Gert Kelfkens

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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 experiments.(More)
BACKGROUND Evidence about a possible causal relationship between non-specific physical symptoms (NSPS) and exposure to electromagnetic fields (EMF) emitted by sources such as mobile phone base stations (BS) and powerlines is insufficient. So far little epidemiological research has been published on the contribution of psychological components to the(More)
The tumorigenic properties of UBV radiation (wavelengths 280-315 nm) are well established, in contrast to those of UVA radiation (315-380 nm). Very little information is available on the short UVA wavelengths (315-340 nm). To expand our knowledge on UVA tumorigenesis we investigated the development of skin tumours in albino hairless mice (SKH-hr1) exposed(More)
An increase in skin cancer incidence due to an increase of solar ultraviolet (UV) radiation is one of the best quantitated effects of stratospheric ozone depletion. Until now, estimates of effective UV dosages could not be based on spectral data on carcinogenicity. Instead the spectral dependence of sunburn or mutations was used. These data contained little(More)
The relative risk of occupational exposure to radiation from UV lasers was estimated using a mathematical model based on both epidemiological data and animal experiments. Calculations were performed for the 193 nm ArF excimer laser cornea shaping, the 308 nm XeCl excimer laser for coronary angioplasty, and other UV lasers in a laboratory environment. The(More)
BACKGROUND There is continuing scientific debate and increasing public concern regarding the possible effects of electromagnetic fields (EMF) on general population's health. To date, no epidemiological study has investigated the possible association between actual and perceived EMF exposure and non-specific physical symptoms (NSPS) and sleep quality, using(More)
Measurement of the temperature change of skin exposed to ultraviolet radiation can be used to draw conclusions on the mechanism responsible for the development of ultraviolet erythema and on the question of which blood vessels are involved in the erythema. Under controlled environmental conditions we measured temperature change of skin areas, mainly on the(More)
To gain an insight into the relationship between the time in which a daily UV dose is delivered and its carcinogenic effectiveness, the following experiment was performed. Three groups of 24 albino hairless mice (Skh-hr1) were exposed to the same daily dose of UVB radiation (600 J m-2; Philips TL12). The exposure times for the three groups were 1.25, 4 and(More)
Measurement of the change in skin temperature caused by exposure of the skin to ultraviolet (UV) radiation may give insight into the mechanism responsible for the development of the UV erythema. Under controlled environmental conditions we determined the temperature change of skin areas exposed to UVA, up to 24 h after irradiation. The UVA doses given were(More)
The Health Council of the Netherlands (HCN) and other organisations hold the basic assumption that induced electric current and the generation and absorption of heat in biological material caused by radiofrequency electromagnetic fields are the only causal effects with possible adverse consequences for human health that have been scientifically established(More)