title: Environmental risk induced by TiO2 dispersions in waters and sediments: a case study.
abstract: A southern Italian area that is characterized by large outcrops of rocks that are rich in titanium oxide (TiO2) phases were investigated to determine the mineralogical risk induced by the natural dispersion of TiO2 minerals. Rock, sediment and surface water samples were collected to determine the physicochemical and mineralogical factors (i.e., size distribution, morphology and alteration) indicative of potential TiO2 toxicity. X-ray diffraction data suggested that titanium oxides were present as rutile and anatase. Scanning electron microscopy images showed elongated TiO2 morphologies; fibres were found as either isolated or embedded/enclosed in flake-like phyllosilicates. The concentration of fibres in stream water ranged from 1.7 to 4.6 million fibres per litre. The highest fibre amounts in the sediments were in the <8-µm fraction, while single fibres were primarily concentrated in the <2-µm fraction. The results indicate that titanium oxide minerals represent a natural source of environmental risk and that the geomineralogical characterization of rich TiO2 areas is indispensable for understanding their geoavailability, dispersion and distribution.
authors: Institute of Methodologies for Environmental Analysis, National Research Council of Italy, Tito Scalo, Potenza, Italy. antonio.lettino@imaa.cnr.it.
authors: Antonio
authors: A
authors: Lettino
authors: Institute of Methodologies for Environmental Analysis, National Research Council of Italy, Tito Scalo, Potenza, Italy.
authors: Claudia
authors: C
authors: Belviso
authors: Institute of Methodologies for Environmental Analysis, National Research Council of Italy, Tito Scalo, Potenza, Italy.
authors: Francesco
authors: F
authors: Cavalcante
authors: Institute of Methodologies for Environmental Analysis, National Research Council of Italy, Tito Scalo, Potenza, Italy.
authors: Saverio
authors: S
authors: Fiore
mesh_terms: D019015:Geologic Sediments / Q000737:chemistry*; D006801:Humans; D007558:Italy; D018570:Risk Assessment; D045483:Rivers / Q000737:chemistry*; D014025:Titanium / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D014025:Titanium
keywords: Anatase; Fibres; Liguride Complex; Rutile; SEM; XRD