Andy Watterson is Professor Emeritus at the University of Stirling, his guest blog looks at occupational disease in Scotland’s tyre manufacturing industry, the connection to bladder cancer and why we know so little about the extent of exposure to occupational disease in tyre workers in Scotland.
Scotland has a long history of invention and innovation in the rubber tyre industry dating back to the 19th Century and the work of Robert William Thompson and John Dunlop. We need tyres for personal and public travel and transport of goods although this will produce tyre wear particles that pollute our environment. We also must address what we do with end of life tyres. If possible, we try to recycle and re-use them. Grinding them up for crumb rubber on sports pitches and playgrounds is not an environmentally sustainable or safe practice nor is incinerating them in India and damaging public and environmental health there. Following through the life cycle of products and the consequences of exposures for worker health should always be built into occupational risk assessments. Historically this has been missing. Standards have been weak and often poorly regulated as well as low levels of enforcement in the rubber industry as well as tyre manufacture and recent exposure to carcinogens may still present a risk to ex-workers.
The focus here is on who made car tyres in the now closed Scottish factories, who was exposed to hazardous substances in the manufacturing process, how might workers have been affected and what can or should be done about it now. Scotland had a Goodyear tyre plant in Drumchapel between 1956 and 1979, a Michelin tyre plant in the Dundee area from 1972 to 2020 and the India tyre plant from 1927 (a Dunlop subsidiary since 1930) at Inchinnan in Renfrew that closed in the early 1980s. The Glasgow Rubber Works/McLellan Rubber Works Factory also operated until the 1990s and made many rubber products.
Retired workers from all these plants may still be at risk from occupational diseases following past work exposure of less than a decade and because of exceptionally long disease latency periods. Tyre production at various stages and times has involved using hazardous chemicals in reinforcing agents, activators, fillers, oils, waxes resins, plasticisers, accelerators, retarders, anti-degradants, blowing agents and solvents (Nutt 1984). Tyre workers may have been involved in milling, curing, extruding, calendaring, assembly, inspection, storage and dispatch operations with different exposures to chemicals and different impacts.
Some industries, especially those making dyestuffs with chemicals like beta-naphthylamine and benzidine, later used in the rubber industry, were found to have contracted occupational bladder cancer in the late 19th and early 20th centuries. By 1921 the International Labour Organisation confirmed these two carcinogenic chemicals were active agents in the rubber industry (Nutt 1984). In the UK, however, it was not until a 1949 study published in 1954 that reliable, and more widely accepted, reports of bladder cancer in the rubber industry appeared (Case and Hosker 1954).
Since that time, a much larger list of bladder carcinogens has emerged. In 1967 the UK Carcinogenic Substances Regulations listed a range of bladder carcinogens used in the rubber industry that were controlled including ortho-tolidine, or prohibited like beta-naphthylamine, benzidine , 4-amino-dipenyl, 4-nitrodipheyl and their salts (Kinnersly 1971). In 1982, the World Health Organization’s International Agency for Research on Cancer was able to state categorically that ‘occupational exposures in the rubber-manufacturing industry are carcinogenic to humans Group1’ (IARC 1982). In 1998, a review of cancer risk in the rubber industry found widespread moderately increased risks among rubber workers, with the most consistent results highlighting risk of bladder cancer (Kogevinas et al 1998).
In the UK, in what is undoubtedly a complex field of occupational disease research (epidemiology), some researchers and regulators considered the risks of getting bladder cancer in the tyre industry had all but vanished by the late 1940s with the removal of beta-naphthylamine from the workplace. In 2004 a study reported the elevated risk of bladder cancer in rubber processing workers, found between 1946 and 1995, had reversed when the carcinogen beta-naphthylamine present in antioxidants was removed from processing in October 1949 (Veys et al 2004).
However, in 2008 bladder cancer was still being reported in workers manufacturing chemicals for rubber industry use and a UK researcher explicitly concluded, “ exposure to ortho-toluidine appears to be responsible for part of this excess (Sorahan 2008). Ortho-Toluidine (o-Toluidine) is an aromatic amine used primarily in the manufacture of dyestuffs, in the production of synthetic rubber, chemicals and pesticides, and as a curing agent for epoxy resin systems.
