Fluoride, of all inorganic substances, is among the least likely to be identified by a routine toxicological analysis. Acute
poisonings with
salts of hydrofluoric or
fluorosilicic acid, however, although relatively uncommon, may occur. Some fluorosilicates,
salts of
fluorosilicic acid (e.g. Al, Zn, Pb, Mg) are used as stone consolidants, others (e.g.
sodium fluorosilicate)--in the production of enamel and milk glass, or as
insecticide. In this paper, two fatal cases of
poisonings are presented: a suicide involving
sodium fluorosilicate of a 39-year-old male who died in his flat, without hospitalization, and an accidental ingestion of
zinc fluorosilicate
solution (probably due to mistaking it for
mineral water) by a 38-year-old male at his workplace (building), who died about 3h after ingestion of the liquid, in spite of
intensive care at hospitals. Post-mortem samples were examined by the use of the spectrophotometric method with
lanthanum nitrate and
alizarin complexone for
fluorine (after isolation of
fluoride compounds by the microdiffusion method) and using a flame atomic absorption spectrometry method for
zinc (after mineralization of
biological material by sulfuric and nitric
acids). In the first case, the results were: blood--130 μg F/ml, stomach--1150 μg F/g, small intestine content --19.6 μg F/g, kidney--56.0 μg F/g, and urine--1940 μg F/ml. In the second case, the contents of
fluorine and
zinc in blood and internal organs were the following: blood--6.03 μg F/ml, 23.8 μg Zn/ml; brain--1.39 μg F/g, 7.54 μg Zn/g; stomach--152 μg Zn/g; stomach content--293 μg F/g, 84.4 μg Zn/g; small intestine--37.5 μg Zn/g; small intestine content--63.4 μg F/g, 19.6 μg Zn/g; liver--9.49 μg F/g, 81.0 μg Zn/g; kidney--29.6 μg F/g, 39.2 μg Zn/g; and exceeded the normal levels of these elements in
biological material many times. In addition, in stomach and liver large amounts of
silica were detected. In the paper, a review of acute intoxications with various
fluoride compounds (17 cases) is also presented.