Andre Vethaak - Academia.edu (original) (raw)
Papers by Andre Vethaak
Guidelines are given for the quantification of the dioxin-like activities of contaminants in sedi... more Guidelines are given for the quantification of the dioxin-like activities of contaminants in sediment, biota and water samples using the DR-Luc reporter gene bioassay. Dioxins and dioxin-like compounds demonstrate high affinity binding to the Aryl hydrocarbon Receptor (AhR). Ah-R is a ligand-activated transcription factor and mediates most, if not all, of the toxic responses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and polybrominated biphenyls (PBBs). The DR-Luc bioassay, or DR-CALUX® (Dioxin Response Chemical Activated LUciferase gene eXpression), utilizes a recombinant rat hepatoma H4IIE cell line with a stably integrated AhR- responsive luciferase reporter gene. Exposure of this bioassay to extracts containing dioxin-like compounds induces the enzyme luciferase in a time, dose, and chemical specific manner. Cells are cultured in the laboratory and transferred to 96-well plates. Luciferase activity is determined by measuring the light emitted, which is directly proportional to the amount of dioxin-like compounds within the test extract. Hence the DR-Luc assay is a rapid, extremely sensitive and cost-effective tool for screening sediment, biota, and water extracts for dioxins and dioxin-like compounds. The DR- Luc assay is recommended in the OSPAR JAMP guidelines as a specific biological effect method for monitoring of PCBs, polychlorinated dibenzodioxins and furans, and also as a suitable biological effect method for general biological effect monitoring. In addition, DR-Luc analysis has proven to be a very powerful tool in emission source monitoring and remediation efforts as it allows for the identification and control of the toxic compounds concerned. Critical steps, such as the extraction of sediment or biota samples and subsequent clean-up of the extracts are discussed, followed by descriptions of the DR-Luc detection technique. Emphasis is placed on analytical quality control and quality assurance.
Environmental Science & Technology, 2014
Current Metabolomics, 2015
Chemosphere, 2015
There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its eth... more There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation model comprising five trophic levels. Using this model, we estimated uptake and elimination rate constants for NPEOs based on the organisms' weight and lipid content and the chemicals' Kow. Further, we calculated accumulation factors for NP and NPEOs, including biota-sediment accumulation factors (BSAF) and biomagnification factors (BMF), and compared these to independent field measurements collected in the Western Scheldt estuary in The Netherlands and field data reported in the literature. The estimated BSAF values for NP and total NPEOs were below 1 for all trophic levels. The estimated BMF values were around 1 for all trophic levels except for the highest level (carnivorous mammals and birds). For this trophic level, the estimated BMF value varied between 0.1 and 2.4, depending on the biotransformation capacity. For all trophic levels, except primary producers, the accumulation estimates that accounted for biotransformation of NPEOs into NP were closer to the field data than model estimates that did not include biotransformation, indicating that NP formation by biotransformation of NPEOs might occur in organisms.
Environmental Toxicology and Chemistry, 2014
Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequentl... more Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequently used technique in algal bioassays to assess toxicity of single compounds or complex field samples. Several test conditions can influence the test results, and because a standardized test protocol is currently lacking, linking the results of different studies is difficult. Therefore, the aim of the present study was to gain insight into the effects of test conditions of laboratory algal bioassays using PAM fluorometry on the outcome of toxicity tests. To this purpose, we described the results from several pilot studies on test development in which information is provided on the effects of the main test factors during the pretest phase, the test preparation, the exposure period, and the actual measurement. The experiments were focused on individual herbicides and complex field samples and included the effects of culturing conditions, cell density, solvent concentration, exposure time, and the presence of actinic light. Several of these test conditions were found to influence the outcome of the toxicity test, and the presented information provides important background information for the interpretation of toxicity results and describes which test conditions should be taken into account when using an algal bioassay with PAM fluorometry. Finally, the application of PAM fluorometry in algal toxicity testing is discussed.
