BackgroundWe have conducted a population-based study of pleural mesothelioma patients with occupational histories and measured asbestos lung burdens in occupationally exposed workers and in the ...general population. The relationship between lung burden and risk, particularly at environmental exposure levels, will enable future mesothelioma rates in people born after 1965 who never installed asbestos to be predicted from their asbestos lung burdens.MethodsFollowing personal interview asbestos fibres longer than 5 µm were counted by transmission electron microscopy in lung samples obtained from 133 patients with mesothelioma and 262 patients with lung cancer. ORs for mesothelioma were converted to lifetime risks.ResultsLifetime mesothelioma risk is approximately 0.02% per 1000 amphibole fibres per gram of dry lung tissue over a more than 100-fold range, from 1 to 4 in the most heavily exposed building workers to less than 1 in 500 in most of the population. The asbestos fibres counted were amosite (75%), crocidolite (18%), other amphiboles (5%) and chrysotile (2%).ConclusionsThe approximate linearity of the dose–response together with lung burden measurements in younger people will provide reasonably reliable predictions of future mesothelioma rates in those born since 1965 whose risks cannot yet be seen in national rates. Burdens in those born more recently will indicate the continuing occupational and environmental hazards under current asbestos control regulations. Our results confirm the major contribution of amosite to UK mesothelioma incidence and the substantial contribution of non-occupational exposure, particularly in women.
This analysis updates two previous analyses that evaluated the exposure-response relationships for lung cancer and mesothelioma in chrysotile-exposed cohorts. We reviewed recently published studies, ...as well as updated information from previous studies. Based on the 16 studies considered for chrysotile (<10% amphibole), we identified the "no-observed adverse effect level" (NOAEL) for lung cancer and/or mesothelioma; it should be noted that smoking or previous or concurrent occupational exposure to amphiboles (if it existed) was not controlled for. NOAEL values ranged from 2.3-<11.5 f/cc-years to 1600-3200 f/cc-years for lung cancer and from 100-<400 f/cc-years to 800-1599 f/cc-years for mesothelioma. The range of best-estimate NOAELs was estimated to be 97-175 f/cc-years for lung cancer and 250-379 f/cc-years for mesothelioma. None of the six cohorts of cement or friction product manufacturing workers exhibited an increased risk at any exposure level, while all but one of the six studies of textile workers reported an increased risk at one or more exposure levels. This is likely because friction and cement workers were exposed to much shorter chrysotile fibers. Only eight cases of peritoneal mesothelioma were reported in all studies on predominantly chrysotile-exposed cohorts combined. This analysis also proposed best-estimate amosite and crocidolite NOAELs for mesothelioma derived by the application of relative potency estimates to the best-estimate chrysotile NOAELs for mesothelioma and validated by epidemiology studies with exposure-response information. The best-estimate amosite and crocidolite NOAELs for mesothelioma were 2-5 f/cc-years and 0.6-1 f/cc-years, respectively. The rate of peritoneal mesothelioma in amosite- and crocidolite-exposed cohorts was between approximately 70- to 100-fold and several-hundred-fold higher than in chrysotile-exposed cohorts, respectively. These findings will help characterize potential worker and consumer health risks associated with historical and current chrysotile, amosite, and crocidolite exposures.
Mineral Fibres Punturo, Rosalda; Kusiorowski, Robert; Bloise, Andrea ...
01/2019
eBook
Odprti dostop
In the last decades, there has been increasing interest in Naturally Occurring Asbestos (NOA) and asbestos containing materials (ACMs) as a source of possible environmental risk. A crucial theme of ...interest related to environmental pollution is the enhanced mobilization of asbestos minerals affecting soils and rocks due to human activities (e.g., road construction, mining activity) in comparison with natural weathering processes. The volume has aimed to gather contributions and to compare results derived from various experiences of research groups regarding NOA minerals as a source of possible environmental risks for population. Case studies from various geological contexts are presented. Moreover, contributions presenting novel and classical approaches for ACM inertization and recycling, together with possible solutions for reducing asbestos exposure, has been also presented.
