Dr. ir. T. Hamers

Summary

Timo Hamers is an environmental toxicologist with training in environmental sciences, aquatic ecotoxicology and air pollution.  His expertise lies in the application, development and optimization of small-scale in vitro bioassays to determine toxicity profiles of sets of individual compounds and complex environmental mixtures of pollutants. Within the EU-funded FIRE and ATHON studies, he was responsible for the in vitro toxicity profiling of brominated fire retardants (BFRs) and non-dioxin-like PCBs, and their metabolites. In addition he studied the toxicity profiles of complex mixtures extracted from abiotic and biotic environmental samples in the MODELKEY study (EU-funded), the Marie-Curie Training Network KeyBioEffects (EU-funded), and the Trouttox project (funded by the Norwegian Research Council). Currently, he is involved in the in vitro toxicity profiling of non-brominated flame retardants within the Enfiro project (EU-funded) and of particulate matter collected during climate-change related events within in the DiPol project (InterReg).

In addition, he is involved in mechanistic in vitro studies into the (epigenetic) mode of action of endocrine disrupting obesogenic chemicals. This work is performed within the EU-funded OBELIX project, of which he acts as the deputy coordinator.

Finally, he is involved in teaching courses in the subject of environmental toxicology and health for Biomedical Sciences (BSc), Biology (BSc), Health & Life Sciences (BSc) and Ecology (MSc). He further supervises students who perform their BSc or Msc internship or PhD research in the IVM laboratories.

Expertise

Environmental toxicology, ecotoxicology, environmental chemistry, aquatic ecology, bio-assays, biomarkers, biotransformation.

Academic training

Professional employment history

Selected publications

Link to full publication list at IVM since 2003

Stenberg, M., Hamers, T., Machala, M., Fonnum, F., Stenius, U., Al Anati, L., Van Duursen, M., Westerink ,R.H.S., Fernandes, E.C.A., Andersson, P.L. (2011). Multivariate toxicity profiles and QSAR modelling of NDL-PCBs – an investigation of in vitro screening data from ultra-pure congeners. Chemosphere (in press)

Simon, E., Bytingsvik, J., Jonker, W., Leonards, P.E.G., De Boer, J., Jenssen, B.M., Lie, E., Aars, J., Hamers, T., Lamoree, M.H. (2011). Blood plasma sample preparation method to determine thyroid hormone-disrupting compounds in Effect-Directed Analysis. Environmental Science and Technology, 45, 7936–7944.

Roos, R., Andersson, P.L., Halldin, K., Håkansson, H., Westerholm, E., Hamers, T., Hamscher, G., Heikkinen, P., Korkolainen, M., Leslie, H., Niittynen, N., Sankari, S., Schmitz, H.J., Van der Ven, L., Viluksela, M., Schrenk, D. (2011). Hepatic effects of a highly purified 2,2’,3,4,4’,5,5’-heptachlorobiphenyl (PCB-180) in male and female rats. Toxicology,284, 42-53.

Hamers, T., Kamstra, J.H., Cenijn, P.H., Pencikova, K., Palkova, L., Simeckova, P., Vondracek, J., Andersson, P.L., Stenberg, M., Machala, M. (2011). In vitro toxicity profiling of ultrapure non-dioxin-like polychlorinated biphenyl (NDL-PCB) congeners and their relative toxic contribution to PCB-mixtures in humans. Toxicological Sciences, 121, 88-100.

Hamers, T., Leonards, P.E.G., Legler, J., Vethaak, A.D., Schipper, C.A. (2010). Toxicity profiling: an integrated effect-based tool for site-specific sediment quality assessment. Integrated Environmental Assessment and Management, 6, 761-773.

Simon, E., Lamoree, M.H., Hamers, T., Weiss, J.M., Balaam, J., De Boer, J., Leonards, P.E.G. (2010). Lipid and natural hormone removal from aquatic biota samples prior to endocrine disrupting testing in bioassays. Environmental Science and Technology, 44, 8322-8329.

Weiss, J., Hamers, T., Thomas, K.V., Van der Linden, S., Leonards, P., Lamoree, M.H. (2009) Masking effect of anti-androgens on androgenic activity in European river sediment unveiled by Effect Directed Analysis. Analytical and Bioanalytical Chemistry 394: 1385-1397

Weiss, J., Andersson, P.L., Lamoree, M.H., Leonards, P.E.G., Van Leeuwen, S.P.J., Hamers T. (2009). Competitive binding of poly- and perfluorinated compounds to the thyroid hormone transport protein transthyretin. Toxicological Sciences,109, 206-216.

Van Gestel, C.A.M., Koolhaas, J.E., Hamers, T., Van Hoppe, M., Van Roovert, M., Korsman, C., Reinecke, S.A. (2009). Effects of metal pollution on earthworm communities in a contaminated floodplain: linking biomarker, community and functional responses. Environmental Pollution,157, 895-903

Rozema, J., Notten, M., Aerts, R., Van Gestel, C.A.M., Hobbelen, P., Hamers, T. (2008). Do high levels of diffuse and chronic metal pollution in sediments of Rhine and Meuse Floodplains affect structure and functioning of terrestrial ecosystems? Science of the Total Environment, 406, 443-448

Ven, L.T.M. van der, Kuil, T. van de, Verhoef, A., Leonards, P.E.G., Slob, W., Canton, R.F., Germer. S., Hamers, T., Visser, T.J., Litens, S., Hakansson, H., Fery, Y., Schrenk, D., Berg, M. van den, Piersma, A.H., Vos, J.G. (2008). A 28-day oral dose toxicity study enhanced to detect endocrine effects of purified technical pentabromodiphenyl ether (pentaBDE) mixture in Wistar rats. Toxicology 245, 109-122.

