[EVALUATION OF THE CARCINOGENIC RISK OF LEAD IN THE COHORT STUDY OF MALE WORKERS OCCUPATIONALLY EXPOSED TO INORGANIC LEAD IN 27 MOSCOW PRINTING-HOUSES].

As millions of people worldwide are expoed to inorganic lead, both in the workplace and in general environment, its potential carcinogenicity is an important health problem. Although lead has been shown to be carcinogenic in laboratory animals, epidemiological studies have been inconclusive, and the relationship between lead and human cancer is still unclear. There were several limitations that complicated the analysis and evaluation of the carcinogenic potential of lead compounds. In particular, many of the cohort studies of lead and cancer, mostly among heavily lead-exposed workers, have been limited by a failure to identify and control for covariates, especially co-exposures to other metals such as arsenic, cadmium, and chromium, which have been shown to be carcinogenic. Most of the epidemiological studies unfortunately do not have data on dose-response. The scientific merit of our study is the virtual absence of confounding by other known carcinogens. Another advantage of our study is the presence of three occupational sub-cohorts with different levels and routes of lead exposure. Most previous studies have data on dose-response provided only by comparisons of exposed to unexposed persons. In summary, the results of this cohort study suggest that occupational exposure to lead may increase the risk of cancers of the pancreas, kidney and rectum. In conclusion, despite several limitations, the results of our study add to the evidence that carcinogenicity to humans may be an additional adverse health effect of lead.

Cancer mortality among women in the Russian printing industry.

BACKGROUND: This study evaluates cancer mortality among women employed in two large printing plants in Moscow. METHODS: A total of 3,473 women who were actively employed as of December 31, 1978, with a minimum of 2 years employment were followed from 1 January 1979 to 31 December 1993. There were 47,791 person-years observed, with only 51 women lost to follow-up (1.5%). Standardized mortality ratios (SMRs) were calculated using the population of Moscow to generate expected numbers. Analyses by job (compositors, press operators, and bookbinders), age hired, latency, and duration of employment were conducted. RESULTS: Among women employed in the two printing plants, there was a significant excess of esophageal cancer, based on seven deaths (expected = 2.7, SMR = 2.7, 95% CI = 1.1-5.4). Four of the seven esophageal cancer deaths occurred among bookbinders (expected = 1.0, SMR = 4.1, 95% CI = 1.1-10.4), all among workers hired before 1957 (expected = 0.6, SMR = 7.1, 95% CI = 1.9-18.3), the last year benzene was used in bookbinding. Ovarian cancer was also significantly elevated among bookbinders (12 observed, 4.2 expected, SMR = 2.9, 95% CI = 1.5-5.0), which, along with one death from mesothelioma of the abdomen, might be related to the use of asbestos-contaminated talc fillers in paper. Press operators had significantly elevated mortality from stomach cancer (observed = 9, expected = 4.1, SMR = 2.2, 95% CI = 1.0-4.2) and, based on two deaths each, melanoma and bladder cancer. CONCLUSIONS: Women in this printing industry cohort experienced excess mortality of cancer of the esophagus and stomach, with suggested increases of melanoma and bladder cancer. Further follow-up of this cohort, which would allow more in-depth analysis of rare cancer sites, latency, and duration of employment, is warranted. Gender comparisons within the cohort should also be conducted to clarify the role of occupational and lifestyle factors in the etiology of cancer among workers in the printing industry.

Cancer incidence and mortality in a cohort of chloroprene workers from Armenia.

We evaluated the risk of cancer among 1897 men and 417 women exposed to chloroprene (2-chloro-1,3-butadiene, CP) at a production plant in Yerevan, Armenia, between 1940 and 1988. The cohort was followed up for cancer incidence for the years 1979-1990 and for cancer mortality for 1979-1988. In the cohort, incidence and mortality from all cancers were below expectation, but increased incidence (standardized incidence ratio 3.27, 95% confidence interval [CI] 1.47-7.27), and mortality (standardized mortality ratio 3.39, 95% CI 1.09-10.5) from liver cancer were noticed. A dose-response relationship was suggested between liver cancer and indices of CP exposure, such as duration of employment, duration of high CP exposure and cumulative exposure to CP. The risk of other neoplasms was not increased.