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The ingestion of lead (Pb) shot pellets is a well-known cause of avian mortality, but exposure of birds to Pb may have other sublethal effects that can affect population sustainability. One of these effects is the alteration of the immunological status. Pb can affect most components of the avian immune system and imbalance the relationship among them. Pb exposure typically alters the ratio between T h1 - and T h2 -type responses mounted by different classes of T-lymphocytes, causing the depression of the T h1 responses that are associated with cell-mediated immunity. Immunodepressing effects of Pb on birds are observed at blood levels above 50 μg dL -1 , but developing birds show immunodepressing effects at much lower concentrations (> 10 μg dL -1 ). Impacts of Pb on the avian immune system also relate to reduced resistance to infection. We review immunotoxic effects of Pb on birds affected by shot ingestion as well as by other sources of exposure to this element., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lead isotopes have been widely used to assess the sources of Pb in the soil environment since lead isotopes ratios have a specific signature that allows us to use them as environmental tracers. However, some lead sources are difficult to be identified. This article contains the lead isotope data from soils and shot pellets collected in an abandoned shooting range (NW Spain). Twelve soil and three-shot pellet samples were randomly collected and analyzed using MC-ICP-MS. The isotope ratios are shown, and analyses proved that Pb originated predominantly from the used shot pellets. Contaminated soils exhibited an isotopic composition (206Pb/207Pb, 208Pb/204Pb, 206Pb/204Pb and 208Pb/206Pb) close to some shot pellets from different manufacturers. These results offer new, valuable data for other researchers working on lead contamination research and the identification sources of Pb for adjacent areas to shooting-range facilities and for wildlife ecotoxicology. Still, the use of several ammunitions derived from different sources, such as recycled Pb, showed that it is hard to identify the lead source and these kinds of facilities. [ABSTRACT FROM AUTHOR]

The Christiansø colony of common eiders (Somateria mollissima) in the central Baltic Sea were exposed to high levels of Pb during the 2018 breeding season that were not present in 2017. Due to these high Pb blood levels, the present study investigated possible Pb sources and Pb dynamics within this vulnerable colony. We analyzed body mass and lead isotopic ratios (Pb-IRs) in blood taken from the same incubating eiders at the early (day 4) and late (day 24) stages of incubation during the 2018 breeding season (n = 23). Pb-IRs 208/207, 208/206, 206/207, and 207/206 were analyzed using high resolution inductively coupled mass spectrometry. We found largely similar Pb-IRs from the different stages of incubation indicating a predominantly constant endogenous source of Pb exposure. We suggest the increasing Pb levels come from pre-nesting and nesting foraging and from medullary bone release. The similar Pb-IRs also indicate continued metabolization of the medullary bone to meet the nutritional and energy demands of incubation. Comparisons to Pb-IR reports from the Baltic Sea showed multiple sources of pollution distinguished by a difference between Pb-IRs in individuals with Pb blood concentrations >500 μg/kg ww and <500 μg/kg ww. The most highly contaminated individuals in the present study had Pb-IRs similar to those of Pb ammunition indicating shot pellet uptake. This study further emphasizes the need for continued biomonitoring of the Christiansø colony, including fecal sampling and environmental field sampling to identify the origin and extent of dietary Pb exposure on Christiansø. As a representative unit of the Baltic Flyway population; the Christiansø colony provides an important opportunity for continued investigation into Pb contamination, population dynamics, and declines., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Fluid preserved animal specimens in the collections of natural history museums constitute an invaluable archive of past and present animal diversity. Well-preserved specimens have a shelf-life spanning centuries and are widely used for e.g. anatomical, taxonomical and genetic studies. The way specimens were collected depended on the type of animal and the historical setting. As many small mammals and birds were historically collected by shooting, large quantities of heavy metal residues, primarily lead, may have been introduced into the sample in the form of lead shot pellets. Over time, these pellets may react with tissue fluids and/or the fixation and preservation agents and corrode into lead salts. As these chemicals are toxic, they could constitute a health issue to collection staff. Additionally, heavy element chemicals interfere with several imaging technologies increasingly used for non-invasive studies, and may confound anatomical and pathological investigations on affected specimens. Here we present a case-study based on platypus (Ornithorhynchus anatinus) and other small mammals containing lead pellets from the collection of The Natural History Museum of Denmark. [ABSTRACT FROM AUTHOR]

