Impact of Naturally Occurring Asbestos on Asbestos Ban: Regulations and Experience of the Republic of Korea

This review examined the main issues debated in Korea regarding the production and use of materials containing naturally occurring asbestos (NOA) as impurities, and investigated the impacts of these debates on the asbestos ban, as well as the future implications. In Korea, incidents associated with the production and use of NOA-contaminated talc powders, construction rocks, serpentinites, and dolomite rocks raised public concern and led to accelerating the ban on asbestos. The main controversies concern policies on appropriate asbestos content limits, whether materials containing a trace amount of NOA should be banned, and the control of materials with high human exposure risk. To address recurring controversies, the implementation of preventive measures to manage elongated mineral particles and the use of transmission electron microscopy for more sensitive analysis need to be discussed, along with reaching social agreement on the controversial policies. To minimize the potential exposure to asbestos that may occur during the production and use of industrial minerals in the future, it is necessary to apply occupational exposure control measures and monitor the health effects of the relevant population groups. These national policies on NOA should be prepared based on close collaboration and discussion with policymakers, industry stakeholders, and related academic experts.

Activity-Based Exposure Levels and Cancer Risk Assessment Due to Naturally Occurring Asbestos for the Residents Near Abandoned Asbestos Mines in South Korea

This study aims to evaluate the overall asbestos exposure intensity and assess the health risk to residents due to naturally occurring asbestos (NOA) near abandoned asbestos mines in South Korea. Of 38 mines, we found 19 with measured concentrations of NOA. We evaluated the average of airborne NOA concentrations according to the environmental exposure category. When evaluated regionally by dividing into two clusters, the mean concentrations in activity-based sampling (ABS) scenarios exceeded the Korean exposure limit (0.01 f/cc) in both clusters. Moreover, airborne NOA concentrations in agricultural activity (5.49 × 10−2 f/cc) and daily activity (6.95 × 10−2 f/cc) had the highest values for clusters A and B, respectively. The excess lifetime cancer risk of one region (cluster A) by the ABS scenarios did not exceed the Korean Ministry of the Environment’s criteria for soil purification (1 × 10−4). However, one of the ABS scenarios—the daily life activity of clusters centered on Chungcheongbuk-do (cluster B)—showed an exposure of 1.08 × 10−4, greater than the limit (1 × 10−4). This indicates non negligible health damage to residents living near the abandoned asbestos mines, and it is necessary to continuously monitor and clean up the asbestos contamination.

Environmental exposure to asbestos and the risk of lung cancer: a systematic review and meta-analysis

Asbestos is a carcinogen associated with lung cancer, but few studies have examined the increased risk of lung cancer due to environmental asbestos exposure. We performed a systematic review and meta-analysis to evaluate the association between environmental asbestos exposure and lung cancer. We searched for articles on non-occupational or environmental asbestos exposure and lung cancer in PubMed, EMBASE, CINAHL and Web of Science databases. Our review included 15 studies, and except studies on ingestion exposure we performed a meta-analysis for 13 studies with respect to the type of exposure (neighbourhood and domestic/household exposure). Subgroup analyses and meta-regression were also performed. A significant increase in the risk of lung cancer was found for neighbourhood exposure (1.48, 95% CI 1.18 to 1.86), while the risk was not significantly increased for domestic/household exposure (1.04, 95% CI 0.85 to 1.27). With regard to neighbourhood exposure, naturally occurring asbestos and women were both associated with a higher risk of lung cancer; however, such an increase was not significantly greater compared with that associated with other sources of asbestos exposure and men. Although cautious interpretation is needed due to the large degree of heterogeneity and the small number of included studies, our findings imply that living near the source of asbestos increases the risk of lung cancer.

Groundwater flow in Naturally Occurring Asbestos (NOA) rich settings: new findings on the relation among concentration, types and mobility of mineral fibres, and geological characteristics of aquifer formations.

<p>Weathering and erosion of asbestos-bearing rocks, such as meta-ophiolites (e.g. serpentinite rocks and metabasites), is the principal natural cause of asbestos water dispersion in Naturally Occurring Asbestos (NOA) rich settings. Water pollution by asbestos may occur as a consequence of superficial and groundwater flow through natural rock formations with NOA, depending on several characteristics of either the rocks (e.g. mineralogical composition, fracture grade) and hence the water (e.g. pH, speed).</p><p>Given the importance of groundwater resources for both drinking water and agricultural and industrial activities, groundwater asbestos pollution represents an environmental problem and could even constitute a risk for human health. In fact, waterborne asbestos can come into contact with human beings as airborne fibres after water vaporization, or by ingestion, especially if they are present in drinking water. While a lot is known about diseases caused by airborne asbestos respiration, not enough has been yet understood about potential noxiousness of its ingestion. For this reason, the necessity to set a Maximum Contaminant Level (MCL) for asbestos in potentially usable water is still debated.</p><p>As the North-Western and Central Alps are rich in NOA and also in naturally occurring asbestiform minerals non-asbestos classified, it’s essential to understand if, how and which type of mineral fibres can eventually be released into water and to correlate them to the geolithological and hydrogeological characteristics of the area.</p><p>The results of a surface water and groundwater sampling and analysis campaign, settled in the North-Western Alps, will be presented. The main aim is to investigate the principal aspects related to asbestos and asbestiform fibres presence in water, in particular their natural occurrence in groundwater, linked to hydrological and geolithological characteristics of the reservoir. Furthermore, laboratory test to study the flow of polluted water through a packed column will be designed and observations on the methodology to evaluate waterborne mineral fibres behaviour into porous media will be presented.</p><p>These data are fundamental to monitor asbestos (and asbestiform) fibres transportation due to water flowing into NOA and to better understand the relationship among geology, hydrogeology and mineral fibres presence in water.</p>

Morphology and Size Distribution of Naturally Occurring Asbestos using TEM in Landscape Rock in Parks

BackgroundAsbestos is a silicate mineral that is naturally generated by geological processes in the Earth's crust. The six types of commercially used asbestos each display the asbestiform crystal habit that is characterized by fibrous aggregates of extremely long, thin crystals. This study provided data that can be used to discriminate asbestiform and non-asbestiform amphiboles contained in landscaping rocks in parks. MethodIn five of the 21 parks, two or more landscaping rocks were found to contain asbestos. These five were selected for additional study. The length and width of fibers being at least 5 ㎛ long and with a minimum aspect ratio of 3:1 were measured using a Transmission Electron Microscope(TEM) and compared to a standard asbestos sample.ResultsThe park samples were thicker than 1 ㎛(average 1.9 ㎛) while the Health and Safety Executive(HSE) reference sample averaged 0.3 ㎛ in width with 100 % thinner than 1.0 ㎛. The average aspect ratios were 7.1 for the park samples and 67.1 for the HSE reference sample. The actinolite contained in the landscape rocks of the five selected parks did not show the typical asbestiform structure that was observed in the standard asbestos sample.ConclusionsBased on these distributions, the amphibole fibers in sampled landscape rocks were found to be thicker and lower aspect ratio than those of the standard sample. The result of this study can contribute to the public policy for managing and controlling of landscaping rocks containing naturally occurring asbestos(NOA) and also to communicate about the possible health risk resulting from NOA contained in landscaping rocks.