Objective: To measure erythemogenic UV radiation in Iceland.

Material and methods: Erythemogenic UV radiation was measured during the period from April through September 2010. We used a UV sensor that measures the Erythema Action Spectrum as has been defined by the Commission Internationale de l'Eclairage (CIE) as the standard representation of the average skin response to UVB and UVA. The sensor was located in Skorradalur, Iceland (64,533287N; -21,526338W; altitude 63 m.). The location of the sensor was carefully chosen to ensure that it was never in the shade.

Results: The maximum UV-index measured was higher than three 21 days in May, 26 days in June, 26 days in July and 23 days in August. The highest value recorded was 7,3 on June 18th, at 13:25. UV index was measured as 5 or higher on 16 days in June.  The highest erythema weighted daily dose was measured  to 19,2 SED in April, 27,1 SED in May, 32,2 SED in June, 30 SED in July, 23,5 SEDin August and 11,6 SED  in September.

Discussion: These are the first results from measurements of UV-index and standard erythema dose (SED) in Iceland. The data shows that on a sunny day the UV-index can be relatively high. When the standard erythema dose was considered, high values were obtained during the summer months, with values up to six times what can cause sunburn.

Key words: UV-index, erythemogenic rays, sunburn, Iceland

Correspondence: Bárður Sigurgeirsson, bsig@hudlaeknastodin.is

 

Figure 1. Location of the weather station and UV sensor.

Figure 2. UV-index during the summer of 2010 in Skorradalur, Iceland.

 Figure 3. Standardised erythema dose (SED) per hour during a few sunny days during the summer of 2010 in Skorradalur, Iceland.

 

Month	SED Daily averages	SED range	Number of days with SED over 20
April	7,2	1,6 - 19,2	0
May	15,5	6,1 - 27,1	9
June	20,3	8,9 – 32,2	15
July	17,5	3,8 – 30,0	11
August	14,1	6,4 – 23,5	6
September	5,3	1,3 – 11,6	0

Table I. Results from measurements of erythemogenic UV rays in Skorradalur, Iceland during the summer of 2010. The first column shows the average daily standard erythema dose (SED). The next column shows the range. The last column shows the number of high intensity days with SED >  20. All values are displayed according to month.

Month	UV-index (average daily maximum )		Number days with UV-index 3 or more		Number days with UV-index 5 or more		UV-index (maximum )
	Skorradalur	Trondheim	Skorradalur	Trondheim	Skorradalur	Trondheim	Skorradalur	Trondheim
April	2,0	2,2	2	1	0	0	3,5	3,1
May	3,4	3,3	21	19	0	0	4,9	4,0
June	4,8	4,2	26	30	16	1	7,3	5,1
July	4,2	4,5	26	31	5	3	5,3	5,3
August	3,4	3,4	23	25	1	0	5,0	5,0
September	1,7	1,9	2	0	0	0	3,7	3,7

Table II. UV index during the summer of 2010 in Skorradalur Iceland and Trondheim, Norway. Both locations are at similar latitude and should therefore be roughly comparable.