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Previous studies have suggested toxic effects of recreational ecstasy use on the serotonin system of the brain. However, it cannot be excluded that observed differences between users and non-users are the cause rather than the consequence of ecstasy use. As part of the Netherlands XTC Toxicity (NeXT) study, we prospectively assessed sustained effects of ecstasy use on the brain in novel ecstasy users using repeated measurements with a combination of different neuroimaging parameters of neurotoxicity. At baseline, 188 ecstasy-naive volunteers with high probability of first ecstasy use were examined. After a mean period of 17 months follow-up, neuroimaging was repeated in 59 incident ecstasy users and 56 matched persistent ecstasy-naives and their outcomes were compared. Neuroimaging included [[superscript 123]I]Beta-carbomethoxy-3Beta-(4-iodophenyl)tropane (CIT) SPECT to measure serotonin transporter densities as indicators of serotonergic function; [superscript 1]H-MR spectroscopy ([superscript 1]H-MRS) to measure brain metabolites as indicators of neuronal damage; diffusion tensor imaging (DTI) to measure the apparent diffusion coefficient and fractional anisotropy (FA) of the diffusional motion of water molecules in the brain as indicators of axonal integrity; and perfusion weighted imaging (PWI) to measure regional relative cerebral blood volume (rrCBV) which indicates brain perfusion. With this approach, both structural ([superscript 1]H-MRS and DTI) and functional ([[superscript 123]I]Beta-CIT SPECT and PWI) aspects of neurotoxicity were combined. Compared to persistent ecstasy-naives, novel low-dose ecstasy users (mean 6.0, median 2.0 tablets) showed decreased rrCBV in the globus pallidus and putamen; decreased FA in thalamus and frontoparietal white matter; increased FA in globus pallidus; and increased apparent diffusion coefficient in the thalamus. No changes in serotonin transporter densities and brain metabolites were observed. These findings suggest sustained effects of ecstasy on brain microvasculature, white matter maturation and possibly axonal damage due to low dosages of ecstasy. Although we do not know yet whether these effects are reversible or not, we cannot exclude that ecstasy even in low doses is neurotoxic to the brain.

Background and Aims: Although European‐wide data on the new psychoactive substances (NPS) drug market are available, country‐specific data are limited. We studied recent NPS trend data relative to all recreational drugs on the Dutch drug market. Design National observational study. Setting: The Netherlands. Data sources Three national indicators were used between 2013 and 2017: (1) forensic drug samples offered to the Netherlands Forensic Institute (NFI); (2) drug samples submitted by consumers to the Drugs Information and Monitoring System (DIMS); and (3) exposures in which the Dutch Poisons Information Center (DPIC) was consulted. Measurements Overall NPS incidence rate was the primary outcome. Numbers and specific categories of NPS were also studied. Changes in NPS incidence rates over time were analyzed using Poisson regression analyses [year effect expressed as incidence rate ratios (IRR)]. Findings From 2013 to 2017, NPS were involved in 1892 forensic samples, 6316 consumer samples and 481 poisons center exposures. In 2013, NPS incidence rates were 2.5, 7 and 4% versus 3, 11 and 11% in 2017, respectively, in the NFI, DIMS and DPIC samples/exposures. NPS incidence rates increased significantly in consumer samples between 2013 and 2016 [IRR = 1.23; 95% confidence interval (CI) = 1.18, 1.29] and in poisons center exposures between 2013 and 2017 (IRR = 1.19; 95% CI = 1.06, 1.35), while the trend in forensic samples appeared more stable. Phenethylamines were the largest class and were detected in 58, 80 and 63% of NFI, DIMS and DPIC samples/exposures, respectively. Detected phenethylamines mainly involved 4‐fluoroamphetamine and 2C‐x derivatives. The second largest class were cathinones, which were detected in 21, 11 and 16% of NFI, DIMS and DPIC samples/exposures, respectively. Conclusions: Analysis of forensic drug samples, consumer drug samples and exposures reported to poison centers from 2013 to 2017 shows the constant presence of new psychoactive substances on the Dutch drug market and its use by the Dutch population. The two largest classes present in the Netherlands were phenethylamines and cathinones. [ABSTRACT FROM AUTHOR]

