The effect of 50, 100, 150, and 400 mu-g sodium pentachlorophenate (Na-PCP) per gram soil was studied in nonsterile soil incubated under aerobic and anerobic conditions, and in sterilized soil inoculated with Azotobacter sp. isolated from the soil. N(,2) fixation was determined by acetylene reduction. Pentachlorophenate at a concentration of 50 mu-g/g had an inhibitory effect in nonsterile soil incubated aerobically while strong inhibition of dinitrogen fixation in nonsterile soil occurred in the presence of 100 mu-g/g and above. The EC(,50) values for the inhibition of nitrogenase activity in nonsterile soil incubated aerobically and anaerobically and in sterlilized soil inoculated with Azotobacter sp. suspensions were 49.8 +/- 1.4 mu-g Na-PCP/g, 186.8 +/- 2.8 mu-g Na-PCP/g, and 660.8 +/- 29.3 mu-g Na-PCP/g, respectively.

The study quantifies the amount of metals, (Na, K, Mg, Ca, Al, Fe, Mn, Ni, Cr, V, Cu, Zn, Cd, Pb) leached from the A-horizon of a podzolic spruce forest soil in southern Sweden during 2.5 yr, and offers statistical evidence of environmental conditions of importance to metal release. Considerable losses of Pb, Cr, Ni and V may occur from the A-horizon of forest soils under conditions favoring leaching of organic matter, Fe, and Al, i.e. during periods of comparably high soil temperature and moisture. Metals with a larger fraction present in exchangeable form (Na, Mg, Ca, Zn, Cd) are more susceptible to minor pH changes. An accelerated deposition or internal production of acidic matter therefore will reduce the retention times of these elements particularly.

Water samples from the Rhode River, an estuary situated on the western shore of the Chesapeake Bay, were analyzed for atrazine residues twice a week for 2 yr. Precipitation samples, which included dryfall, rainfall, and snowfall were collected with wide-mouth stainless steel collection pans situated about 20 m above ground in an open space. A total of 68 precipitation samples was collected from December 1976 to February 1979. Atrazine residues were detectable in estuarine water and in rainwater year-round. Atrazine residues in estuarine water were generally 6 to 190ng/l, atrazine residues in rainwater (bulk precipitation) were 3 to 2190ng/l. Atrazine residues in rainwater samples collected during the winter season (January to April 1977) were unexpectedly high (e.g. 3 to 970ng/l). The highest atrazine concentration of 2190ng/l was detected from a 0.76 cm rainfall event collected on May 19, 1977. Intermittent spraying operations of atrazine within the cornfields were generally done during May of each year. Rain samples collected during May of 1978 also showed higher atrazine residues than the rest of the 1978 growing season, but at levels much less than those detected in 1977 rainwater. Although high attrazine concentrations were detected in winter rainfall, these did not result in similarly higher atrazine concentrations in estuarine receiving waters. Our data showed a decline of atrazine concentrations in estuarine water in October and November which continued until a rainfall following Spring herbicide applications. Atrazine is enriched at the microsurface layer of estuarine water, but direct atmospheric input of atrazine did not seem to contribute significantly to the enrichment mechanism. Atrazine is believed to be transported long distances in polluted air masses. The estuarine microsurface layer could be a source of atmospheric atrazine, but the importance of the source is yet to be determined. Atrazine was quantitatively determined by GC using a nitrogen specific electrolytic detector and was confirmed by GC/Mass.

The existence of a rainfall anomaly downwind of the St. Louis urban-industrial areas prompted a survey of area soils for elevated heavy metal concentrations. The goals of this work were to measure concentrations of Zn, Cd, and Pb, and to evaluate the role of the urban rainfall anomaly in their accumulation, in potentially-affected soils. Samples from three soil layers were collected from agricultural fields at 21 sites along two NE-SW transects. The samples were analyzed for pH, texture, cation exchange capacity, and total organic carbon, in addition to the three metals. The highest metal concentrations were observed near Granite City, Illinois, and coincided with an area of maximum Zn deposition in rain found in an earlier study. Only slight increases of the metals over background were found in the area of rainfall anomaly. Present rates of atmospheric deposition can account for these slightly elevated metal concentrations. However, the maximum concentrations found near Granity City cannot be accounted for by present atmospheric deposition rates. Other kinds of sources, or larger atmospheric deposition rates, perhaps during the operation of a local Zn smelter which closed about 1960, must have contributed.

Visakhapatnam Basin, located on the east coast of India adjoining the Bay of Bengal, is surrounded by hills. Groundwater in the basin is utilized for domestic, irrigational, and industrial purposes. The basin measures about 148 km('2) in which 35% of the land is utilized for irrigation, and 10% of the land for industries. However there is a rapid industrial development in the basin along with increasing population initiating the necessity to evaluate groundwater resources. The chemical quality of groundwaters available in the basin is discussed in relation to domestic, irrigational, and industrial purposes.

Element mass balance estimates for South Carolina Coastal Plain watersheds indicate that fertilizers and liming materials are the major sources for inputs of Ca, Mg, K, Cl, and HCO(,3) whereas precipitation is the major input for Na and SO(,4). Stream flow is the chief mode of output for all of these elements. A balance between input and output is evident only for Cl. Retentions of 50% or more are shown by Ca, Mg, K, HCO(,3), and SO(,4) whereas Na shows an apparent net loss. The retention of Ca, Mg and HCO(,3) suggests that less than 25% of the dolomitic liming materials applied to the landscape actually dissolve and that the carbonate chemistry of Lower Coastal Plain streams is therefore probably largely controlled by seepage of groundwaters from underlying calcareous aquifers. The retention of K and the loss of Na may be due to cation exchange reactions on soil clays whereas the apparent retention of SO(,4) is probably due to reduction to H(,2)S in floodplain environments and soil adsorption.