Rethinking Nano‐TiO₂ Safety: Overview of Toxic Effects in Humans and Aquatic Animals

Abstract

Titanium dioxide nanoparticles (nano‐TiO2) are widely used in consumer products, raising environmental and health concerns. An overview of the toxic effects of nano‐TiO2 on human and environmental health is provided. A meta‐analysis is conducted to analyze the toxicity of nano‐TiO2 to the liver, circulatory system, and DNA in humans. To assess the environmental impacts of nano‐TiO2, aquatic environments that receive high nano‐TiO2 inputs are focused on, and the toxicity of nano‐TiO2 to aquatic organisms is discussed with regard to the present and predicted environmental concentrations. Genotoxicity, damage to membranes, inflammation and oxidative stress emerge as the main mechanisms of nano‐TiO2 toxicity. Furthermore, nano‐TiO2 can bind with free radicals and signal molecules, and interfere with the biochemical reactions on plasmalemma. At the higher organizational level, nano‐TiO2 toxicity is manifested as the negative effects on fitness‐related organismal traits including feeding, reproduction and immunity in aquatic organisms. Bibliometric analysis reveals two major research hot spots including the molecular mechanisms of toxicity of nano‐TiO2 and the combined effects of nano‐TiO2 and other environmental factors such as light and pH. The possible measures to reduce the harmful effects of nano‐TiO2 on humans and non‐target organisms has emerged as an underexplored topic requiring further investigation.

Face masks and nanotechnology: Keep the blue side up

“…Copper and silver nanoparticles can induce important toxic health and environmental effects, such as immunotoxicity in both dams and offspring in mice [38] , and toxic effects on marine species [39] . Although originally classified as biologically inert, there is a growing body of evidence on the toxicity of TiO 2 to humans and non-target organisms, as recently outlined by Luo and colleagues [40] . A type of multiwalled carbon nanotube (MWCNTs) has also been classified as possibly carcinogenic to humans [10] .…”

“…It has been pointed out that more skin-friendly materials and interface design are needed to take in consideration the changing skin conditions that arise from perspiration [5] . As an example, TiO 2 cannot penetrate the deeper layers of skin and can be considered a skin-friendly nanomaterial [40] . A panel of graphene-based materials, including few-layer graphene, graphene, graphene oxide, and reduced GO did not induce irritation unless they were prepared with irritant surfactants such as sodium dodecyl sulfate and sodium dodecyl-benzenesulfonate [44] .…”

Conferring Ti‐Based MOFs with Defects for Enhanced Sonodynamic Cancer Therapy

“…[ 11 ] Furthermore, increasing studies have manifested that TiO 2 nanoparticles could cause great toxicity damage to human body. [ 12 ] In addition to TiO 2 , most of the currently reported inorganic sonosensitizers are nondegradable, which may also raise safety concerns for in vivo applications. Accordingly, it is highly desired to develop novel sonosensitizers concurrently with high ROS generation efficiency and biosecurity.…”

Surface and Antibacterial Properties of Titanium Dioxide Nanoparticles Synthesized in Plasma Discharge under Ultrasonic Cavitation

“…Therefore, an important task is to study the effect of intensive ultrasonic action on the synthesis of bactericidal nanoparticles, as well as to obtain quantitative information about the adsorption polymer layers formed during this action as an informative method for studying the properties of the surface of nanoparticles and its activity and reactivity. Thus, titanium dioxide nanoparticles were synthesized for detailed studies, including because it is known from the literature about their bactericidal properties (see, for example, [5,6]).…”

“…Mechanical stress due to the interaction of cells with nanoparticles can disrupt the integrity of the cell membrane and affect ion homeostasis and the activity of membrane-bound receptors and enzymes. TiO2 particles with a primary particle size of ~ 40 nm interact to a significant extent with phospholipid layers [5,6]. The aggregation of these particles initially has little effect on this interaction, but long-term aggregation affects the interaction, as a result, the aggregates penetrate the lipid layer rather than being adsorbed on the surface.…”