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Objectives: Very few studies have investigated the incidence and risk of malignant mesothelioma (MM) associated with distinct sources of asbestos exposure, especially exposure to naturally occurring asbestos (NOA)., Methods: Subjects were MM, lung, and breast cancer patients who were diagnosed and followed in Diyarbakir Province between 2008 and 2013. The birthplaces of patients were displayed on a geologic map. Geological and meteorological effects on MM were analyzed by logistic regression., Results: A total of 180 MM, 368 breast, and 406 lung cancer patients were included. The median distance from birthplace to ophiolites was 6.26 km for MM, 31.06 km for lung, and 34.31 km for breast cancer (p < 0.001). The majority of MM cases were seen within 20 km from NOA areas. The MM incidence inside of NOA was 1059/100.000, and out of NOA was 397/100.000; this difference was significant (p = 0.014). The largest concentration of MM residential areas was within ± 30° (34 residential areas 36.6%) of the dominant wind direction. Most MM patients were found in or near the dominant wind direction, especially in the acute angle defined by the dominant wind direction. MM incidence was directly proportional to {[area of NOA (km(2))] * [cosine α of wind direction angle]} and was inversely proportional to the square of the distance (R = 0.291, p = 0.023)., Conclusions: MM was higher near NOA and in the downwind direction. MM incidence and risk were affected by geological and meteorological factors.

Objective: To examine the potential relationship between the presence of asbestos-related diseases (ARDs) in the region of Kastamonu, Turkey. Methods: The places of birth of patients with ARDs and control subjects diagnosed between 2008 and 2019 and identified in a tertiary hospital in Istanbul. Soil samples were taken from plaster surfaces and quarries. The analysis was done with transmission electron microscopy. Results: ARDs was detected in 55(17.9%) of 307 participants. Patients had a mean age of 68 ± 11 years. Residential proximity to ophiolites increased ARDincidence by 6.2%per kilometer (P = 0.003). Birthplaces were identified as being inside an ophiolitic unit, or if they were not, the Google Earth software was used to determine the beeline distance between the settlement's center and the edge of the closest ophiolitic unit. The appropriate threshold for this case is 12.75 km, with 75% sensitivity and 87% specificity. Conclusion: ARDs due to naturally occurring asbestos (NOA) are present in hitherto unknown places. Geological maps including ophiolites can help locate these places. [ABSTRACT FROM AUTHOR]

High concentrations of airborne asbestos in the ambient air are still a serious problem of air quality in numerous localities around the world. Since 2002, elevated concentrations of asbestos minerals of unknown origin have been detected in the ambient air of Pilsen, Czech Republic. To determine the asbestos fibre sources in this urban air, a systematic study was conducted. First, 14 bulk dust samples were collected in Pilsen at nine localities, and 6 bulk samples of construction aggregates for gravel production were collected in a quarry in the Pilsen-Litice district. The quarry is the largest quarry in the Pilsen region and the closest quarry to the built-up urban area. X-ray diffraction of the asbestos minerals revealed that monoclinic amphibole (MA, namely actinolite based on subsequent SEM-EDX analysis) in the bulk samples accounted for < 1-33% of the mass and that the highest values were found in the bulk dust samples from the railway platform of the Pilsen main railway station. Simultaneously, 24-h samples of airborne particulate matter (PM) at three localities in Pilsen were collected. Actinolite was identified in 40% of the PM samples. The relationship between the meteorology and presence of actinolite in the 24 PM10 samples was not proven, probably due to the long sampling integration time. Therefore, highly time-and-size-resolved PM sampling was performed. Second, sampling of size-segregated aerosols and measurements of the wind speed (WS), wind direction (WD), precipitation (P) and hourly PM10, PM2.5 and PM1 were conducted in a suburban locality near the quarry in two monthly highly time-resolved periods (30, 60, 120 min). Three/eight PM size fractions were sampled by a Davis Rotating-drum Uniform-size-cut Monitor (3/8DRUM) and analysed for the presences of asbestos fibres by scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM-EDX). Asbestos fibre detection in highly time-resolved PM samples and current WD and WS determination allows the apportionment directionality of asbestos fibre sources. The number of critical actinolite asbestos fibres (length ≥ 5 μm and width < 3 μm, 3:1) increased with the PM1-10/PM10 and PM2.5-10/PM10 ratios, WS > 2 m s−1 and precipitation < 1 mm. Additionally, the number of critical actinolite asbestos fibres was not related to a specific WD. Therefore, we conclude that the sources of airborne critical actinolite asbestos fibres in Pilsen’s urban area are omnipresent. Frequent use of construction aggregates and gravel from the metamorphic spilite quarries in the Pilsen region and in many localities around the urban area is a plausible explanation for the omnipresence of the critical actinolite asbestos fibres concentration in Pilsen’s ambient air. Mitigation strategies to reduce the concentrations of critical actinolite asbestos fibres must be developed. Continuous monitoring and performing SEM-EDX analysis of highly time-and-size-resolved PM samples, correlated with fast changing WS and WD, seems to be a strong tool for efficiently controlling the mitigation strategies of critical actinolite asbestos fibres. [ABSTRACT FROM AUTHOR]

