John Corbett McDonald

John Corbett McDonald (Avatar)

1918-2016

Vol XII

Web

John Corbett McDonald

1918-2016

Vol XII

Web

b.20 April 1918 d.25 April 2016

MRCS LRCP(1942) MB BS Lond(1947) MD(1949) DPH(1949) DIH(1950) MSc Harvard(1951) MRCP(1964) FRCPC(1970) FRCP(1976) FFCM(1976) FFOM(1978) FFPHM

John Corbett McDonald (‘Corbett’) was one of the leading epidemiologists of his generation, best known for his definitive studies of asbestos workers in Quebec and North America.

Corbett was born in Belfast, the son of John Forbes McDonald, a civil servant. He obtained his medical qualification during the Second World War from St Mary’s Hospital, London, playing hooker for a Mary’s rugby team, which included a number of international players, that beat the All Blacks in 1938.

After serving as an officer in the Royal Army Medical Corps, he returned to St Mary’s, where he worked for Sir Alexander Fleming [Munk’s Roll, Vol.V, p.132]. He studied epidemiology at the London School of Hygiene and Tropical Medicine and spent two years at Harvard University on a Rockefeller fellowship, where he co-authored an important paper on the nature and hazards of air pollution, published immediately prior to the London smog in 1952 (‘The epidemiology and social significance of atmospheric smoke pollution’ Am J Med Sci. 1951 Mar;221[3]:325-42). He joined the Public Health Service in Colindale in 1951 and was head of the epidemiological research laboratory from 1960 to 1964, working on the epidemiology of viral infections, particularly influenza.

He was recruited to McGill University, Montreal in 1964, where he remained until 1976, as the first chair of the department of epidemiology and health (later the department of epidemiology and biostatistics). He recruited a multidisciplinary team, which was to become internationally renowned.

In 1964, he attended the New York Academy of Sciences conference on the biological effects of asbestos, which recommended that research was needed into whether the risks to health posed by the different types of asbestos fibres – chrysotile and the amphiboles, particularly crocidolite and amosite asbestos – differed. Working in Montreal, Corbett recognised the opportunity to address the question of the risks of exposure to chrysotile asbestos, through study of the miners and millers in the Quebec chrysotile mines. These had opened in 1879, the first step towards the extraction of ‘Canada’s gold’. Over the succeeding decades, Corbett reported his findings in a series of publications, comparing his findings in Quebec miners with other workforces engaged in the manufacture and use of asbestos products, in particular asbestos workers in a South Carolina textile factory, which exclusively used asbestos mined in Quebec. He showed that while the risk of lung cancer was increased in Quebec miners who had been heavily exposed to chrysotile; the risk to workers in the South Carolina textile factory was some 50 times greater than the risk in Quebec miners at similar cumulative levels of exposure. This remarkable observation was confirmed by others, but never wholly explained.

He also undertook extensive research into mesothelioma, showing that the risk in those working with crocidolite and amosite was increased as compared to those exposed to chrysotile. He later showed the risk of mesothelioma, and also lung cancer, in Quebec miners was directly related to the level of contamination by the amphibole tremolite in the different chrysotile mines in Asbestos and Thetford, Quebec. He confirmed the capacity of tremolite to cause mesothelioma by showing a similar risk of mesothelioma in miners of vermiculite, also contaminated by tremolite, in Libby, Montana.

These seminal contributions to understanding that the risks of asbestos exposure differed in relation to different fibre types and in different circumstances of occupational exposure were marred by allegations over his probity, raised by those who wished to discredit his research findings, in particular that the risks of mesothelioma differed between different fibre types, chrysotile and amphibole asbestos, on the basis that his research, particularly in the early years, was funded at least in part by industry.

Corbett was meticulous in his research and his observations have since been reproduced by other independent research groups. In addition, an enquiry by the research integrity officer at McGill concluded that ‘…there is no evidence that the design of the research, its conduct and its reporting was influenced by the industry’ and there was no evidence his research ‘…was influenced or undermined by the sources of funds’. His asbestos research findings remain a testament to the high quality of his science, his courage and persistence in the face of loud opposition by interested parties.

He returned to London between 1976 and 1981 to lead the TUC Centenary Institute of Occupational Health at the London School of Hygiene and Tropical Medicine (LSHTM), returning to McGill in 1981, before coming back in 1990 to chair the department of clinical epidemiology at the National Heart and Lung Institute (NHLI) in London.

While at LSHTM, he inspired a generation of respiratory physicians who attended his MSc course to undertake epidemiological studies investigating the causes and determinants of occupational lung diseases, in particular occupational asthma. These respiratory physicians later became the bedrock of the surveillance scheme for occupational lung disease (surveillance of work-related and occupational respiratory disease, SWORD), which he initiated while at NHLI, developed and led for over a decade. This surveillance scheme provided, and continues to provide, information which informs the priorities for prevention of occupational lung diseases by the UK’s Health and Safety Executive.

In the 1990s he introduced training courses in epidemiology for physicians in Bangladesh, and collaborated with them in a number of investigations into the risks to community health of arsenic, which contaminated drinking wells, on cancer rates and the outcomes of pregnancy.

Corbett was an international leader in the outstanding generation of epidemiologists in the UK which followed the Second World War. His seminal contributions to our knowledge of the risks of asbestos have been confirmed and inform policy to prevent asbestos-related disease worldwide. Bruce Case, who worked as a pathologist with Corbett at McGill, recalled asking Sir Richard Doll [Munk’s Roll, Vol.XII, web], the first to demonstrate conclusively the link between asbestos and lung cancer, who had made the greatest contribution to knowledge of asbestos and disease, Doll replied, ‘You mean besides Corbett McDonald?’ He died in 2016, aged 98. Predeceased by his wife, Alison Dunstan McDonald née Wells, he was survived by his son and three daughters.

Sir Anthony Newman Taylor

[Occupational Medicine Vol.68 Issue 1 January 2018 p.45 https://academic.oup.com/occmed/article/68/1/45/4866334 – accessed 30 April 2019; BMJ 2016 353 3161 www.bmj.com/content/353/bmj.i3161 – accessed 30 April 2019]