Dutch Approaches

Principally, the overall assessment factor is established by multiplication of the separate factors. The authors note that in practice it is not possible to distinguish all above-mentioned factors, and some factors are not independent of each other. Therefore, straightforward multiplication may lead 

Toxicological Risk Assessments of Chemicals A Practical Guide 

Vermeire et al. (1999) have published a discussion paper with focus on assessment factors for human health risk assessment. The status quo with regard to assessment factors is reviewed and the paper discusses the development of a formal, harmonized set of assessment factors. Options are presented for a set of default values and probabilistic distributions for assessment factors based on the state of the art. Methods of combining default values or probabUistic distributions of assessment factors (Section 5.11) are also described. In relation to assessment factors, the authors recommended  

A more recent Dutch report (Vermeire et al. 2001) provides a practical guide for the application of probabilistic distributions of default assessment factors in human health risk assessments, and it is stated that the proposed distributions will be applied in risk assessments of new and existing substances and biocides prepared at RIVM (the National Institute of Public Health and the Environment) and TNO. The report concentrated on the quantification of default distributions of the assessment factors related to interspecies extrapolation (animal-to-human), intraspecies extrapolation (human-to-human), and exposure duration extrapolation. 

---

Neither Alpers nor Cook have paid much attention to the importance of religion in the Dutch approach. Alpers has left Calvinism out of her account because in her view the picturing of the world is contrary to the Protestant emphasis on the Scriptures. Cook has stated that strong claims on the relationship between science and Protestantism must be treated with the same scepticism with which the Merton thesis is treated by historians of English science. Rather than pointing to Calvinism, Cook has followed Hooykaas in stating that Catholic, Jewish and Protestant natural philosophers were uni-... 

At sectoral level the Dutch approach to chemical hazards is distinguished by the particular prominence of the debate on substitution and the strategies to achieve this in certain sectors, as well as by the recent emphasis on the use of convenanten (covenants) to set agreed sector specific targets for improvement of the work environment - which in some cases, include agreement to improve on OEls. At worlq)lace level several features have a bearing on the approach to dealing with chemical hazards. They include ... 

The second element reflect a changed view of foe state s role in society and ax>nomy with respect to health md safety policy, with greater emphasis on self-reliance from employers and employees. H xi foe Dutch approach was influaiccxl by foe example of... 

J. Uitermark, 2004. The origins and future of the Dutch approach towards Amgs. Journal of Drug Issues 511—532. 

Flood risk is not just about probabUities, but also about the consequences of floods. The Dutch approach to the evaluation of flood safety has traditionally been to minimize the sum of the discounted investments in flood defense and the discoimted expected value of fhmre losses (Van Dantzig 1956). Various intangible losses, including loss of life, are valued in money terms and included in the financial balance. 

Today this approach may seem comparatively unsophisticated, but the parallels with the Dutch approach some ten years later can be seen. Inevitably, there will be a greater integration of intensification technologies and process simulation software that will allow routine use of PI over the coming decades, particularly as constraints on energy use and the need for sustainability become imperative. 

The Dutch approach [57], which advocated an electrostatic model based on a Stem model and introduced the 1-pK concept This approach can be interpreted as a special case of a much more comprehensive model. It is, at the same time, simple and versatile. The numbers of adjustable parameters are more restricted, in particular compared to the 2-pK triple-layer model. 

In dealing with future uncertainties. Royal Dutch/SheU pioneered Scenario planning (54,55). Alternative assumptions for future developments can be combined under this approach in various ways to give a number of consistent possible outcomes (56) and provide a basis for both actions and reactions. The approach has rewarded Shell handsomely. 

Westbroek, de Jong, and Pilot (2006) reported on a Dutch research approach using authentic practices as contexts. It is notable that some of the above approaches have been adopted in a number of other countries. 

DUTCH STUDY CONFIRMS INTEGRATED APPROACH TO WASTE MANAGEMENT IS WAY FORWARD... 

Owing to the complexity of multi-residue methods for products of animal origin, it is not possible to outline a simple scheme however, readers should refer to methods described in two references for detailed guidance (Analytical Methods for Pesticides in Foodstuffs, Dutch method collection and European Norm EN 1528. ) There is no multi-method specifically designed for body fluids and tissues. The latter matrix can be partly covered by methods for products of animal origin. However, an approach published by Frenzel et al may be helpful (method principle whole blood is hemolyzed and then deproteinized. After extraction of the supernatant, the a.i. is determined by GC/MS. The LOQ is in the range 30-200 ag depending on the a.i.). 

In Chapter 5 the conceptual approach from the previous Chapter will be tested and evaluated and finally applied to a single case study in the Dutch chemical process industry. This exercise is performed to test the conceptual approach in practice. The findings of the case study will be evaluated and will lead to refinements in the conceptual approach. Finally a structured protocol will be derived and applied to the same case study to ascertain if the structured protocol is effective and suitable for practical use and leads to answering the research questions posed in Chapter 1. 

However, the Dutch group around Victor Feron (Groten et al. 2001, Feron and Groten 2002, Jonker et al. 2004), as well as US-EPA (1999, 2000b) and the Agency for Toxic Substances and Disease Registry (ATSDR 2004) have suggested approaches that cover also chemicals that differ in their modes of action. 

Approach to Assess Simple and Complex Mixtures Suggested BY the Dutch Croup... 

As regards complex mixtures, the Dutch group initially recommended a two-step approach (see Figure 10.5) first to identify the n (e.g., 10) most risky chemicals in the mixture, and then to perform hazard identification and risk assessment of the defined mixture of the (10) priority chemicals using procedures appropriate for simple, defined mixtures (Feron et al. 1995a,b, 1998 Cassee et al. 1998. 

In the present study a weight-of-evidence approach derived on the basis of three LOEs has been evaluated in order to better assess the risk from TBT in Dutch harbours and open waters. Based on chemical data, risk values were determined according to Aldenberg et al. (2002) and ISI values were calculated based on the dose-response curve reported by Oehlmann (2002). Actual ISI observations were made in the field and the presence of gastropods was recorded. In the overall approach evidence from the different LOEs was combined. 

The discovery of superconductivity was not very dramatic. When Dutch physicist Heike Kamerlingh Onnes succeeded in liquefying helium in 1908 he looked around for something worth measuring at that temperature range. His choice feU upon the resistivity of metals. He tried platinum first and found that its resistivity continued to decline at lower temperatures, tending to some small but finite value as the temperature approached absolute zero. He could have tried a large number of other metals with similar prosaic results. But he was in luck. His second metal, mercury, showed quite unorthodox behavior, and in 1911 he showed that its resistivity suddenly... 

---