Swedish pre-school children's UVR exposure - a comparison between two outdoor environments.

BACKGROUND: Overexposure to ultraviolet radiation (UVR) in childhood is a major risk factor for skin cancer. Shady environments are recommended as one method of protection. METHODS: Environmental exposure to UVR and environmental protection were assessed by dosimeter measurements on 64 children aged 1-6 years at two geographically close and topographically similar pre-schools outside Stockholm. Outdoor play constructions of site 1 (34 children) were mainly exposed to the sun, and those of site 2 (30 children) were mainly shaded. Dosimetry was carried out during 11 work days in May-June 2002 under clear weather conditions. The reliability of dosimeters was tested with meteorologically modelled data from SMHI, and with stationary dosimeters exposed to free sky, and compared with other UV instruments. The differences between children's outdoor stays were adjusted for. RESULTS: The children's average daily exposures were approximately 200 J(CIE)/m(2) erythemally effective UVR. The average relative UVR exposure (% total available UVR 08:30-18:30) was 6.4% (7.0% at site 1, 5.7% at site 2). Fractions of available UVR during outdoor stay were 14.4% (both sites), 15.3% (site 1), and 13.3% (site 2). In terms of relative differences, 5-6-year-old children at site 2 were exposed to 41% less UVR, and 1-4-year-old children 6% less than those at site 1. CONCLUSION: The difference can be explained by the children's outdoor pre-school environments, and the behaviors linked to these environments. It is recommended to consider the attractiveness of shady environments in the design of children's pre-school playgrounds, particularly if these are extremely exposed to the sun.

Chondrodysplasia punctata (CDP) with features of the tibia-metacarpal type and maternal phenytoin treatment during pregnancy.

We describe a 2-year-old boy with chondrodysplasia punctata (CDP). The boy was exposed to phenytoin, in combination with carbamazepine, during pregnancy. There has been previous evidence for a connection between phenytoin exposure during pregnancy and chondrodysplasia punctata. The boy had clinical and some radiological characteristic features of CDP, of the tibia-metacarpal type. We know of no other report on a child exposed to phenytoin during pregnancy who developed CDP of this type.

Population UV-dose and skin area--do sunbeds rival the sun?

From the perspective of skin cancer risks, sunbed tanning may give the population group of Swedish adolescents a yearly total dose in terms of ultraviolet radiant energy to the skin which is comparable to sunlight. For populations, a dosage scheme is applied, where exposed skin area is estimated to be two to ten times larger in tanning units than in outdoor sunlight. The normal dose fluence rate is multiplied by the exposure time and by the exposed body surface area. A study of sunbed use among adolescents was reinvestigated. Skin dose from artificial tanning in that population group is calculated and compared to sun exposure for erythemally effective radiation and for UVA (315-400 nm). Skin doses from tanning units to the adolescent population agree with estimates based on information concerning sunbed lamp sales/year. For the population, the erythemal skin dose from tanning units exceeds an increase in solar ultraviolet radiation to the skin projected from 10% ozone depletion. The dosage scheme might help to interpret data suggesting an increased melanoma risk among young people using sunbeds > or = 10 times per year. Tanning and sunburns in sunbeds and in sunlight is discussed with regard to skin area.

An analysis of UVA emissions from sunlamps and the potential importance for melanoma.

Exposure to solar UV radiation is a risk factor for cutaneous malignant melanoma (CMM). Epidemiologic studies have also considered the use of sunlamps as a possible contributor to CMM. We measured and analyzed the emission spectra of six different currently marketed sunlamps and a historical sunlamp, the UVB-emitting FS lamp, and compared the results to solar exposure. For a typical tanner (20 sessions @ 2 minimal erythema doses (MED)/session), the annual UVA doses from commonly used fluorescent sunlamps were 0.3-1.2 times that received from the sun. For a frequent tanner (100 sessions @ 4 MED/session), the annual UVA doses from fluorescent sunlamps were 1.2-4.7 times that received from the sun and 12 times for recently available, high-pressure sunlamps. To determine biologically effective doses, action spectra for squamous cell carcinoma (SCC) in humans and for melanoma in the Xiphophorus fish (XFM) were applied to the sunlamps' emission spectra. The results for the effective doses using the SCC action spectrum tracked the UVB doses, while the results using the XFM action spectrum tracked the UVA doses. When combined with UV exposure received from the sun, typical sunlamp use results in an approximate doubling of annual effective dose, if the XFM action spectrum is applied. Frequent use, however, can increase the annual effective XFM dose by as much as 6 times what would be received from the sun alone for fluorescent sunlamps and as much as 12 times for newer, high-pressure sunlamps.

Dose distribution around a new flexible afterloading applicator.

A new afterloading applicatory, together with a computer program, is described. A comparison of the calculated and measured dose distribution around different applicators shows that in the future the described computer program can be used. The development of the new applicator and the computer program increases the flexibility of possible dose distribution.

The quantitative effect of visual and tactile stimuli on the prey-catching behaviour of ferrets (Putorius furo L.).

The influence of visual and tactile stimuli on the elicitation of prey-catching behaviour of ferrets was to be studied. For this study 16 animals, males and females, some naive and others experienced in catching and killing mice and rats were used. The behaviour of the ferrets toward 16 dummies with different characteristics was analysed under standardized conditions. Prey catching reactions of ferrets can be elicited by moving dummies. Dummies up to a certain size reliably elicit hunting reactions if they are moving at a speed of 25 cm/sec to 45 cm/sec. Moving objects, more than double the size of a ferret, cause avoiding reactions. Objects with a fur-like surface release more biting than objects with a hard surface. When hunting, ferrets-innately-tend to aim at the most anterior part of the "prey" and to bite into it, independent of whether there is a head-like structure with a neck or not.