Biomaterial Database

The risk of mesothelioma from exposure to chrysotile asbestos. 2007

Charles M Yarborough

Department of Medicine, University Medical Center at Princeton, Princeton, New Jersey, USA.

OBJECTIVE This review assesses the risk of developing diffuse malignant mesothelioma of the pleura from exposures to chrysotile fibers and contrasts it with the known risk of amphibole asbestos. RESULTS Although a rare cancer, the mortality rates of pleural mesothelioma continue to be significantly elevated because of past occupational exposures to airborne asbestos fibers. New analyses of occupational epidemiologic studies for highly exposed workers show a substantially lower potency and suggest an empiric threshold for chrysotile compared with amphibole asbestos. Important kinetic and pathological differences between chrysotile and amphiboles have been substantiated that support chrysotile's impotency in causing pleural mesothelioma. CONCLUSIONS Excess risk of pleural mesothelioma from past exposures to asbestos, as evidenced by a trend of high incidence rates during the last half century, appears to be the result of nonchrysotile asbestiform fibers. Although scientific efforts and legal arguments continue, the risk of pleural mesothelioma in human populations is probably negligible for exposures to airborne chrysotile asbestos that is not known to be contaminated by amphibole. This distinction for asbestos fiber types is pivotal for understanding hazards and characterizing risks of continued use of natural chrysotile asbestos today and also new nanofibers.

UI	MeSH Term	Description	Entries
D008654	Mesothelioma	A tumor derived from mesothelial tissue (peritoneum, pleura, pericardium). It appears as broad sheets of cells, with some regions containing spindle-shaped, sarcoma-like cells and other regions showing adenomatous patterns. Pleural mesotheliomas have been linked to exposure to asbestos. (Dorland, 27th ed)	Mesotheliomas
D009784	Occupational Diseases	Diseases caused by factors involved in one's employment.	Diseases, Occupational,Occupational Illnesses,Disease, Occupational,Illnesse, Occupational,Illnesses, Occupational,Occupational Disease,Occupational Illnesse
D010997	Pleural Neoplasms	Neoplasms of the thin serous membrane that envelopes the lungs and lines the thoracic cavity. Pleural neoplasms are exceedingly rare and are usually not diagnosed until they are advanced because in the early stages they produce no symptoms.	Neoplasms, Pleural,Neoplasm, Pleural,Pleural Neoplasm
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D012307	Risk Factors	An aspect of personal behavior or lifestyle, environmental exposure, inborn or inherited characteristic, which, based on epidemiological evidence, is known to be associated with a health-related condition considered important to prevent.	Health Correlates,Risk Factor Scores,Risk Scores,Social Risk Factors,Population at Risk,Populations at Risk,Correlates, Health,Factor, Risk,Factor, Social Risk,Factors, Social Risk,Risk Factor,Risk Factor Score,Risk Factor, Social,Risk Factors, Social,Risk Score,Score, Risk,Score, Risk Factor,Social Risk Factor
D014943	Global Health	A multi- and interdisciplinary field concerned with improving health and achieving equity in health for all people. It transcends national boundaries, promotes cooperation and collaboration within and beyond health science fields, and combines population-based disease prevention with individually-based patient care.	International Health Problems,World Health,International Health,Worldwide Health,Health Problem, International,Health Problems, International,Health, Global,Health, International,Health, World,Health, Worldwide,Healths, International,International Health Problem,International Healths,Problem, International Health,Problems, International Health
D015994	Incidence	The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases in the population at a given time.	Attack Rate,Cumulative Incidence,Incidence Proportion,Incidence Rate,Person-time Rate,Secondary Attack Rate,Attack Rate, Secondary,Attack Rates,Cumulative Incidences,Incidence Proportions,Incidence Rates,Incidence, Cumulative,Incidences,Person time Rate,Person-time Rates,Proportion, Incidence,Rate, Attack,Rate, Incidence,Rate, Person-time,Rate, Secondary Attack,Secondary Attack Rates
D015996	Survival Rate	The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.	Cumulative Survival Rate,Mean Survival Time,Cumulative Survival Rates,Mean Survival Times,Rate, Cumulative Survival,Rate, Survival,Rates, Cumulative Survival,Rates, Survival,Survival Rate, Cumulative,Survival Rates,Survival Rates, Cumulative,Survival Time, Mean,Survival Times, Mean,Time, Mean Survival,Times, Mean Survival
D016273	Occupational Exposure	The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.	Exposure, Occupational,Exposures, Occupational,Occupational Exposures
D017632	Asbestos, Serpentine	A type of asbestos that occurs in nature as the dihydrate of magnesium silicate. It exists in two forms: antigorite, a plated variety, and chrysotile, a fibrous variety. The latter makes up 95% of all asbestos products. (From Merck Index, 11th ed, p.893)	Chrysotile,Serpentine (Mineral),Serpentine Asbestos,Antigorite,Asbestos, Serpentine, Chrysotile (Mg3(OH)4(Si2O5))