Nationwide supplementation of sodium selenate to commercial fertilizers: history and 25-year results from the Finnish selenium monitoring programme.

Abstract

Selenium is unevenly distributed in soils worldwide. For climatic and geochemical reasons, Finland is one of the low-selenium regions in the world. To improve the quality of Finnish foods and animal health and to increase the selenium intake of the population, an official decision was made in 1984 to supplement compound fertilizers with selenium. Practically all fertilizers used in Finland have contained selenium since 1985. The objective of this chapter is to report the effects of the supplementation of selenium to commercial fertilizers on soils, feeds, basic foodstuffs, dietary selenium intake, human tissues and the environment. Within a monitoring programme, sampling of cereals, basic foodstuffs, feeds, fertilizers, soils and human tissues has been carried out at least annually since 1985. The systematic error in selenium analyses has been followed annually by a quality assessment scheme involving seven participating laboratories. The selenium concentration of spring cereals increased on average 15-fold compared with the level before the selenium fertilization practice. The mean selenium concentration in beef and pork increased six- and twofold, respectively, and in milk threefold, compared with levels before selenium fertilization. The average dietary intake increased from 0.04 mg Se/day to a plateau of 0.07 mg Se/day in the mid-2000s. Foods of animal origin in 2006 contributed over 75% of the total daily intake of selenium. The mean human plasma selenium concentration increased by 60% and the selenium status is optimal. Evident signs of selenium transport into natural waters have not been found. In Finland, where the geochemical conditions are relatively uniform, the nationwide supplementation of fertilizers with selenium has proved to be an effective, safe and controlled way of bringing the selenium intake of the whole population to the recommended level. Moreover the well-being of animals has been secured.

Nutrition policy in Finland

“…To improve the quality of Finnish foods, animal health and to increase the selenium intake of the population, an official decision was made in 1984 to supplement compound fertilizers with selenium. Practically all fertilizers used in Finland have contained selenium since 1985 (15) .…”

Continued Selenium Biofortification of Carrots and Broccoli Grown in Soils Once Amended with Se-enriched S. pinnata

“…In Finland, where the geochemical soil conditions are relatively uniform, two decades of supplementation of soils nationwide with fertilizers containing inorganic-Se has proven to be a safe and effective way of significantly increasing Se concentrations in most crops grown for human consumption (Alfthan et al, 2010). Similarly, Great Britain has undertaken efforts to develop soil amendment practices with inorganic-Se designed to increase dietary Se intake in the general population via the Se biofortification of food (Rayman, 2012).…”

Monitoring diet and diet-related chronic disease risk factors in Finland

“…Sodium intakes have been monitored by 24 h urinary excretion measurements in four risk factor surveys since the late 1970s (28) . The low level of selenium in the Finnish soil and disturbingly low intakes of selenium were the reason for the enrichment of fertilisers with selenium in 1984, and the selenium status of different population groups have been monitored by a special monitoring programme since then (29) . Since 1992, nutritional status has been monitored in smaller sub-samples of the National FINRISK Studies.…”