Skin cancer, ultraviolet radiation and occupation
Non-melanoma skin cancer (NMSC) is the most common form of cancer in fair-skinned populations, globally. Exposure to solar UV radiation (UVR), classified by the World Health Organization (WHO) as a group 1 carcinogen to humans, alongside substances such as plutonium and asbestos, is the leading cause of NMSC worldwide. Thus, each year, between 2 and 3 million people around the globe are diagnosed with NMSC, with an average annual increase of 3-8% in Australia, Europe, the US and Canada over the last 30 years 
While a clear association between solar UVR exposure, skin cancer, and recreational outdoor activities has been established, it is only quite recently that research has been focusing on the long-term impact of occupational UVR exposure with regard to developing NMSC. Recent meta-analyses have shown an at least twofold, or even higher, risk of developing NMSC in outdoor workers compared to the general population. Henceforth, current long-term measurements with 1,000 workers in approx. 100 outdoor occupations in Germany and other European countries show that many of these workers receive an unexpectedly high work-related UVR exposure of more than 600 SED annually. Thus, the daily work exposure limit by ICNIRP of 1 SED per day 
is exceeded regularly by up to 5 times. There is no other occupational carcinogen in countries with established work protection regimen, where thresholds are being ignored at that magnitude. This is worrying, as skin cancer by UVR is the most frequent occupational cancer, as currently showcased in Germany with 8,000 cases reported annually since 2015, when it was legally recognized.
To date, very few countries recognize occupational skin cancer by UVR as an occupational disease. Yet, even in those countries, patients with skin cancers related to chronic occupational solar UVR exposure mostly do not benefit from recognition because of lack of notification and underreporting. Hence, attention on occupational UVR NMSC is still surprisingly low, and a quite neglected field of attention of policy-makers. For that reason, in the last years, the WHO Intersun Project has put a focus on the occupational health risks by UVR. In accordance with this activity, WHO and ILO are currently undertaking worldwide systematic reviews on prioritized ten occupational risk factors, including occupational exposure to solar UVR, as UVR is likely to account for a highly considerable disease burden. Also, as of 2018, the WHO ICD 11 project will allow for more detailed coding for NMSC and for its occupational causation, to help reveal its true epidemiology. Moreover, recently, notification forms have been published 
, which are distributed by ILDS, which aim at reducing the underreporting and underdiagnosing of occupational cancers caused by UVR, this invisible occupational threat.
 SM Trakatelli M, Gehring R, Finlay K, Fionda C, Wittlich M, Augustin M, Hilpert G, Barroso Dias JM, Ulrich C, Pellacani G (2016) Consensus report: Recognizing non-melanoma skin cancer, including actinic keratosis, as an occupational disease - A call to action. J Eur Acad Dermatol Venereol. 2016. 30 (Suppl. 3):38-45. doi:10.1111/jdv.13608
 Commission on Non-ionizing Radiation Protection (ICNIRP) (2010). ICNIRP statement of protection of workers against ultraviolet radiation. Health Physics 99: 66-87
 C, Tiplica GS, Salavastru C, John SM (2017) Instructions for use of the OSD notification forms. J Eur Acad Dermatol Venereol 31(Suppl. 4):44–46.
Swen Malte John, MD, PhD
Professor and Chairman
Dept. Dermatology, Environmental Medicine, Health Theory
Faculty of Human Sciences
UNIVERSITY OF OSNABRUECK
Institute for Interdisciplinary Dermatological Prevention
and Rehabilitation (iDerm) at the University of Osnabrück
Lower-Saxonian Institute of Occupational Dermatology (NIB)
Postbox University, Dept. Dermatology, D-49069 Osnabrueck, Germany