Geographic variation in hematological variables in adult and prefledgling herring gulls (Larus argentatus) and possible associations with organochlorine exposure.

The objectives of this study were (1) to describe variation in hematological values found in adult and prefledgling herring gulls (Larus argentatus) over a large geographic area, (2) to investigate relationships between hematological variables and other physiological indices, and (3) to examine potential associations between exposure to organochlorines and hematological variables. During 1991-93, we sampled 160 breeding adult gulls from 13 colonies and 101 4-week-old gulls from 11 colonies. All colonies were in the Great Lakes ecosystem, except for two colonies on Lake Winnipeg and the Atlantic coast. The hematological values measured in this study were similar to published values for herring gulls and related species. Significant intersite differences were found in hematological variables. Sex had little or no influence on leukocyte variables. Adults had lower total leukocyte counts and higher heterophil to lymphocyte ratios than chicks. PCV was lower in adult females than males. In adults, total leukocyte and total heterophil numbers were negatively associated with liver activity of ethoxyresorufin-O-deethylase (EROD) and concentrations of highly carboxylated porphyrins (HCPs), two biomarkers of organochlorine exposure. Total leukocyte and total heterophil numbers were positively associated with liver concentrations of DDE (1, 1-dichloro-2,2-bis(p-chlorophenyl)ethylene), and total lymphocytes were associated positively with PCB (polychlorinated biphenyl) and HCP concentrations. The heterophil to lymphocyte ratio was negatively associated with liver EROD activity and HCPs. In chicks, there was a positive association between the heterophil to lymphocyte ratio and HG-TEQs (dioxin toxicity equivalents calculated using herring gull-specific equivalency factors). PCV was associated with some measures of contaminant exposure in adults and chicks. Additional research is needed to elucidate causal relationships between hematological indices and such factors as contaminants, disease, and nutrition.

Geographic variation in blood plasma protein concentrations of young herring gulls (Larus argentatus) and Caspian terns (Sterna caspia) from the Great Lakes and Lake Winnipeg.

Relative and total amounts of plasma protein fractions are affected by infections, inflammation, and nutritional and physiological status, and are therefore important health indicators in free-living animals. Our objectives were: (1) to examine intercolony differences in plasma protein fractions in prefledgling gulls and terns; (2) to investigate relationships between plasma proteins and other physiological measures such as weight loss, growth, and immune function; and (3) to examine potential associations between organochlorine exposure and plasma proteins. During 1992, blood was collected from 3-week-old herring gull (Larus argentatus) chicks from six sites on Lakes Superior, Huron, Michigan, Erie, and Winnipeg and from 3-week-old Caspian tern (Sterna caspia) chicks from five sites on Lakes Huron, Michigan, and Ontario. These sites provided a wide gradient of organochlorine contamination. Plasma proteins were separated by high-resolution agarose gel electrophoresis and stained with Coomassie brilliant blue dye. Six major fractions were quantified: prealbumin, albumin, alpha-globulins, beta(1)-globulins, beta(2)-globulins, and gamma-globulins. Total protein, prealbumin, albumin, and gamma-globulin concentrations and the albumin/globulin ratio did not differ among sites. Total protein, albumin, and the albumin/globulin ratio were not decreased in birds experiencing food stress or weight loss. Intersite differences were found in alpha- and beta-globulins. In gulls, beta(2)-globulins were positively associated with polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ether (DDE). In terns, PCBs were negatively associated with alpha-globulins and positively associated with beta(1)-globulins. Additional research is needed to identify individual proteins and elucidate causal relationships between the particular protein concentrations and factors such as contaminants, growth, and condition.

Organochlorine-associated immunosuppression in prefledgling Caspian terns and herring gulls from the Great Lakes: an ecoepidemiological study.

The objectives of study were to determine whether contaminant-associated immunosuppression occurs in prefledgling herring gulls and Caspian terns from the Great Lakes and to evaluate immunological biomarkers for monitoring health effects in wild birds. During 1992 to 1994, immunological responses and related variables were measured in prefledgling chicks at colonies distributed across a broad gradient of organochlorine contamination (primarily polychlorinated biphenyls), which was measured in eggs. The phytohemagglutinin skin test was used to assess T-lymphocyte function. In both species, there was a strong exposure-response relationship between organochlorines and suppressed T-cell-mediated immunity. Suppression was most severe (30-45%) in colonies in Lake Ontario (1992) and Saginaw Bay (1992-1994) for both species and in western Lake Erie (1992) for herring gulls. Both species exhibited biologically significant differences among sites in anti-sheep red blood cells antibody titers, but consistent exposure-response relationships with organochlorines were not observed. In Caspian terns and, to a lesser degree, in herring gulls, there was an exposure-response relationship between organochlorines and reduced plasma retinol (vitamin A). In 1992, altered White blood cell numbers were associated with elevated organochlorine concentrations in Caspian terns but not herring gulls. The immunological and hematological biomarkers used in this study revealed contaminant-associated health effects in wild birds. An epidemiological analysis strongly supported the hypothesis that suppression of T-cell-mediated immunity was associated with high perinatal exposure to persistent organochlorine contaminants.