This book examines how asbestos activists living in remote rural villages in South Africa activated metropolitan resources of representation at the grassroots level in a quest for justice and ...restitution for the catastrophic effects on their lives caused by the asbestos industry. It follows the Asbestos Interest Group (AIG) over a fifteen-year period through its involvement in grassroots research, in legal cases and in the compensation systems for asbestos-related disease. It examines how the AIG became grassroots technicians of translocal paperwork, moving texts back and forth between periphery and center, pushing documents through the textual mazeways of the courts, medical institutions, the compensation system and various government agencies. The book addresses rhetorical mobility and the extent to which, given the AIG's position on the periphery, it has been able to enter the voices and interests of villagers into formerly inaccessible forums of deliberation and decision-making.
Asbestos-related diseases and cancers represent a major public health concern.
To conduct a systematic review and meta-analysis to demonstrate that asbestos exposure increases the risk of prostate ...cancer.
The PubMed, Cochrane Library, Embase, and ScienceDirect databases were searched using the keywords (prostate cancer OR prostatic neoplasm) AND (asbestos* OR crocidolite* OR chrysotile* OR amphibole* OR amosite*). To be included, articles needed to describe our primary outcome: Risk of prostate cancer after any asbestos exposure.
We included 33 studies with 15,687 cases of prostate cancer among 723,566 individuals. Asbestos exposure increased the risk of prostate cancer (effect size = 1.10, 95% confidence interval CI = 1.05-1.15). When we considered mode of absorption, respiratory inhalation increased the risk of prostate cancer (1.10, 95% CI = 1.05-1.14). Both environmental and occupational exposure increased the risk of prostate cancer (1.25, 95% CI = 1.01-1.48; and 1.07, 1.04-1.10, respectively). For type of fibers, the amosite group had an increased risk of prostate cancer (1.12, 95% CI = 1.05-1.19), and there were no significant results for the chrysotile/crocidolite group. The risk was higher in Europe (1.12, 95% CI = 1.05-1.19), without significant results in other continents.
Asbestos exposure seems to increase prostate cancer risk. The main mechanism of absorption was respiratory. Both environmental and occupational asbestos exposure were linked to increased risk of prostate cancer.
Patients who were exposed to asbestos should possibly be encouraged to complete more frequent prostate cancer screening.
We analyzed the mesothelioma mortality in cohorts of workers exposed to crocidolite, amosite, and chrysotile to estimate asbestos fiber potency for mesothelioma, using the method of Hodgson and ...Darnton (2000). We relied on the original 17 cohort studies in their analysis, along with 3 updates of those studies and 3 new asbestos cohort studies published since 2000. We extended the analyses to examine the mesothelioma potency of tremolite in vermiculite from Libby, Montana, and for non-asbestiform elongate mineral particles (EMPs) in taconite iron ore, talc, and South Dakota gold mining. Mesothelioma potency (RMeso) was calculated as the percent of all expected deaths that were due to mesothelioma per fiber/cc-year of exposure.The RMeso was 0.0012 for chrysotile, 0.099 for amosite, and 0.451 for crocidolite: thus, the relative potency of chrysotile:amosite:crocidolite was 1:83:376, which was not appreciably different from the estimates by Hodgson and Darnton in 2000. The RMeso for taconite mining fibers was 0.069 which was slightly smaller than that for amosite. The RMeso for Libby fibers was 0.028 which was greater than that for chrysotile and less than that for amosite. Talc and gold mining EMPs were non-potent for mesothelioma. Although there are a number of methods for estimating fiber potency of asbestos and non-asbestiform EMPs, the method of Hodgson and Darnton provides a uniform method by which fiber potency can be compared across many fiber types. Our estimates of RMeso provide a useful addition to our knowledge of mesothelioma potency for different asbestos and non-asbestiform EMP fibers.
