Papers by Harrie Van Dijk
Oxford University Press eBooks, 2013
In many countries, it is the government’s responsibility to protect and prornote public health. I... more In many countries, it is the government’s responsibility to protect and prornote public health. Instead of relying on the curative care alone, governments actively promote preven tion approaches with the airn of providing health protection for all. A complicating factor is that people differ considerably in terms of their risk of disease and health impairment. How can such variations in the population be dealt with consistently, across a broad range of issues? Identification of high-risk groups requires a standard, weli-documented approach. This chapter describes a systematic approach to identify high-risk groups for specific issues. It is based on a recent advisory report of the Health Council of the Netherlands (HCN) (2011a). The approach is illustrated with a case study on Q fever in the Netherlands, also based on Health Council advisory reports (HCN, 2010a, 2010b, 201 1h).
Springer eBooks, Jan 4, 2008
Biochimica Et Biophysica Acta - Proteins And Proteomics, Mar 1, 1983
Abstract Coenzyme MF 430 is a yellow, non-fluorescing nickel-containing tetrapyrrole derivative w... more Abstract Coenzyme MF 430 is a yellow, non-fluorescing nickel-containing tetrapyrrole derivative which constitutes the prosthetic group of methylcoenzyme M reductase, the enzyme involved in the final step of metanogenesis. Coenzyme MF 430 contains an additional base, which is tentatively identified as 6,7-dimethyl-8-ribityl-5,6,7,8-tetrahydrolumazine on the basis of ultraviolet-visible absorption, 1 H-NMR and mass spectra. The location of this compound in the prosthetic group is discussed.
Journal of Risk Research, 2011
... b , Erik Lebret c d , Wiebe E. Bijker e & Daniëlle RM Timmermans f pages 451-466. ... A p... more ... b , Erik Lebret c d , Wiebe E. Bijker e & Daniëlle RM Timmermans f pages 451-466. ... A psychometric study of attitudes towards technological risks and benefits. Policy Sciences , 9: 12752. [CrossRef], [Web of Science ®] View all references; Granger Morgan et al. 200222. ...
Communications Medicine, 2022
Although often overlooked, the use of disinfectants can lead to antimicrobial resistance and this... more Although often overlooked, the use of disinfectants can lead to antimicrobial resistance and this may exacerbate resistance to antibiotics. Here, we explain why all antimicrobial agents, including disinfectants, should be used prudently in a way that is guided by evidence. Disinfectants are antimicrobial products that incorporate one or more active substances, such as chlorine, iodine, alcohols, hydrogen peroxide, silver, chlorhexidine, triclosan and quaternary ammonium compounds. They are indispensable in human and veterinary health care, the food industry and water treatment for the prevention of infections and intoxications. Presently, their use in public and private domains is increasing: the current COVID-19 pandemic has boosted 1 an already ongoing trend of an increasing array of consumer products that contain disinfectants 2. Whereas resistance to antibiotics is regarded as a major health threat, resistance to disinfectants is receiving little attention from practitioners in human and veterinary health care and in food production, and from administrators and authorities. One potential reason is the lack of a broadly accepted definition of resistance to disinfectants 3. Another is that the reductions in susceptibility to disinfectants commonly observed in settings of frequent use are mostly modest. Minimum concentrations of disinfectants needed to arrest the growth of strains (minimum inhibitory concentration (MIC)) or to kill strains (minimum bactericidal concentration (MBC)) isolated from such places are normally less than ten times higher than the MIC or MBC of strains from settings where disinfectants are hardly used. As in-use concentrations of disinfectants are still considerably higher, the relevance of these moderate increases in MIC or MBC is disputed 3. We fear to be trapped in a vicious circle of the presumed insignificance of resistance to disinfectants and the lack of attention for it. While the term 'tolerance' for these lower levels of resistance to disinfectants is often used 4 , we think that this term downplays the importance of the phenomenon. In line with EUCAST 5 , we advocate to use the term 'tolerance' only in cases where the MBC of a strain is much increased, such that the strain is not readily killed anymore, while its MIC remains unchanged. In a microbiological sense, the term 'resistance' is used to denote any reduction in susceptibility demonstrated phenotypically by increases in MIC or MBC. The emergence of resistance is the inevitable consequence of all use of disinfectants, rather than just improper use. Generally, a heterogeneous community of bacteria is present at the application site, consisting of species and strains that are more and less