Skin tumors among employees of a tar refinery: the current data and their implications

Abstract

Objective

Skin tumors and their preliminary stages may be recognized and compensated as an occupational disease only after exposure to soot, raw paraffin, tar, anthracene, pitch or similar substances. The presented study was carried out in one of the world’s largest tar refineries and special attention was paid to the dermatological long-term effects and today’s relevance of tar-induced skin lesions.

Methods

The data were generated by means of a standardized questionnaire based on occupational disease records and dermatological reports that have been carried out on a regular basis retrospectively. Among other things, the localization, the number and type of skin tumor, the date of diagnosis and the histological evaluation, where available, were taken into account.

Results

In a longitudinal analysis from 1946 to 2002, a total of n = 618 employees were examined. Squamous cell carcinomas n = 393, basal cell carcinomas n = 298, keratoacanthomas n = 194 and melanomas n = 6 were diagnosed. Latency periods for keratoacanthomas (median 29.5 years) and squamous cell carcinomas (median 28.0 years) were almost identical and could possibly imply that the pathomechanisms for both types of skin tumor might be comparable. Of the persons diagnosed, the skin tumors were mainly localized in the head region (n = 1,662). A remarkable divergence in the localization and distribution of the lesions was found when compared to the general population, for example the relative susceptibility of the upper lip (n = 67) compared to the lower lip (n = 31) as well as the less sun-exposed forearms (n = 381) compared to the back of the hand (n = 331), being typically preferred sites of squamous cell carcinomas. Furthermore, a discrepancy between the distribution of premalignant nonmelanoma skin tumors and carcinomas on the back of the nose, which is more exposed to the sun (n = 56) and those in the nostrils (n = 89), which are less exposed to the sun, but are in the act of breathing more exposed to tar, could be found.

Conclusions

Tar-induced skin lesions are still of importance nowadays, which is reflected in the incidence of new cases and in the relapses of skin tumors. As a consequence, intensified measures are necessary, in the form of primary and secondary prevention. In view of the high incidence of malignant skin tumors in the general public, it is urgently necessary to take occupational hazards into consideration as well.