Distribution of mercury in the environment at Almaden, Spain

An ecological survey of the concentration and distribution of mercury in terrestrial and aquatic systems near the mercury mine at Almaden, Spain, was initiated in 1974. Field studies were completed in 1977, and chemical analyses were completed in 1979. Sample collection at Almaden followed a trophic-level approach in which certain compartments were sampled at a given instant in time (fall 1974, fall 1975, spring 1976, fall 1976, spring 1977). Mean total mercury concentration in terrestrial plants (8 taxa combined) ranged from >100 ..mu..g/g within 0.5 km of the mine to 1 ..mu..g/g 20 km distant from the mine. Different plant species had different affinities for mercury, but moss species usually had higher total mercury concentration than vascular plants. Woody plants were lower in mercury concentration than forbs. Total mercury concentration in muscle, brain, kidney, and liver tissue from mice was highest at a station near the stream receiving liquid effluent from the mine (mean total mercury at this station ranging from 0.18 ..mu..g/g in muscle to 4.74 ..mu..g/g in kidney). Approximately 15 to 30% of total mercury in mouse tissue was in the methylated form. Total mercury concentration in muscle tissue from house sparrows varied inversely with distance from the mine, with highest concentrations exceeding 0.1 ..mu..g/g. Approximately 1 to 4% of total mercury in sparrow muscle was in the methylated form

Sampling of technetium-99 in vegetation and soils in the vicinity of operating gaseous facilities. Environmental Sciences Division Publication No. 1550

Technetium-99 was measured in vegetation and soils collected near three operating gaseous diffusion facilities to obtain estimates of the soil-to-vegetation concentration factor. Analyses were performed primarily using radiochemical separations and low-level beta counting techniques with selected samples checked by isotope dilution mass spectroscopy. The concentration factor pooled from all three facilities appeared to be lognormally distributed with a geometric mean of 9.5 and a geometric standard deviation of 2.4. These values are comparable to calculated equilibrium concentration factors derived from other field experiments in which concentrations in soil and vegetation were observed to decrease with time subsequent to a single application of/sup 95m/TcO/sub 4//sup -/. These field values are one to two orders of magnitude less than concentration factors derived from laboratory experiments using potted plants. It is suggested that the radiologic significance of /sup 99/Tc in terrestrial food chains of importance to humans may be substantially lower than indicated by the simple difference between laboratory and field concentration factors if the time dependence of technetium activity in vegetation and soil is taken into consideration in radiological assessment models

U.S. Bureau of Plant Industry. [Soil survey report] series 1936, no. 3

Text describes climate, agricultural history, soils and crops, land uses, agricultural methods, productivity ratings, and morphology and genesis of soils for Kaufman County, Texas

U.S. Bureau of Chemistry and Soils. [Soil survey report] ; series 1934 ; no. 10

Text describes the area, climate, agricultural history and statistics, soil-survey methods and definitions, soils and crops, agricultural methods and management, and morphology and genesis of soils in Williamson County, Texas

[U.S. Bureau of Plant Industry, Soils, and Agricultural Engineering. Soil survey report] Series 1938, no. 10

Text describes Fannin County Texas; includes geography, climate, water supply, industries and transportation, agriculture, and soils