title: Toxicity of bauxite manufacturing by-products in sea urchin embryos.
abstract: By-products from a bauxite manufacturing plant located in Seydişehir, Turkey, were investigated for their composition and any toxicity to sea urchin embryogenesis. Samples from three other bauxite plants located in France, Greece, and Italy were simultaneously tested for toxicity in sea urchin embryos. Samples included sludge and solid residues in the plant and sediment and water columns from two holding ponds (red sludge or cryolite residues). Samples were analyzed for their inorganic content by inductively coupled plasma optical emission spectroscopy (ICP-OES). Analyses were carried out either following strong acid extraction or after release of soluble components from seawater-suspended pellets. Toxicity was tested by sea urchin bioassays, to evaluate the following endpoints: (a) acute and/or developmental toxicity, (b) changes in fertilization success, and (c) transmissible damage from sperm to offspring. The results revealed the following: (1) inorganic analysis, following strong acid extraction, showed a prevalence of Al and Fe; (2) seawater release of soluble contaminants was confined to Fe and Mn, whereas Al levels were not changed by suspending increasing sample amounts in seawater; (3) the most severe toxicity to sea urchin embryos was exerted by a 2% water column from the red sludge holding pond and by soil and sludge collected near the plant reactor; (4) sludge supernatant was the most toxic sample to sperm and offspring. The data showed a prevailing association of free Fe (and possibly Mn) levels with Seydişehir sample toxicity. The water column of the red sludge holding pond showed both excess levels of free Al and high pH, thus suggesting a combined effect. The differences in sample toxicity in the Seydişehir plant compared with other bauxite manufacturing plants suggest a possible variable toxicity as related to bauxite ore composition and/or manufacturing processes.
authors.affiliation: Istituto Nazionale per lo Studio e la Cura dei Tumori, Fondazione Pascale, I-80131, Naples, Italy. gbpagano@tin.it
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pagano
authors.forename: Süreyya
authors.initials: S
authors.lastname: Meriç
authors.forename: Antonella
authors.initials: A
authors.lastname: De Biase
authors.forename: Mario
authors.initials: M
authors.lastname: laccarino
authors.forename: Domenico
authors.initials: D
authors.lastname: Petruzzelli
authors.forename: Olcay
authors.initials: O
authors.lastname: Tünay
authors.forename: Michel
authors.initials: M
authors.lastname: Warnau
mesh_terms: D000537:Aluminum Oxide / Q000009:adverse effects*; D000818:Animals; D001681:Biological Assay; D004625:Embryo, Nonmammalian / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000009:adverse effects*; D008420:Manufactured Materials; D019216:Metals, Heavy / Q000009:adverse effects; D012037:Refuse Disposal; D012617:Sea Urchins; D014873:Water Pollutants / Q000009:adverse effects*
chemical_list: D007220:Industrial Waste; D019216:Metals, Heavy; D014873:Water Pollutants; D000537:Aluminum Oxide