Risk assessment of titanium dioxide nanoparticles via oral exposure, including toxicokinetic considerations

Abstract

Titanium dioxide white pigment consists of particles of various sizes, from which a fraction is in the nano range (5100 nm). It is applied in food as additive E 171 as well as in other products, such as food supplements and toothpaste. Here, we assessed whether a human health risk can be expected from oral ingestion of these titanium dioxide nanoparticles (TiO 2 NPs), based on currently available information. Human health risks were assessed using two different approaches: Approach 1, based on intake, i.e. external doses, and Approach 2, based on internal organ concentrations using a kinetic model in order to account for accumulation over time (the preferred approach). Results showed that with Approach 1, a human health risk is not expected for effects in liver and spleen, but a human health risk cannot be excluded for effects on the ovaries. When based on organ concentrations by including the toxicokinetics of TiO 2 NPs (Approach 2), a potential risk for liver, ovaries and testes is found. This difference between the two approaches shows the importance of including toxicokinetic information. The currently estimated risk can be influenced by factors such as absorption, form of TiO 2 , particle fraction, particle size and physico-chemical properties in relation to toxicity, among others. Analysis of actual particle concentrations in human organs, as well as organ concentrations and effects in liver and the reproductive system after chronic exposure to well-characterized TiO 2 (NPs) in animals are recommended to refine this assessment.

Encapsulation of colorants by natural polymers for food applications

“…The most well-known and widely used colorant is titanium dioxide, which accounts for 70% of the total production volume of pigments worldwide [6]. However, additional research on this topic is necessary to provide a good overview of the potential long-term negative effects associated with titanium dioxide nanoparticles [13,14]. Additionally, it is also used as a pigment in plastics, paper, inks, textiles, photovoltaic cells, biomedical devices, cosmetics, and even as a food additive [7,8].…”

Mechanisms of titanium dioxide nanoparticle‐induced oxidative stress and modulation of plasma glucose in mice

“…per day. 4 In view of the wide usage of TiO 2 NPs, it is crucial to ascertain whether these NPs pose a threat to human and animal life.…”

Application of Bayesian networks for hazard ranking of nanomaterials to support human health risk assessment

“…The risk assessment (RA) of nanomaterials (NMs) faces difficulties as it requires an extensive datasets on physiochemical parameters, hazard identification and exposure assessment (Stone et al, 2014a). For this reason, only a few attempts to perform a RA of NMs are available in the scientific literature (i.e., (nano)silica, (nano)titanium , CNTs and silver NMs) (Dekkers et al, 2011(Dekkers et al, , 2013Heringa et al, 2016;Wijnhoven et al, 2009). Interestingly, US-EPA published a conditional registration of a nanosilver containing product (EPA, 2011).…”