Harry Slaper

National Institute for Public Health and the Environment (RIVM) | RIVM

Radon and thoron progenies in Dutch dwellings cause ~400 cases of lung cancer per year. Some 30% of the risk is due to thoron progeny, which demonstrates that the influence of thoron progeny is much larger than previously anticipated. This was concluded from a national survey in 2500 Dutch dwellings, built since 1930. Radon concentrations (15.6 ± 0...

Databases gathering atmospheric data have great potential not only as data storages but also in serving as platforms for coherent quality assurance (QA). We report on the flagging system and QA tools designed for and implemented in the European UV DataBase (EUVDB; http://uv.fmi.fi/uvdb/) for measured data on solar spectral UV irradiance. We confine...

Vitamin D3 photosynthesis in the skin is formulated as a set of reaction equations, including side-reactions to lumisterol, tachysterol and toxisterols, and the accompanying reverse reactions, isomerisation of preVitamin D3 to Vitamin D3 and photodegradation of Vitamin D3. The solution of this set is given for the stationary irradiance spectrum. Th...

Databases gathering atmospheric data have great potential not only as data storages but also in serving as platforms for coherent quality assurance (QA). We report on the flagging system and QA tools designed for and implemented in the European UV DataBase EUVDB (http://uv.fmi.fi/uvdb/) for measured data on solar spectral UV irradiance. Spectra sca...

Databases gathering atmospheric data have great potential not only as data storages but also in serving as platforms for coherent quality assurance (QA). We report on the flagging system and QA tools designed for and implemented in the European UV DataBase (EUVDB; http://uv.fmi.fi/uvdb/) for measured data on solar spectral UV irradiance. We confine...

Radon and thoron in Dutch dwellings built since 1930 Concentrations of radon and thoron progeny are low in virtually all Dutch dwellings, built since 1930. That is the outcome of a national survey, conducted by RIVM in approximately 2500 dwellings in the period 2013-2014. Radon and thoron are naturally occurring radioactive noble gasses, which are...

In the presence of clouds the ability to calculate instantaneous spectral irradiance values is limited by the ability to acquire appropriate input parameters for radiative transfer solvers. However, the knowledge of the statistical characteristics of spectral irradiance as a function of season and time of the day is relevant for solar energy and he...

For the annual course of the long-term monthly means of the daily integrals of irradiance at 305 nm and 324 nm, and of the CIE-weighted and UV-B integrals, Thessaloniki has by far the highest values, while the Scandinavian stations of Sodankyla, Jokioinen and Norrkoping the lowest. The same pattern appears also for the maximum values (Figure 1). At...

This paper is based on a comparative study on Ultraviolet radiation (UV) measurements and UV reconstructions models for eight sites in Europe. Reconstruction models include neural network techniques and radiative transfer modeling combined with empirical relationships. The models have been validated against quality controlled ground-based measureme...

Long-term analysis of cloud effects on ultraviolet (UV) radiation on the ground using spaceborne observations requires the use of instruments that have operated consecutively. The longest data record can be built from the reflectivity measurements produced by the instruments Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 19...

The assessment model for ultraviolet radiation and risk "AMOUR" is applied to output from two chemistry-climate models (CCMs). Results from the UK Chemistry and Aerosols CCM are used to quantify the worldwide skin cancer risk avoided by the Montreal Protocol and its amendments: by the year 2030, two million cases of skin cancer have been prevented...

The Lambertian Equivalent Reflection (LER) produced by satellite-carried instruments is used to determine cloud effects on ground level UltraViolet (UV) radiation. The focus is on data use from consecutive operating instruments: the Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005,...

The standard erythema action spectrum provides an internationally accepted representation of the erythema-inducing effectiveness of wavelengths in the UV part of the spectrum. The action spectrum forms the basis of the UV index used for public health information, defines the standard erythema dose unit and the minimum erythema dose and is the defau...

Depletion of the stratospheric ozone layer is mainly caused by emissions of persistent halocarbons of anthropogenic origin. The resulting increase of solar ultraviolet radiation at the Earth's surface is associated with increased exposure of humans and increased human health damage. Here we assessed the change in human health damage caused by three...

This paper describes the PROMOTE UV Record, which aims to provide a global long-term record of the surface UV radiation. The algorithm developed takes as input cloud information from the International Satellite Cloud Climatology Project (ISCCP) and a recently developed multisensor assimilated record of the total ozone column. Aerosols and surface a...

Since the realization that the ozone protective layer was at risk from the build‐up of anthropogenic trace gases in the atmosphere, there has been an increased interest in understanding the trends and variability of the solar UV radiation received at the surface of the earth. But during the last few decades an unfolding controversy has risen. It wa...