Stratigraphic units with the potential for carbonate-hosted asbestos account for <3% of the land area of South Australia. Known asbestos occurrences are small, low grade and commonly weathered. The main mode of occurrence is as cross-fibre and slip-fibre veins of asbestiform magnesio-riebeckite (AMR) in metasomatised dolomites, and fibrous tremolite associated with talc mineralisation in the Adelaide Geosyncline. Small occurrences of chrysotile asbestos are hosted by dolomites in the Hutchison Group in the eastern Gawler Craton. Hyperspectral mapping could be used to locate additional asbestos mineralisation. Disturbance of natural asbestos-bearing materials in South Australia has been through mining, agriculture and natural weathering processes. Release of respirable asbestos fibres from rocks and soils is feasible and could potentially account for some cases of mesothelioma in South Australia. Only a very small portion of the population is considered at risk of being exposed to fibres from disturbance of natural asbestos fibres. Persons considered most at risk of potential exposure include: rural workers and communities residing close to areas of intense agricultural disturbance of asbestos-bearing soils; construction workers involved in large-scale earthworks projects in areas underlain by asbestos-bearing rocks and soils; and quarry workers who unwittingly disturb asbestos-bearing materials. Populations regularly exposed to amphibole fibres for a long period of time are at greatest risk with respect to mesothelioma. Epidemiological studies suggest that the risks of mesothelioma for those exposed to chrysotile fibres alone are negligible. Toxicological studies are required to better understand the potential health risks associated with AMR. Current medical reporting of asbestos in South Australia does not include detailed residential or occupational histories required to undertake a statistically significant study of the possible health effects of asbestos from natural sources. Government authorities and private enterprises need to take geological factors into account to reduce the likelihood of unplanned disturbance of natural asbestos-bearing materials. [ABSTRACT FROM AUTHOR]

Potential asbestos-bearing rocks account for about 0.2% of the land area of eastern Australia. The main mode of occurrence is as narrow cross fibre and slip fibre veins of chrysotile asbestos in serpentinised ophiolite complexes along the boundaries of major tectonic domains. Smaller deposits of chrysotile and amphibole asbestos occur in metamorphosed mafic and ultramafic rocks associated with the Macquarie Volcanic Arc in New South Wales. Amphibole asbestos is also known from Proterozoic and Palaeozoic amphibolite and from Devonian basalt. Natural asbestos-bearing materials in eastern Australia have been disturbed by mining, road construction, agriculture and forestry, urban development and through natural weathering processes. Persons most at risk of potential exposure to asbestos from natural sources include: farmers who work or live in areas where asbestos-bearing materials may be routinely disturbed by agricultural activities; construction workers involved in large-scale earthwork projects in areas underlain by asbestos-bearing rocks; and quarry workers who unwittingly disturb asbestos-bearing materials. Government authorities and private enterprise need to take geological factors into account to reduce the likelihood of unplanned disturbance of natural asbestos-bearing materials. [ABSTRACT FROM AUTHOR]