Recent research suggests that more and more citizens select news and information that is congruent with their existing political preferences. This increase in political selective exposure (PSE) has allegedly led to an increase in polarization. The vast majority of studies stem from the US case with a particular media and political system. We contend that there are good reasons to believe PSE is less prevalent in other systems. We test this using latent profile analysis with national survey data from the Netherlands (n = 2,833). We identify four types of media use profiles and indeed only find partial evidence of PSE. In particular, we find that public broadcasting news cross-cuts all cleavages. This research note offers an important antidote in what is considered a universal phenomenon. We do find, however, a relatively large segment of citizens opting out of news consumption despite the readily available news in today’s media landscape. [ABSTRACT FROM AUTHOR]

Background In recent years, the number of new psychoactive substances (NPS) appearing on the illicit drug market strongly increased. However, little is known about their toxic effects and risks. Therefore, we determined the most frequently occurring NPS in The Netherlands and combined this with data regarding drug-related intoxications. Methods Data from the Drugs Information and Monitoring System (DIMS) and the Dutch Poisons Information Centre (DPIC) were combined and jointly analyzed. Results The number of drug samples submitted to DIMS for analysis containing NPS increased from 22 in 2007 to 431 samples in 2013. The most frequently submitted NPS in 2013 included 4-bromo-2,5-dimethoxyphenethylamine (2C-B), 4-fluoroamphetamine (4-FA), methoxetamine (MXE) and 6-(2-aminopropyl)benzofuran (6-APB). From 2012 onwards, the number of NPS bought as drug of choice exceeded those appearing as adulterants in established drugs. The DPIC was consulted about 35 NPS exposures in 2013, most frequently involving 4-FA, mephedrone, MXE, 2C-B and 6-APB. Following NPS exposure, neurological and psychological symptoms were most frequently reported, like agitation and hallucinations. In addition, cardiovascular symptoms like hypertension and tachycardia often occurred. Conclusions NPS are currently being purchased as drug of choice in The Netherlands and their availability and use is increasing. Although pharmacological and toxicological data are scarce, NPS can induce pronounced clinical effects. Therefore, the monitoring of trends in NPS prevalence needs to be continued, combined with reported clinical effects, and preferably supported by analytical confirmation of exposures in such patients. [ABSTRACT FROM AUTHOR]

In accordance with Article 6 of Regulation (EC) No 396/2005, the United Kingdom (hereafter - evaluating Member State UK (EMS UK)), received an application from the company BASF to modify the existing MRLs for chlormequat in cereals and several commodities of animal origin. The EMS UK proposed to raise MRLs in rye and oat grain and several animal commodities to accommodate the NEU use of chlormequat on cereals. The Netherlands (EMS NL) received an application from Nederlandse Fruittelers Organisatie to maintain the temporary MRL of 0.1 mg/kg for chlormequat in pears until 31 July 2017, in order to accommodate for carry-over of chlormequat residues due to formerly authorized uses on pear trees. The targeted monitoring data provide evidence that, in general, chlormequat residues in pears produced in the Netherlands and Belgium are declining. In 2013 and onwards, 95 % of the samples of pears produced in the Netherlands and Belgium in areas where chlormequat was used in pear orchards before 2003 will contain residues at or below the level of 0.1 mg/kg. The submitted residue trials on cereals indicate that a higher MRL is required for oat and rye grain to support the intended NEU use. The new use on cereals results in a need to raise the existing MRLs for chlormequat in ruminant muscle, liver, kidney, swine kidney and milk. Based on the risk assessment results, EFSA concludes that the temporary MRL for pears and the intended use of chlormequat on rye and oats and the subsequent residues in animal commodities will not result in a consumer exposure exceeding the toxicological reference values and therefore is unlikely to pose a public health concern. [ABSTRACT FROM AUTHOR]

Abstract: The International Neurotoxicology Association (INA) is a scientific society whose members have interest and expertise in the discipline of neurotoxicology. The idea of forming INA was born in 1984, as a follow-up to a NATO-sponsored meeting on Toxicology of the Nervous System. INA held its first meeting in the Netherlands in 1987 and has had continuous meetings every other year since then. INA is registered as a scientific society in the Netherlands, and is an affiliated society of IUTOX. This paper presents a personal account of the events that led to the birth of INA, and of the first fifteen years of this association. [Copyright &y& Elsevier]

