Mortality among shipyard workers in Genoa, Italy

Our plain-English summary of Mortality among shipyard workers in Genoa, Italy, by R. Puntoni, M. Vercelli, F. Merlo, et al (Annals of the New York Academy of Sciences, 1979).

The study

• Authors: R. Puntoni, M. Vercelli, F. Merlo, F. Valerio, L. Santi
• Journal: Annals of the New York Academy of Sciences
• Published: 1979;330:353-77
• Cited by: 62 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001044).

Abstract

The dockyards of Genoa are exposed to many known or suspect carcinogenic agents, namely, asbestos, silica, polycyclic aromatic hydrocarbons, and halogenated hydrocarbons; other possibly harmful substances are trace amounts of aromatic amines, welding smokes, paints, and lipid-removing solvents. A cohort study of causes of death of 2190 dockyard workers in Genoa was conducted between January 1, 1960 and December 31, 1975. Mortality rates were calculated for 20 different occupational categories, for which there exist different levels of exposure to noxious substances. Two control groups were selected: the general male population of Genoa and all male employees (462) of San Martino Hospital, Genoa for the same period of time. Causes of death that demonstrated significant excesses for both control groups were: cancer of the colon, excluding the rectum; cancer of the larynx; cancer of the lung, bronchus, and trachea; cancer of the kidney, urinary bladder, and other urinary organs; respiratory diseases; and cirrhosis of the liver. The data obtained from these 20 job categories revealed different types and levels of risk for various carcinogenic agents.

In plain English

This cohort study followed 2190 men who repaired, refitted and built ships at the port of Genoa, Italy, from January 1, 1960 to December 31, 1975. Deaths were compared with those expected from Genoa's male population and from San Martino Hospital's male staff. The workers were exposed to asbestos, silica, hydrocarbons, solvents and welding smoke. There were 1070 deaths against 853.74 expected from Genoa rates (relative risk 1.25). Cancer of the lung, bronchus and trachea caused 123 deaths against 54.86 expected (relative risk 2.24; 3.62 against hospital rates). Significant excesses against both comparison groups were also reported for cancers of the colon, larynx, and kidney and urinary organs, and for respiratory diseases and liver cirrhosis. Among insulation workers, 5 lung cancer deaths occurred against 0.94 expected. The authors called asbestos exposure the most important environmental stimulus for cancer of the trachea, bronchus and lung. They also noted a possible combined effect of polycyclic hydrocarbons and cigarette smoking. They stated that their results demonstrated the laryngeal cancer excess resulted from silica dust. They added that excess deaths are not easy to attribute to specific substances.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Cohort mortality study comparing observed deaths with deaths expected from two comparison groups
• Who was studied: 2190 men (counted in 1960) of the Industrial Branch of the Consorzio del Porto of Genoa, Italy, in 20 job categories. They were followed from January 1, 1960 to December 31, 1975, giving 34,746 person-years and 1070 deaths. The comparison groups were the general male population of Genoa and the male staff of San Martino Hospital (462 men in 1960, 171 deaths).
• Exposure: Asbestos from ship refitting and insulation, without appropriate protection. No fiber type is named. Exposure was heavy during 1949-60, when ocean liners were refitted. Asbestos sources included valve insulation, Marinite panels (wood and asbestos), insulating panels on passenger liners and insulated cold storage bins. Workers were also exposed to silica and silicate dusts, polycyclic aromatic hydrocarbons, halogenated hydrocarbons, solvents (benzene, carbon tetrachloride), welding smoke and paints containing chromium, lead and arsenic. Exposure varied by job category.
• Main results:
  • All dockyard workers, total deaths: 1070 observed against 853.74 expected from Genoa male population rates (relative risk 1.25, p less than 0.0005).
  • All dockyard workers, cancer of the lung, bronchus and trachea: 123 deaths observed against 54.86 expected from Genoa male population rates (relative risk 2.24). Against San Martino Hospital staff rates, the relative risk was 3.62.
  • Causes of death with significant excesses against both comparison groups were: total deaths, all cancers, and cancers of the colon (excluding rectum), larynx, lung/bronchus/trachea, and kidney, urinary bladder and other urinary organs. Respiratory diseases, ictus and senility, liver cirrhosis and all other causes also showed significant excesses. Against Genoa rates: colon 26 observed against 14.38 expected (relative risk 1.81); larynx 15 against 7.67 (1.96); kidney and urinary organs 29 against 14.65 (1.98); respiratory diseases 148 against 97.41 (1.52); liver cirrhosis 50 against 23.17 (2.16).
  • Insulation workers (41 members in 1960, 693 person-years), cancer of the lung, bronchus and trachea: 5 deaths observed against 0.94 expected from Genoa rates (relative risk 5.31) and 0.58 expected from hospital staff rates (relative risk 8.62). Significance levels for this table are not legible in the text.
• The authors' conclusion: The authors concluded that excess deaths are not easy to attribute to specific carcinogenic substances. They stated that asbestos exposure is considered the most important environmental stimulus for the induction of cancer of the trachea, bronchus and lung, and that it may be partly responsible for excess colon cancer. They cautioned against underestimating a possible synergistic relationship between polycyclic hydrocarbons and cigarette smoking. They stated that their results demonstrated that excess laryngeal cancer results from silica dust exposure. They said their analysis located the most seriously affected work areas and job classifications, and that their data led to regulations on asbestos use by dockyard workers in Italy.
• Limitations the authors state:
  • Exposures overlap across job categories because workers share the same spaces, which makes the job-category results hard to interpret.
  • Excess death rates are not easy to attribute to specific carcinogenic substances.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Shipyards and maritime work.

Medical terms in this study, explained in our Lexicon: Carcinogenic, Cohort Study, Laryngeal Cancer, Bronchus.

Related studies

• A historical cohort mortality study among shipyard workers in Genoa, Italy — R. Puntoni, F. Merlo, et al. (2001)
• Mortality among workers exposed to asbestos at the shipyard of Genoa, Italy: a 55 years follow-up — D.F. Merlo, M. Bruzzone, et al. (2018)
• Mortality among dock-yard workers in Genoa, Italy — R. Puntoni, L. Russo, et al. (1977)
• Mortality among shipyard Coast Guard workers: a retrospective cohort study — S. Krstev, P. Stewart, et al. (2007)
• Incidence of bronchial carcinoma in shipyard workers with pleural plaques — J.R. Edge (1979)
• Prevalence of radiographic abnormalities among Northern California shipyard workers — P.L. Polakoff, B.R. Horn, et al. (1979)

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