Hamers, T, Kamstra, J.H., Sonneveld, E., Murk, A.J., Visser, T.J., Van Velzen, M.J.M. van, Brouwer, A., Bergman, Å. (2008). Biotransformation of brominated flame retardants into potentially endocrine disrupting agents, with special attention to 2,2’,4,4’-brominated diphenyl ether (BDE-47). Molecular Nutrition & Food Research, 52, 284-298.

Harju, M., Hamers, T., Kamstra, J.H., Sonneveld, E., & Boon, J.P. (2007). Quantitative structure-activity relationship modeling on in vitro endocrine effects and metabolic stability involving 26 selected brominated flame retardants. Environmental Toxicology and Chemistry, 26, 816-826.

Veltman, K., Huijbregts, M.A.J., Hamers, T., Wijnhoven, S., & Hendriks, A.J. (2007). Cadmium accumulation in herbivorous and carnivorous small mammals - Meta-analysis of field data and validation of the bioaccumulation model optimal modeling for ecotoxicological applications. Environmental Toxicology and Chemistry, 26, 1488-1496.

Morgado, I., Hamers, T., Ven, L. van der, & Power, D.M. (2007). Disruption of thyroid hormone binding to seabream recombinant transthyretin by ioxinyl and polybrominated diphenyl ethers. Chemosphere, 69, 155-163.

Kamstra, J.H., Du, T., Visser, T.J., Ven, L.T.M. van der, Murk, A.J., & Hamers, T. (24-04-2007). In vitro induction of organic anion transporting polypeptides (OATPs) as a possible mechanism for thyroid hormone disruption by hexabromocyclododecane (HBCD). Amsterdam, The Netherlands, The fourth international workshop on brominated flame retardants, BFR 2007.

Van der Ven, L.T.M., Verhoef, A., Van de Kuil, T., Slob, W., Leonards, P.E.G., Visser, T.J., Hamers, T., Herlin, M., Hakansson, H., Olausson, H., Piersma, A.H., Vos, J.G. (2006). A 28-day oral dose toxicity study enhanced to detect endocrine effects of hexabromocyclododecane (HBCD) in Wistar rats. Toxicological Sciences,94, 281-292.

Hamers, T., Kamstra, J.H., Sonneveld, E., Murk, A.J., Kester, M.H.A., Andersson, P.L., Legler, J. & Brouwer, A. (2006). In vitro profiling of the endocrine disrupting potency of brominated flame retardants. Toxicological Sciences, 92, 157-173.

Hamers, T., Van den Berg, J.H.J., Van Gestel, C.A.M., Van Schooten & F.J., Murk, A.J. (2006). Risk assessment of metals and organic pollutants for herbivorous and carnivorous small mammal food chains in a polluted floodplain (Biesbosch, The Netherlands). Environmental Pollution, 144, 581-595.

Zegers, B.N., Mets, A., Van Bommel, R., Minkenberg, C., Hamers, T.,, Kamstra, J.H., Pierce, G.J. & Boon, J.P. (2005). Levels of hexabromocyclododecane in harbor porpoises and common dolphins from Western European seas, with evidence for stereoisomer-specific biotransformation by cytochrome P450. Environmental Science and Technology,39, 2095-2100.

Hamers, T., Kalis, E.J.J., Berg, J.H.J. van den, Maas, L.M., Schooten, F.J. van & Murk, A.J. (2004). Applicability of the black slug Arion ater for monitoring exposure to polycyclic aromatic hydrocarbons and their subsequent bioactivation into DNA binding metabolites. Mutation Research, 552, 219-233.

Hamers T., Van den Brink, P.J., Mos, L., Van der Linden, S.C., Legler, J., Koeman, J.H.
& Murk, A.J. (2003). Estrogenic and esterase-inhibiting potency in rainwater in relation to pesticide concentrations, sampling season and location. Environmental Pollution, 123, 47-65

Houtman, C.J., Cenijn, P.H., Hamers, T., Lamoree, M.H., Legler, J., Murk, A.J. & Brouwer, A. (2004). Toxicological profiling of sediments using in vitro bioassays, with emphasis on endocrine disruption. Environmental Toxicology and Chemistry23, 32-40.

Hamers, T., Smit, L.A.M., Bosveld, A.T.C., Van den Berg, J.H.J., Koeman, J.H., Van Schooten, F.J. & Murk, A.J. (2002). Lack of a distinct gradient in biomarker responses in small mammals collected at different distances from a highway. Archives of Environmental Contamination and Toxicology, 43, 345-355.

Hamers, T. (2002). Toxic potency and effects of diffuse air pollution. PhD Disseration, Wageningen University, The Netherlands. 176 pp.

Hamers, T., Smit, M.G.D., Murk, A.J. & Koeman, J.H. (2001). Biological and chemical analysis of the toxic potency of pesticides in rainwater. Chemosphere,45, 609-624.

Hamers, T., Molin, K.R.J., Koeman, J.H., & Murk, A.J. (2000). A small-volume bioassay for quantification of the esterase inhibiting potency of mixtures of organophosphate and carbamate insecticides in rainwater: development and optimization. Toxicological Sciences,58, 60-67.

Hamers, T., Van Schaardenburg, M.D., Felzel, E.C., Murk, A.J. & Koeman, J.H. (2000). The application of reporter gene assays for the determination of the toxic potency of diffuse air pollution. The Science of the Total Environment,262, 159-174.