Imidacloprid is one of the most widely used insecticides in the world. Its concentration in surface water exceeds the water quality norms in many parts of the Netherlands. Several studies have demonstrated harmful effects of this neonicotinoid to a wide range of non-target species. Therefore we expected that surface water pollution with imidacloprid would negatively impact aquatic ecosystems. Availability of extensive monitoring data on the abundance of aquatic macro-invertebrate species, and on imidacloprid concentrations in surface water in the Netherlands enabled us to test this hypothesis. Our regression analysis showed a significant negative relationship (P<0.001) between macro-invertebrate abundance and imidacloprid concentration for all species pooled. A significant negative relationship was also found for the orders Amphipoda, Basommatophora, Diptera, Ephemeroptera and Isopoda, and for several species separately. The order Odonata had a negative relationship very close to the significance threshold of 0.05 (P = 0.051). However, in accordance with previous research, a positive relationship was found for the order Actinedida. We used the monitoring field data to test whether the existing three water quality norms for imidacloprid in the Netherlands are protective in real conditions. Our data show that macrofauna abundance drops sharply between 13 and 67 ng l−1. For aquatic ecosystem protection, two of the norms are not protective at all while the strictest norm of 13 ng l−1 (MTR) seems somewhat protective. In addition to the existing experimental evidence on the negative effects of imidacloprid on invertebrate life, our study, based on data from large-scale field monitoring during multiple years, shows that serious concern about the far-reaching consequences of the abundant use of imidacloprid for aquatic ecosystems is justified. [ABSTRACT FROM AUTHOR]

Reports on cases of alleged drug-facilitated sexual assault (DFSA) have increased since the mid-1990s. The aim of this study was to identify the extent and types of drugs found in cases of alleged sexual assault (DFSA) in the Netherlands. In total, 135 cases of alleged DFSA were identified. Most of the victims were women (94%), and the mean age of the victims was 25 years. Blood and urine samples were tested for the presence of alcohol, drugs (drugs of abuse and prescription drugs), or both. In 27% of the cases, no alcohol and/or drugs were found. With increasing time delay, more cases were found to be negative. Alcohol is the most commonly found drug followed by nonopiate analgesics, illicit drugs, and benzodiazepines. In some cases, the absence of alcohol and drugs may represent false-negative results owing to the time delay between alleged sexual assault and sampling. [ABSTRACT FROM AUTHOR]

The article presents the result of the reassessment of occupational exposure limits (OEL) conducted by the Health Council of the Netherlands as requested by the Dutch Ministry of Social Affairs and Employment. A total of 161 compounds were documented and evaluated by the committee of international experts. After reassessing the toxicological hazards of the compounds, it was compared with the maximum allowable concentration (MAC) values of the 1994 Dutch list, ACGIH TLVs, and existing German OELs. It was found that the toxicological database met the committee's criteria for a health-based OEL for only about 40% of the compounds. It is concluded that may older MAC values were either too high or not scientifically supported and therefore not health-based.

The article discusses a study that analyzed the ways in which the entry into the area of nanosciences impacts on the formation of disciplinary identities. It cites interviews conducted with particle toxicologists in Germany, Holland and Switzerland to show that toxicology is in a transitional phase and which emphasized the necessity of repositioning toxicology. It suggests that the disciplinary identity formation of toxicology set against the background of its entry into the nanosciences remains an open-ended scientific development.

Because of the pioneering vision of certain leaders in the biomedical field, the last two decades witnessed rapid advances in the area of chemical mixture toxicology. Earlier studies utilized conventional toxicology protocol and methods, and they were mainly descriptive in nature. Two good examples might be the parallel series of studies conducted by the U.S. National Toxicology Program and TNO in The Netherlands, respectively. As a natural course of progression, more and more sophistication was incorporated into the toxicology studies of chemical mixtures. Thus, at least the following seven areas of scientific achievements in chemical mixture toxicology are evident in the literature: (a) the application of better and more robust statistical methods; (b) the exploration and incorporation of mechanistic bases for toxicological interactions; (c) the application of physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) modeling; (d) the studies on more complex chemical mixtures; (e) the use of science-based risk assessment approaches; (f) the utilization of functional genomics; and (g) the application of technology. Examples are given for the discussion of each of these areas. Two important concepts emerged from these studies and they are: (1) dose-dependent toxicologic interactions; and (2) “interaction thresholds”. Looking into the future, one of the most challenging areas in chemical mixture research is finding the answer to the question “when one tries to characterize the health effects of chemical mixtures, how does one deal with the infinite number of combination of chemicals, and other possible stressors?” Undoubtedly, there will be many answers from different groups of researchers. Our answer, however, is first to focus on the finite (biological processes) rather than the infinite (combinations of chemical mixtures and multiple stressors). The idea is that once we know a normal biological process(es), all stimuli and insults from external stressors are merely perturbations of the normal biological process(es). The next step is to “capture” the biological process(es) by integrating the recent advances in computational technology and modern biology. Here, the computer-assisted Reaction Network Modeling, linked with PBPK modeling, offers a ray of hope to dealing with the complex biological systems. [Copyright &y& Elsevier]

