{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,27]],"date-time":"2026-05-27T15:34:22Z","timestamp":1779896062890,"version":"3.53.1"},"reference-count":39,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,10,3]],"date-time":"2025-10-03T00:00:00Z","timestamp":1759449600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:p>\n                    The McGill University cohort of Qu\u00e9bec chrysotile miners and millers (total of 11,379 members) has been a major determinant of risk assessment. The U. S. EPA and some other meta-analyses omit this cohort, the largest ever exposed to high concentrations of chrysotile. Preliminary analyses using new data showed average cumulative exposures in the full cohort of 528.5 f\/cc-years (95% CI 510.3, 546.7) or 979 f\/cc-years (95% CI 945, 1,013), depending on the regression equation used for the modeling. The lowest estimated exposure level observed for any mesothelioma case with diagnostic certainty was 68 f\/cc-years. We confirmed that the estimation of potency factor for Qu\u00e9bec chrysotile should not be expected to differ significantly from Darnton\u2019s estimation for non-textile chrysotile (R\n                    <jats:sub>M<\/jats:sub>\n                    \u202f=\u202f0.0014%), if better quality data for correspondence between impinger and fiber count measurements is involved. Among several estimations we made, the average meta-analytical mesothelioma potency factor for all types of chrysotile would be 0.0014% (95% CI 0.0010, 0.0.0018), and for non-textile chrysotile 0.0011% (95% CI 0.0008, 0.0015). Several estimations of a possible threshold that would correspond to non-elevated mesothelioma risk based on the Qu\u00e9bec cohort were also made. The minimal cumulative exposure in mesothelioma cases demonstrated values that ranged from 4.8\u20136 MPCF-years, or 18\u201350 f\/cc-years. Also, based on theoretical models, the threshold can be found at the level of 6.38 MPCF-years (standard deviation 2.6), or in the range from 35.9 f\/cc-years (standard deviation of 15.4) to 65.9 f\/cc-years (standard deviation of 29.6).\n                  <\/jats:p>","DOI":"10.3389\/fpubh.2025.1654772","type":"journal-article","created":{"date-parts":[[2025,10,3]],"date-time":"2025-10-03T13:48:32Z","timestamp":1759499312000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Updates on exposure estimation for the Qu\u00e9bec cohort of chrysotile miners and millers: implications for risk assessment and threshold hypothesis"],"prefix":"10.3389","volume":"13","author":[{"given":"Bruce W.","family":"Case","sequence":"first","affiliation":[{"name":"Department of Pathology, McGill University","place":["Montreal, QC, Canada"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrey A.","family":"Korchevskiy","sequence":"additional","affiliation":[{"name":"Chemistry and Industrial Hygiene, Inc.","place":["Lakewood, CO, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Arseniy","family":"Korchevskiy","sequence":"additional","affiliation":[{"name":"Chemistry and Industrial Hygiene, Inc.","place":["Lakewood, CO, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2025,10,3]]},"reference":[{"key":"ref1","first-page":"189","article-title":"Cancer in chrysotile mines and mills","volume-title":"Biological effects of Asbestos","author":"McDonald","year":"1973"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"11","DOI":"10.1136\/oem.37.1.11","article-title":"Dust exposure and mortality in chrysotile mining, 1910-75","volume":"37","author":"McDonald","year":"1980","journal-title":"Br J Ind 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mesothelioma in the 1891\u20131920 birth cohort of Quebec chrysotile workers: a descriptive study","volume":"41","author":"Case","year":"1997","journal-title":"Ann Occup Hyg"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"1583469","DOI":"10.3389\/fpubh.2025","article-title":"Associated minerals in chrysotile deposits and their potential health risks","volume":"13","author":"Chatfield","year":"2025","journal-title":"Front Public Health"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1080\/10408440802273156","article-title":"A meta-analysis of asbestos-related cancer risk that addresses fiber size and mineral type","volume":"38","author":"Berman","year":"2008","journal-title":"Crit Rev Toxicol"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"699","DOI":"10.1016\/S0003-4878(97)89350-7","article-title":"Chrysotile, tremolite asbestos and carcinogenicity","volume":"41","author":"McDonald","year":"1997","journal-title":"Ann Occup 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