susceptible to the disinfectant. Individual cells may be resistant enough to survive a disinfection procedure. In addition, microorganisms may reside in dirt, in nooks and crannies and in biofilms, where disinfectants cannot reach easily. In these places, and at the margins of the disinfected area, microorganisms are exposed to lower disinfectant concentrations enabling less susceptible strains to survive. Disinfectants end up in surface waters or soil via sewer lines and fertilizing manure 6. Dilution and degradation result in environmental levels that are much lower than those used at the point of application. Exposure to sub-MIC concentrations of disinfectants can trigger stress responses in bacteria that induce temporary, adaptive changes in the composition and permeability of their cell envelopes 7 or in the activity of their efflux pumps 8. They also trigger an increase in the frequency
1. Atmospheric transport of pesticides: assessing environmental risks H.F.G. van Dijk, et al. 2. ... more 1. Atmospheric transport of pesticides: assessing environmental risks H.F.G. van Dijk, et al. 2. Environmental risk assessment for pesticides in the atmosphere the results of an international workshop R. Guicherit, et al. 3. Atmospheric dispersion of current-use pesticides: a review of the evidence from monitoring studies H.F.G. van Dijk, R. Guicherit. 4. Ecotoxicological risk assessment of pesticides subject to long-range transport N.M. van Straalen, C.A.M. van Gestel. 5. Micrometeorologic methods for measuring the post-application Volatilization of pesticides M.S. Majewski. 6. Atmospheric transport and air-surface exchange of pesticides T.F. Bidleman. 7. Modelling of atmospheric transport and deposition of pesticides J.A. van Jaarsveld, W.A.J. van Pul. 8. Regulatory risk assessment of pesticide residues in air A.J. Gilbert. 9. Emission of pesticides into the air F. van den Berg, et al. 10. Transformations of pesticides in the atmosphere: a state of the art R. Atkinson, et al. 11. Atmospheric transport and deposition of pesticides: an assessment of current knowledge W.A.J. van Pul. 12. Implementing atmospheric fate in regulatory risk assessment of pesticides: (how) can it be done? D.J. Bakker, et al. List of participants. The organising committee. About the Health Council of the Netherlands.
On request of the Dutch government a committee of the Health Council of the Netherlands Ž has rev... more On request of the Dutch government a committee of the Health Council of the Netherlands Ž has reviewed the role that results of field research in its broadest sense i.e., including multi-species. toxicity tests in the laboratory, research on model ecosystems et cetera can play in ecotoxicological risk assessment for the authorisation of pesticides. The Committee believes that field research can provide valuable additional data about the exposure of non-target organisms and the resultant effects at population, community and ecosystem level. However, it frequently is unclear how these data might be used in reaching a decision about authorisation. To solve this problem, it is necessary to specify what is understood by ''unacceptable damage''. Both more clearly formulated protection goals of the government and a better understanding of the ecological significance of effects are needed to clarify this. Furthermore, the Committee points out that the statistical power of field trials must be sufficient to allow for the detection of changes that might be regarded as ecologically relevant. Finally, it recommends keeping a finger on the pulse in relation to authorised pesticides by monitoring their presence in environmental compartments and by investigating their role in suddenly occurring mortality among conspicuous animal species, such as birds, fish and honeybees. This kind of research forms a safety net for substances that have been wrongly authorised.
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
A handbook for field professionals, 2013
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
The Health Council of the Netherlands organised an international workshop on the fate of pesticid... more The Health Council of the Netherlands organised an international workshop on the fate of pesticides in the atmosphere and possible approaches for their regulatory environmental risk assessment. Approximately forty experts discussed what is currently known about the atmospheric fate of pesticides and major gaps in our understanding were identified. They favoured a tiered approach for assessing the environmental risks of
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
Physiologia Plantarum, 1988
... PUinl. 1^. IM88 495 Page 3. Tab. 1. Contents of leaf pigments in needles of Scots pine collec... more ... PUinl. 1^. IM88 495 Page 3. Tab. 1. Contents of leaf pigments in needles of Scots pine collected in April 1986. Medians with 25 and 75% quartiles in parentheses. ... Significance ** «* Tab. 2. Chemical composition of needles of Scots pine collected in April 1986. ...
