Hair mercury content among residents of Cumana, Venezuela.

Mercury in scalp hair of 135 individuals (65 males, 70 females) between the ages of 6 and 61 residing in Cumaná, Venezuela, were determined by cold vapour atomic absorption. The average hair mercury content was 2.01 +/- 0.51 ppm, with a range of 0.42-6.08 ppm. The differences in the distribution of Hg in the hair of male and female subjects were insignificant. Hair mercury content was not correlated with age.

Trace elements in hair: a study of residents in Darjeeling (India) and San Diego, California (U.S.A).

Trace element contents of scalp hair from randomly selected, ethnically homogeneous subjects of Darjeeling (India) were compared with those of the residents of San Diego, California (U.S.A.). The differences between mean concentrations of Ca, Mg, Cu, Na and Cd in the two groups were not significant, and the concentrations of K, Fe, Mn and Zn were significantly higher (P less than 0.01), and that of Al was significantly lower (P less than 0.01), in hair of the residents of Darjeeling. Concentrations of lead in four of the Darjeeling hair samples were very high (greater than 30 micrograms g-1) and in the remaining samples the mean concentration was similar to San diego hair samples. In two mentally retarded Darjeeling subjects, abnormally high values of aluminum (50 and 70 micrograms g-1) and iron (155 and 196 micrograms g-1) were observed. The mean aluminum concentration (2.4 micrograms g-1) in the remaining Darjeeling hair samples was significantly lower than the mean aluminum concentration (10.6 micrograms g-1) in the San Diego hair samples (P less than 0.01). The mean manganese concentration in Darjeeling hair was 20 times higher than the mean manganese content in San Diego hair samples.

Trace elements in hair of epileptic and normal subjects.

The concentrations of Ca, Mg, Zn, Fe and Cu in scalp hair of 101 epileptic patients (48 males and 53 females, average age 25 years) and 101 normal subjects (47 males and 54 females, average age 22 years) were determined by atomic absorption spectrophotometry. Mercury was also determined in some samples. The aim of this investigation was to use scalp hair as a possible indicator of trace element abnormality and to determine whether or not differences in their levels might occur due to this neurological disorder. The results showed significant differences in Fe, Cu, Mg and Zn in the hair between the two groups but no differences were observed in the levels of Ca and Hg. The high Mg and low Zn content in the hair of epileptic patients is reported as of particular interest in the investigation of this neurological disorder.

A preliminary study of mercury contamination in the surface soil and river sediment of the Roscio District, Bolivar State, Venezuela.

The present study constitutes a comparison of mercury in surface soil and river sediments of a contaminated and an uncontaminated area of Venezuela. In the contaminated area, gold prospectors have been using mercury to separate gold from auriferous sand and rock powders for many years. The baseline level of mercury in the river sediments of the uncontaminated area (Manzanares River, Sucre State) was 0.06 micrograms g-1, while in the contaminated area in the Roscio District of Bolivar State the concentration varied from 0.12 to 129 micrograms g-1. In the river sediments the average level of mercury was 0.71 micrograms g-1 and in the surface soil of the working areas 37 micrograms g-1, which shows a significant increase in the mercury level in the contaminated areas. This high level of mercury in the soil and sediments constitutes a serious risk to public health in the contaminated area, where the local people use the water for drinking and other domestic purposes; moreover, they also consume fish from these rivers.

Mercury content of some marine fish from the southern Caribbean Sea.

The mercury concentration in muscle and liver of 63 specimens, comprising 17 species of edible fish from coastal waters of the Caribbean Sea near Cumaná, was determined by cold vapour atomic absorption spectrophotometry. The Hg content of edible muscle tissue, expressed on a fresh weight basis, varied from 0.048 microgram g-1 in lisa (Mugil curema) to 0.190 microgram g-1 in tajali (Trichiurus lepturus), with an average value of 0.096 +/- 0.042 microgram g-1. The corresponding values for liver varied from 0.135 microgram g-1 in lebranche (Mugil brasiliensis) to 0.361 micrograms g-1 in tajali (Trichiurus lepturus), with an average value of 0.269 +/- 0.059 microgram g-1. Of the 17 species analysed, seven had a mercury concentration greater than 0.10 microgram g-1 and the remainder contained less than 0.08 microgram g-1 in edible muscle tissue.

Lithium in drinking water and the incidences of crimes, suicides, and arrests related to drug addictions.

Using data for 27 Texas counties from 1978-1987, it is shown that the incidence rates of suicide, homicide, and rape are significantly higher in counties whose drinking water supplies contain little or no lithium than in counties with water lithium levels ranging from 70-170 micrograms/L; the differences remain statistically significant (p less than 0.01) after corrections for population density. The corresponding associations with the incidence rates of robbery, burglary, and theft were statistically significant with p less than 0.05. These results suggest that lithium has moderating effects on suicidal and violent criminal behavior at levels that may be encountered in municipal water supplies. Comparisons of drinking water lithium levels, in the respective Texas counties, with the incidences of arrests for possession of opium, cocaine, and their derivatives (morphine, heroin, and codeine) from 1981-1986 also produced statistically significant inverse associations, whereas no significant or consistent associations were observed with the reported arrest rates for possession of marijuana, driving under the influence of alcohol, and drunkenness. These results suggest that lithium at low dosage levels has a generally beneficial effect on human behavior, which may be associated with the functions of lithium as a nutritionally-essential trace element. Subject to confirmation by controlled experiments with high-risk populations, increasing the human lithium intakes by supplementation, or the lithiation of drinking water is suggested as a possible means of crime, suicide, and drug-dependency reduction at the individual and community level.

Lithium in scalp hair of adults, students, and violent criminals. Effects of supplementation and evidence for interactions of lithium with vitamin B12 and with other trace elements.

The lithium content of human hair shows an approximately linear response to extradietary lithium supplementation at dosage levels of up to 2000 micrograms/d. From the mean hair lithium concentration of 0.063 micrograms/g in 2648 predominantly American adults, and the reference hair lithium concentrations determined in the present study, the mean lithium intakes were calculated to be 730 micrograms/d. Hair lithium concentrations were extremely low in nearly 20% of the American samples, and in samples collected in Munich, Germany and Vienna, Austria. Hair lithium levels are low in certain pathological conditions, e.g., heart disease, in learning-disabled subjects, and in incarcerated violent criminals. The highest levels were observed in samples of a lithium-treated psychiatric patient. A statistically highly significant direct association was observed between the hair lithium and cobalt concentrations, which suggests a role of lithium in the transport and distribution of vitamin B12. Interactions of lithium with other trace elements are also discussed.

Hair trace elements and mental retardation among children.

The calcium, magnesium, zinc, iron, and copper content found in scalp hair of 40 children with mental retardation were compared with 37 healthy normal children who were between the ages of 4 and 14 yr. The hair of children with mental retardation showed significantly lower levels of iron, copper, and magnesium (p less than .001) and higher levels of calcium (p less than .001). The zinc content did not differ between the two groups. The differences in levels of hair trace elements between normal children and those with mental retardation could be of particular interest in the investigation of the cause of mental retardation among children.