title: 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.
abstract: 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 0.877mgkg(-1) but most samples (90%) could be classed as Se-deficient (<0.6mgkg(-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 0.37mgkg(-1), respectively). Water-soluble soil-Se (6.69 to 26.78μgkg(-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.
authors.affiliation: British Geological Survey, West Mains Road, Edinburgh EH9 3LA, United Kingdom. fmf@bgs.ac.uk
authors.forename: F M
authors.initials: FM
authors.lastname: Fordyce
authors.forename: N
authors.initials: N
authors.lastname: Brereton
authors.forename: J
authors.initials: J
authors.lastname: Hughes
authors.forename: W
authors.initials: W
authors.lastname: Luo
authors.forename: J
authors.initials: J
authors.lastname: Lewis
mesh_terms: D000818:Animals; D018556:Crops, Agricultural / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data; D004784:Environmental Monitoring / Q000379:methods*; D005504:Food Analysis; D005506:Food Contamination; D019015:Geologic Sediments / Q000737:chemistry; D008460:Meat / Q000032:analysis; D008892:Milk / Q000737:chemistry; D006109:Poaceae / Q000737:chemistry; D012606:Scotland; D012643:Selenium / Q000032:analysis* / Q000378:metabolism; D012987:Soil / Q000032:analysis; D012989:Soil Pollutants / Q000032:analysis* / Q000378:metabolism; D011198:Solanum tuberosum / Q000737:chemistry; D014908:Triticum / Q000737:chemistry
chemical_list: D012987:Soil; D012989:Soil Pollutants; D012643:Selenium