It was exactly this chemical, not to be confused with ortho-tolidine, that US researchers and lawyers found had caused bladder cancer in Dupont chemical workers and in Goodyear tyre workers throughout the 2000s (Morris 2024). By 1992, eighteen Goodyear New York tyre workers had developed bladder cancer and several workers from 1950s onwards had bladder cancer and reported cases to OCAW by 1981. From 1957 the Goodyear workers had been exposed to ortho-toluidine supplied by Dupont and by 2013, there were 58 cases at Goodyear Niagara Falls’ plant. US studies still found elevated bladder cancer risks in a rubber chemical manufacturing plant department in 2015 that researchers linked strongly to o-toluidine exposure although aniline and nitrobenzene were also used to synthesise rubber accelerators and antioxidants (Carreón et al 2015). US milling workers, calender operatives and final inspection workers historically had had higher bladder cancer rates than other workers.
Significantly in 2018, N-nitrosamines exposures in UK rubber workers employed in 1967 and followed up to 2015 were associated with bladder cancer mortality (Hidajat et al 2018). Yet again the UK regulators, despite the above evidence, continued to state on their web site in 2025 that “Historically there used to be an excess of bladder cancer in rubber industry workers. This was associated with the antioxidant beta-naphthylamine, which was banned in the 1950s. There has also been links to rubber dust and fume exposures and stomach and lung cancers in the past. However, more recent studies have shown increased risks to cancers are no longer present in the rubber industry” (HSE 2025).
The conundrum, bearing in mind the scientific studies available into the 2010s and 2020s, is this? Why have retired European rubber tyre workers including Scottish workers, Goodyear tyre workers in Amiens, France and other rubber workers( known to use many but not necessarily all the chemicals that caused bladder cancer in the American Goodyear tyre plants) apparently not contracted this occupational disease (Watterson 2025)? Did the Scottish plants not use any of the US bladder carcinogens in similar ways and in the same formulations? Were the technologies, processes, control measures and working conditions in the Goodyear Glasgow or French tyre plants for instance much superior to the US rubber plants? It seems unlikely.
We now have reports from ex-workers in the India Tyre Factory in East Renfrew that working conditions in part of their plant before it closed were challenging with high exposures to dust and fumes and poor housekeeping. Then we find many cases of bladder cancer resulting in legal claims were brought for example by Goodyear tyre plant workers in the 2010s in both England and France. There have also been at least a few civil cases in Scotland. In 2016 A senior coroner connected the death of a former worker at Goodyear’s Wolverhampton tyre factory in England to years of employment in tyre production and exposure to carcinogens at work over 42 years (Tyre Press 2016). None of these civil cases succeeded, often because it was argued lifestyle factors including smoking or passive smoking trumped considerations of workplace causes of bladder cancer. Smoking could alternatively of course be considered a contributory, and not a confounding factor in occupational disease recognition.
Another explanation could be that the UK legal systems, civil and statutory, differed from those in the US and levels of proof needed to establish diseases were occupationally caused also differed. What we do know is that in the UK the state industrial injuries benefit system (IIDB) that compensates workers and the mechanisms to assess whether diseases are occupational or not through the Industrial Injuries Advisory Council (IIAC) has failed (Watterson and O’Neill 2015). Double the relative risk is often needed in epidemiological studies before a UK occupational disease will be recognised by IIAC, listed by IIDB and state claims settled. This level of proof is higher than in several other countries that recognise both more occupational diseases and compensate more cases. The UK process is over-medicalised and excessively slow. For example, in 2015 when the UK and French Goodyear civil claims were appearing, only 30 IIDB occupational bladder cancer cases covering all causes, not necessarily in the rubber industry were compensated in GB. Yet HSE at that time estimated 550 people develop occupational bladder cancer each year. For bladder cancer, HSE listed just eight jobs or exposures which might lead to the disease and IIAC only two (IIAC 2014).
