Inhibited Cell Growth and Asbestos Concentrations

Mesothelioma deaths among workers is a sadoccupational exposure were identified for ten who
part of this country's history.  However, there ishad been employed in the residential construction
some important research being done regardingindustry. One maintenance worker was exposed
asbestos and its complications.to asbestos in the household and another had
One interesting study is called, "Asbestos-inducedneighborhood exposure. For 9 (75%) of the
sister chromatid exchanges in cultured Chineseschool teachers, the only identifiable potential
hamster ovarian fibroblast cells." By Livingston GK,source of asbestos exposure was derived from
Rom WN, Morris MV. - J Environ Pathol Toxicol.in-place ACBM in schools. One teacher had spent a
1980 Sep;4(2-3):373-82.  Here is an excerpt:season in the merchant marine aboard an iron
"Abstract - Asbestos fibers were tested forore-hauling ship and 2 had worked in the residential
possible mutagenic activity using the Fluorescentconstruction industry. Two of the teachers were
Plus Giemsa (FPG) sister chromatid exchangesisters, and in two instances, two teachers had
(SCE) technique. Amosite, crocidolite, andtaught in the same school facility. We conclude
chrysotile fibers were added to cell cultures atthat individuals occupationally exposed to in-place
final concentrations of 10 and 100 micrograms/ml.ACBM are at risk for the subsequent
Chrysotile completely inhibited cell growth at bothdevelopment of mesothelioma."
concentrations; cells exposed to amosite andAnother interesting study is called, "Predictions of
crocidolite proliferated but only at the lowermortality from pleural mesothelioma in Italy: A
concentration. Crocidolite significantly elevated themodel based on asbestos consumption figures
SCE rate and larger (greater than 5 mu)supports results from age-period-cohort models" -
chromosomes were most sensitive. AmositeInternational Journal of Cancer - Volume 115,
appeared to have a lesser effect on SCEIssue 1, pages 142–147, 20 May 2005.  Here
frequency. Asbestos fibers are capable ofis an excerpt: "Abstract - Italy was the second
disturbing cellular processes associated withmain asbestos producer in Europe, after the
chromosomal stability and effects vary with theSoviet Union, until the end of the 1980s, and raw
asbestos type."asbestos was imported on a large scale until 1992.
Another interesting study is called, "MesotheliomaThe Italian pattern of asbestos consumption lags
among employees with likely contact with in-placeon average about 10 years behind the United
asbestos-containing building materials." ByStates, Australia, the United Kingdom and the
Anderson HA, Hanrahan LP, Schirmer J, Higgins D,Nordic countries. Measures to reduce exposure
Sarow P. - Ann N Y Acad Sci. 1991 Dec 31.  Herewere introduced in the mid-1970s in some
is an excerpt: "Abstract - The occurrence ofworkplaces. In 1986, limitations were imposed on
mesothelioma is a sentinel event in occupationalthe use of crocidolite and in 1992 asbestos was
and environmental disease. A mesotheliomadefinitively banned. We have used primary pleural
surveillance system was established utilizingcancer mortality figures (1970–1999) to
existing computerized Wisconsin vital statisticspredict mortality from mesothelioma among Italian
data maintained since 1959 and a Cancermen in the next 30 years by age-cohort-period
Reporting System (CRS) established in 1978.models and by a model based on asbestos
Review of the death certificate listing of usualconsumption figures. The pleural cancer
occupation and industry from 487 mesotheliomamesothelioma ratio and mesothelioma misdiagnosis
deaths in Wisconsin from 1959 to 1989 led to thein the past were taken into account in the
investigation of 41 persons with likely exposure toanalysis. Estimated risks of birth cohorts born
inplace asbestos-containing building materialsafter 1945 decrease less quickly in Italy than in
(ACBM): 12 school teachers, 10 schoolother Western countries. The findings predict a
maintenance employees, 7 public buildingpeak with about 800 mesothelioma annual deaths
maintenance workers, 5 private buildingin the period 2012–2024. Results estimated
maintenance workers, and 7 commercial andusing age-period-cohort models were similar to
factory workers performing maintenancethose obtained from the asbestos consumption
activities. For 10 (34%) of the 29 maintenancemodel."
workers the only source of asbestos exposure We all owe a debt of gratitude to these fine
identified was their maintenance work. For fiveresearchers for their important work.  If you
(17%) histories indicated some prior employmentfound any of these excerpts helpful, please read
in occupations and industries with probablethe studies in their entirety.
asbestos exposures. Opportunities for indirect