Effects of acute lead ingestion and diet on antibody and T-cell-mediated immunity in Japanese quail.

This study investigated the interacting effects of acute lead exposure and different diets on antibody and T-cell-mediated immunity in Japanese quail (Coturnix coturnix). Nine quail (nine week old males) were assigned randomly to each group in a factorial experiment with four treatments and two diets. The treatments were 1) a positive control group fed 20 micrograms/g corticosterone, 2) a negative control group given no lead or corticosterone, 3) a low-lead group, and 4) a high-lead group. The low and high lead groups received 100 and 400 micrograms/ml lead as lead acetate in drinking water for 7 d. The two diets were poultry feed and ground corn. Control quail fed corn lost 13-14% of initial body mass, but lead-dosed quail fed corn lost 23-24%. All quail fed poultry feed gained body mass. On the corn diet, three high-lead and one low-lead quail died of lead poisoning. Corn increased the percentage of heterophils in white blood cells (P = 0.0018) and decreased lymphocytes (P = 0.019) and monocytes (P = 0.0073). There was marginal evidence that lead increased the heterophil/lymphocyte ratio in corn-fed quail (P = 0.064). Corn decreased the T-cell-mediated response to an intradermal injection of phytohemagglutinin (P = 0.0001). Corticosterone suppressed this response more than lead. In corn-fed quail, lead suppressed the primary total antibody response to immunization with chukar partridge (Alectoris graeca) erythrocytes (P < 0.05). Lead reduced the secondary total antibody and IgG responses in the low lead, corn group (P < 0.05). Lead suppressed antibody-mediated immunity only at dosages that also caused clinical lead poisoning.

Bioavailability of lead from contaminated sediment in northern bobwhites, Colinus virginianus.

Sediment from Killarney Lake, Idaho was added to the diet of captive northern bobwhites (Colinus virginianus) to determine absorption of Pb from contaminated sediment. The sediment, containing 4,500 micrograms g-1 Pb dry weight (d.w.), was added to ground poultry ration at 8% dry matter intake (DMI) for 21 days. Concentrations of Pb in blood, liver, and kidneys of each bobwhite were determined and compared to concentrations in untreated control bobwhites. Treated bobwhites showed no significant decline (P > 0.05) in food intake or body mass over time. In 90% of treated bobwhites, blood Pb concentrations reached levels associated with clinical Pb poisoning (> 0.8 microgram g-1 wet weight, w.w.); and all treated bobwhites had elevated liver and kidney Pb concentrations. It was shown that tissue Pb accumulation can occur from ingestion of Pb-contaminated sediment.

Muskrat populations in Virginia's Elizabeth River: physiological condition and accumulation of environmental contaminants.

This study evaluated the physiological condition and environmental contaminant concentrations in muskrats inhabiting the contaminated lower region of the Elizabeth River, Virginia, (USA). Muskrats trapped in the lower region of the Elizabeth River weighed less, had lower mean fat indexes, lower relative spleen weights, greater relative adrenal weights, and an increased incidence of disease and parasitism compared to muskrats trapped in the less contaminated upper region of the Elizabeth River or Nansemond River. Concentrations of the metals aluminum, cadmium, copper, nickel, and zinc and the number of polyaromatic hydrocarbon compounds were greater in lower Elizabeth River muskrats compared to upper region Elizabeth River or Nansemond River muskrats. These physiological data indicated that muskrats in the lower region of the Elizabeth River were in poor health relative to muskrats from the other regions studied. However, no significant difference in fecundity or density was observed among regions studied, suggesting that the level of environmental contaminant exposure was not sufficient to elicit a population level response. Greater population declines following severe natural environmental stresses (large storms, extreme cold, etc.) would be anticipated in lower region Elizabeth River muskrats; however, the muskrat population in this region does not now appear to be at risk of extirpation.

Effects of handling and pair management on reproduction in Japanese quail (Coturnix coturnix ).

