Fate of Contaminants
Natural toxins are compounds produced by organisms typical as a chemical weapon against predators and competing species. Many such natural compounds are toxic to highly toxic - just think about ricin from the castor oil plant, amatoxins from mushrooms, coniine from poison hemlock, cyanogenic glucosides from clover, microcystins from cyanobacteria, or phytoestrogenic isoflavanoids from beans. There is a huge diversity of such toxins, with more than 50,000 different compounds. In our research group we work with these toxins because we think they are as important for the quality of natural waters including drinking water as are industrial pollutants. Today we know very little about the fate of these compounds in the environment and data are ugently needed. Also for natural toxins we need to know their fate in the environment. We also need to know how much of the toxins are produced, how much is deposited into the soil, and when the toxins released. One example is the compound ptaquiloside – a carcinogenic glucosidic compound produced by bracken. Ptaquiloside is highly soluble in water and leach fast through in soils to surface water and groundwater in rural and forest areas with bracken. We focus on fate and pathway from plants, fungi, animals and microorganisms that produce toxic compounds to our drinking water to improve the risk assessment and damage control of this poisonous toxin.
We are currently running a bigger initiative in the area called NaToxAq where we together with a number of research groups in Europe study how natural toxins may end up in drinking waters from plant or bacterial sources.
Pesticides and other xenobiotics
Pesticides are designed to protect crops from pests to ensure high quality food products. It is inevitable that some will be spread in the environment and hit non-target organisms in soil and freshwater. Understanding sorption and degradation kinetics of pesticides in agricultural soils allow us to reduce non-target exposure and effects to organisms in streams after leaching via drain and surface run-off. We study sorption and desorption to minerals and mobile particles coated with natural organic matter, and thus the retention of pesticides in the soil. As for pesticides many other organic contaminants are added to soils with manure or waste, e.g. antibiotics, steroidhormones, and plasticizers. Also here we investigate degradation and sorption to assess the risk of leaching to the aquatic environment.
Heavy metals and speciation
Heavy metals and other toxic elements are unfortunate bioactive pollutants in the soil-water continuum. The fundamental knowledge of microbial ecosystem functioning and fate of toxic elements in food production systems is used for better risk evaluation and efficient remediation in soils, sediments and freshwaters in both urban and agricultural areas. We study the speciation, complexation, sorption and leaching processes of elements in the environment. For instance we investigate and optimize element speciation analysis techniques for the determination of microbiological available Cu and Zn in the soil-water-manure system.