Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Toxicology”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources
USGS1979

Tolerance of developing salmonid eggs and fry to nitrate exposure

This paper reports on tests which show significant effects on early salmonid life stages of nitrates at levels commonly found in groundwaters in geographical areas that are influenced by fertilizer application. It has long been known, from fish cultural experience, that in certain site specific locations, chronic problems can be expected with salmonid egg development and early fry mortality. However, fingerlings which survive usually grow normally. A complete explanation is lacking although several environmental factors have been proposed to account for this phenomenon. One, which has so far received little attention, is that nitrate levels in the ground and surface waters of many areas have been increasing significantly over historical background levels. Ammonia, urea, and other potential sources of nitrate can enter natural waters from a variety of sources, such as domestic or industrial sewage, animal feedlots, or seepage and return flows from agricultural lands. The latter may be the largest contributor, since billions of tons of nitrate fertilizers are applied to agricultural crops on a worldwide basis each year. In addition, intensive forest management techniques include the aerial application of nitrate fertilizer to increase the yield of wood products, while range management practices call for use of nitrates to increase forage production. The nitrate that is not taken up by plants ultimately appears in ground or surface waters.

Bulletin of Environmental Contamination and Toxico↗
USGS1971

DDE thins eggshells and lowers reproductive success of captive black ducks

Eggs of captive black ducks fed diets containing DDE at 10 and 30 ppm (dry weight) experienced significant shell thinning and an increase in shell cracking when compared to eggs of untreated black ducks. Eggshells from dosed ducks were: 18-24 percent thinner at the equator than shells from undosed ducks; 28-31 percent thinner at the cap; and 29-38 percent thinner at the apex. Shell cracking averaged 21 percent among eggs fram the 30 ppm DDE dosage and 10 percent among eggs from the 10 ppm dosage. Only 2 percent of the eggs from untreated black ducks were cracked. Survival of ducklings fram dosed parents in terms of 'percentage of 21-day ducklings of embryonated eggs' was 40-76 percent lower than survival of ducklings from undosed parents. Average DDE residues (wet weight) in eggs from hens fed 10 and 30 ppm DDE were 46 ppm and 144 ppm, respectively.

Bulletin of Environmental Contamination and Toxico↗
USGS1972

DDE at low dietary levels kills captive American kestrels

Two of 14 male American kestrels died after 14 and 16 months on a diet containing 2.8 p.p.m., wet weight, p, p'-DDE. The brains of the two birds contained DDE residues of 213 and 301 p.p.m. compared with 14.9 p.p.m. (range, 4.47-26.6 p.p.m.) (wet weights) for 11 of the adult males which were sacrificed after 12 to 16 months on dosage. Autopsies of the two birds compared with autopsies of the sacrificed birds, revealed other characteristics typical of DDE poisoning. Neither bird, when autopsied, displayed characteristics which would suggest that they died of causes other than DDE poisoning.

Bulletin of Environmental Contamination and Toxico↗
USGS1973

DDE: Interference with extra-renal salt excretion in the mallard

The effects of DDE on the function of the salt gland, the main route of sodium chloride excretion in marine birds, were investigated in mature mallards, Anas platyrhynchos, maintained on either fresh water or 1 percent salt water and given 0, 10, 100, or 1000 ppm DDE in the diet (12 birds per level). The rate of sodium chloride excretion by the salt gland following injections of concentrated salt solutions was not reduced (from that of controls) in DDE -treated birds maintained on salt water, but was significantly reduced in DDE -treated birds not previously given salt.

Bulletin of Environmental Contamination and Toxico↗
USGS1980

Toxicity of five forest insecticides to cutthroat trout and two species of aquatic invertebrates

The Northern Rocky Mountain region has had scattered infestation of the western spruce budworm Christoneura occidentalis since the early 1900's (U.S. DEPARTMENT OF AGRICULTURE (USDA) 1976b). On the basis of aerial surveys in 1975, TUNNOCK et al. (1976), estimated that budworm defoliation occurred on 2,278,804 acres of six National Forests in Montana. Since the use of DDT was banned in 1972, there has been a need to develop alternative insecticides with the efficacy of DDT but without its environmental risk. These insecticides must be effective in controlling the budworm, but should not persist in the environment or be toxic to other organisms. The organophosphate and carbamate insecticides are relatively nonpersistent and generally present only a moderate hazard to fish when applied according to label recommendations. The USDA Forest Service has been investigating the effectiveness of these two classes of insecticides against the budworm, and the Columbia National Fisheries Research Laboratory of the U.S. Fish and Wildlife Service has been cooperating with the Forest Service conducted pilot control projects in eastern Montana in 1975 and 1976 to determine the efficacy and environmental impact of acephate, carbaryl, and trichlorfon in controlling the western budworm (USDA 1976 b). In 1975, a similar type project was carried out in Maine with aminocarb, fenitrothion, and trichlorfon (USDA 1976 a). Acephate, fenitrothion, and trichlorfon (organophosphate insecticides) and aminocarb and carbaryl (carbamate insecticides) were selected for toxicity tests against cutthroat trout ( Salmo clarki ), a stonefly ( Pteronarcella badia ), and a freshwater amphipod ( Gammarus pseudolimnaeus ) edemic in streams of the northern Rocky Mountains. Populations of cutthroat trout inhabit lakes and streams in the Rocky Mountains which include some of the most pristine habitat and fisheries in North America. Pteronarcella and Gammarus provide forage for cutthroat trout and feed on decaying vegetation in riffle areas in streams and rivers. Stonefly naiads and amphipods were selected as test organisms because of their importance as trout food and their wide distribution in mountain stream communities. We determined the effect of various water types representing different biogeographical areas in the Intermountain West on the toxicity of these five forest insecticides.

Bulletin of Environmental Contamination and Toxico↗
USGS1988

Toxicity of six heterocyclic nitrogen compounds to Daphnia pulex

We determined the relative toxicities to the aquatic crustacean Daphniz pulex of six heterocyclic nitrogen compunds. These compounds were selected because they were detected in lake trout or walleyes and were commercially available. Stress to the daphnid populations may affect forage fish populations that depend either directly or indirectly on zooplankton as a food source in the Great Lakes.

Bulletin of Environmental Contamination and Toxico↗
USGS1974

Eggshell thinning and residues in mallards one year after DDE exposure

A group of 16 mallard hens ( Anas platyrhynchos ), that had been given feed containing 40 ppm of p,p' -DDE for 96 days, laid eggs with shells averaging about 15%–20% thinner than those of ten control birds during and up to 42 days after treatment. In eight of the treated birds killed at that time, whole-body DDE residues averaged 33.1 ppm (wet weight). The other eight treated birds and ten controls were kept through the winter with no additional DDE exposure and penned separately five days for individual egg collection about three weeks after laying began in spring. At that time (nearly 11 months after DDE feeding had stopped), the treated birds laid eggs with shells averaging 7.4% thinner than control eggshells (significant at P≤0.05) and their whole-body DDE residues averaged 9.6 ppm (wet weight). Variations in eggshell thickness and DDE residues were considerable among treated birds. However, regression analysis showed moderate negative correlations (r=−0.51 to −0.62) between eggshell thickness and DDE residues in whole bodies and eggs, and strong positive correlations (r=0.73 and 0.91) between DDE residues in whole bodies and in eggs.

Archives of Environmental Contamination and Toxico↗