Agricultural areas can provide sources of food and hiding and nesting places for wild birds. Thus, the chemical load of potentially toxic elements (Cd, Cu, Pb) due to industrial and agricultural activities can affect not only the adult birds but also the embryos developing in the egg. The toxic effects of heavy metals applied alone were investigated on chicken embryos in the early and late stages of embryonic development using injection and immersion treatment methods. On day 3 of incubation, permanent preparations were made from the embryos to study the early development stage. There were no significant differences observed in embryo deaths and developmental abnormalities in this stage. On day 19 of incubation, the number of embryonic deaths, the body weight of the embryos, and the type of developmental abnormalities were examined. The embryonic mortality was statistically higher in the groups treated with cadmium and lead in the case of the injection treatment. A significant increase in developmental disorders was observed in the copper-treated group using the immersion application. The body weight significantly decreased in the cadmium- and lead-treated group using both treatment methods. However, a significant change in the body weight in the copper-treated group was only realized due to the injection method. [ABSTRACT FROM AUTHOR]

Birds that display grit ingestion behavior are potentially at risk of lead (Pb) poisoning from mistaken ingestion of spent Pb shot pellets. The majority of available studies designed to assess such risk have used unspent shot pellets rather than field-obtained spent shot, which is oxidized and otherwise changed by weathering. Available studies also often administered more or heavier shot pellets to a bird than it might be expected to ingest. The current study dosed northern bobwhite quail (Colinus virginianus) weighing 194.6 ± 23.1 g (female birds) and 199.3 ± 12.2 g (male birds) with one to three spent no. 9 Pb shot collected from a skeet range, with particular interest in the toxicity that may occur from ingestion of a single 2-mm, 50 mg shot. An 8 week post-dosing clinical observation period was employed, over which feed consumption, body weight, blood Pb levels, and a battery of blood physiological parameters were made. Weight loss occurred in the birds, including male birds dosed with one Pb pellet. Erythrocyte delta aminolevulinic acid dehydratase (δ-ALAD) levels were decreased for the duration of the study across exposures and to levels associated with injury in wild bird populations. Decreased ALAD was particularly severe in female birds dosed with one Pb pellet and was still 92 % decreased at 8 weeks after dosing. Together, these results suggest that inadvertent ingestion of a single no. 9 Pb shot pellet can adversely affect the health of northern bobwhite quail.

Forty captive Mallards (Anas platyrhynchos), of both sexes, were separated into five groups and dosed with lead shot via oral intubation; one group was used as a control. Lead dosage differed in terms of shot number and size, as well as administration time. One hundred and thirty-five wild mallards were trapped between 1998 and 2001 in the Boada and Nava lagoons near the Canal de Castilla, in the Spanish province of Palencia. Radiologic techniques (ventrodorsal and lateral views) were used to detect lead shot in the gizzard and to determine degradation in dosed birds over time. Heparinized blood samples were taken from wild and captive mallards and blood lead levels were determined using anodic stripping voltammetry with a dropping mercury electrode. Clinical signs, injuries, and body weight were recorded. In approximately 90% of the experimentally dosed mallards, administered shot stayed in their gizzard until it degraded; this took approximately 30 days. Peak lead levels in blood were observed between days 10 and 20, and 10 days following a repeat dosage; males were more sensitive than females to a repeat dosage. During the experimental phase, 34% of birds died, and those that survived had varying degrees of anorexia, lethargy, and a decreased response to external stimulus. Of 135 tested wild mallards, 41% had a blood lead concentration higher than 0.200 microg/g. Lead shot was found embedded in 3.6% of the wild birds and 1.2% had a lead shot pellet in their gizzard.

The present study was performed to investigate the weathering and dissolution rates of Pb shot pellets differing in elemental composition (Pb, Sb, and As) exposed under various aqueous and soil conditions using five commercial shot pellet preparations. Upon immersion in distilled water, the dissolution rates of shot pellets, calculated from the difference in weight before versus after immersion, decreased with increasing Sb + As contents and the dominant precipitate was hydrocerussite. These subsidiary ingredients may be related to the difficulty of metallic Pb oxidation (transformation to PbO). Weight losses standardized by the amount of rainfall upon exposure to rainfall on open grassland and under canopies of Japanese cedar (Cryptomeria japonica) and bamboo-leafed oak (Quercus myrsinaefolia) were 1.11, 1.07, and 7.35 mg g pellets(-1) year(-1) L(-1), respectively, and was also related to Sb + As contents in shot pellets. However, annual dissolution rates of Pb standardized by the amount of rainfall as the soluble fraction at the same sites were 0.72, 0.33, and 0.40 mg Pb g pellets(-1) year(-1) L(-1) in the same order. These trends seemed to be related to the rainfall pH, which induces precipitation of Pb dissolved as PbCO(3) under conditions of higher pH at the Q. myrsinaefolia site or organic matter released from leaves, etc., which can form metal complexes. Dissolution rates of shot pellets buried in soils (Cambisol, Fluvisol, Regosol, Andosol) also seemed to be related to the soil pH and dissolved organic matter contents but were about sixfold faster than those with exposure to rainfall.