Environmental Science & Technology, 2002
Science of The Total Environment, 2002
ICES Journal of Marine Science, 2010
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1997
Journal of Sea Research, 2013
Netherlands Journal of Sea Research, 1992
ABSTRACT
Guidelines are given for the quantification of the dioxin-like activities of contaminants in sedi... more Guidelines are given for the quantification of the dioxin-like activities of contaminants in sediment, biota and water samples using the DR-Luc reporter gene bioassay. Dioxins and dioxin-like compounds demonstrate high affinity binding to the Aryl hydrocarbon Receptor (AhR). Ah-R is a ligand-activated transcription factor and mediates most, if not all, of the toxic responses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and polybrominated biphenyls (PBBs). The DR-Luc bioassay, or DR-CALUX® (Dioxin Response Chemical Activated LUciferase gene eXpression), utilizes a recombinant rat hepatoma H4IIE cell line with a stably integrated AhR- responsive luciferase reporter gene. Exposure of this bioassay to extracts containing dioxin-like compounds induces the enzyme luciferase in a time, dose, and chemical specific manner. Cells are cultured in the laboratory and transferred to 96-well plates. Luciferase activity is determined by measuring the light emitted, which is directly proportional to the amount of dioxin-like compounds within the test extract. Hence the DR-Luc assay is a rapid, extremely sensitive and cost-effective tool for screening sediment, biota, and water extracts for dioxins and dioxin-like compounds. The DR- Luc assay is recommended in the OSPAR JAMP guidelines as a specific biological effect method for monitoring of PCBs, polychlorinated dibenzodioxins and furans, and also as a suitable biological effect method for general biological effect monitoring. In addition, DR-Luc analysis has proven to be a very powerful tool in emission source monitoring and remediation efforts as it allows for the identification and control of the toxic compounds concerned. Critical steps, such as the extraction of sediment or biota samples and subsequent clean-up of the extracts are discussed, followed by descriptions of the DR-Luc detection technique. Emphasis is placed on analytical quality control and quality assurance.
Environmental Science & Technology, 2014
Current Metabolomics, 2015
Chemosphere, 2015
There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its eth... more There are several studies on bioaccumulation and biomagnification of nonylphenol (NP) and its ethoxylates (NPEOs), but their toxico-kinetic mechanisms remain unclear. In the present investigation, we explored the accumulation of NP and NPEOs in estuarine-marine food chains with a bioaccumulation model comprising five trophic levels. Using this model, we estimated uptake and elimination rate constants for NPEOs based on the organisms' weight and lipid content and the chemicals' Kow. Further, we calculated accumulation factors for NP and NPEOs, including biota-sediment accumulation factors (BSAF) and biomagnification factors (BMF), and compared these to independent field measurements collected in the Western Scheldt estuary in The Netherlands and field data reported in the literature. The estimated BSAF values for NP and total NPEOs were below 1 for all trophic levels. The estimated BMF values were around 1 for all trophic levels except for the highest level (carnivorous mammals and birds). For this trophic level, the estimated BMF value varied between 0.1 and 2.4, depending on the biotransformation capacity. For all trophic levels, except primary producers, the accumulation estimates that accounted for biotransformation of NPEOs into NP were closer to the field data than model estimates that did not include biotransformation, indicating that NP formation by biotransformation of NPEOs might occur in organisms.
Environmental Toxicology and Chemistry, 2014
Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequentl... more Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequently used technique in algal bioassays to assess toxicity of single compounds or complex field samples. Several test conditions can influence the test results, and because a standardized test protocol is currently lacking, linking the results of different studies is difficult. Therefore, the aim of the present study was to gain insight into the effects of test conditions of laboratory algal bioassays using PAM fluorometry on the outcome of toxicity tests. To this purpose, we described the results from several pilot studies on test development in which information is provided on the effects of the main test factors during the pretest phase, the test preparation, the exposure period, and the actual measurement. The experiments were focused on individual herbicides and complex field samples and included the effects of culturing conditions, cell density, solvent concentration, exposure time, and the presence of actinic light. Several of these test conditions were found to influence the outcome of the toxicity test, and the presented information provides important background information for the interpretation of toxicity results and describes which test conditions should be taken into account when using an algal bioassay with PAM fluorometry. Finally, the application of PAM fluorometry in algal toxicity testing is discussed.
Environmental Science & Technology, 2002
Science of The Total Environment, 2002
ICES Journal of Marine Science, 2010
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 1997
Journal of Sea Research, 2013
Netherlands Journal of Sea Research, 1992
ABSTRACT