The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health agency that investigates and strives to prevent human health problems produced by exposure to toxic chemicals and their mixtures in the environment. Most human exposures involving toxic chemicals or mixtures are thought to originate from environmental and occupational sources; however, concurrent exposures are also likely from other sources, such as prescription and nonprescription drugs, indoor air pollutants, alcohol, and tobacco smoke. Thus, in evaluating the potential hazard following exposure to environmental mixtures, ATSDR not only considers the inherent joint toxicity of the mixture but also the influence of environmental, demographic, occupational, and lifestyle factors. To foster these goals, ATSDR has pursued a Mixtures Research and Assessment Program that consists of three component efforts: trend analysis, joint toxicity assessment, and experimental testing. Through trend analysis, ATSDR sets priorities for environmental mixtures of concern for which joint toxicity assessments are conducted as needed. If data are not available to conduct appropriate assessments, a research agenda is pursued through established extramural mechanisms. Ultimately, the data generated are used to support ATSDR’s work at sites involving exposure to chemical mixtures. This pragmatic approach allows testable hypotheses or research needs to be identified and resolved and enhances our understanding of the mechanisms of joint toxicity. Several collaborative and cooperative efforts with national and international organizations such as the Toxicology and Nutrition Office, the Netherlands, and the Department of Energy are being pursued as part of these activities. ATSDR also develops guidance manuals to consistently and accurately apply current methodologies for the joint toxicity assessment of chemicals. Further, expert panels often are assembled to resolve outstanding scientific issues or obtain expert advice on pertinent issues. Recently, the need for studies on chemical mixtures has been proposed as one of the six priority areas the agency identified in its agenda for public health environmental research. This has been reinforced through the agency’s close work with communities whose leaders have spoken passionately about their concern for information on exposures to chemical mixtures. The five other priority research areas the agency identified are exposure, susceptible populations, communities and tribal involvement, evaluation/surveillance of health effects, and health promotion/prevention. [ABSTRACT FROM AUTHOR]

In 2001, a retail market survey of 19 samples of teats and soothers was performed in the Netherlands. The migration of 2-mercaptobenzthiazol (MBT), N -nitrosamines and nitrosatable substances was measured. A screening was also performed for other potential migrants. Of the soothers, shield size and yield strength were determined. Most of the teats and soothers on the Dutch market were made of silicone rubber, although a few were made of natural rubber. The migration of N -nitrosamines and nitrosatable substances was far below the migration limit of 0.01 and 0.1 mg kg -1 teat, respectively, with the exception of one natural rubber soother. For this soother, the migration of nitrosatable substances was 0.23 mg kg -1 and measures were therefore taken against the supplier. MBT was detected in only one natural rubber sample, migration being well below the limit of 0.3 mg/teat. The extractable substances in the silicone teats and soothers are siloxanes. From the two natural rubber products, substances were extracted that were not on the positive list of the Dutch Packaging and Food-Utensils Regulation. Most of these substances are allowed in other countries, or authorized for plastic food contact materials. The size of the shields of all soothers and yield strengths were in compliance with the Regulation. [ABSTRACT FROM AUTHOR]

Hybrid scientific fields consist of a collection of knowledge-producing and -utilising organisations, fulfilling a dual role of providing specific knowledge services as well as contributing to increased scientific understanding. In this article, the processes that govern scientific knowledge production in hybrid scientific fields are explored. While such sets of organisations are targeted in science policy as receivers of resources, as well as providers of services and other knowledge products, attention in science studies is all but lacking. Data from a study on toxicology as a representative of public health sciences are used. The author will focus on the effects on scientific research and its organisational relations by discussing three social processes relevant to knowledge production, problem choice, resource distribution, and reputational control. [ABSTRACT FROM AUTHOR]

This paper presents the design of the self-instructive multimedia program "Behavioural Toxicological Research".This computer program offers professionals in health care, nutrition, clinical psychology and treatment of drug addicts a basic understanding of neurobehavioural research and addiction research.The program focuses on the cognitive aspects of scientific research, emphasising the strategic decisions, domain-specific choices and discussions on validity that go with the process of designing and interpreting scientific research. Results from both formative and summative evaluations of the program are briefly discussed. [ABSTRACT FROM AUTHOR]