Lead pellets from a skeet range impart Pb to the local soil, plants, and animals. Concentrations and distributions of Pb in the various media were studied at the now-abandoned skeet range bordering a cordgrass marsh at the Naval Weapons Station Seal Beach in Southern California. The concentrations of Pb in soil (maximum = 16,200 ppm, dry mass) are significantly correlated to the shot pellet densities. Lead concentrations in plants vary according to species' abilities to inhibit Pb uptake from soil. Horn snails had a mean Pb concentration (1987 ppm, dry mass) over 100 times greater than the leaves of the plant species with the highest mean concentration (18.1 ppm, dry mass) at the same site. Avian predators of gastropods may receive minimum exposure to Pb due to calcium in the shells, but incidental ingestion of soil in addition to direct ingestion of shot pellets may provide significant exposure to birds. Because shotgun pellets may persist in wetland soil for 300 yr, reduction of wildlife exposure to Pb in such cases requires deliberate action.

The transition to non-lead ammunition has been enforced by regulations on use and possession of lead shot and rifle bullets. Here we review the scientific and technical literature about this regulatory process in Europe and give some notes of its effectiveness to reduce this source of lead contamination in aquatic and terrestrial environments. Presently, lead shot use has been legally restricted in 23 European countries. Two, Denmark and The Netherlands, have a total ban of lead gunshot use in all types of habitats, 16 countries have a total ban in wetlands and/or for waterbird hunting, and 5 have a partial ban implemented only in some wetlands. The legal regulation of lead bullets is limited to some German regions. This review also highlights the need to know the level of compliance with the ban on lead ammunition and the subsequent benefits for the susceptible species and for game meat safety. [ABSTRACT FROM AUTHOR]

Poisoning of wild birds following ingestion of lead from ammunition has long been recognised and considerable recent research has focused on terrestrial birds, including raptors and scavengers. This paper builds upon previous reviews and finds that both the number of taxa affected and geographical spread of cases has increased. Some lead may also be absorbed from embedded ammunition fragments in injured birds which risk sub-lethal and welfare effects. Some papers suggest inter-specific differences in sensitivity to lead, although it is difficult to disentangle these from other factors that influence effect severity. Sub-lethal effects have been found at lower blood lead concentrations than previously reported, suggesting that previous effect-level 'thresholds' should be abandoned or revised. Lead poisoning is estimated to kill a million wildfowl a year in Europe and cause sub-lethal poisoning in another ≥ 3 million. Modelling and correlative studies have supported the potential for population-level effects of lead poisoning in wildfowl, terrestrial birds, raptors and scavengers. [ABSTRACT FROM AUTHOR]

Tundra swans ( Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter. [ABSTRACT FROM AUTHOR]

Reserve regulations at El Palmar State Reserve, Yucatan, Mexico, prohibit the use of lead (Pb) shot, but hunters continue to use it, and no enforcement is implemented. Pb was quantified in sediments and in blue-winged teal Anas discors. No shot pellets were found in the sediment samples, nor were differences in sediment Pb concentrations observed within the reserve between popular hunting sites and those no longer used for hunting. However, there were differences between the hunting sites and sediments from an adjacent area where hunting is prohibited. Average Pb concentrations were highest at hunting entrances (15.69 ± 18.69 mg/kg) and lowest at decoy locations (5.24 ± 4.84 mg/kg). These averages are lower than the lowest effects level (31 mg/kg), although 10 samples exceeded this level. Pb-shot prevalence in gizzards was 4.88 % ( n = 41). Pb levels exceeded 5.0 mg/kg dry weight in one or more of the tested tissues (liver, gizzard, and bone) in 14 (34.14 %; 7 female, 7 male; 11 adult, 3 juvenile) of the total birds. Bird weight, sex, and age had no effect on Pb concentration. Hunting using Pb shot in the reserve clearly affects Pb levels in sediments and in A. discors that winter there. [ABSTRACT FROM AUTHOR]

Avian wildlife species commonly ingest lead (Pb) spent shot or bullet fragments as grit or mistakenly as food. In previous studies in our laboratory and others, the toxicity varied based on the diet as well as type and quantity of Pb ingested. In the current study, domestic pigeons were gavaged with 1, 2, or 3 Pb pellets and then followed with weekly radiographs and blood physiologic endpoints for 28 days. Pellet retention decreased by roughly 50 % per week as pellets were either absorbed or excreted, except for week 4 where pellet number no longer was diminished. Size of retained pellets visually decreased over retention time. Birds dosed with a single #9 pellet showed mean blood Pb levels over 80 times higher than those of the controls, verifying Pb pellet absorption from the gut. A single Pb pellet also reduced plasma δ-aminolevulinic acid dehydratase (δ-ALAD) activity by over 80 % compared to controls, suggesting the potential for population injury in Pb pellet-exposed pigeons. [ABSTRACT FROM AUTHOR]

