HX06 Mule spinners’ cancer: a brief history

Abstract

By the Industrial Revolution, Manchester had become the capital of cotton manufacture in the UK. During the 18th century, technological innovations like the ‘spinning mule’ enabled a production boom. Operating this machinery exposed workers to the lubricant mineral oils, which splashed onto clothing and seeped into the skin. The scrotum was particularly vulnerable. Reports of the high incidence of scrotal epitheliomas (squamous cell carcinoma) in textile workers first appeared in 1887, but it took almost 40 years for it to be recognized as an occupational disease following a 1926 Home Office enquiry. Mule spinners’ cancer developed in stages. Initially keratotic plaques appeared. With continued exposure, transformation into invasive squamous cell carcinoma occurred, with metastasis to the inguinal nodes being common. Leitch estimated that 20% of scrotal cancers causing death occurred in mule spinners. Southam put the incidence of the disease at 2.5 per 1000 workers annually, and Brockbank reported at least 64 cases and 21 deaths between 1923 and 1939. After the initial enquiry there was some debate over the aetiology; Savatard, a Manchester dermatologist, suggested underlying ichthyosis as a causative factor. A consensus eventually developed that prolonged exposure to mineral oils was the principal factor, with shale oil being the primary carcinogen. Recommendations from the enquiry included installing splash guards to the machinery and education of workers on skin lesions, alongside regular medical examinations. Research into noncarcinogenic oil substitutes was considered; however, determined use of personal protective equipment became the norm. Mule spinners’ cancer offers a snapshot of industrial occupational health in an era without regulation. By highlighting the risk of occupational carcinogenesis, it laid a foundation for modern occupational dermatology, underscoring the need for legislation to limit preventable deaths. It is an example of how chronic inflammation and epidermal damage, combined with harmful environmental factors, can drive malignant transformation.