| Ökotoxizitätsauszüge | /BIRDS and MAMMALS/ ... Young herring gulls, Larus argentatus, were used to examine the effect of lead on sibling recognition. Each of 80 one-day-old herring gull chicks was randomly assigned to either a control group or a lead treatment group that received a single dose of lead acetate solution (100 mg/kg) at day 2. Matched controls were injected with isotonic saline at the same age. At 10 days of age, there was no demonstrable sibling recognition in control chicks, but recognition was clearly developed by 15 days of age. Lead disrupted sibling recognition, and there still was no evidence of sibling recognition in lead-injected chicks by 26 days of age .../BIRDS and MAMMALS/ Four pairs of raccoons were treated orally with the following doses of lead acetate (mg/kg5 days/wk, for 8 ws: 0 (control), 1, 2, and 4. In the six experimental animals, this treatment produced dose-dependent increases in blood lead, without clinical signs or changes in hematological parameters. After 8 wk, the liver and kidney of all lead-treated animals and the calvarium and radius of those receiving doses of 2 and 4 mg/kg contained elevated concn of lead. Acid-fast inclusions were observed by light and electron microscopy in the kidneys of all raccoons receiving the two highest doses and in one animal receiving the lowest dose. Hepatic acid-fast inclusions were seen in only one animal (dose 4 mg/kg). No inclusions were seen in osteoclasts of the radius .../BIRDS and MAMMALS/ ... The toxicity of lead-contaminated sediment from the Coeur d'Alene River Basin (CDARB) in Idaho was examined on posthatching development of mallard (Anas platyrhynchos) ducklings for 6 wk. Day-old ducklings received either untreated control diet, clean sediment (24%) supplemented control diet, CDARB sediment (3,449 ug/g lead) supplemented diets at 12% or 24%, or a positive control diet containing lead acetate equivalent to that found in 24% CDARB. The 12% CDARB diet resulted in a geometric mean blood lead concn of 1.41 ppm (WW) with over 90% depression of red blood cell Aminolevulinic Acid Dehydratase (ALAD) activity and over threefold elevation of free erythrocyte protoporphyrin concn. The 24% CDARB diet resulted in blood lead of 2.56 ppm with over sixfold elevation of protoporphyrin and lower brain wt. In this group the liver lead concn was 7.92 ppm (WW), and there was a 40% increase in hepatic reduced glutathione concn. The kidney lead concn in this group was 7.97 ppm, and acid-fast inclusion bodies were present in the kidneys of four of nine ducklings. The lead acetate positive control group was more adversely affected in most respects than the 24% CDARB group. With a less optimal diet (mixture of two thirds corn and one third standard diet), CDARB sediment was more toxicblood lead levels were higher, body growth and liver biochemistry (TBARS) were more affected, and prevalence of acid-fast inclusion bodies increased. Lead from CDARB sediment accumulated more readily in duckling blood and liver than reported in goslings, but at given concn was generally less toxic to ducklings. Many of these effects are similar to ones reported in wild mallards and geese within the CDARB./BIRDS and MAMMALS/ ... A 15 yr research program on the behavioral effects of lead using herring gulls (Larus argentatus) and common terns (Sterna hirundo), referred to as larids, as models is reviewed. The doses used in laboratory studies were sufficient to produce lead concn in feathers that were equivalent to those found in some birds living in the wild. The exposure consisted of a single or multiple ip injection(s) of lead acetate. Both dose and day of exposure influenced behavioral development in young larids, with most effects increasing with dose, and decreasing with age. Low-level lead affected growth, locomotion, balance, food begging, feeding, thermoregulation, depth perception, and individual recognition in laboratory and in wild birds. The accuracy of individual recognition was most affected by lead exposure from 2 to 6 days of ageexposure at 12 days did not affect accuracy, but it delayed response time significantly. Behavioral deficits observed in lead-injected young in the wild were similar to those observed in the laboratory, except that recovery was more complete by fledging than it was in laboratory-raised chicks. Further, parents in the wild were able to provision lead-exposed chicks sufficiently so that they fledged at similar weights as control chicks, a feat that is difficult to achieve in the laboratory. The lead-induced behavioral deficits observed in the laboratory and in the wild are sufficient to affect growth and survival in wild herring gulls. Lead treatment altered the expression of cell adhesion molecules (CAMs), which play a crucial role in the formation and deployment of neurons in the developing brain. The timing and sequencing of CAM expression is critical to normal development, and the different consequences of lead exposure at different ages may be related to interference at different points in the sequence.For more Ecotoxicity Excerpts (Complete) data for LEAD ACETATE (36 total), please visit the HSDB record page. |
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