Three experiments were designed to study the effects of handling, pairing, and frequency of mating opportunities on reproduction in Japanese quail (Coturnix coturnix ) when the sexes were caged separately except during the 90 minute mating periods. In Experiments 1 and 2, 48 females and 48 males were allocated randomly to one of four treatments: 1) continuously paired, 2) paired daily with the same male, 3) paired daily with a different male, and 4) paired every third day with the same male. In Experiment 3, 44 males and 44 females used in Experiments 1 and 2 were again assigned randomly to one of four treatments: 1) continuously paired, 2) paired continuously but the females were handled at the beginning and end of a 90 minute period every third day to simulate the handling associated with moving birds between cages for mating, 3) paired every third day with the same male, and 4) paired every third day with a different male. In Experiments 1 and 3, the females were introduced into the males' cages, while in Experiment 2 males were introduced into the females' cages. In Experiment 1, the females paired every 1 or 3 days with the same males had fewer eggs with embryonic development than continously paired females. In Experiment 2, a reduced number of eggs with embryonic development was observed only in fermales paired every 3 days with the same male. In Experiment 1, more eggs hatched from continuously paired females than from females paired every third day with the same male. In Experiment 3, the females paired every third day with the same males had fewer settable, developing, or hatching eggs. In conclusion, it was found that when the sexes need to be caged separately, it is better to expose the females to different males.

A comparison between intubation and food addition as routes of oral exposure for northern bobwhites to DDT insecticide.

Our objective was to compare two methods of oral dosing of p,p'-DDT (1,1,1-trichloro-2,2-bis (p-chlorophenyl) ethane) on uptake of DDT metabolites and isomers (i.e., p,p'-DDT, o,p'-DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD, o,p'-DDD) in livers and brains. p,p'-DDT was administered to northern bobwhite (Colinus virginianus) by intubation with corn oil or as a feed additive for 56 days. When adjusted for amount of DDT consumed, total DDT (sigma DDT, the summation of all DDT metabolites and isomers) and p,p'-DDE concentrations differed significantly (P less than 0.10) in both brains and livers, whereas p,p'-DDD differed only in brains and p,p'-DDT differed only in livers. Paired comparisons between brains and livers differed significantly for sigma DDT, (P less than 0.05), p,p'-DDE (P less than 0.05) and p,p'-DDT (P less than 0.1) for both intubated and food-dosed treatment groups, whereas p,p'-DDD (P less than 0.05) differed only in the intubated group. We concluded that method of oral exposure affected the uptake of DDT in livers and brains for northern bobwhites.

Heavy metals in small mammals in roadside environments: implications for food chains.

Lead, cadmium, nickel, and zinc were measured in soil, vegetation, earthworms, small rodents, and shrews from the immediate environs of 4 highways of various traffic densities (range less than 1,000 to c.100,000 vehicles per day) and from 2 control areas. Concentrations of all elements in soil, vegetation, and earthworms varied with volume of traffic and with distance from highways. Concentrations in earthworms of all elements were especially high. Shrews had higher concentrations of lead and cadmium than other small rodents from similar areas.

Histology and ultrastructure of kidney tissue from ringed turtle doves that ingested lead.

Ringed turtle doves (Streptopelia risoria) ingested 4 x 122 mg lead pellets or lead acetate (75 micrograms Pb/g body weight) and their kidneys were examined by histological and electron microscopic techniques. Doves that received lead treatments had readily discernable lead intranuclear inclusion bodies in cells of the proximal convoluted tubules. At 33,000 X, the inclusions had a characteristic dense central core, and outer fibrillary zone. Necrosis in the proximal tubular area was seen as deterioration of cell cytoplasm and reduction in mitochondria. In doves ingesting lead, histological evaluation of proximal convoluted tubular cells revealed acid-fast pinkish granules in cell nuclei. Inclusions from rapidly as 1 dove that died after receiving the first of two lead doses (75 micrograms Pb/g body weight/day) had relatively small intranuclear inclusions in cells of the proximal convoluted tubules.

Effects of cadmium ingestion and food restriction on energy metabolism and tissue metal concentrations in mallard ducks (Anas platyrhynchos).

