Showing papers in "Environmental Science & Technology in 1972"

Factors affecting plant uptake and phytotoxicity of cadmium added to soils

Abstract: Smelting and electroplating of metals, motor oils, motor vehicle tires, and fungicide sprays are sources of cadmium in the environment. The factors affecting plant uptake and phytotoxicity of cadmium added to soils were investigated. For a set of 30 surface soils, the addition of 50 mg Cd (from CdCl/sub 2/) to 500 g of soil reduced yield and sharply increased Cd levels in analyzed portions of radish and lettuce plants when compared to those plants grown on control soil. For the treated soil, plant Cd was significantly related to Cd in the soil. From among 18 potential independent variables, stepwise linear regressions to predict Cd found in plant parts harvested from treated soils included a measure of the relative ability of soils to absorb Cd, acetate-soluble Cd in the soil, soil reaction, and organic matter as significantly contributing independent variables. Plant Cd levels were significantly correlated with amounts of nickel, iron, zinc, and copper in the same plant portion. 22 references.

Mercury pathways in a river and estuary

Abstract: A method for measuring total mercury in water, suspended particulate matter, and bottom sediments has been evaluated. Some data have been applied to a study of the geochemical pathways of mercury in a rural river and estuary system. Concentrations of mercury in the LaHave River (Nova Scotia) are related to the proximity of a small rural town. The dissipation of mercury in solution appears to be through dilution, as well as by adsorption on suspended particulate matter which raises the level in particulate matter to the range of 2.04-34.4 ppm. Bottom sediments in the LaHave River are affected by sedimentation of particulate matter containing high levels of mercury, but the mercury concentration in the bottom sediments ranges from 0.09 to 1.06 ppm. Mercury released to the natural environment from industrial waste effluents appears to be discharged mostly in the dissolved form but may be quite rapidly adsorbed as shown by analyses of suspended particulate matter and bottom sediments. 9 references, 2 figures, 4 tables.

Cadmium contamination of soil and its uptake by oats

Abstract: The extent of cadmium contamination of soils in the Lower Fraser Valley (SW, BC, Canada) was evaluated. Nitric acid-soluble cadmium in the surface samples among 33 agricultural soils averaged 0.88 ppM. However, nitric acid-soluble cadmium reached as high as 95 ppM in a surface sample taken near a battery smelter, but this level decreased considerably with distance and depth. The effect of soil application of carbonate, nitrate, chloride, sulfate, and phosphate salts of calcium on cadmium uptake by oats was determined in a growth chamber study involving soils taken near a battery smelter and from farmland. Oats grown on the contaminated soils contained very high amounts of cadmium in the roots, with smaller amounts in the above-ground portions. Soil treatments affected the cadmium content of roots significantly but did not affect the cadmium content of tops.

Recent sedimentary history of Lake Mendota, Wis

Abstract: The chemical composition of several sediment cores taken from Lake Mendota, Madison, Wis., has been investigated to determine changes in the flux of various chemicals to this lake. The uppermost sediments consist of approximately 1/2 meter of black gyttja. The chemical stratigraphy of a 9.9 meter-long core indicates that stable conditions existed in Lake Mendota and its watershed prior to the settlement of the area surrounding the lake by white man in the mid to late 1800s. Since that time, there has been an appreciable increase in the amounts of phosphorus, iron, manganese, aluminum, and potassium in the uppermost sediments. The organic carbon content of the sediments has fluctuated several times in the past with the most recent sediments showing slightly higher values than the older sediments. This study has demonstrated the feasibility of using the chemical composition of lake cores to estimate the influence of cultural activities of man on the rate of eutrophication of a lake.

Experimental characterization of ventilation systems in buildings

Abstract: Experiments were run to determine the extent that laboratory fume hood exhausts are recirculated in buildings. In one experiment, 20% of the exhausted fumes were found to reenter the ventilation system. -- AATA

Mercury and other metals in urban soils

Abstract: A suite of 264 surface soil samples, selected from a 300 sq mile region which includes industrial, agricultural, and residential areas, has been analyzed for mercury and Ag, Ca, Cd, Co, Cr, Cu, Fe, Ni, Pb, and Zn. All these metals are more concentrated in industrial areas than in residential and agricultural areas. All except lead are more concentrated around the airport. An asphalt plant appears to act as a point of mercury discharge.