Giorgio Piolatto

An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy.

The mortality experience of a cohort of chrysotile miners employed since 1946 in Balangero, northern Italy was updated to the end of 1987 giving a total of 427 deaths out of 27,010 man-years at risk. A substantial excess mortality for all causes (standardised mortality ratio (SMR) = 149) was found, mainly because of high rates for some alcohol related deaths (hepatic cirrhosis, accidents). For mortality from cancer, however, the number of observed deaths (82) was close to that expected (76.2). The SMR was raised for oral cancer (SMR 231 based on six deaths), cancer of the larynx (SMR 267 based on eight deaths), and pleura (SMR 667 based on two deaths), although the excess only reached statistical significance for cancer of the larynx. Rates were not increased for lung, stomach, or any other type of cancer. No consistent association was seen with duration or cumulative dust exposure (fibre-years) for oral cancer, but the greatest risks for laryngeal and pleural cancer were in the highest category of duration and degree of exposure to fibres. Although part of the excess mortality from laryngeal cancer is probably attributable to high alcohol consumption in this group of workers, the data suggest that exposure to chrysotile asbestos (or to the fibre balangeroite that accounts for 0.2-0.5% of total mass in the mine) is associated with some, however moderate, excess risk of laryngeal cancer and pleural mesothelioma. The absence of excess mortality from lung cancer in this cohort is difficult to interpret.

The carcinogenic effect of aromatic amines: An epidemiological study on the role of o-toluidine and 4,4′-methylene bis (2-methylaniline) in inducing bladder cancer in man

Abstract Cause-specific mortality of 906 workers first employed 1922–1970 in a dyestuff factory in Northern Italy was compared to national figures: a marked excess of bladder cancer was observed (36 observed vs 1.23 expected deaths). The mean latent period was 25 years. The excess was higher among those with longer duration of exposure. Some excess of mortality from lung cancer, laryngeal cancer, and esophageal cancer was also found, but a clear explanation could not be provided regarding the causal role of aromatic amines. Mortality from bladder cancer was very much higher among those exposed in benzidine and naphthylamines manufacture as compared to those only exposed in use or intermittent contact. Excess bladder cancer was also very high among workers in fuchsin manufacture. There is evidence that o-toluidine and 4,4′-methylene bis(2-methylaniline) should be implicated in such excess mortality. Caution in handling these compounds is therefore suggested and the need for further studies to confirm such findings is stressed.

Bladder Cancer Mortality of Workers Exposed to Aromatic Amines: A 58-Year Follow-up

We previously investigated bladder cancer risk in a cohort of dyestuff workers who were heavily exposed to aromatic amines from 1922 through 1972. We updated the follow-up by 14 years (through 2003) for 590 exposed workers to include more than 30 years of follow-up since last exposure to aromatic amines. Expected numbers of deaths from bladder cancer and other causes were computed by use of national mortality rates from 1951 to 1980 and regional mortality rates subsequently. There were 394 deaths, compared with 262.7 expected (standardized mortality ratio = 1.50, 95% confidence interval = 1.36 to 1.66). Overall, 56 deaths from bladder cancer were observed, compared with 3.4 expected (standardized mortality ratio = 16.5, 95% confidence interval = 12.4 to 21.4). The standardized mortality ratio for bladder cancer increased with younger age at first exposure and increasing duration of exposure. Although the standardized mortality ratio for bladder cancer steadily decreased with time since exposure stopped, the absolute risk remained approximately constant at 3.5 deaths per 1000 man-years up to 29 years after exposure stopped. Excess risk was apparent 30 years or more after last exposure.

BLADDER CANCER MORTALITY OF WORKERS EXPOSED TO AROMATIC AMINES : AN UPDATED ANALYSIS

Bladder cancermortality ofa cohort ofdyestuff workers ata factory intheprovince ofTurin, Northern Italy, was followed up to1981, when41deaths frombladder cancerwere observed. Lessthanone hadbeenexpected (Decarli etal., 1985). Oneoftheopen questions inthatanalysis concerned thepattern ofrelative andabsolute excessriskafter stopping exposure,sincetheuse ofknowncarcinogenic aminesin dyestuff production was stopped in1972(Rubino etal., 1982). Thiswouldhaveimportant implications asregards our understanding oftheprocessofcarcinogensis byaromatic amines, particularly their potential impact on one ofthe latter stagesoftheprocess(promotion) (Day& Brown, 1980). A better knowledge oftheriskfollowing cessation of exposurewouldalsohaveclear public health relevance, since itcouldprovide indications foroptimising follow-up schemes forex-workers. Inthis analysis, we havethusadded8yearsoffollow-up tothesame cohort. Briefly, thedataset comprised allmen whohadbeenemployed since 1946, andhadworkedforat least Iyearinthefactory between 1922and1970. Forthe 906workers meeting these criteria, dateofbirth, ofemployment(s) andtermination ofemployment(s), thelastknown address, anddetailed jobparticulars including categories of exposuretoselected chemicals were abstracted fromthefactorys personnel records. Only38subjects werelost tofollowup.Further, 204workers notdirectly involved inexposureto aromatic amineswere excluded. Deathcertificates were obtained fromregistration offices inthemunicipality of death, andfurther verification ofvital status was obtained fromregistries ofcurrentresidence. Causesofdeath were codedaccording to theInternational Classification of Diseases (ICD). No further detail was available on tumour characteristics, or on potentially relevant covariates, suchas smoking. Further details on exposure classification and follow-up aregiven inDecarli etal.(1985). Forthepresent report, follow-up was updated toDecember 1989, fora total numberof271deaths among 664exposed subjects (49from