Introduction

One in ten cases of bladder cancer are attributed to occupational exposure to carcinogens. Multiple substances used in the chemical industries have been linked to the disease. We review the milestones that led to the discovery of carcinogens and changes in employment regulations leading to a fall in occupational bladder cancer.

Methods

A literature review on occupational bladder cancer was performed using Medline, Embase and the Archives of the Royal Society of Medicine.

Results

In 1895, German surgeon Ludwig Rehn reported three cases of bladder cancer in workers at the Hoechst aniline factory, Greisheim. However, the association with the chemical was difficult to prove as chemical manufacturers used other coal- and oil-based compounds. Beta-naphthylamine (BNA), produced by distilling coal, was used in the production of dyestuffs, cables and rubber. In 1938, Delaware-based pathologist Wilhelm Hueper showed an increase in bladder tumours when BNA was administered orally to dogs but, being funded by the chemical industry, had difficulty publishing his research. BNA was prohibited worldwide following a landmark study by Case and Holster on British rubber industry workers in 1954 after discovering a 200-fold increased risk of bladder cancer. In 1972 Miyakawa subsequently demonstrated a significantly decreased incidence of bladder cancer.

Conclusions

The groundbreaking discovery of aromatic amines as the most important carcinogens in occupational bladder cancer prompted worldwide regulatory changes to the manufacture of rubber and dyestuffs. The incidence of occupational bladder cancer has decreased in the Western world but is still widely reported in less developed countries.