Ultraviolet tanning equipment: six questions

FDA-sunlamp recommended Maximum Timer Interval And Exposure Schedule: consensus ISO/CIE dose equivalence

The authors compared calculations of sunlamp maximum exposure times following current USFDA Guidance Policy on the Maximum Timer Interval and Exposure Schedule, with USFDA/CDRH proposals revising these to equivalent erythemal exposures of ISO/CIE Standard Erythema Dose (SED). In 2003, [USFDA/CDRH proposed replacing their unique CDRH/Lytle] erythema action spectrum with the ISO/CIE erythema action spectrum and revising the sunlamp maximum exposure timer to 600 J m(-2) ISO/CIE effective dose, presented as being biologically equivalent. Preliminary analysis failed to confirm said equivalence, indicating instead ∼38% increased exposure when applying these proposed revisions. To confirm and refine this finding, a collaboration of tanning bed and UV lamp manufacturers compiled 89 UV spectra representing a broad sampling of U.S. indoor tanning equipment. USFDA maximum recommended exposure time (Te) per current sunlamp guidance and CIE erythemal effectiveness per ISO/CIE standard were calculated. The CIE effective dose delivered per Te averaged 456 J(CIE) m(-2) (SD = 0.17) or ∼4.5 SED. The authors found that CDRH's proposed 600 J(CIE) m(-2) recommended maximum sunlamp exposure exceeds current Te erythemal dose by ∼33%. The current USFDA 0.75 MED initial exposure was ∼0.9 SED, consistent with 1.0 SED initial dose in existing international sunlamp standards. As no sunlamps analyzed exceeded 5 SED, a revised maximum exposure of 500 J(CIE) m(-2) (∼80% of CDRH's proposal) should be compatible with existing tanning equipment. A tanning acclimatization schedule is proposed beginning at 1 SED thrice-weekly, increasing uniformly stepwise over 4 wk to a 5 SED maximum exposure in conjunction with a tan maintenance schedule of twice-weekly 5 SED sessions, as biologically equivalent to current USFDA sunlamp policy.

Development of a sky imager for cloud cover assessment

Based on a CCD camera, we have developed an in-house sky imager system for the purpose of cloud cover estimation and characterization. The system captures a multispectral image every 5 min, and the analysis is done with a method based on an optimized neural network classification procedure and a genetic algorithm. The method discriminates between clear sky and two cloud classes: opaque and thin clouds. It also divides the image into sectors and finds the percentage of clouds in those different regions. We have validated the classification algorithm on two levels: image level, using the cloud observations included in the METAR register performed at the closest meteorological station, and pixel level, determining whether the final classification is correct.

Quantitative risk assessment of sunbeds: impact of new high power lamps

BACKGROUND

A survey of all sunbeds in a local authority area was carried out in 1998. Since then, there have been technological developments leading to new 'fast-tan' sunlamps which have become increasingly popular, along with unmanned sun parlours. In addition, new British and European sunbed standards have been set.

OBJECTIVES

To discover the commercial uptake of new high power sunlamps and to determine the impact on carcinogenic risk from sunbeds.

METHODS

Onsite spectral measurements, traceable to national standards, were conducted at all commercial sunbed premises within two local authorities and a quantitative risk assessment applied to the findings using a skin cancer model. Sunbed users were asked to complete a questionnaire regarding their reasons for using a sunbed and the risk associated with its use.

RESULTS

We found a 30% increase in the number of privately operated sunbeds since our 1998 survey. The median cancer-weighted exposure of all 133 sunbeds was comparable to that of Mediterranean sunlight. This was a significant increase compared to 1998. Moreover, 83% of sunbeds produced ultraviolet (UV) B radiation levels that exceeded the European standard. Fifteen per cent of respondents thought that there were no risks from use of sunbeds.

CONCLUSIONS

Sunbeds in current use carry a cancer risk comparable to Mediterranean sunlight. This is due to the use of new high power lamps. New British and European standards are being largely ignored with more than four out of five sunbeds exceeding the limit specified in the standard. There is a strong case for regulation of sunbed operators coupled to improved public education.