News

Published on September 30, 2014

knack

 

Due to the multitude of negative effects on the environment and human health, the environmental fate and toxicity of persistent organic pollutants (POPs) are of a global concern. In one of our recent publications, we reported that the international efforts to reduce PCB emissions have effectively reduced concentrations in open water ecosystems like the Belgian coastal zone.

Published on September 22, 2014

chemosphere thumb100 Due to their extensive use, continuous discharge and inefficient removal by wasterwater treatment plants, increasing levels of antibiotics are commonly detected in surface waters. Even though environmental levels are generally low, it has been shown that long-term exposure may adversely affect aquatic organisms. As such, there is an urgent need to improve classical water treatment techniques.

Published on September 13, 2014

janaToday, September 15th, is the start of the second international Environmental Omics (iEOS) Conference in Liverpool, UK.  The iEOS conference and the Environmental Omics Synthesis Centre was founded to bring together people, ideas, research fields and organisations using omics approaches to advance environmental sciences. The EOS and the conference are funded through the Natural Environmental Research Council and the UK Science and Technology Facilities Council.

Published on August 20, 2014

plantsoilThe biotic ligand model (BLM) is a bioavailability model for metals based on the concept that toxicity depends on the concentration of metal bound to a biological binding site; the biotic ligand. Here, we evaluated the BLM to interpret and explain mixture toxicity of metals (Cu and Zn). The mixture toxicity of Cu and Zn to barley (Hordeum vulgare L.) was tested with a 4 days root elongation test in resin buffered nutrient solutions.

Published on August 10, 2014

GhEnToxLab at the ESA annual meeting

ESA

Founded in 1915, the Ecological Society of America has strived to stimulate and promote ecological science for nearly a decade. Over the years, it has steadily grown from the original (mostly American) 307 members to an astounding 10.000 international members today. It is the single largest community of professional ecologists in the world and therefore a reliable and critical source of ecological knowledge. Its core business is to improve the communication among scientists as well as raising public awareness through their yearly conference. Today, their 99th anual meeting kicks off in Sacramento (California, USA) and our resident ecologist Jan Baert will be there. During his pitch presentation (COS 57-6), he will explain how the effects of biodiversity on community functioning shifts along a toxic gradient. Read more about his research below to discover the venue.

Published on August 6, 2014

Toxicity of lead (Pb) to freshwater green algae: Development and validation of a bioavailability model and inter-species sensitivity

aquatic toxicology thumb100 Scientifically sound risk assessment and derivation of environmental quality standards for lead (Pb) in the freshwater environment are hampered by insufficient data on chronic toxicity and bioavailability to unicellular green algae. Here, we first performed comparative chronic (72-h) toxicity tests with three algal species in medium at pH 6, containing 4 mg fulvic acid (FA)/L and containing organic phosphorous (P), i.e. glycerol-2-phosphate, instead of PO43− to prevent lead-phosphate mineral precipitation. Pseudokirchneriella subcapitata was 4-fold more sensitive to Pb than Chlorella kesslerii, with Chlamydomonas reinhardtii in the middle. The influence of medium physico-chemistry was therefore investigated in detail with P. subcapitata. In synthetic test media, higher concentrations of fulvic acid or lower pH protected against toxicity of (filtered) Pb to P. subcapitata, while effects of increased Ca or Mg on Pb toxicity were less clear. When toxicity was expressed on a free Pb2+ ion activity basis, a log-linear, 260-fold increase of toxicity was observed between pH 6.0 and 7.6. Effects of fulvic acid were calculated to be much more limited (1.9-fold) and were probably even non-existent (depending on the affinity constant for Pb binding to fulvic acid that was used for calculating speciation).

Published on July 28, 2014

Microplastics in bivalves cultured for human consumption

env pollutToday, 27 years after Cpt. Charles J. Moore first discovered the Great Pacific Garbage Patch, marine plastic pollution continues to be a growing threat to the marine environment. As plastic debris is ubiquitious across the world's seas and oceans, the consequences of macroplastics for most (vertebrate) wildlife have been identified over the years. Yet, to date, the impacts of microplastics are less understood. These plastic particles (< 1mm), which are found in cosmetics and can be formed through the degradation of larger plastic items, are becoming increasingly abundant. As our research has shown, they can now be found from the surface layer all the way down to the deep-sea sediment. Worringly, microplastics can be ingested by a wide range of marine organisms because of their small dimensions which in turn creates an understudied risk of exposure for human consumers. Here we present the first study to report on the possible consequences of marine microplastics for human consumers by analysing the occurence of microplastics in commercially available shellfish. From our results, we calculated that the average European shellfish consumer has an uptake of 6400 microplastics per year. As there is a lack of (mammal) effect studies, this exposure poses an unknown risk for human health.

Published on July 16, 2014

Inferring time-variable effects of nutrient enrichment on marine ecosystems using inverse modelling and ecological network analysis

scitotenv thumb100 Despite the restrictions imposed by the ever increasing legislation, anthropogenic nutrient inputs continue to be a worldwide threat to our marine ecosystems. The resulting elevated nitrogen and phosphorus concentrations can promote intensive algal blooms which may decrease transparancy, deplete oxygen and change the composition of the fish community. In recent years, these ecosystem-level consequences  of anthropogenic nutrient enrichment are being studied from a topological perspective (ie. who eats whom). However, it has been noted that this perspective is insufficient to understand the magnitudes of energy and materials that flow through natural food webs. To circumvent this, we used a mesocosm approach combined with linear inverse modelling to estimate carbon flows in a foodweb subjected to different nutrient treatments. In doing so, we found that the systems activity is positively but nonlinearly affected by the addition of nutrients. Surprisingly, detritus appears to be a crucial, if not predominant, driver of the ecosystem functioning under all nutrient conditions.

Published on July 10, 2014

Are there species-specific tolerances towards cyanobacteria in Daphnia?

HA

Cyanobacterial blooms have been a growing environmental concern due to their ability to produce toxins. Yet to date, few studies have focused on comparing the effects of different cyanobacteria. In this publication, we determined the effects of six common cyanobacteria on two keystone species in the aquatic environment, Daphnia magna and Daphnia pulex. Sensitivity depended upon the concentration of the cyanobacteria and differed between the Daphnia species. The publication of this paper coincided with the recent webinar 

Published on July 10, 2014

Prof. Janssen explains the relevance of the EU SCHER to 22.000 readers... in 23 languages

EUC

While conducting innovative research to improve the ecological risk assessment of chemicals remains the core business of the GhEnToxLab, we actively encourage societal participation, social debate and public outreach. In light of this, Prof. Dr. Colin Janssen, chair of the European Scientific Committee on Health and Environmental Risks (SCHER), explains the role of SCHER in the European decision making. In 23 languages!

 

 Role of SCHER

 

 

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