Toxicity Risks of Nanomaterials Used in the Building Construction Materials

In recent years, there has been a growing research interest on the applicationsof a range of nanostructured materials in construction industry (i.e., asphalt concrete, bricks,concrete, timber, steel, and mortar), manufacturing, electronics, cosmetics, and medicine. The useof nanoscale structures in the construction industry offers exceptional physicochemical characteristicsfor the modification of construction materials. Nanomaterials, which are being used in cementand concretes, are carbon nanomaterials (Graphene, CNTs, CNFs), nanosilica, nano Al 2 O 3 , nanometakaoline,nano CaCO 3 , nano Fe 2 O 3 and nanoTiO 2 . Methods: These materials improve the properties of concretes by modifying the microstructure andalso improve the mechanical properties. The improvement in mechanical and durability propertiesof concretes in the presence of nanoparticles is due to their smaller size (<100 nm), high surface area,and energy. Results: Nevertheless, all these nanoscale particles find their way (either directly or indirectly) tovarious environmental matrices, such as groundwater, surface water, rivers, seas, lakes, and soil.The potential bioaccumulation of metal oxide nanostructures results in undesirable effects on animals,aquatic biota, plants, and humans. Therefore, it has become crucial to determine toxicity levelsduring the use of these multifunctional nanoscale materials. Conclusion: This study presents an overview of the advantages and disadvantages of nanomaterialsin concretes and related materials. A particular emphasis has been given to discuss the potentialtoxicity risks of nanomaterials used in building construction materials.