An initial study to assess the use of geological parent materials to predict the Se concentration in overlying soils and in five staple foodstuffs produced on them in Scotland

• Published in: The Science of the total environment Vol. 408; no. 22; pp. 5295 - 5305
• Main Authors: Fordyce, F.M., Brereton, N., Hughes, J., Luo, W., Lewis, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.10.2010; [Amsterdam; New York]: Elsevier Science; Elsevier
• Subjects: Animals; Biological and medical sciences; Brassica; Commodities; Correlation; Crops, Agricultural - chemistry; Environment. Living conditions; Environmental Exposure - analysis; Environmental Exposure - statistics & numerical data; Environmental Monitoring - methods; Farms; Food Analysis; Food Contamination; Foodstuffs; Geologic Sediments - chemistry; Geology; Grass; Meat - analysis; Medical sciences; Milk; Milk - chemistry; Organic matter; Parents; Poaceae - chemistry; Public health. Hygiene; Public health. Hygiene-occupational medicine; Scotland; Selenium; Selenium - analysis; Selenium - metabolism; Soil; Soil - analysis; Soil Pollutants - analysis; Soil Pollutants - metabolism; Soils; Solanum tuberosum; Solanum tuberosum - chemistry; Staples; Triticum - chemistry; Triticum aestivum; Wheat; United Kingdom; Scotland; Great Britain; Europe; British Isles, Scotland; Organic matter; Foodstuffs; pH; Soil; Scotland; Selenium; Grass; Vegetables; Foodstuff; Essential; Meat; Trace element; Soils; Health and environment; Regional geology; Cereal; Trace element (nutrient); Public health; Food
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2010.08.007

Evidence suggests that dietary-intakes of the essential element selenium have fallen in Scotland in recent years, due to changing sources of bread-making wheat. The Scottish environment is thought to be Se-poor due to the geology and climate. This initial study assessed whether geological parent-materials could be used to predict relatively high and low soil-Se areas in Scotland and whether differences in soil-Se were reflected in foodstuff-Se produced on them. Samples (n = 8 per farm) of wheat, calabrese (broccoli), potato, beef-steak, milk, cattle pasture (grass) and soil were collected from pairs of farms (one in each high/low predicted Se area (PSA)). Potatoes and soils were collected from a further 34 farms in high/low PSAs to assess a greater geographical zone. Total soil-Se ranged from 0.115 to 0.877 mg kg -1 but most samples (90%) could be classed as Se-deficient (< 0.6 mg kg −1), irrespective of PSA. Total soil-Se was significantly higher (p < 0.05) in the high than in the low PSAs as expected; however, the difference between the two was small (mean 0.48 and 0.37 mg kg −1, respectively). Water-soluble soil-Se (6.69 to 26.78 μg kg −1) concentrations were not significantly different between the two PSAs (p = 0.71). Soil loss-on-ignition (indicating organic matter content) correlated significantly with total and water-soluble soil-Se (p < 0.001) and exerted a greater control than parent-material on soil-Se. Significant differences between the PSAs for beef-Se (p < 0.001), wheat-Se (p < 0.001), calabrese-Se (p < 0.01) and beef-farm grass-Se (p < 0.05) indicated partial success of the parent-material soil-Se prediction. However, only wheat-Se (p < 0.001) and potato-Se (p < 0.001) correlated significantly with total soil-Se. The results suggest that soil-Se concentrations in the main agricultural areas of Scotland are generally low. Given the low Se concentrations also reported in the food commodities; further investigations may be warranted to fully characterise the Se-status of Scottish produce and dietary-Se intakes in Scotland.