Merja Eurola

Effects of nationwide addition of selenium to fertilizers on foods, and animal and human health in Finland: From deficiency to optimal selenium status of the population

Despite different geological features the Nordic countries are generally selenium-poor areas. In each country various factors such as food importation and life-style determine the selenium (Se) intake. Due to an extremely low Se intake in the 1970s in Finland, 0.025 mg/day, an official decision was made in 1984 to supplement multinutrient fertilizers with Se in the chemical form of sodium selenate. Almost all fertilizers used in Finland since 1985 have contained Se. Currently all crop fertilizers contain 15 mg Se/kg. Finland is still the only country to take this country-wide measure. In a national monitoring programme, sampling of cereals, basic foodstuffs, feeds, fertilizers, soils, and human tissues has been carried out annually since 1985 by four governmental research organizations. Sampling of foods has been done four times per year and human blood has been obtained annually from the same (n=60) adults. The accuracy of analyses has been verified by annual interlaboratory quality control. During this programme the selenium concentration of spring cereals has increased on average 15-fold compared with the level before the Se fertilization. The mean increase in the Se concentration in beef, pork and milk was 6-, 2- and 3-fold. In terms of Se, organically grown foods of plant origin are generally comparable to products produced before the Se supplementation of fertilizers. Milk from organically fed cows is 50% lower in Se than the usual milk. The average dietary human intake increased from 0.04 mg Se/day/10 MJ in 1985 to a present plateau of 0.08 mg Se/day/10 MJ, which is well above the current nutrition recommendations. Foods of animal origin contribute over 70% of the total daily Se intake. The mean human plasma Se concentration increased from 0.89 μmol/L to a general level of 1.40 μmol/L that can be considered to be an optimal status. The absence of Se deficiency diseases and a reference population have made conclusions on the impact on human health difficult. However, the rates of cardiovascular diseases and cancers have remained similar during the pre- and post-supplementation indicating medical and life-style factors to be much stronger determinants than Se. The nationwide supplementation of fertilizers with sodium selenate is shown to be effective and safe in increasing the Se intake of the whole population. Also, the health of animals has improved.

Effects of Selenium Fertilization on the Selenium Content of Selected Finnish Fruits and Vegetables

Abstract In order to raise the selenium (Se) content of Finnish foods all agricultural and horticultural multinutrient fertilizers have been supplemented with sodium selenate since autumn 1984. This intervention has affected practically all agricultural products in Finland. The Se content of 16 fruits and vegetables was determined by electrothermal atomic absorption spectrophotometry. The selenate supplemented fertilization has clearly increased the Se content of most vegetables, with onion and the cruciferous vegetables (cabbages, broccoli and swede) showing the highest increments; fruits are still low in Se. The mean Se values (mg/kg dry matter) were potato 0.07, carrot 0.07, swede 0.18, white cabbage 0.23, chinese cabbage 0.35, broccoli 0.75, lettuce 0.03, spinach 0.11, rhubarb 0.05, onion 0.25, pea 0.23, tomato 0.03, cucumber 0.13, apple 0.01, strawberry 0.02 and black currant 0.04. The Se levels for a single food type varied considerably, perhaps reflecting differences in fertilization practices. The...

Contents of trichothecenes in oats during official variety, organic cultivation and nitrogen fertilization trials in Finland

. The differences in DON concentrations between organic and conventional cultivation were small. The results showed also that the use of various nitrogen fertilization levels only slightly affected the trichothecene concentrations. The contents of trichothecenes in Finnish grains appeared to be similar to or lower than those reported earlier in the Northern Hemisphere.

Selenium content of Finnish oats in 1997-1999: effect of cultivars and cultivation techniques

-1 dw. Considerable regional and seasonal variations existed. The Se contents of oats were significantly higher in 1999 probably due to the combined effect of not increased fertilizer level (from 6 to 10 mg Se kg -1 fertilizer) and very low precipitation in 1999. The Se contents of oats were significantly lower in organic cultivation, due to the absence of Se-supplemented fertilization. Sig- nificant (P < 0.001) cultivar differences were detected in official variety trials. The cultivars Veli and Leila showed higher levels of Se.