[1] Department of Social Medicine,
[2] Center of Occupational & Environmental Dermatology,undefined
[3] University of Heidelberg,undefined
[4] Bergheimer Str. 58,undefined
[5] D-69115 Heidelberg,undefined
[6] Germany Tel.: +49-6221-568751; Fax: +49-6221-565584,undefined
[7] Occupational & Environmental Dermatology Unit,undefined
[8] Universiy Hospital Groningen,undefined
[9] The Netherlands,undefined