-CLIMATE-02 Strengthening policies concerning contaminants of biological origin in irrigation water to increase EU agriculture resilience

Cyanobacteria blooms occur in eutrophic water bodies, preferably at high temperatures. Understandably, these blooms occur most often when irrigation water sources are at their most precious. This increases the impact of the restricted use of these water bodies during blooms, making it all the more detrimental, yet not without merit. Cyanobacterial blooms can produce hepatotoxins that accumulate in crops when bloom-contaminated irrigation water is used. Therefore, legislation in some EU countries, including Belgium, based on EU food legislation, prohibits the use of contaminated water for crop irrigation and for use in the food industry in general. Yet, standardized monitoring and safety assessment of irrigation water is generally lacking. For the moment, restrictions on water use from canals and rivers are commonly imposed along their entire length based solely on the presence of blooms, even though not all blooms are toxic. On the other hand, basins for irrigation water are not monitored at all in most EU countries, resulting in potential risks to human health. 

Improving monitoring and analytical capacity for cyanobacterial blooms in these water sources through in situ monitoring and stakeholder engagement could lead to smarter use and greater resilience for European agriculture. Moreover, mitigation techniques could reduce the presence of cyanobacteria and their toxins in the water bodies when water demand is critical. Besides activities directly in the water bodies, improving the current risk assessment of cyanotoxin accumulation in crops by improving analytical detection in primary crop production, accumulation rates, and human exposure could better inform policymakers in imposing more evidence-based limits for cyanotoxins in irrigation water and crops compared to the current no-tolerance (in some EU countries).