Risk analysis consists of risk assessment (RA), risk management (RM), and risk communication (RC). In most countries, RA and RM of food safety are separated to achieve a high scientific integrity, and typically occur in sequential order. However, in case of a food safety incident, even though being separate processes, RA and RM are performed simultaneously due to great time pressure and expected high impacts. The aim of this study was to analyze and evaluate the observed interactions between RA and RM processes, during three major food incidents in Europe, and to provide suggestions for possible improvement. Based on the differences observed between the three cases, strengths and weaknesses of each system have been identified. The enterohemorrhagic Escherichia coli (EHEC) crisis in 2011 in Germany, the horsemeat scandal in 2013 in Ireland, and the fipronil incident in 2017 in the Netherlands were used as case studies. Timelines of these incidents and crisis management procedures in place in each of the three countries provided the basis for further analysis. First, results showed that details of the communication processes between RA and RM bodies were frequently lacking in crisis management protocols. Second, RA, RM, and RC processes differed for each incident, due to differences in estimated risk for public health, but also due to differences in the organization within a country. Based on our results, we recommend that crisis management protocols should contain a section on communication between RA, RM, and on communication between member states in the EU., (© 2021 The Authors. Journal of Food Science published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Abstract: A 36-year old man, having injured himself severely by smashing windows in a rage of fury, was arrested by the police. He died despite resuscitation attempts. The forensic autopsy showed many superficial skin lacerations, bruises and minor brain swelling, but there was no definitive cause of death. Toxicological analysis showed a high concentration of mephedrone in femoral blood (5.1mg/L) and traces of cocaine, MDMA and oxazepam. The remaining dose of mephedrone in the stomach contents was estimated at 113mg. Tablets that were found in the house of the deceased also contained mephedrone. We attribute this man''s death to a fatal oral intake of mephedrone, which probably led to a state of excited delirium. This was aggravated by blood loss from multiple wounds. [Copyright &y& Elsevier]

Changing environmental conditions may influence the fate and bioavailability of lanthanides (part of the rare earth elements [Ln]) in estuaries. The aim of this study was to quantify the variation in estuarine lanthanide solid/water distribution, speciation, and bioaccumulation. The latter was studied in the amphipod Corophium volutator underfield and laboratory conditions. Calculations with the chemical equilibrium model MINEQL+ indicate that dissolved lanthanides are complexed mainly to carbonates and dissolved organic matter. In the water phase, the relative abundance of the free ion, LnCO3, and humic complexes decreases from lanthanum to lutetium, whereas the relative abundance of Ln(CO3)2 increases. Cerium andeuropium anomalies were found in the water. Europium anomalies were also found in some biota. The biota sediment accumulation factors (BSAFs) decreased across the series from lanthanum to lutetium. Regression analysis revealed that alkalinity correlated negatively with lanthanide uptake. This suggests that increasing complexation reduced bioavailability under the prevailing conditions. The BSAFs did not dependon salinity or pH, which may simplify sediment-quality criteria for fresh versus saline waters. Field BSAFs were significantly lower thanlaboratory values for the same sediments, which is explained by adaptation of the organisms to lanthanides. [ABSTRACT FROM AUTHOR]

Information about several papers discussed at an international workshop hosted by the Ministry of Social Affairs and Employment in the Netherlands is presented. Topics include the pesticide toxicology studies for worker risk assessment, the application of probabilistic exposure assessment for evaluating risks, and the importance of use information in exposure and risk assessment processes. The workshop featured several experts including John H. Ross, Neil G. Carmichael, and Paul Y. Hamey.

In risk assessment, information from toxicity studies is combined with information on worker exposure. In general, agricultural practice implies long-term intermittent exposure to various pesticides. This issue can only be addressed when sufficient information exist, on exposure regimes. Patterns of application of pesticides and the use frequency of single pesticide products on a number of representive key crops from various agricultural sectors in the Netherlands were studied. The results show that there is an enormous variation in pesticide usage between and within sectors. On nearly all crops studied the number of applications with insecticides and fungicides was higher than the number of applications with herbicides. The average frequency of application of a the most used insecticide and fungicide products on the most intensively treated crops was between 10 and 20 times a year. But on most crops single pesticide products were used not more than seven times a year. [ABSTRACT FROM PUBLISHER]

Reports on the discovery of salinomycin in dried cat food which caused a deadly cat epidemic in Holland in the spring of 1996. The compound, which is toxic for cats; Possible ways the compound was placed in the cat food; The Dutch factory belonging to the manufacturer Spillers Petfoods; The reason for such a long investigation.

