Mapping Cumulative Environmental Risks: Examples from The EU NoMiracle Project

We present examples of cumulative chemical risk mapping methods developed within the NoMiracle project. The different examples illustrate the application of the concentration addition (CA) approach to pesticides at different scale, the integration in space of cumulative risks to individual organisms under the CA assumption, and two techniques to (1) integrate risks using data-driven, parametric statistical methods, and (2) cluster together areas with similar occurrence of different risk factors, respectively. The examples are used to discuss some general issues, particularly on the conventional nature of cumulative risk maps, and may provide some suggestions for the practice of cumulative risk mapping

Preliminary study on the presence of a surplus of Ra-226 in harbour sludge dumps in polders in the Rijnmond area

Abstract niet beschikbaarIn this report the results are given of a preliminary study into the presence of enhanced concentrations of natural radionuclides, notably RA-226, in harbour sludge dumps in polders in the Rijnmond area in the Netherlands. Enhanced concentrations due to human activities are thought to be the result of emissions of phosphogypsum into the River Nieuwe Waterweg. Six polders were sampled at four locations and two depths at each location. The samples were analyzed for the presence of Ra-226 and the element cadmium. The values obtained by measurement were compared with reference values obtained by calculations with a model applicable for many normal Dutch soils. The difference (surplus) between the measured and calculated values was tested for statistical significance. A significant surplus was found only in the uninhabited polders (five of six). The correlation between cadmium and Ra-226 was found to be conspicuous. The calculations allowed a rough estimation of a possibly enhanced radon concentration in houses due to the Ra-226 surplus and also of the related dose level. For the one inhabited polder this estimation amounted to 0.4 mSv/a for persons spending 80% of their time inside the house. Habitation of the polders uninhabited to data might result in an extra dose level of 3.6 mSv/a. Actual measurements of radon concentrations have not been performed in this study. The conclusions of the report are followed by recommendations on further research.DGM/SV

[Research programme on the presence and consequences of enhanced levels of Ra-226 in polders where harbour sludge was used as landfill - Definition report.]

Abstract niet beschikbaarIn this study on three construction sites in the Rijnmond area (around the Rotterdam harbour) which were elevated with dredged sediment from the New Waterway area, the radium level of the soil has been determined and data on the groundwater level and the thickness of the (natural) soil horizon have been collected. On all the sites the average radium level was found to be above 60 Bq/kg. The calculated radium levels ranged from 54-143 Bq/kg for Spaland to 90-96 Bq/kg for Stormpolder-Noord. There is no clear explanation for the large variation in the results. For the Spaland site the available data show that the groundwater level in the built-up section remains constantly above the dredged sediment-soil horizon interface. For the Stormpolder-Noord (built-up section) site the groundwater level is found below the soil horizon. Data collected in 1990-1992 show that for part of the year the groundwater level for the site in Spijkenisse remains below the soil horizon-dredged sediment interface.DGM/SV

Interim measuring method for the radon exhalation of building materials

In het Beleidsstandpunt Radon kiest het Ministerie van VROM voor een stand-still tot 1996, gevolgd door een reductie, van de risico's door radon en gammastraling uit bouwmaterialen. Op verzoek van de Directie Stoffen, Veiligheid en Straling van VROM/DGM heeft het RIVM advies uitgebracht over een interim-methode voor het meten van de radonexhalatie van bouwprodukten. Als meetmethode wordt de voorkeur gegeven aan het principe van de drukvrije exhalatiekamer, met een doorgaande stikstofstroom en een radonabsorber in de uitgaande gasstroom. Dit principe benadert het beste de vrije, diffusiegestuurde exhalatie. Tevens wordt, vanwege de betere aansluiting bij de praktijk-situatie, gekozen voor het meten van de een-dimensionale exhalatie van monsters bouwprodukt geconditioneerd bij 50% relatieve vochtigheid en 20 graden C. Aanbevolen wordt door middel van modelberekeningen en praktijkonderzoek het belang van drukgestuurde radonexhalatie vast te stellen. Voorts wordt een aantal aanbevelingen gedaan op het terrein van vergroting van de kennis over radonexhalatie, kwaliteitsborging van de meetmethode en het waarborgen van de optimale bruikbaarheid van de verkregen meetresultaten. Na publikatie van een Nederlandse Voornorm terzake (NVN 5699), naar verwachting medio 1995, vervalt dit RIVM-advies en dient NVN 5699 te worden toegepast bij het meten van de radonexhalatie van bouwprodukten.In the framework of its Policy Paper on Radon, the Ministry of Housing, Physical Planning and Environment (VROM) has chosen for a stand-still until 1996, followed by a future reduction, of the radiation risks due to radon and gamma radiation originating from building materials. Standard methods for the determination of the radon exhalation are lacking. RIVM has been asked by the VROM Directorate of Substances, External Safety and Radiation (VROM/DGM/SVS) to advise on such a measuring method. This report recommends using the principle of a pressure-free exhalation chamber as a measuring method, in which a continuous nitrogen flow and a radon absorber in the outgoing flow is applied. This principle gives the best approximation of free, diffusion-controlled radon exhalation. Furthermore, one-dimensional exhalation has been concluded to best simulate common building practices. Measuring of samples conditioned at 50% relative humidity and 20 degrees C is proposed as a standard. Additional research on the importance of pressure-driven exhalation, using model calculations and laboratory tests, is recommended. Further research, quality assurance of the measurement method and optimalization of the use of measuring data are also advised. After publication of pre-standard NVN 5699 by the Netherlands Normalization Institute, which is expected in 1995, this interim method will expire and NVN 5699 will have to be used in exhalation measurements.DGM/SV

[Risk comparison radiation/compounds. First report.]

This report presents a general overview of the field of risk comparison for radiation radioactive and chemical substances and industrial safety. It summarizes the results of interviews with representatives of DGM and RIVM, and describes different risk methods in a graphical presention.DGM/SV