The Scottish government recently had great opportunities to establish its own IIAC, with its own list of occupational diseases in line with available international lists, but to date has not done so. It appears happy to continue to follow the failed UK system and, hence, denies justice to those workers affected. In Scotland and elsewhere in the UK, significant under-reporting of occupational diseases is evident, along with major regulatory deficits on workplace inspections as well as enforcement relating to cancer prevention and toxics use reduction (Hazards 2021 onwards, Watterson et al 2008; Watterson et al 2021). Other workplace chemicals in different industries and occupations are known to cause bladder cancer, as well as chemicals outwith the workplace. Exposure to diesel may cause such tumours, hence taxi and bus drivers may be at increased risk as could hairdressers because of being exposed to a wide range of dyes. Manufacturing jobs involving dyes; textiles; rubbers; paints; plastics; leather tanning are also at higher risk, as are firefighters. Improving listing, recognition and compensation for all occupational bladder cancers is therefore urgently needed.
Unite and GMB unions in contrast have actively raised the issue of occupational bladder cancer with their members and continue campaigning for stricter controls of chemical exposures in rubber plants. History has shown us that, in addition to researchers, sometimes workers and their unions have identified bladder cancer risks in a variety of industries. However, actions to safeguard those workers still often lagged well behind the disease dates of knowledge (Watterson 1993; Michaels 1995).
Unions have flagged the wider deterioration in the structures set up by the UK Government to monitor health and safety of tyre production workers. This includes the decline of the tripartite industrial advisory committee structure, creating further barriers to investigation of this issue. In 2019 Unite highlighted the fact that HSE previously had a tripartite body, the Tyre and Rubber Industries Safety Action Group (TRISAG) which allowed for safety concerns to be raised and dealt with (Unite 2019). However, TRISAG was scrapped due to government pressure and the ideological attack on our health and safety system we have witnessed since 2010.
No similar body replaced its work, exactly at a time when research indicated bladder cancer risks due to n-nitrosamine exposure, for example, were elevated in the rubber industry. The GMB has promoted general awareness campaigns linking bladder cancer to workplace exposures ( GMB 2019, Fight Bladder Cancer 2024).
Sadly, it appears there was no contact between the US Oil, Chemical and Atomic Workers Union (OCAW), and unions elsewhere in the world who organised rubber tyre factories, at a time when OCAW had successfully obtained US settlements out of court for Dupont chemical and Goodyear tyre workers with bladder cancer.
In Scotland, we are left with two possibilities to explain the apparent absence of occupational bladder cancer and other occupational diseases in retired workers. Either such cases do not exist or, much more likely and consistent with under-estimates of the disease made by HSE, they have not been recorded, reported and remain uncompensated.
Scotland should do much better on occupational cancer and the wider issue of toxics use reduction in workplaces today. It should also commit to setting up a Scottish Employment Injuries Advisory Council, prescribing occupational diseases affecting Scottish workers based on the Council’s own research as well as evidence from countries across the world.
Note: “If you, a member of your family or know of anyone who worked in tyre manufacture in Scotland, and have had a diagnosis with bladder cancer, please contact Ian Tasker, Scottish Hazards CEO at CEO@hazards.scot”
References
Carreón T, Hein MJ, Hanley KW, Viet SM, Ruder AM (2014) Bladder cancer incidence among workers exposed to o-toluidine, aniline and nitrobenzene at a rubber chemical manufacturing plant. Occup Environ Med. Mar;71(3):175-82. doi: 10.1136/oemed-2013-101873
Case RE and Hosker ME (1954) Tumour of the urinary bladder as an occupational disease in the rubber industry in England and Wales. Br J Prev Soc Med. 1954 Apr;8(2):39-50. doi: 10.1136/jech.8.2.39.
Chamot S, Delzard M, Leroy L et al (2023) Occupational exposures in the rubber tire industry and risk of cancer: a systematic review. International Archives of Occupational and Environmental Health, 2023, ff10.1007/s00420-023-01972-xff. ffhal-04083787f
Fight bladder cancer (2024) Fight Bladder Cancer at GMB Congress 2024 https://www.fightbladdercancer.co.uk/blog/fight-bladder-cancer-gmb-congress-2024/
GMB (2019) GMB to launch awareness campaign on link between workplaces and bladder cancer. https://www.gmblondon.org.uk/news/gmb-campaign-on-link-between-workplaces-and-bladder-cancer
Hazards (2021) Safety enforcement collapses – record numbers harmed at work. https://www.hazards.org/wmd/nosaviour.htm#:~:text=Preventive%20Health%20and%20Safety%20Executive,anything%20to%20fear%2C%20it’s%20you.
