Abstract
Photocatalytic cement is self-cleaning due to the addition of titanium dioxide (TiO2) nanoparticles, which react with sunlight (UV) and produce reactive oxygen species (ROS). Construction workers using photocatalytic cement are exposed not only to cement particles that are irritants but also to nano TiO2 and UV, both carcinogens, as well as the generated ROS. Quantifying ROS generated from added nano TiO2 in photocatalytic cement is necessary to efficiently assess combined health risks. We designed and built an experimental setup to generate, under controlled environmental conditions (i.e., temperature, relative humidity, UV irradiance), both regular and photocatalytic cement aerosols. In addition, cement working activities—namely bag emptying and concrete cutting—were simulated in an exposure chamber while continuously measuring particle size distribution/concentration with a scanning mobility particle sizer (SMPS). ROS production was measured with a newly developed photonic sensing system based on a colorimetric assay. ROS production generated from the photocatalytic cement aerosol exposed to UV (3.3∙10−9 nmol/pt) was significantly higher than for regular cement aerosol, either UV-exposed (0.5∙10−9 nmol/pt) or not (1.1∙10−9 nmol/pt). Quantitatively, the level of photocatalytic activity measured for nano TiO2-containing cement aerosol was in good agreement with the one obtained with only nano TiO2 aerosol at similar experimental conditions of temperature and relative humidity (around 60%). As a consequence, we recommend that exposure reduction strategies, in addition to cement particle exposures, also consider nano TiO2 and in situ–generated ROS, in particular if the work is done in sunny environments.Graphical abstract
Highlights
Nanotechnology—the study of matter in nano range from 1 to 100 nm—is widely used to improve materials’ properties especially strength, weight, and insulation
The aerosol reactive oxygen species (ROS) generation calculated in the present study indicates that the aerosolized
The combination of an efficient aerosol generation setup coupled with a solar simulation lamp and a sensitive photonic detection device made it possible to assess the production of ROS by photocatalytic and regular cement aerosols
Summary
Nanotechnology—the study of matter in nano range from 1 to 100 nm—is widely used to improve materials’ properties especially strength, weight, and insulation. Photocatalytic cement has been introduced for its self-cleaning properties (Lan et al 2013; Carp et al 2004; Banerjee et al 2015) related to the photocatalytic activity of titanium dioxide nanoparticles (nano TiO2) (Hernández-Rodríguez et al 2019; Feng et al 2013; Folli et al 2010). This cement is composed of regular cement made up of fine inorganic particles such as CaO, SiO2, Fe2O3, and MgO (Meo 2004; Batsungnoen et al 2019) and nano TiO2. Numerous studies have shown that nano TiO2 is genotoxic and cytotoxic (NIOSH 2009; Sayes et al 2006), especially for the lung bronchial epithelial cells (Sha et al 2015; Lee et al 2010) but can translocate to other organs via the blood circulation (Wang et al 2008; Kreyling et al 2010; Geiser and Kreyling 2010; Shi et al 2013)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
