Selenium levels of Estonians.

BACKGROUND: The objective of this study is to sum up the dietary selenium intake of the Estonian people according to the serum selenium concentrations. SUBJECTS/METHODS: This research compiles the information published in the literature about the levels of selenium in the serum of the Estonian people. We compare these results with the findings obtained from the analyses of serum samples gathered by us in the 1990s in Estonia. RESULTS: The selenium concentration in sera of 404 Estonians ranged from 26 to 116 microg/l; the mean was 75 microg/l. The selenium contents of Estonians were at a similar level as reported for Finns before the selenium supplementation of fertilizers carried out in Finland in 1984. CONCLUSION: In view of the selenium concentration in the sera, we suggest that the dietary selenium intake among the Estonian people might be scarce, and Estonian authorities should consider in their nutrition policies the possible low intake of selenium of Estonians.

Alterations of heme metabolism in lymphocytes and metal content in blood plasma as markers of diesel fuels effects on human organism.

Workers in the diesel fuel distribution trade are intensively exposed to fuel vapours. Diesel fuel presents the main source of air pollution by benzene at a marine diesel fuel terminal. Levels of benzene are used to evaluate the external exposure to diesel fuel. Since benzene causes alterations in porphyrin metabolism, and some of these may lead to the generation of tumours, heme synthesis is proposed as a biomarker of early health effects of diesel fuel. A group of 20 workers exposed to diesel fuel and a group of 20 unexposed persons were examined and interviewed using structured questionnaires. The levels of 5-aminolevulinic acid (ALA) and protoporphyrin (PP), activities of ALA synthase and ferrochelatase, as well as levels of PP associated with DNA were determined in lymphocytes spectrophotometrically. Amounts of the metals Cd, Mn, Zn, Cu and Ca were measured in blood plasma by flame atomic absorption spectrometry method. Both ALA and PP levels were significantly increased in marine terminal workers: 3.0 +/- 0.4 vs. 0.8 +/- 0.2 nmol/10(6) lymphocytes: and 511 +/- 164 vs. 389 +/- 77 pmol/10(6) lymphocytes in exposed and control individuals, respectively. ALA-synthase activity was 2.5 fold higher in lymphocytes of workers exposed to diesel fuels (P < 0.01). At the same time ferrochelatase activity was decreased and protoporphyrin level was accordingly elevated. The amount of porphyrin associated with DNA increased 1.4 fold in exposed workers (P = 0.05). Among all investigated metals in blood plasma of exposed workers only zinc levels were statistically significantly increased (P < 0.05). The disturbances of heme metabolism in lymphocytes and zinc level in blood plasma caused by diesel fuel exposure seems to be a useful biomarkers for carcinogenic risk assessment.