The American woodcock is an important migratory species to both consumptive and nonconsumptive users throughout the species range. Woodcock populations have been declining steadily since surveys began in 1968. Laboratory and field studies have demonstrated several adverse effects associated with metals in other species, which has led to their inclusion as potential contributing factors to the woodcock population decline. We investigated the concentrations of arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb), and selenium (Se) in pectoral muscle ( n = 100), livers ( n = 108), and kidneys ( n = 104) and Pb in wing bones ( n = 53) from woodcock harvested in Connecticut. Cd concentrations were elevated in 99% of woodcock livers and kidneys; 30% of kidneys were above 100 μg/g dry weight, a Cd level of reported adverse tissue and reproductive effects in other species. Hg and Cr concentrations were below current biologically significant thresholds. Asc, Pb, and Se in soft tissues were associated with lead shot use in collection. Se in 24% of livers was above 10 μg/g dry weight, the reported threshold for avian health. Wing-bone Pb was elevated above 20 μg/g in 61% of adults and 23% of juveniles examined. Our findings indicate that woodcock are being exposed to potentially damaging levels of at least two metals with known effects in other species. [ABSTRACT FROM AUTHOR]

Birds are exposed to Pb by oral ingestion of spent Pb shot as grit. A paucity of data exists for retention and clearance of these particles in the bird gastrointestinal tract. In the current study, northern bobwhite quail ( Colinus virginianus) were orally gavaged with 1, 5, or 10 Pb shot pellets, of 2-mm diameter, and radiographically followed over time. Blood Pb levels and other measures of toxicity were collected, to correlate with pellet retention. Quail dosed with either 5 or 10 pellets exhibited morbidity between weeks 1 and 2 and were removed from further study. Most of the Pb pellets were absorbed or excreted within 14 d of gavage, independent of dose. Pellet size in the ventriculus decreased over time in radiographs, suggesting dissolution caused by the acidic pH. Birds dosed with one pellet showed mean blood Pb levels that exceeded 1,300 µg/dl at week 1, further supporting dissolution in the gastrointestinal tract. Limited signs of toxicity were seen in the one-pellet birds; however, plasma δ-aminolevulinic acid dehydratase (d-ALAD) activity was persistently depressed, suggesting possible impaired hematological function. Environ. Toxicol. Chem. 2010;29:2869-2874. © 2010 SETAC [ABSTRACT FROM AUTHOR]

In this study, the speciation, vertical distribution and soil particle size fractions of lead in soil samples at a recreational firing range was determined. This study was performed to gain a better understanding of how lead shot breaks down at ranges. Both the chemical form of lead and the types of soil particles with which lead is associated are important for understanding not only the mobility and persistence, but also the human and ecological impact of lead at these ranges. Lead as shot gun pellets was found to be the dominant form of lead in soil samples. The highest levels were measured in surface samples located in the "fall zone" of the range. Results indicate shot to be relatively absent below surficial samples. Lead concentrations in soil decreased markedly across a 0-6'' depth profile. Lead carbonates were the dominant non-shot form of lead present at all depths. Water-soluble lead species made up a minor fraction of the non-shot lead present in the samples. Based on soil particle sizes measured, highest concentrations of lead were measured in soil particles passing a 0.075 mm sieve. [ABSTRACT FROM AUTHOR]

Background: Owing to the high environmental risk of lead-based gunshot, especially as the main source of acute lead poisoning in waterfowl, restrictions on its use in European wetlands are being put into place. In order to assess potential risks of alternative gunshot pellets to aquatic systems, we validated a recently published study that compared the leaching behavior of different game shot materials in an artificial solution and their toxicological effects to Daphnia magna. We therefore investigated the altered leaching of shot materials in natural spring waters. Results: The different water conditions (geology/redox conditions) had a strong influence on the leaching behavior of the examined shot types. Spring water originating from siliceous bedrock showed the highest concentrations of nearly all leached metals under aerobic conditions. The results were similar to the former study, which used an artificial standardized medium for daphnids. Conclusions: According to the conducted leaching tests, Cu- and Zn-based as well as Zn-coated gunshot should be avoided by reason of the high risks they pose to the aquatic environment. Furthermore, the use of Pb-based and Ni-alloyed or -coated game shot also should be hampered owing to their impact on birds or other wildlife. Since some of these shot materials are still on the European market, an effective toxicity screening of alternative gunshot materials is necessary. By conducting standardized leaching tests, in addition to chemical compositional standards and toxicity tests regarding birds, the environmental risks of each game shot would entirely be assessed. The method presented in this study provides a further step for initial ecotoxicological risk assessment of gunshot for aquatic systems, since it additionally assesses minor components, like thin coatings, which also can have a high impact to these ecosystems. [ABSTRACT FROM AUTHOR]