TiO2 NPs have a broad range of industrial and household applications. With the increasing production, TiO2 NPs’ emissions in the environment continue to grow. Unintentionally released TiO2 NPs may interact with pre-existing heavy metal cadmium (Cd) in aquatic environments and eventually modify their behavior, fate, toxicity. However, the influence of TiO2 NPs on the multigenerational impairments caused by heavy metals is largely unknown.
In XU’s study, they investigated the combined multigenerational reproductive toxicity of TiO2 NPs and Cd in Caenorhabditis elegans. They found that TiO2 NPs had strong adsorption and enriching ability towards Cd. Parental exposure to TiO2 NPs at a non-toxic concentration promoted the reproductive toxicity of Cd not only in the C. elegans parental generation but also in their pollutant-free cultured F1 and F2 offspring.
TiO2 NPs promoted the ingestion of Cd, while the lower pH environment in the gut accelerated desorption of Cd from TiO2 NPs, leading to enhanced Cd bioaccumulation. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), a in situ imaging technology, they found that TiO2 NPs promoted the accumulation of Cd. They also found that TiO2 NPs were mainly concentrated in the gut, pharyngeal pump, vulva, and anus. However, a considerable amount of Cd was detected in other parts of C. elegans. They further confirmed Cd gonad burden was increased by concurrent exposure to TiO2 NPs, indicating the potential transfer of Cd to the next generation through germline.
The multigenerational reproductive toxicity of co-exposure to TiO2 NPs and Cd (Image by WANG Jingjing)
