Occupational disease “Skin cancer caused by UV radiation” – unambiguous facts, heterogeneous consequences

INTRODUCTION

Cutaneous squamous cell carcinoma (SCC) is the second most common malignant tumor after basal cell carcinoma. ¹ The main cause is ultraviolet (UV) radiation from sunlight, which has mutagenic and immunosuppressive effects. In many countries, occupational UV exposure is an increasing occupational health challenge, especially in outdoor work. Despite alarming incidence rates and clear scientific evidence regarding its etiology, SCC and its precursors are not recognized as an occupational disease in many countries. Legislative measures vary greatly – from complete neglect to the establishment of comprehensive prevention and compensation programs. ¹ This imbalance is often due to a lack of awareness of the problem and low reporting rates. ²

UV RADIATION AS A HUMAN CARCINOGEN

UV radiation has been classified by the International Agency for Research on Cancer (IARC) as a Group 1 carcinogen. ³ Relevant for this are DNA mutations in keratinocytes, which lead to tumor induction. Moreover, UV radiation has an immunosuppressive effect and suppresses the elimination of transformed cells, which promotes tumor development.

The extent of skin damage depends not only on the duration and intensity of exposure but is also influenced by individual factors such as Fitzpatrick skin type, genetic disposition, and sex, as well as environmental factors (geographical longitude, time of year and day, weather, reflection from water, sand, or snow). ⁴ The damage often manifests only after decades, which complicates the attribution of causality. ⁴

OCCUPATIONAL EXPOSURE AND DISTINCTION FROM RECREATIONAL EXPOSURE

UV exposure occurs in both private and professional settings. While acute sunburns in childhood are particularly associated with melanomas, it is cumulative UV exposure that is relevant for SCC. ⁴ In numerous professions – especially in construction, agriculture and forestry, fisheries, tourism, as well as for security personnel or outdoor teachers – UV exposure is significantly increased. However, it is not the profession per se, but the individual level of exposure in relation to risk that determines the hazard.

Keratocytic carcinoma has reached the status of a common disease due to its high incidence. In particular, SCC and its precursors, together with the even more common basal cell carcinoma, have historically been grouped under the term “non‐melanoma skin cancer” (NMSC). In assessment practice, a clear distinction between occupational and private exposure can often only be made to a limited extent, which complicates recognition as an occupational disease. ⁵

INTERNATIONAL ASSESSMENTS AND LEGAL DIFFERENCES

Both the World Health Organization (WHO) and the International Labour Organization (ILO) have classified occupational UV exposure as a risk factor for NMSC.³ According to global data, nearly 30 % of all deaths from NMSC are attributable to occupational UV exposure. Both organizations derive from this the obligation to protect outdoor workers through legal regulations – for example, through exposure limits, education, mandatory protective measures, and screenings.

In daily practice, however, these measures vary greatly. ⁶ SCC and its precursors caused by UV‐radiation during outdoor work have been recognized as an occupational disease in Germany since January 1, 2015. ⁷ Although the neighboring countries Austria and Switzerland have in the meantime followed this example, the reporting rates and recognition cases in these three countries differ dramatically: In Germany, almost 10,000 suspected cases of SCC were reported in 2018, and just over half of these were recognized. ⁸ In Switzerland, only twelve cases of UV‐related NMSC were recognized as occupational diseases in 2022 – compared to 135 recognized cancer cases caused by asbestos. ⁹ In Austria, in 2024, 81 recognized cases of asbestos carcinoma contrast with only one recognized NMSC case. In Italy – with high sun exposure and many outdoor workplaces – the reporting rate for occupationally induced NMSC was estimated at 3.5 % to 6.2 % of the estimated cases until 2017. ¹⁰ Denmark, which has listed SCC as an occupational disease since the year 2000, recorded only 36 recognized cases in ten years. ¹¹

REASONS FOR UNDERREPORTING

Several factors contribute to the low reporting and recognition rates: ¹²

• lack of awareness of the problem among affected employees,

• insufficient knowledge among treating physicians,

• lack of legal basis or unclear regulations,

• challenges in providing proof for distinguishing an occupational exposure,

• inadequate information for companies and insurers.

