A critical review of asbestos concentrations in water and air, according to exposure sources

Asbestos, a group of minerals with unique physical and chemical properties, has been widely used in various industries. However, extensive exposure to asbestos fibers, present in the environment, has been linked to several types of cancer, mesothelioma, and asbestosis. Despite worldwide regulations prohibiting or regulating the use of this material, the uncertainty surrounding the concentrations of asbestos fibers in the environment (air and water) from different sources of exposure persists. The objective of this review paper is to identify the levels of asbestos in air and water reported in the literature based on the source of exposure in diverse contexts to assess conformity with the reference limits for this mineral. Initially, the review delineates various forms of exposure and the origin of fiber generation in the environment, whether direct or indirect. Regarding the presence of asbestos in the environment, high concentrations were identified in natural water bodies known as Naturally Occurring Asbestos (NOA), and there is a risk in the process of distributing drinking water due to the presence of asbestos-cement pipes. In the air, studies to determine asbestos concentrations vary based on the sources of exposure in each region or city studied. The presence of asbestos mines around the city and the intensity of vehicular traffic are some of the most relevant sources found to be related to high concentrations of asbestos fibers in the air. The present review paper features a critical review section in each chapter to highlight critical points found in the literature and suggest new methodologies/ideas to standardize future research. It emphasizes the necessity to standardize methods for measuring asbestos concentrations in air and water arising from diverse sources of exposure to enable comparisons between different regions and countries.