The single and combined effects of cadmium ingestion and food restriction were examined in a 42-day experiment with male, juvenile mallard ducks. A 2 X 3 factorial design was employed consisting of two levels of food supply (ad libitum and 55% of ad libitum intake) and three levels of cadmium in the food (0, 5, or 50 micrograms Cd/g food). Cadmium ingestion alone had no effect on body or tissue weights, liver glycogen, plasma concentrations of glucose, urea, uric acid, nonesterified fatty acids (NEFA), triiodothyronine (T3), thyroxine (T4), or plasma or adrenal concentrations of corticosterone. The food restriction resulted in reduced body weights and reduced weights of livers, kidneys, and testes, increased adrenal weights, reduced liver glycogen, increased plasma NEFA concentrations, reduced plasma T3 and T4 concentrations, and increased adrenal corticosterone concentrations. In combination with the food restriction, cadmium ingestion further reduced plasma T3 concentrations and a similar trend was noted for T4. Additionally, the highest plasma NEFA concentrations and highest plasma and adrenal concentrations of corticosterone were observed in food-restricted ducks receiving the highest level of dietary cadmium. These results suggest the ability of cadmium ingestion to enhance food restriction-induced alterations in energy metabolism at levels of dietary cadmium that are by themselves without apparent effect. Also, cadmium ingestion resulted in increased kidney concentrations of copper and zinc; this effect on kidney zinc concentrations was increased in food-restricted ducks.

The toxicology of lead shot ingestion in ringed turtle doves under conditions of cold exposure.

Ringed turtle doves (Streptopelia risoria) were dosed with 0 (N = 3) or 4 X 110 mg lead shot (N = 7) and were held at temperatures of 6 degrees C (+/- 1) for 7 days beginning 48 hr after lead shot dosing. Doves given 0 (N = 3) or 4 X 110 mg lead shot (N = 7) were maintained at 21 degrees +/- 1 degree C for a 9-day experimental period. Bone, liver and brain lead concentrations were higher in birds that ingested lead shot. Doves that ingested lead shot and were exposed to 6 degrees C temperatures had the highest liver lead concentration (155.94 micrograms/g dw) and 5 of 7 died. There was no mortality among doves maintained at 21 degrees C and among those maintained at 6 degrees C but not given lead shot. Among doves which accumulated high brain lead concentrations (mean = 11.32 micrograms/g) convulsive seizures were observed. Linear relationships were noted between liver lead and lead concentrations in breast muscle (breast muscle lead = 0.942 + 0.036 X), between liver lead and kidney lead (kidney lead = 495.75 + 8.47 X), and between hemoglobin and packed cell volume (packed cell volume = -1.57 + 2.52 X).

Histologic and ultrastructural lesions of mourning doves (Zenaida macroura) poisoned by lead shot.

Studies were conducted in which mourning doves (Zenaida macroura) were administered lead shot, and their tissues were examined by histology and their kidneys were examined by electron microscopy. Doves that ingested four number 8 lead shot and were sacrificed 4 days later had highly elevated lead concentrations in kidney and had acid-fast intranuclear and acid-fast intracytoplasmic inclusions in the cells of the proximal convoluted tubules. Hemosiderin loading was present in the liver as was elevated concentrations of lead in liver. Doves that ingested either four or eight number 8 lead shot and were sacrificed 9 days later had elevated lead concentrations in liver, and hemosiderin loading was present. Acid-fast intranuclear inclusions were present in the proximal convoluted tubule cells. Kidney lead was highly elevated and cellular degeneration was evident with electron microscopic examination.

The effect of lead shot ingestion on the testes of adult ringed turtle doves (Streptopelia risoria).

Gross and microscopic testicular changes were seen in 11 out of 14 adult ringed turtle doves (Streptopelia risoria) given 4 x 110 mg lead shot orally and housed at either 21 +/- 1 C (lead-treated, LT) or 6 +/- 1 C (lead-treated, cold-exposed; LTCE). The testes of the LT and LTCE doves were yellower than the ivory-colored testes of the control doves. The testicular weight of the LT and LTCE doves was 0.557 +/- 0.117 g, (mean +/- standard error), whereas the testicular weight of the control doves was 1.064 +/- 0.161 g. The relative testicular weight (mg testes/100 g body weight) of the LT doves was lower (P less than or equal to 0.05) than that of the LTCE or control doves. Microscopic testicular changes of the LT and LTCE doves consisted primarily of degeneration of the convoluted seminiferous tubules. A few affected testes had cytoplasmic swelling of the interstitial (Leydig's) cells. The testes of all six control doves appeared active and normal on microscopic examination. All seven LT doves, two of seven LTCE doves, and all control doves survived 9 days post lead treatment. The five LTCE doves not surviving 9 days died from 2 to 7 days post lead treatment; death was attributed to the combined effect of cold stress and lead ingestion. These results establish that significant testicular degeneration in adult male ringed turtle doves can occur following ingestion of lead shot.