A particular obstacle for a long time was the distinction between private and occupational UV exposure. However, since the introduction of portable UV dosimeters, it has been shown that occupational exposure is often many times higher than previously assumed. ¹³ These measurements provide objective data that strengthen the argumentation basis for recognition as an occupational disease.

LEGAL FRAMEWORK AND PREVENTION

With the introduction of occupational disease BK 5103 in Germany, comprehensive measures for primary, secondary, and tertiary prevention have been established. ¹⁴ In addition to personal protective clothing and sunscreen products, technical and organizational measures, such as shift models or workplace shading, are also included. Regular instructions and occupational health care offers are legally mandated.

The recognition criteria for an occupational disease are clearly defined in Germany: ¹⁵

• histologically confirmed SCC or multiple actinic keratoses or field cancerization,

• on UV‐exposed areas of the skin,

• long‐term occupational UV exposure with > 40 % additional exposure compared to the private lifetime UV dose – corresponding to a doubling of the risk.

Other countries, such as Austria, have only recently established legal frameworks for recognition, but are still at the beginning of implementation. The dissemination of information to doctors and companies is still incomplete, and the level of awareness is low. Reporting obligations in cases of suspicion are also not universally known among physicians or are not observed.

ROLE OF THE MEDICAL PROFESSION, EMPLOYERS, AND LEGISLATORS

Effective implementation requires the collaboration of all parties involved. The medical profession must be informed, sensitized, and structurally supported – for example, through clearly defined reporting procedures and adequate remuneration for diagnostics, counseling, and follow‐up care. Employers must be obligated to take effective protective measures and implement them. And the legislators must not only formulate the legal framework conditions but also enforce and monitor them.

Some countries allow the reporting of occupationally induced skin cancers such as basal cell carcinoma or malignant melanoma, while others exclude them. ⁶ In Austria, basal cell carcinoma is not recognized as an occupational disease but can only be acknowledged on a case‐by‐case basis through a general clause. This heterogeneity between countries reflects not only different legal systems but also variations in exposure, economic environments, and the availability of preventive services.

RAISING AWARENESS – MAKING RISKS VISIBLE

A central prerequisite for successful prevention is creating awareness of the problem: among outdoor workers, their supervisors, the treating physicians, and social and insurance institutions. The danger of UV exposure is often invisible, and the long‐term consequences are underestimated or ignored. Tanned skin is still considered an ideal of beauty – an outdated perception that urgently needs to be revised. Comprehensive information campaigns are required for this purpose.

EPIDEMIOLOGICAL SIGNIFICANCE AND DEMOGRAPHIC CHANGES

Demographic developments further exacerbate the problem: According to Statistics Austria, in 2024 every fifth Austrian was over 65 years of age – by 2050 it will be every fourth. Cumulative UV exposure increases with age, as does the risk for SCC. Skin cancer is therefore not only a medical but also an economic problem. Rising disease numbers and costs for treatment, rehabilitation, and early retirement make this issue a societal challenge. ¹⁶

EUROPEAN PERSPECTIVE AND WHO INITIATIVES

International organizations such as WHO and ILO have long recognized UV radiation as a major occupational health risk. In the new WHO resolution “Skin Disease as a Global Public Health Priority,” protection against UV‐induced skin cancer is explicitly emphasized. ¹⁷ The European Union has also created a framework with the “Beating Cancer Plan” that could ideally be used for national prevention strategies – provided that political actors implement it resolutely. ¹⁸ And the international dermatological professional societies have issued a global call to all stakeholders to take the problem of NMSC among outdoor workers seriously. ¹⁹

CONCLUSIONS AND OUTLOOK

Squamous cell carcinoma of the skin is a widespread, though treatable, carcinoma — provided it is detected early and taken seriously. Occupationally induced UV exposure is a clearly proven risk that has so far been insufficiently addressed in legislation, prevention, and care. Germany has already taken a decisive step forward in this regard ²⁰ — other countries should follow suit.

What is now important at the international level:

• clearly defined legal requirements,

• targeted information campaigns,

• low‐threshold reporting processes,

• comprehensive prevention offers, and

• awareness in politics, medicine, and the public that reflects the actual level of threat.

Only by meeting these requirements can skin cancer caused by UV radiation be effectively combated as a preventable, though currently underestimated, occupational disease.

CONFLICT OF INTEREST STATEMENT

None.