•Updated mesothelioma potency from asbestos is similar to Hodgson and Darnton.•Elongate mineral particles from taconite mining are 58 times more potent than chrysotile.•Libby fibers are 23 times more potent than chrysotile.•Talc and gold mining are non-potent.
An earlier meta-analysis of mortality studies of asbestos-exposed worker populations, quantified excess mesothelioma and lung cancer risks in relation to cumulative exposure to the three main ...commercial asbestos types. The aim of this paper was to update these analyses incorporating new data based on increased follow-up of studies previously included, as well as studies of worker populations exposed predominantly to single fibre types published since the original analysis.
Mesothelioma as a percentage of expected mortality due to all causes of death, percentage excess lung cancer and mean cumulative exposure were abstracted from available mortality studies of workers exposed predominantly to single asbestos types. Average excess mesothelioma and lung cancer per unit of cumulative exposure were summarised for groupings of studies by fibre type; models for pleural and peritoneal mesothelioma risk and lung cancer risk in terms of cumulative exposure for the different fibre types were fitted using Poisson regression.
The average mesothelioma risks (per cent of total expected mortality) per unit cumulative exposure (f/cc.yr), RM, were 0.51 for crocidolite, 0.12 for amosite, and 0.03 for the Libby mixed amphiboles cohort. Significant heterogeneity was present for cohorts classed as chrysotile, with RM values of 0.01 for chrysotile textiles cohorts and 0.0011 for other chrysotile-exposed cohorts. Average percentage excess lung cancer risks per unit cumulative exposure, RL, were 4.3 for crocidolite and amosite combined, 0.82 for Libby. Very significant heterogeneity was present for chrysotile-exposed cohorts with RL values spanning two orders of magnitude from 0.053 for the Balangero mine to 4.8 for the South Carolina textiles cohort. Best fitting models suggest a non-linear exposure-response in which the peritoneal mesothelioma risk is proportional to approximately the square of cumulative exposure. Pleural mesothelioma and lung cancer risk were proportion to powers of cumulative exposure slightly less than one and slightly higher than one respectively.
•Fibre-specific potencies for mesothelioma and lung cancer can be estimated from mortality studies of workers exposed to particular asbestos types.•Potency for mesothelioma was highest for crocidolite: about 4 times higher than amosite, 17 times higher than the Libby mixed amphiboles and 50-500 times higher than chrysotile.•Some of the substantial variation in mesothelioma risk for chrysotile cohorts could be due to varying degrees of amphibole contamination.•Potency for lung cancer was similar for crocidolite and amosite, and about a factor of 5 higher than for Libby mixed amphiboles.•Potency for lung cancer spans two orders of magnitude from available studies, with the highest values similar to crocidolite and amosite.•Inter-study Poisson regression shows peritoneal mesothelioma risk is related to about the square of cumulative exposure.•The relationship between pleural mesothelioma and lung cancer risk and cumulative exposure may be non-linear, though this is uncertain.
The work shows the effect of counting rules, such as analysis magnification and asbestos fiber dimension to be count (with length ≥5 µm or also asbestos fibers with length <5 µm) in the lung asbestos ...fiber burden analysis for legal medicine evaluations.
On the same lung tissue samples, two different analyses were carried out to count any asbestos fibers with length ≥1 µm and with length ≥5 µm. Results of the amphibole burden of the two analyses were compared by linear regression analysis on log10-transformed values.
The analysis should be carried out at an appropriate magnification and on samples prepared in such a way as they allow the counting of very fine fibers. If the analysis is limited to the asbestos fibers with length ≥5 µm, there is a high risk of not detecting possible residual chrysotile fiber burden and thinner crocidolite asbestos fibers.
On average we estimated that 1 amphibole fiber with length ≥5 µm corresponds to ∼8 amphibole fibers with length ≥1 µm in the lung. The values of the Helsinki criteria should be updated taking this into account.
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