Hidajat M, McElvenny DM, Ritchie P et al (2018) Lifetime exposure to rubber dusts, fumes and N-nitrosamines and cancer mortality in a cohort of British rubber workers with 49 years follow-up. Occup Environ Med. 2019 Apr;76(4):250-258. doi: 10.1136/oemed-2018-105181. Epub 2019
HSE (nd) RUBIAC statement on occupational cancers https://www.hse.gov.uk/rubber/cancerstatement.htm#:~:text=Epidemiological%20studies%20carried%20out%20by,the%20removal%20of%20the%20contaminated
HSE (2025) Frequently asked questions: rubber dust and fumes. 29 January 2025 https://www.hse.gov.uk/rubber/faqs.htm
Industrial Injuries Advisory Committee (2014) Bladder cancer in hairdressers, barbers and textile workers https://assets.publishing.service.gov.uk/media/5a7edff240f0b6230268c16a/bladder-cancer-dyes-iiac-pp-31.pdf
International Agency for Research on Cancer [IARC] (1982). Monographs on the evaluation of the carcinogenic risk of chemicals to humans. Volume 28; the rubber industry. Lyons, France.
Kinnersly P (1971) The Hazards of Work. Pluto Press, London
Kogevinas M, Sala M, Boffetta P, Kazerouni N, Kromhout H, Hoar-Zahm S (1998). Cancer risk in the rubber industry: a review of the recent epidemiological evidence. Occup Environ Med. Jan;55(1):1-12. doi: 10.1136/oem.55.1.1
Michaels D (1995) When Science Isn’t Enough: Wilhelm Hueper, Robert A. M. Case, and the Limits of Scientific Evidence in Preventing Occupational Bladder Cancer. Int J Occup Environ Health. Jul;1(3):278-288. doi: 10.1179/oeh.1995.
Nutt AR ( 1984) Toxic Hazards of Rubber Chemicals . Elsevier Applied Science Publications. London
Sorahan T (2008) Bladder cancer risks in workers manufacturing chemicals for the rubber industry. Occup Med (Lond). 2008 Oct;58(7):496-501. doi: 10.1093/occmed/kqn104. https://pubmed.ncbi.nlm.nih.gov/18725381/
Tyre Press (2016) Coroner suggests worker’s death connected to tyre manufacturing work at Goodyear. https://www.tyrepress.com/2016/06/coroner-suggests-workers-death-connected-to-tyre-manufacturing-work-at-goodyear/
Unite (2019) Tyre and rubber industry hamstrung on new research into health threats due to government cuts, warns Unite. https://www.unitetheunion.org/news-events/news/2019/april/tyre-and-rubber-industry-hamstrung-on-new-research-into-health-threats-due-to-government-cuts-warns-unite
Veys CA (2004) Bladder tumours in rubber workers: a factory study 1946-1995. Occup Med (Lond). Aug;54(5):322-9. doi: 10.1093/occmed/kqh010. PMID: 15289589
Watterson A (1993) ‘Occupational Health in the UK Gas Industry’. in Platt S., Thomas H., Scott S. and Williams G. in Locating Health. Avebury Press. London, pp172-194
Watterson A, Gorman T, O’Neill R (2008) Occupational cancer prevention in Scotland: a missing public health priority. Eur.J.Oncol., vol. 13 (3): 161-169.
Watterson A and O’Neill R (2015) Double trouble on relative risk for occupational diseases. Hazards Magazine, March https://www.hazards.org/compensation/meantest.htm
Watterson A, Tasker I, Palmer H, Jenkins K (2021) Toxics Use Reduction: beyond analysis to action Linking public health, occupational health and safety, environmental sustainability and new or better employment: a position paper. January 2021 DOI: 10.13140/RG.2.2.12814.59204. Report number: 30. University of Stirling, Stirling, Scotland.
Watterson A (2025) Review of The Cancer Factory: industrial chemicals, corporate deception and the hidden deaths of American Workers, by Jim Morris. Beacon Press, , January 23, 2024, 264pp., ISBN: 9780807059142 (ISBN10: 0807059145. British Journal of Industrial Relations First published: 15 January 2025 https://doi.org/10.1111/bjir.12873
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