Erik J. Joner

Head of Department/Head of Research

(+47) 450 00 567
erik.joner@nibio.no

Place
Ås O43

Visiting address
Oluf Thesens vei 43, 1433 Ås

Biography

Erik Joner has a PhD in soil microbiology (Norwegian University of Life Sciences, 1994) and a senior scientist habilitation (HDR; Habilitation a Diriger des Recherches, Universite Henri Poincare, 2001). He has worked on degradation of environmental pollutants, plant uptake of heavy metals, ecotoxicology and soil biology within a number of national and international projects.
 
His expertize covers soil biology and soil health, fate of microplastics in soil, effects of biochar on soil and soil organisms, uptake of heavy metals and organic pollutants in plants and earthworms, degradation of organic pollutants in soil and compost, use of biochar in produced soil and "soil" for green roofs, mycorrhiza as mechanism for nutrient uptake in plants, antimicrobial resistance in soil, etc.

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Abstract

We investigated dissipation, earthworm and plant accumulation of organic contaminants in soil amended with three types of sewage sludge in the presence and absence of plants. After 3 months, soil, plants and earthworms were analyzed for their content of organic contaminants. The results showed that the presence of plant roots did not affect dissipation rates, except for galaxolide. Transfer of galaxolide and triclosan to earthworms was significant, with transfer factors of 10–60 for galaxolide and 140–620 for triclosan in the presence of plants. In the absence of plants, transfer factors were 2–9 times higher. The reduced transfer to worms in the presence of plants was most likely due to roots serving as an alternative food source. Nonylphenol monoethoxylate rapidly dissipated in soil, but initial exposure resulted in uptake in worms, which was detected even 3 months after sewage sludge application. These values were higher than the soil concentration at the start of the exposure period. This indicates that a chemical's short half-life in soil is no guarantee that it poses a minimal environmental risk, as even short-term exposure may cause bioaccumulation and risks for chronic or even transgenerational effects.

To document

Abstract

There is an increasing global production and demand for biodegradable plastics. But there are still many uncertainties about how and to what extent these plastics degrade and their environmental impacts. To gain a better understanding of these aspects, the Scientific Committee for Food and Environment (VKM) has conducted a self-initiated scoping review of existing scientific literature on biodegradable plastics and their environmental impacts. VKM has specifically focused on studies that are relevant to Norwegian and Nordic conditions. The first literature search (June 2024) revealed 2428 international research studies, including primary studies and systematic and non-systematic review articles. The primary studies were divided into three categories: materials, microbiology and ecotoxicology, based on the main focus of the studies. From each category, a quarter of the primary studies and non-systematic review articles were randomly selected for full text analysis. A total of 168 articles were included in the final mapping. A new literature search (October 2025), with a focus on Nordic research and particularly Norwegian conditions, revealed 178 articles, of which 19 were subject to further analysis. The most studied types of biodegradable plastics were polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene adipate terephthalate (PBAT). Many of the studies focused on the degradation process of biodegradable mulch film used in agriculture, and how their use affects the environmental conditions in agricultural soils. Most studies reported incomplete degradation during the trial period, which underlines the concern for accumulation of plastic material with repeated use. Other studies simulated different pollution scenarios, such as lost fishing gear, an area that has received attention in recent Nordic studies. Ecotoxicological effects of biodegradable plastics were often only observed at concentrations far above those expected to occur in natural environments. There were indications that effects observed in soil and aquatic ecosystems could just as well be indirect, resulting from changes in physical and chemical properties of soil and water. In general, the effects of biodegradable plastics are comparable to those of conventional (micro)plastics in both terrestrial and aquatic ecosystems. However, there were studies that suggest that biodegradable plastics are more toxic than conventional plastics under specific conditions, such as after UV exposure, or for certain test organisms. Testing the ecotoxicity of commercial biodegradable plastics was complicated by the lack of transparency about their chemical composition. Only a minority of studies investigated the ecotoxicity of chemical substances leaching from plastic materials, and the results reported were inconsistent. There is a lack of studies that combined degradation studies with toxicological effects. This knowledge gap has also been pointed out in systematic review articles. The review revealed several weaknesses in the existing research, related to study design, analytical methods, definitions and terminology. Current research practice provides many individual studies that are difficult to compare. Thus, they provide limited insight into how degradation and environmental impact occur over time, and in different environments. The review points to the need for strengthened and standardized research, so that the knowledge base becomes more robust and a better understanding of the environmental impact of plastics over time and in different environments can be gained.

Abstract

Sammen med et ekspertpanel gir Torkild Jemterud deg svar på alt du ikke visste du ville vite: Hvorfor redde jorda når sola vil sluke oss? Har livet oppstått flere ganger? Hvordan påvirker insektdøden oss helt konkret? Hvordan lager spekkhoggere hatter av laks? I dagens panel paleontolog Lene Liebe Delsett, jordforsker Erik Joner og geolog Ingrid Anell