Irradiation in the ultraviolet wavelength range is found to be up to 50% lower in the European summer compared to sites with comparable latitudes in New Zealand. We have developed a method to quantitatively attribute the causes for such differences between sites by analysis of spectra. We conclude that these large differences are caused mainly by d...

Artificial Neural Networks (ANN) are efficient tools to derive solar UV radiation from measured meteorological parameters such as global radiation, aerosol optical depths and atmospheric column ozone. The ANN model has been tested with different combinations of data from the two sites Potsdam and Lindenberg, and used to reconstruct solar UV radiati...

The Dutch-Finnish Ozone Monitoring Instrument (OMI) on board the NASA EOS Aura spacecraft is a nadir viewing spectrometer that measures solar reflected and backscattered light in a selected range of the ultraviolet and visible spectrum. The instrument has a 2600 km wide viewing swath and it is capable of daily, global contiguous mapping. The Finnis...

The diurnal and annual variability of solar UV radiation in Europe is described for different latitudes, seasons and different biologic weighting functions. For the description of this variability under cloudless skies the widely used one-dimensional version of the radiative transfer model UVSPEC is used. We reconfirm that the major factor influenc...

The variation of UV-irradiance during the last decades is of interest for skin cancer development and other long-term studies of UV effects. Thus, to determine the geographical distribution of the UV-daily dose for whole Europe during the last 50 years, the COST action 726 ”Long term changes and climatology of UV radiation over Europe” has been est...

Re-evaluated UV-measurements of 4 sites have been gathered and compared with modelled UV ir- radiances using 5 different techniques on several time scales ranging from daily to yearly doses. UV-reconstruction include techniques based on neural networks (2), and radiative transfer modelling combined with empirical methods (3). Generally, the modelle...

The stratospheric ozone layer effectively serves as a protective shield that reduces the most harmful part of the solar ultraviolet (UV) radiation reaching the earths surface. As a consequence, the depletion of stratospheric ozone observed over the last two decades has probably led to an increase in ambient UV radiation. An increase in UV at ground...

The objectives of the COST action 726 are to establish long-term changes of UV-radiation in the past, which can only be derived by modelling with good and available proxy data. To find the best available models and input data, 16 models have been tested by modelling daily doses for two years of data measured at four stations distributed over Europe...

Solar spectral UV-monitoring data for 8 European sites with 5-10 years of data, and covering a latitudinal range from 41 degrees North to 67 North have been re-evaluated and resubmitted to the European UV-database (EUVDB) in Finland as part of the EU-project SCOUT-03. All resubmitted spectra (420000) were quality checked, flagged, and corrected wit...

Satellite-derived ultraviolet (UV) irradiances may form the basis for estab-lishing a global UV climatology, provided that their accuracy is confirmed against ground-based measurements of known quality. In this study quality-checked spectral UV irradiance measurements from four European stations (Sodankyla, Finland; Bilthoven, The Netherlands; Ispr...

The variability and long-term changes in the ultraviolet (UV) climate in the Netherlands have been studied in relation to ozone and clouds, by analyzing modeled and measured values for daily, monthly, and yearly integrated erythemally weighted UV doses. At Bilthoven, Netherlands (longitude 5.19°E, latitude 52.12°N), UV irradiance measurements for t...

The paper presents an approach to the treatment and analysis of long-range transport and dispersion model forecasts. Long-range is intended here as the space scale of the order of few thousands of kilometers known also as continental scale. The method is called multi-model ensemble dispersion and is based on the simultaneous analysis of several mod...

The data collected during the long-range European tracer experiment (ETEX) conducted in 1994, are used to estimate quantitatively the ensemble dispersion concept presented in Part I. The modeling groups taking part to the ENSEMBLE activities (see, Part I) repeated model simulations of the dispersion of ETEX release 1 and the model ensemble is compa...

Is atmospheric dispersion forecasting an important asset of the early-phase nuclear emergency response management? Is there a 'perfect atmospheric dispersion model'? Is there a way to make the results of dispersion models more reliable and trustworthy? While seeking to answer these questions the multi-model ensemble dispersion forecast system ENSEM...

1] An extensive intercomparison has been made between the daily averaged reduction factors in UV irradiance due to the presence of clouds as derived from ground-based (pyranometer) and satellite based measurements for the summer months of six years over Europe. Two independent satellite datasets were used for this purpose (ISCCP D1 and TOMS) and th...

There is overwhelming evidence, discussed elsewhere in this book, that exposure of the skin to UV-radiation can lead to, or at least contribute to, the development of skin cancer. The sun is the major source of UV-radiation to which the human skin is exposed. Within the earth’s atmosphere, ozone serves as a partly protective shield by absorbing mos...

