Oxidative stress parameters in rats exposed to fluoride and caffeine.

In our experiment, the 1-month effects of caffeine (Caff) and fluoride (F) administered separately and together on nitric oxide and total antioxidant status in serum, brain, liver and kidney of rats were investigated. Also, the influence of caffeine on fluoride excretion with urine was studied. Thirty adult male Wistar rats were divided into five equal groups of six each: (I) controls drinking tap water; (II) controls drinking tap water and receiving intragastrically 0.5 ml of tap water; (III) animals receiving 25 mg F/L in drinking water; (IV) animals receiving 4.7 mg Caff/kg bw/day; (V) animals receiving 25 mg F/L in drinking water and 4.7 mg Caff/kg bw/day. The applied fluoride caused increase of nitric oxide level (NO), intensified lipid peroxidation (TBARS) and decreased total antioxidant status in serum (TAS), brain, kidney and liver. Caffeine administered intragastrically, as an antioxidant, was relatively efficient in alleviating these adverse effects of F. In rats treated only with fluoride the F excretion in urine significantly increased in an exposure-time dependent-manner and did not change both in rats treated with Caff and co-exposed to Caff and F.

Assessment of fluoride concentration and daily intake by human from tea and herbal infusions.

The fluoride content in infusions of commercially available black, green, oolong, pu-erh and white teas was determined by ion-selective electrode. Herbal infusions as well as instant tea and ready-to-drink tea beverages were also examined. It is found that brewing time (5, 10 and 30 min) does increase the fluoride content, which in infusions of black tea (5 min brewing) was higher than that in the other types of tea, with contents ranging between 0.32 and 4.54 mg/l for black tea to 0.37-0.54 mg/l for white tea and with even lower values for herbal tea infusions of 0.02-0.09 mg/l. On the basis of the results obtained, the daily intake of fluoride provided from tea and herbal beverages was estimated for an adult person and for children in comparison with the Polish SAI (Safe and Adequate Daily Intake) of fluoride which is strictly attributable to ADI (Acceptable Daily Intake). The fluoride intake resulted from the regular consumption of black tea infusions was raised as compared to the other types of teas as well as herbal teas. For adult and children tea drinkers consuming five cups of black tea per day the intake of fluoride will be in the range of 8.0-303% and 12-303% of the SAI, respectively. People are often exposed to multiple sources of fluoride, such as in food, water, air and excessive use of toothpaste. The control of tea quality is important to protect human against too high uptake of this element from black tea, which is the most popular beverage. Excessive intake of fluoride with black tea, especially in the regions with its high level in the drinking water, increases the risk of dental fluorosis in children during the years of tooth development. The long-term exposure to large amounts of fluoride can lead to potentially skeletal fluorosis (WHO, 1984).

Distribution of mercury and other trace metals in the cockle Cerastoderma glaucum from the Mediterranean Lagoon Etang de Thau.

The concentrations of Ag, Cd, Co, Cr, Cu, Ni, Pb, Zn, Mn, and Fe in the soft tissue of the cockle Cerastoderma glaucum from six sites along the Mediterranean Lagoon Etang de Thau were determined by AAS; Hg was determined by the cold-vapor technique. Significant spatial variations in metal concentrations within the lagoon were recorded. Elevated levels of tissue Pb, Cr, and Hg in the Etang des Eaux Blanches, an area adjacent to the harbor and highly industrialized region, are likely of anthropogenic origin. Seasonally dependent variations in the tissue concentrations of trace elements at Crique de l'Angle were observed. The highest levels of Cr and Pb in the tissue were identified in March 1992, of Hg, Co, and Fe in period August 1990-January 1991, of Mn in August 1992, and Ag in January 1991. The gills contained the maximum amounts of Co and Ni, the mantle the most Fe and Hg, and the digestive gland (hepatopancreas) had most Cu.

Lead and fluoride content in human bone and hair in the Gdansk region.

The post-mortem lead and fluoride content in the rib bone and hair of 59 persons from the Gdansk region was determined. Fluoride was estimated potentiometrically using a fluoride-specific electrode. Lead was determined by atomic absorption spectrometry. The mean lead concentration in bone was 3.0 micrograms/g and 5.2 micrograms/g in hair. The mean fluoride concentrations were 625.7 micrograms/g and 1.4 micrograms/g in bone and hair, respectively. A positive correlation between the lead content in bone and hair was found in this study (r = 0.308, P < 0.05), no such correlation was observed between the fluoride content in bone and hair. A positive correlation between the fluoride and lead contents in bones and the age of the investigated persons was found. The results obtained correspond well with the comparably moderate exposure to lead and fluoride in the Gdansk region.

Fluoride in drinking water and human urine in northern and central Poland.

The fluoride concentration in drinking water and in urine of the inhabitants of 94 localities in Northern and Central Poland was determined. The analyses were performed potentiometrically using a fluoride-specific electrode. In most of the localities the fluoride concentration in water was < 0.3 mg/l, which is far below the recommended level for caries control. In these communities fluoridation of water is advised. In six localities the water fluoride concentration was 1.2 mg/l. The elevated water fluoride is of natural (Malbork) as well as of anthropogenic (Wislinka) origin. The mean fluoride level in the urine in the investigated localities was 1.10 mg/l (range 0.10-2.67 mg/l). No significant correlation between the concentration of fluoride in drinking water and human urine was found in this study. This suggests that the elevated fluoride level in urine may be caused not only by the water fluoride, but also by the inhalation of dust particles containing fluoride, and by the diet.

Mercury and major essential elements in seals, penguins, and other representative fauna of the Antarctic.

Concentrations of total Hg and major essential elements, Ca, Mg, Na, and K, were measured in the muscle, liver, and kidney of three species of seals, crabeater seal (Lobodon carcinophagus), leopard seal (Hydrurga leptonyx), and Weddell seal (Leptonychotes weddelli) collected in the Antarctic. The muscle and liver of three species of penguins, i.e., gentoo penguin (Pygoscelis papua), Adelie penguin (P. adeliae), chinstrap penguin (P. antarctica), and other representative fauna were also analyzed for the elements. Distinct inter-tissue differences in the metal concentration were observed; liver had the greatest concentrations of Hg, kidney showed maximum concentration of Ca and Na, while muscle was characterized by the greatest content of Mg and K. Inter-specimen differentiation of concentrations among the same species was distinctly visualized for Hg but not for the major essential elements. The Hg concentration in the seals analyzed are in keeping with those reported previously by other authors. Such comparison for Ca, Mg, Na, and K was impossible because of the lack of available literature data for their concentrations in marine seals. Numerous significant correlations were observed between concentrations of the several metals analyzed. There was no correlation between Hg, which is a non-essential element and both Zn and Cd which are essential and non-essential elements, respectively in the liver or kidney of seals. However, there were significant correlations between concentration of Zn and the sum of molar concentrations of Hg+Cd in kidney (r = 0.82) and liver (r = 0.76). The results suggest that several control mechanisms operate to maintain physiologically required levels that decreases any effect of heavy metal toxicants such as Hg and Cd.

Fluoride in the urine, hair, and nails of phosphate fertiliser workers.

The fluoride content in the urine, hair, and nails of 106 workers employed in a phosphate fertiliser plant was significantly raised above the control level. Positive correlations were found between the group means for concentrations of fluorides in urine and hair (r = 0.77), urine and nails (r = 0.99), and hair and nails (r = 0.70). Individual values in the whole population gave significant correlations between concentrations in urine and nails (r = 0.73). The obtained results indicate that the fluoride content in hair and nails may be used as an indicator of occupational exposure to fluorides.