Concentrations of trace elements in human blood serum from different places in Norway determined by neutron activation analysis

Biomonitoring for environmental exposures to arsenic

Arsenic (As) is a widely occurring environmental contaminant. To assess human exposures to As, public health officials and researchers often conduct biomonitoring. Samples of urine, hair, nails, or blood are collected from potentially exposed people and are analyzed for As compounds and their metabolites. When analyzing for As exposure, it is useful to distinguish between As species, since they differ in their origin and toxicity. Urine is the most frequently used biological medium for biomonitoring. Measuring the urinary concentration of As is useful in assessing recent exposure to As, and high-quality reference ranges are available for urinary As concentrations in the U.S. population. Biomonitoring for As in hair and nails has been used in many studies and is particularly useful in evaluating chronic exposures to As. Interpreting the health implications of As concentrations in biological samples is limited by the small number of studies that provide information on the correlation and dose-response relationship between biomonitoring test results and adverse health effects. This study discusses the advantages and limitations of biomonitoring for As in biological samples and provides illustrative case studies.

Trace element reference values in serum determined by inductively coupled plasma atomic emission spectrometry

Serum reference values for Ba, B, Cd, Cu, Fe, Mn, Li, Se, Sr, and Zn in 141 healthy Norwegians were determined. The trace element concentrations were determined by the inductively coupled plasma atomic emission spectrometry technique that we have recently validated. The reference intervals were established according to the recommendations of the International Federation of Clinical Chemistry and Laboratory Medicine. Also coverage intervals with coverage uncertainties were calculated according to the International Union of Pure and Applied Chemistry. The population studied consisted of 69 men and 72 women of the ages 21-87 years. The effects of gender, age, smoking, and oral contraceptives on serum levels of trace elements were investigated. Median concentrations of the different trace elements in (micromol/l) were as follows: Ba (0.44), B (1.50), Cd (0.004), Cu (17.1), Fe (21.4), Li (0.06), Mn (0.003), Se (1.26), Sr (0.17), and Zn (13.3). An increase in serum Ba and Sr was detected with age. These metals and Se were also significantly higher in women over 50 years of age in comparison to younger women. Women had higher serum Cu than men and those on oral contraceptives had higher serum Cu and Fe. Serum B tended to increase with age, while it was significantly reduced with smoking.

Essential trace elements in humans. Serum arsenic concentrations in hemodialysis patients in comparison to healthy controls

Serum arsenic concentrations of persons suffering from renal failure and undergoing hemodialysis treatment (n = 85) and of healthy controls (n = 25) were determined by hydride-generation AAS technique after microwave digestion. The results were evaluated by comparing the values of both groups, considering physiological factors and individual data, as well as comorbid conditions of the hemodialysis (HD) patients. Serum arsenic levels were diminished in the patient group compared with controls (mean values 8.5 +/- 1.8 ng/mL vs 10.6 +/- 1.3 ng/mL). Furthermore, additional diseases within the hemodialysis group, particularly injuries of the central nervous system (CNS), vascular diseases, and cancer, were correlated to occasionally markedly decreased serum arsenic concentrations. It was concluded that arsenic homeostasis is disturbed by HD treatment and certain additional diseases. Desirable arsenic concentrations in the body seem to be reasonable. This consideration results in the conclusion that arsenic could play an essential role in human health. Thus, reference arsenic concentrations in different human tissues and body fluids should be established in order to recognize not only arsenic intoxication, but also arsenic deficiency. Perhaps arsenic deficiency contributes to the increased death risk of HD patients, and therefore, arsenic supplementations for patients with extremely low serum arsenic concentrations should be taken into account.

Supplementation with wheat selenium induces a dose-dependent response in serum and urine of a Se-replete population

In spite of a rather modest dietary intake of selenium (80 micrograms/10 MJ), Norwegian serum Se levels are among the highest in Europe. As part of an ongoing study of Se bioavailability, effects of different doses of wheat Se were investigated in eighteen healthy, Norwegian women. The participants were given Se-rich bread providing 100, 200 and 300 micrograms Se daily for 6 weeks. About 50% of the Se intake was excreted in the urine by week 6, compared with 67% before the intervention started. Serum Se increased by 20, 37 and 53 micrograms/l respectively, in the three group (P less than 0.001). The blood response and renal clearance results compare well with data obtained from less Se-replete populations, and support the hypothesis that selenomethionine from the diet is incorporated into a non-specific amino acid pool. Our study indicates that the intake of wheat Se is the main determinant of blood Se levels in Norway.

Observations on biochemical and haematological parameters in healthy people above 80 years of age

Ninety-five apparently healthy people, aged 80 years or above, living in the Stockholm County Council of Sweden, participated in a pilot study in 1984. Reference values were obtained for routine haematological and biochemical analyses. Deviations from expected levels were confined to thyroid-stimulating hormone (TSH), vitamin B12 and calcium. It is noteworthy that a low-risk cholesterol level characterized this elderly population. It is suggested that in order to evaluate the influence of age, a dynamic aspect should be added using functional tests of various organs.

The Tromsø Heart Study: serum selenium and risk of myocardial infarction a nested case-control study

The association between serum selenium concentration and the risk of myocardial infarction was studied in a nested case-control study. Altogether 59 men, initially free of disease, aged 28-54 at the time of blood sampling, died suddenly or experienced a fatal or non-fatal myocardial infarction during a six year follow-up period. Case-control pairs came from a population of 9364 persons examined in 1979-80 in the second Tromsø Heart Study. No significant difference was observed between serum selenium in cases and controls (p = 0.34). The major determinants of myocardial infarction and sudden death were raised levels of serum cholesterol and triglycerides (p less than or equal to 0.001) and high systolic blood pressure (p less than 0.05). Thus, in this population with intermediate selenium intake, low serum selenium is not associated with an excess risk of myocardial infarction.