As part of a health-hazard survey on the health risk of hospital cleaning workers from exposure to Lyorthol, a hazard assessment of o-phenylphenol (and its sodium salt), one of the constituents of Lyorthol,has been prepared. In this paper, the physical and chemical characteristics, kinetics and effects of o-phenylphenol and its sodium salt are described and discussed, and an overall, summarizing hazard evaluation is presented. [ABSTRACT FROM AUTHOR]

4-Methylamphetamine (4-MA) was originally developed as an appetite suppressant, but development was halted due to side effects. It has recently resurfaced as a new psychoactive substance in Europe, and is mostly found together with amphetamine. Around 11.5% of tested Dutch speed samples were positive for 4-MA. In Belgium, 4-MA was also found in speed samples. In 2011 and 2012, several fatal incidents after amphetamine use were observed in Belgium, the United Kingdom and The Netherlands. In all victims, toxicological analysis confirmed the presence of 4-MA, in addition to amphetamine. The observed blood amphetamine levels were too low to be fatal. Contrary to amphetamine, which displays noradrenergic and dopaminergic activity, 4-MA also shows serotonergic activity, which may contribute to the observed toxicity. Other mechanisms of toxicity are put forward in this paper as well. To conclude, the observed toxicity is most likely the result of the combined dopaminergic activity of amphetamine and the serotonergic activity of 4-MA. In addition, the presence of 4-MA may have dampened the psychoactive effects of amphetamine by attenuation of the amphetamine-induced dopamine release, potentially inclining users to ingest higher doses of contaminated speed. Also, slower metabolism of 4-MA and its MAO-inhibiting properties can also contribute to the unusual high toxicity of 4-MA.

To assess soil and groundwater quality two generic (i.e. multifunctional) risk-based standards, Target and Intervention Value, have been developed, in the framework of the Dutch Soil Protection Act. These standards allow soil and groundwater to be classified as clean, slightly contaminated or seriously contaminated. The Target Value is based on potential risks to ecosystems, while the Intervention Value is based on potential risks to humans and ecosystems. In the case of serious soil contamination the site has, in principle, to be remediated, making it necessary to determine the remediation urgency on the basis of actual (i.e. site-specific) risks to humans and ecosystems and, besides, actual risks due to contaminant migration.

When wanting to treat birds and other unusual companion animals, veterinarians must often refer to data for other animal species and humans. Doses must often be extrapolated from data for other animals, and there is little, or only empirical, information about pharmacology, toxicity, effectiveness, etc. On the basis of what is known, and especially for 'ordinary' companion animals and farm animals, the pharmacokinetics and pharmacodynamics of drugs vary considerably as a result of species differences in drug absorption, distribution, metabolism and elimination. Differences in anatomy, physiology and genetics underlie these variations. For instance, environmental temperature is important in the elimination of drugs by cold-blooded animals. The character and nature of unusual companion animals, their zootechnology, feeding habits, housing requirements etc. often require special and imaginative solutions to the problem of how to administer veterinary medicines. Moreover, when the Veterinary Medicine Act becomes law, terms such as 'off-label use', 'orphan drugs' and 'minor species' will also play a role.

Veterinary environmental toxicology is concerned with environmental pollution and its possible ill-effects on animals. The Department of Analytical Chemistry and Toxicology of the Central Veterinary Institute has become increasingly involved in industrial and environmental toxicological problems affecting domestic as well as free-living wild animals during the last five years. Its main duties lie not only in the field of diagnostic procedures but it also deals with other factors such as inquiries into the facts of poisoning, tracing poisons to their sources, modes of dissemination and contamination of the environment and food of animals with toxic substances. Some typical features and characteristics of research projects of the department, which are closely connected with these duties, are described. The results of investigations of special cases in the field and the experience thus gained clearly show the close relationship between veterinary and environmental toxicology.

Large scale pollution of the environment by pesticides and other chemicals only started in the fifties and early sixties. Chlorinated hydrocarbon pesticides and methyl mercury compounds appeared to have a marked impact on the populations of many animal species, especially birds. It is recognized that prof. dr. H. van Genderen, who retired this month, made a most valuable contribution to the timely detection of these problems in the Netherlands. Environmental toxicologists engaged in studies to predict environmental hazards by chemicals require toxicological skill as well as insight into the structure and functioning of ecosystems.