title: Rare earth elements in human and animal health: State of art and research priorities.
abstract: BACKGROUND
  A number of applications have been developed using rare earth elements (REE), implying several human exposures and raising unsolved questions as to REE-associated health effects.
  
  
  METHODS
  A MedLine survey was retrieved from early reports (1980s) up to June 2015, focused on human and animal exposures to REE. Literature from animal models was selected focusing on REE-associated health effects.
  
  
  RESULTS
  Some REE occupational exposures, in jobs such as glass polishers, photoengravers and movie projectionists showed a few case reports on health effects affecting the respiratory system. No case-control or cohort studies of occupational REE exposures were retrieved. Environmental exposures have been biomonitored in populations residing in REE mining areas, showing REE accumulation. The case for a iatrogenic REE exposure was raised by the use of gadolinium-based contrast agents for nuclear magnetic resonance. Animal toxicity studies have shown REE toxicity, affecting a number of endpoints in liver, lungs and blood. On the other hand, the use of REE as feed additives in livestock is referred as a safe and promising device in zootechnical activities, possibly suggesting a hormetic effect both known for REE and for other xenobiotics. Thus, investigations on long-term exposures and observations are warranted.
  
  
  CONCLUSIONS
  The state of art provides a limited definition of the health effects in occupationally or environmentally REE-exposed human populations. Research priorities should be addressed to case-control or cohort studies of REE-exposed humans and to life-long animal experiments.
authors.affiliation: University of Naples "Federico II", Environmental Hygiene, via Cinthia, I-80126 Naples, Italy. Electronic address: gbpagano@tin.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pagano
authors.affiliation: University of Naples "Federico II", Environmental Hygiene, via Cinthia, I-80126 Naples, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Aliberti
authors.affiliation: University of Naples "Federico II", Environmental Hygiene, via Cinthia, I-80126 Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Guida
authors.affiliation: Ege University, Faculty of Fisheries, TR-35100 Bornova, İzmir, Turkey.
authors.forename: Rahime
authors.initials: R
authors.lastname: Oral
authors.affiliation: University of Naples "Federico II", Environmental Hygiene, via Cinthia, I-80126 Naples, Italy.
authors.forename: Antonietta
authors.initials: A
authors.lastname: Siciliano
authors.affiliation: University of Naples "Federico II", Department of Chemical Sciences, I-80126 Naples, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Trifuoggi
authors.affiliation: "Aldo Moro" Bari University, Department of Biology, I-70126 Bari, Italy.
authors.forename: Franca
authors.initials: F
authors.lastname: Tommasi
mesh_terms: D000821:Animal Feed; D000818:Animals; D001682:Biological Availability; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D005308:Fertilizers; D006801:Humans; D008674:Metals, Rare Earth / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D012106:Research
chemical_list: D005308:Fertilizers; D008674:Metals, Rare Earth
keywords: Biomonitoring; Feed additives; Occupational/environmental/iatrogenic exposure; Organ toxicity; Pneumoconiosis; Rare earth elements