Cancer research is making great strides in the fundamental understanding of how a normal cell can turn malignant, i.e., proliferate and spread uncontrollably. The relevant changes (carcinogenic “events”) that lead to cancer can be detected or even quantified in terms of frequency of occurrence. In animal experiments on UV-induced skin cancers, the...

Ground-based UV-irradiance measurements are crucial for determining the long-term changes and trends in biologically and/or photo-chemically relevant solar UV-radiation reaching the Earth's surface. Such changes in UV-radiation levels have probably occurred and/or are expected due to ozone depletion and climate change. In order to analyse UV-irradi...

The potential health effects of elevated levels of ambient UV-B radiation are diverse, and it is difficult to quantify the risks, especially as they are likely to be considerably modified by human behaviour. Nevertheless epidemiological and experimental studies have confirmed that UV radiation is a definite risk factor for certain types of cataract...

Four different satellite-UV mapping methods are assessed by comparing them against ground-based measurements. The study includes most of the variability found in geographical, meteorological and atmospheric conditions. Three of the methods did not show any significant systematic bias, except during snow cover. The mean difference (bias) in daily do...

In this study the spectra gathered during the SUSPEN campaign are compared to examine the effect of the different cosine responses and correction procedures on the measured spectral irradiances. Assuming that the three instruments with the superior cosine diffusers would suffer least by the cosine error, the average of their spectra at the same tim...

We designed a 6-week retrospective questionnaire on sunlight exposure. Estimation of the short-term exposure to sunlight is important for observational human studies concerning the effects of ultraviolet radiation (UVR) on the human immune system and related resistance to infections. This questionnaire was given to the parents of 1672 1-year-old ch...

Fourteen spectroradiometers measuring ultraviolet radiation participated in a Nordic intercomparison in Halmstad, Sweden, 10-15 June, 2000. Measurements were performed at both clear and cloudy conditions. Protocols and tools for analysing measurements were much the same as in previous large campaigns (Bais et al. 2001, Kjeldstad et al. 1997), for i...

The validation of real time atmospheric dispersion calculations requires an evaluation of the temporal and spatial characteristics of air concentrations and deposition. An extended statistical method is described for the validation and intercomparison of short-range atmospheric dispersion models. With this method multiple aspects of air dispersion...

Results from an intercomparison campaign of ultraviolet spectroradiometers that was organized at Nea Michaniona, Greece July, 1-13 1997, are presented. Nineteen instrument systems from 15 different countries took part and provided spectra of global solar UV irradiance for two consecutive days from sunrise to sunset every half hour. No data exchange...

A method is described to determine low excess dose rates from a radiation source in the environment, which are small compared to the natural fluctuations of the background radiation. First a 'virtual reference dose rate meter' is constructed from data of the national monitoring network, to know the natural variations of the background radiation. Re...

A method to describe the observed yearly variability of ground-level UV has been developed and validated. The method uses UV transfer model calculations and measured ozone values, by satellite or ground based stations, in combination with an empirical cloud correction based on widely available global solar radiation measurements. Good agreement is...

Increased exposure to UV radiation is known to have a significant effect on human health, ecosystems or crop production. The link between stratospheric ozone depletion and increased surface UV radiation is now established. Large increases in UV radiation have been observed in association with the ozone hole at high southern latitudes. A clear sign...

Assessment of the effects of ozone depletion on biologically effective solar UV at ground level has been greatly advanced through the use of remote sensing data. Satellite data on atmospheric properties allow the construction of geographically distributed surface UV radiation maps based on radiative transfer calculations. In this respect, clouds pl...

The health risks associated with ozone depletion will principally be those due to increased ultraviolet B (UV-B) radiation in the environment, i.e., increased damage to the eyes, the immune system, and the skin. Some new risks may also be introduced with the increased use of alternatives to the ozone-depleting substances (ODSs). Quantitative risk e...

The 1986 accident with the nuclear power plant in Chernobyl has shown that severe accidents with a nuclear power plant can lead to a large scale contamination of Europe. At present, over 200 nuclear power reactors for commercial electricity production are operational in Europe. An integrated assessment of probabilistic cancer mortality risks due to...

The atmospheric ozone layer serves as a protective filter against (part of) the harmful ultraviolet (UV) radiation from the sun. The depletion of the ozone layer, which was observed on a global scale over the past decades, is most probably caused by the global emission of halocarbons, and leads to an increase in UV at groundlevel, and thus, to incr...

Depletion of the ozone layer has been observed on a global scale, and is probably related to halocarbon emissions. Ozone depletion increases the biologically harmful solar ultraviolet radiation reaching the surface of the Earth, which leads to a variety of adverse effects, including an increase in the incidence of skin cancer. The 1985 Vienna Conve...

