Surface-clearance levels for the normal reuse of objects for 413 radionuclides.

This paper provides surface-clearance levels for 413 radionuclides for the normal reuse of objects leaving the controlled area of a nuclear facility. Four sets of surface-specific clearance levels are derived based on choices of dose coefficients (DCs) in probabilistic dose assessments using the SUrface DOse QUantification model (SUDOQU; van Dillen and van Dijk 20181147-203). The general dose criteria for clearance, extended with a suitable dose constraint for the concept of the representative person, are applied in the derivations.

Accounting for ingrowth of radioactive progeny in dose assessments: generic weighting factors for dose coefficients.

In this paper, we describe a practical and convenient method to include the contribution of the ingrowth of radioactive progeny in dose assessments of the corresponding parent nuclides. This method modifies the dose coefficients (DCs) of parent nuclides by adding weighted DCs of the corresponding daughter nuclides to them. Based on the decay kinetics of serial nuclear transformations, the progeny weighting factors, with values between 0 and 1, are derived by analysis of the time-integrated activity of each nuclide in the (branched) decay chain headed by a parent nuclide.

SUDOQU, a new dose-assessment methodology for radiological surface contamination.

A new methodology has been developed for the assessment of the annual effective dose resulting from removable and fixed radiological surface contamination. It is entitled SUDOQU (SUrface DOse QUantification) and it can for instance be used to derive criteria for surface contamination related to the import of non-food consumer goods, containers and conveyances, e.g.

How radiation influences atherosclerotic plaque development: a biophysical approach in ApoE⁻/⁻ mice.

Atherosclerosis is the development of lipid-laden plaques in arteries and is nowadays considered as an inflammatory disease. It has been shown that high doses of ionizing radiation, as used in radiotherapy, can increase the risk of development or progression of atherosclerosis. To elucidate the effects of radiation on atherosclerosis, we propose a mathematical model to describe radiation-promoted plaque development.

Modeling Lung Carcinogenesis in Radon-Exposed Miner Cohorts: Accounting for Missing Information on Smoking.

Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-control study onto an entire cohort by means of a Monte Carlo resampling technique. As a proof of principle, this method is tested on a subcohort of 35,084 former uranium miners employed at the WISMUT company (Germany), with 461 lung cancer deaths in the follow-up period 1955-1998.

SUDOQU: a new dose model to derive criteria for surface contamination of non-food (consumer) goods, containers and conveyances.

The Fukushima nuclear accident (Japan, 11 March 2011) revealed the need for well-founded criteria for surface contamination and associated screening levels related to the import of non-food (consumer) goods, containers and conveyances. The only available European-harmonised criteria are those laid down in the IAEA transport regulations, but these criteria date back from the early 1960s and only apply to the safe transport of radioactive materials. The main problem is that a generic dose-assessment model for consumer products is missing.

Modelling breast cancer in a TB fluoroscopy cohort: implications for the Dutch mammography screening.

Breast cancer incidence in a tuberculosis fluoroscopy cohort has been modelled with a two-stage carcinogenesis model. The relatively simple model, in which hormonal influences only affect the number of sensitive target cells, fits the data very well. Under the assumption that individual hormonal differences average out, and with a relative biological effectiveness for mammographic X rays of 1, the model yields ∼10 fatal breast cancer cases induced by the entire Dutch screening programme over a period of 25 y.

Lung cancer from radon: a two-stage model analysis of the WISMUT Cohort, 1955-1998.

A biologically based two-stage carcinogenesis model is applied to epidemiological data for lung cancer mortality in a large uranium miner cohort of the WISMUT company (Germany). To date, this is the largest uranium miner cohort analyzed by a mechanistic model, comprising 35,084 workers among whom 461 died from lung cancer in the follow-up period 1955-1998. It comprises only workers who were first employed between 1955 and 1989 and contains information on annual exposures to radon progeny.

Modelling lung cancer due to radon and smoking in WISMUT miners: preliminary results.

A mechanistic two-stage carcinogenesis model has been applied to model lung-cancer mortality in the largest uranium-miner cohort available. Models with and without smoking action both fit the data well. As smoking information is largely missing from the cohort data, a method has been devised to project this information from a case-control study onto the cohort.

Breast cancer risk from different mammography screening practices.

Mammography screening is an accepted procedure for early detection of breast tumors among asymptomatic women. Since this procedure involves the use of X rays, it is itself potentially carcinogenic. Although there is general consensus about the benefit of screening for older women, screening practices differ between countries.

Combined optical tweezers/ion beam technique to tune colloidal masks for nanolithography.

A method is presented to control the in-plane ordering, size, and interparticle distance of nanoparticles fabricated by evaporation through a mask of colloidal particles. The use of optical tweezers combined with critical point drying gives single-particle position control over the colloidal particles in the mask. This extends the geometry of the colloidal masks from (self-organized) hexagonal to any desired symmetry and spacing.