Cytotoxic and inflammatory responses of TiO2 nanoparticles on human peripheral blood mononuclear cells.

Titanium dioxide nanoparticles (TiO2 -NPs) have been widely used in many applications. Owing to their nanoscale size, interactions between cells and NPs have been expansively investigated. With the health concerns raised regarding the adverse effects of these interactions, closer examination of whether TiO2 -NPs can induce toxicity towards human cells is greatly needed. Therefore, in this study, we investigated the cytotoxicity of TiO2 -NPs towards human blood cells (peripheral blood mononuclear cells [PBMCs]) in serum-free medium, for which there is little information regarding the cytotoxic effects of TiO2 -NPs. Our results provide evidence that PBMCs treated with TiO2 -NPs (at concentrations ≥25 µg ml(-1) ) for 24 h significantly reduced cell viability and significantly increased production of toxic mediators such as reactive oxygen species and inflammatory response cytokines such as interleukin-6 and tumor necrosis factor-α (P < 0.05). Cell apoptosis induction also occurred at these concentrations. Significant expressions of cyclooxygenase-2 and interleukin-1ß were also observed in PBMCs treated with TiO2 -NPs at concentrations ≥125 µg ml(-1) . Our data presented here clearly indicate that the concentration of TiO2 -NPs (at size ~26.4 ± 1.2 nm) applied to human blood cells has a strong impact on cytotoxic induction. Copyright © 2016 John Wiley & Sons, Ltd.

The role of food waste hierarchy as Thai hotels seek to fulfill their corporate social responsibility.

Although food waste reduction has been recognized as an important method for managing the environment in the past, it has not received much attention from the hotel business sector. This article reveals that food waste hierarchy is an important strategy for hotels, as it helps them to reduce food waste at the generation point, while reducing food costs and protecting the environment. The process of food waste reduction can be holistically integrated with the distribution process. The study found that there were significant differences related with hotel size in the 7-step food distribution process. The mean distribution process of large hotels is higher than the one of medium and small hotels. The results also show that the hierarchy of food waste management motivates the hotel business sector to implement food waste reduction by ensuring that hotel operations achieve Corporate Social Responsibility (CSR) goals in the form of Creating Shared Value (CSV). The primary goal of CSR is to align corporate and social values.