Evidence indicates that the concentration of stratospheric ozone has already decreased globally over the past several years and additional decreases are to be expected over the coming decades. A further depletion of the ozone layer would lead to an increase in the amount of ultraviolet (UV) radiation. One of the adverse effects of particularly UV-B...

Spectrally resolved UV measurements are important for the study of biologically relevant UV in relation to changes in atmospheric parameters. The inter-comparison of spectral instruments is essential as measurement techniques and calibrations are not standardized. The differences in slit functions cause large spectral variations when comparing the...

Since clouds and aerosols contribute substantially to the attenuation of biologically effective UV at ground level it is important to consider their role in studies on UV climatology on earth. We describe a method to quantify this attenuation using spectral measurements of UV radiation at ground level and measurements of total solar radiation. The...

During the past decade a decrease in stratospheric ozone has been observed over large parts of the globe. Stratospheric ozone is the primary absorber of solar UV-B and UV-C and serves as a partially-protective shield against harmful UV irradiance in the biosphere. Decreased levels of ozone appear to increase the levels of harmful UV-B (280–315 nm)...

A UV spectrometer system is developed consisting of a highly accurate scanning double monochromator for especially the biologically relevant UV-B region and a multichannel detection system for UV-A radiation measurements. Integrated global irradiance is monitored continuously using a pyranometer. The operation of the combined system is fully automa...

Information on the variation in carcinogenicity with wavelength is crucial in risk assessments for skin cancers induced by UV radiation. Until recently the wavelength (lambda) dependencies of other detrimental UV effects, such as sunburn, have been used as substitutes. Direct information on the lambda dependency can only be obtained from animal exp...

A descriptive dose-response model is presented to evaluate the long-term risk with respect to non-melanoma skin cancer associated with UVB therapy. The model is based on the results of animal dose-response studies and epidemiological data. A number of factors that influence the risk associated with therapy are evaluated: annual dose applied, solar...

Solar UV radiation interacts with many organisms and systems within the biosphere. The pathway leading from the entrance of photons into the system to the system’s ultimate response is different for various systems and responses. Nevertheless, there are clear-cut parallels between various types of UV responses. This analysis is focused on the effec...

A possible increase in the risk of skin cancer in psoriatic patients treated with long-term maintenance UVB phototherapy was assessed by comparing the cumulative doses of UVB with the amount of UVB received from sunlight by normal healthy people. The biologically-effective UVB dose (termed UVB(EE) ) was measured using polysulphone film and worn as...

Abstract The dependence of radiation transmission on sample thickness was studied in isolated samples of human stratum corneum and full-thickness epidermis. The investigation also included samples of skin repeatedly exposed to UV-B. Transmission was measured in the ultraviolet and in the visible from 248–546 nm. Two methods, one microscopic and the...

UV irradiances for eight sites located across Europe have been reconstructed using a merge of five different UV-models and ground-based measurements. Reconstruction models include techniques based on neural networks (2), and radiative transfer modelling only (1) or combined with empirical methods (2). All models use pyranometer data to determine th...

The UV-radiation, which reaches the Earth's surface, has been studied by analysing UV-irradiation spectra obtained from over 15 European measurement stations covering a latitude range from 33^o-68^o. The overall goal is to establish a UV climatology for Europe and infer possible long-term changes in relation to stratospheric ozone depletion and cli...

The economic assessment of priorities for a European environmental policy plan focuses on twelve identified Prominent European Environmental Problems such as climate change, chemical risks and biodiversity. The study, commissioned by the European Commission (DG Environment) to a European consortium led by RIVM, provides a basis for priority setting...

The economic assessment of priorities for a European environmental policy plan focuses on twelve identified Prominent European Environmental Problems such as climate change, chemical risks and biodiversity. The study, commissioned by the European Commission (DG Environment) to a European consortium led by RIVM, provides a basis for priority setting...

The number of factors in the physical environment possibly having an adverse effect on human health is very substantial. There are, for example, all kinds of pathogenic micro-organisms, countless substances which have been shown to be carcinogenic in laboratory animals, as well as various forms of radiation. In addition, many hazardous activities,...

Over 200 nuclear power plants for commercial electricity production are presently operational in Europe. The 1986 accident with the nuclear power plant in Chernobyl has shown that severe accidents with a nuclear power plant can lead to a large scale contamination of Europe. This report is focussed on an integrated assessment of probabilistic cancer...

At present over 200 nuclear power reactors are operational. The question raised is to what extent possible accidents with nuclear power reactors pose a risk for the European population. In this report a method is described for evaluating the probability of death due to stochastic effects, combining the probability of accidental releases with the co...