Water Air and Soil Pollution, 1999
The Health Council of the Netherlands organised an international workshop on the fate of pesticid... more The Health Council of the Netherlands organised an international workshop on the fate of pesticides in the atmosphere and possible approaches for their regulatory environmental risk assessment. Approximately forty experts discussed what is currently known about the atmospheric fate of pesticides and major gaps in our understanding were identified. They favoured a tiered approach for assessing the environmental risks of
Forest Ecology and Management, 1995
In large regions of Europe and eastern North America atmospheric deposition of inorganic nitrogen... more In large regions of Europe and eastern North America atmospheric deposition of inorganic nitrogen compounds has greatly increased the natural external supply to forest ecosystems. This leads to nitrogen saturation, in which availability of inorganic nitrogen is in excess of biological demand and the ecosystem is unable to retain all incoming nitrogen. The large-scale experiments of the NITREX project (nitrogen saturation experiments) are designed to provide information regarding the patterns and rates of responses of coniferous forest ecosystems to increases in N deposition and the reversibility and recovery of impacted ecosystems following reductions in N deposition. The nitrogen input-output data from the NITREX sites are consistent with the general pattern of nitrogen fluxes from forest ecosystems in Europe. At annual inputs of less than about 10 kg ha-' year-', nearly all the nitrogen is retained and outputs are very small. At inputs above about 25 kg ha-' year-' outputs are substantial. In the range lo-25 kg ha-' year-' these forest ecosystems undergo a transition to nitrogen saturation. The 10 kg ha-' year-' apparently represents the minimum threshold for nitrogen saturation. The NITREX experiments indicate that nitrogen outputs respond markedly across the lo-25 kg ha-' year-' range of inputs. In contrast, the nutrient concentrations in foliage, a measure of tree response, is delayed by several years. Nitrogen saturation can apparently be induced or reversed within only a few years, at least with respect to the commonly used diagnostic of nitrogen saturation-nitrogen output in leachate or runoff.
Archives of Biochemistry and Biophysics, 1983
Factors FdaO are nickel tetrapyrroles from methanogenic bacteria. Two methods are described to ex... more Factors FdaO are nickel tetrapyrroles from methanogenic bacteria. Two methods are described to extract these compounds from cells of Methanobacterium thermoautotre phicum, namely, by boiling with 40% ethanol and by treatment of disrupted cells with HClO, at pH 2 and 0°C. The subsequent purification procedures involving column chromatography are outlined. Ethanol extraction yielded one yellow compound which will be denoted coenzyme MFdsO (CoMF&. Extraction with HCIOl yielded a yellow derivative, called Factor F&I, and a red component (F5&. In addition, a number of derivatives were prepared by preparative thin-layer chromatography, acid hydrolysis, and methanolysis of acid hydrolyzates. On the basis of ultraviolet-visible light absorption and mass spectral data, it was concluded that the methylated chromophores obtained by treatment of acid hydrolyzates are derivatives of Ni(II)sirohydrochlorin and its ?rcation radical. Reduction studies and ultraviolet-visible light, 'H-NMR, and mass spectroscopy indicate that the chromophoric derivatives of CoMFbsO differ from the native compound with respect to the reduction level of the tetrapyrrole and the structural elements that are attached to the chromophore.
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
A handbook for field professionals, 2013
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
The Health Council of the Netherlands organised an international workshop on the fate of pesticid... more The Health Council of the Netherlands organised an international workshop on the fate of pesticides in the atmosphere and possible approaches for their regulatory environmental risk assessment. Approximately forty experts discussed what is currently known about the atmospheric fate of pesticides and major gaps in our understanding were identified. They favoured a tiered approach for assessing the environmental risks of
Fate of Pesticides in the Atmosphere: Implications for Environmental Risk Assessment, 1999
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Papers by Harrie Van Dijk