High priority has been given to coordinate the complimentary work of the 16 ESRs and to ensure active involvement of all partners including fruitfull secondments and industria-academia interaction. The water supply sector has been particularly active in the project as part of their strive to ensure safe drinking water for water consumers. The ESRs have performed pioneering work on many aspects of natural toxins - in many cases the ESRs have been forerunners and provided data and results that are the first of its kinds. Results have been communicated first of all in scientific journals (45 papers planned; 40 has been published so far:
https://natoxaq.ku.dk/publications/(s’ouvre dans une nouvelle fenêtre)) but also at numerous conferences, via the NaToxAq homepage, via popular science magazines, social media and local meetings, and last but not least, our final conference, which was performed online in September 2020.
Innovative results comprise:
- Novel analytical methods for natural toxins via targeted high-sensitivity LC-MS methods, but also effect-directed screening, non-targeted and suspect screening MS based methods. In addition high-throughput screening methods have been developed, e.g. for cyanotoxins. These new methods have enabled quantification of toxins in plants, soils and waters which was not previously possible. In addition, full scan MS spectra of new toxins have been uploaded to Norman Mass Bank which now make it possible for other workers to include the natural toxins in future studies and monitoring programmes.
- Occurence of natural toxins in water resources. Natural toxins have been monitored in plants, soils and water resources in field studies in different parts of the EU. A variety of toxins have been detected with most toxins falling with in the groups of flavanoids, alkaloids, terpenoids, coumarins and polyketides. Water samples typically contain a mixture of natural toxins. Many natural toxins appear in pulses initiated by rain events. Certain toxins appear more dominating than others, and our studies point to alkaloids (e.g. pyrrolizidine alkaloids) as one of the groups of phytotoxins that need future attention. The monitoring work also has shown the strong need for analytical methods that can include many toxin classes, the need for improved MS databases including more natural toxins and the need for reference materials.
- Properties, fate and modelling of natural toxins. Much new data has been generated for the hydrolysis, biodegradability, photodegradation and sorption properties of a larger set of natural toxins. We have looked into predictive tools for estimating natural toxin properties, and we have developed the first model to describe the fate of phytotoxins in the soil-water-plant system. In addition, we have applied advanced oxidation and microbial degraders for water treatment at water works.
- Toxicity, exposure and risk assessment. A knowledge gap on hazard assessment of different cyanotoxins has been addressed using a new in-vitro test for exposure via the respiratory and gastrointestinal tract including tests of developmental neurotoxicity. This has contributed with new knowledge on toxicity testing platforms currently being explored in the EU and applicable to other natural toxin exposure via water. Further two databases - one on cyanotoxins and the other one comprising phytotoxins, have been developed in order to assist in surveys, toxin prioritization and for future coupling with models to predict exposure through water. As a first example a leaching model was applied to natural toxins for estimating risk of groundwater contamination.
The results are of immediate interest for the water supply sector and water consumers, and for future development of EU drinking water regulation, where selected natural toxins should be considered for inclusion in the list of critical water quality parameters. Water suppliers using surface water or upper groundwater in regions with larger coverage of toxin producing plants (such as bracken) or affected by algal blooms may share an interest in testing if toxins are present in drinking water supplied their consumers and thus to excerpt due diligence and to ensure safe water. Companies providing chemical analysis of water samples may include natural toxins in their analytical services; this in turn creates a need for reference materials and MS data. Regional and national environmental protection authorities should perform monitoring of priority natural toxins to further document their occurrence in water bodies. The needs may be further stimulated by increasing production and use of "biologicals" such as biopesticides, plant growth promoters and regulators, and biomedicine. On a higher level, the presence and toxicity of natural toxin cocktails in natural waters raise questions on water quality concepts used communicated to society and used in legislation and regulation. Natural toxins contribute to the overall chemical and toxicity profile of a water sample, and not only anthropogenic chemicals are toxic.
