Toxicity of rare earth elements: An overview on human health impact

Rare earth elements (REEs) are metals including the 15 lanthanides together
with Yttrium and Scandium. China is the leading country in their exploitation and
production (~90%). REEs are necessary for the production of several
technological devices. This extended use of REEs has raised concerns about
human health safety. In this review, we investigated the hazard of REEs to
human health and the main gaps into the knowledge like as the need to develop
further focused research activity. We categorized the research papers collected
into eight main sections: environmental exposure, association of REEs with
health problems, exposure to REEs due to lifestyle, REE exposure through the
food chain, Gd contrast agents causing health problems, occupational REE
exposure, and cytotoxicity studies of REEs. This review provided information
about the exposome of REEs (the exposure of REEs to the human body), the
existing research data, and the gaps that require attention and must be further
investigated. More than one third of the literature about REE toxicity to human
health concerns their cytotoxicity to human cell lines, while hair, blood serum
and blood are the most studied matrices. The main results evidenced that REEs
can enter human body via several routes, are associated with numerous
diseases, can cause ROS production, DNA damage and cell death, and are
more toxic to cancer cells than normal cells.