High human exposure to lead through consumption of birds hunted with lead shot

We assess lead contamination of Greenland seabirds killed with lead shot having studied thick-billed murre and common eider, the two most important species in the diet. The lead concentration is very high in meat of eiders killed with lead shot (mean 6.1 microg/g-wet wt, 95% CL 2.1-12). This level is about 44 times higher than in drowned eiders and eight times higher than in shot murres. Analyzing whole breasts instead of sub-samples reveals about seven times higher lead levels in birds' meat. We conclude that in some cases the lead intake by Greenland bird eaters will largely exceed the FAO/WHO tolerable lead intake guideline and that lead shot is a more important source of lead in the diet than previously estimated.     

Lead shot from hunting as a source of lead in human blood

This study investigates the relationship between the intake of birds hunted with lead shot and the lead concentration in human blood. Fifty adult men from Nuuk, Greenland took part in the study. From September 2003 to June 2004 they regularly gave blood samples and recorded how many birds they ate. We found a clear relationship between the number of bird meals and blood lead and also a clear seasonal variation. The concentration was highest in mid-winter when bird consumption is at its highest. Blood lead was low (15 microg/L, mean concentration) among the participants reporting not eating birds. Among those reporting to eat birds regularly, blood lead was significantly higher, up to 128 microg/L (mean concentration). Concentrations depended on the frequency of bird meals: the more the bird meals, the higher the resulting blood lead. This clear relationship points to lead shot as the dominating lead source to people in Greenland.     

Accumulation in and effects of lead and cadmium on waterfowl and passerines in northern Idaho

Waterfowl and passerines in northern Idaho in 1987 had high levels of lead in their blood and tissues that originated primarily from mining and smelting activities. Four Canada geese (Branta canadensis) and one common goldeneye (Bucephala clangula) found dead contained 8 to 38 microg/g (wet mass) of lead in their livers. These levels exceed the lower lethal limit of 5 microg/g in experimental birds. Two of the Canada geese (one each from the contaminated and reference areas) died with ingested lead shotgun pellets (shot) in their gizzards, whereas the other three birds from the contaminated area contained no ingested shot and evidently died from ingesting environmental lead in sediment or biota. Lead burdens in most American robins (Turdus migratorius) and mallards (Anas platyrhynchos) were high, whereas those in tree swallows (Tachycineta bicolor) were slightly elevated. Lead accumulated to potentially hazardous levels in blood and tissues of some nestling robins (maxima of 0.87 microg/g in blood and 5.6 microg/g in liver) and mallards (maxima of 10.2 microg/g in blood and 2.8 microg/g in liver). In mallards, lead levels and associated physiological characteristics of blood were significantly different in juveniles (HY) versus adults (AHY). Activity of delta-aminolevulinic acid dehydratase (ALAD) was about 87 to 95% lower than values for control birds in experimental studies. Activity of ALAD was significantly inversely correlated with blood lead levels. Cadmium was detected in kidneys of most birds, but even the maximum concentration of 7.5 microg/g in an AHY mallard was below known harmful levels.     

Lead poisoning in swans in Japan

We investigated the occurrence, source and exposure time of lead poisoning in whooper swans (Cygnus cygnus cygnus) and Bewick's swans (Cygnus columbianus bewickii) in Japan during the winters of 1984-1987. Concentrations of lead in various tissues and physiological evidence of lead shot in some birds indicated that lead shotgun pellets were the source of lead, and exposure occurred after the birds arrived in Japan. Mortality probably occurred within 30 days after exposure to, and retention of, lead shot in the gizzard.     

Lead shot pellets in the Ebro delta, Spain: densities in sediments and prevalence of exposure in waterfowl

Lead (Pb) poisoning has been found to be a serious problem for waterfowl in some southern European countries, but few studies have been conducted in Spain. In order to obtain these data, studies were made in the Ebro delta, a Spanish Ramsar site, during 1992 and 1993. Lead shot densities in the first 20 cm of sediment ranged from < 8 900 to 2 661 000 shot ha(-1). A similar proportion of birds had lead shot in the gizzard and elevated liver lead (> 5 microg g(-1) DW) concentrations. Northern pintail and common pochard (both with declining populations in Europe) showed the highest levels of shot ingestion, with 70.8 and 69.2%, respectively. Body condition index in the northern pintail was negatively correlated with the number of pellets in the gizzard and liver Pb concentration. Levels of exposure were higher than in other northern countries of the western Palearctic flyway, where lead shot have been banned recently.     

Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional seafood items from western Greenland

In this study, contamination levels were determined for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and perfluorinated alkylated substances (PFASs) in traditional Greenland seafood items, such as raw and smoked fish fillet (salmon and halibut), whale and seal meat and narwhal mattak (skin and blubber). The daily intake of PCBs, PBDEs and PFASs through traditional seafood items in Greenland was assessed. Based on the presented levels of contaminants, in combination with earlier food intake studies, suggests that the daily exposure was below the tolerable daily intake threshold for all compounds. BDE-47 was the only PBDE-congener detected in all food items, except in smoked halibut. The levels of BDE-47 varied from < LOD in smoked halibut up to 18 ng/g lw in narwhal mattak and 21 ng/g lw in whale beef. ∑PCB were lowest in smoked halibut (37 ng/g lw) and highest in narwhal mattak with 1,146 ng/g lw. Perfluorooctane sulfonate (PFOS) was the most common of the PFASs. However, ΣPFASs were below detection limits in most fish fillet samples, and varied from 2.9 ng/g ww in whale beef to 13.5 ng/g ww in seal beef. The present study shows that the exclusion from the diet of local food items such as intestines and blubber have a strong positive effect for the reduction of POPs levels in food, without a reducing the health benefits of traditional food intake considerably.     

Lead shot toxicity to passerines

This study evaluated the toxicity of a single size 7.5 lead shot to passerines. No mortalities or signs of plumbism were observed in dosed cowbirds (Molothrus ater) fed a commercial diet, but when given a more natural diet, three of 10 dosed birds died within 1 day. For all survivors from which shot were recovered, all but one excreted the shot within 24 h of dosing, whereas, the dead birds retained their shot. Shot erosion was significantly greater (P < 0.05) when weathered shot were ingested compared to new shot, and the greatest erosion was observed in those birds that died (2.2-9.7%). Blood lead concentrations of birds dosed with new shot were not significantly different (P = 0.14) from those of birds exposed to weathered shot. Liver lead concentrations of birds that died ranged from 71 to 137 ppm, dry weight. Despite the short amount of time the shot was retained, songbirds may absorb sufficient lead to compromise their survival.     

Review on persistent organic pollutants in the environment of Greenland and Faroe Islands

The literature concerning persistent organic pollutants (POPs) in the environment of Greenland and the Faroe Islands covering the period up to 1995 has been revisited. It is difficult to compare data from earlier studies with those from more recent investigations. Thus as the former quantified the content of CBs by comparison to a technical mixture of CBs (e.g. Aroclor 1254), the latter analyses typically are quantified on a single congener level. Single CB congeners have in some cases been determined, but the results were subsequently expressed as total PCB related to an Aroclor standard. For studies based on single CB congener determinations, the highest levels are reported for porpoise blubber from Greenland (700-4500 micrograms/kg wet weight), the conclusion, however being based on two determinations only. In Greenlandic seal blubber and peregrine falcon plasma equal levels of CBs (130-750 micrograms/kg ww) and of DDTs (150-860 micrograms/kg ww) were found. Levels of CBs and DDTs in fish liver were found to be around 40-75 micrograms/kg ww. In sediment samples the CBs were almost all below the detection limit (< 0.02-0.1 microgram/kg dry weight), and thereby being the matrix with the lowest CBs concentration levels. Earlier data based on Aroclor standards showed DDT levels in Greenlandic whale blubber in the range of 2700-4100 micrograms/kg ww and PCB levels of 3700 micrograms/kg-5400 micrograms/kg ww. DDT levels for seal blubber were at the same level (2700-4500 micrograms/kg ww) whereas the PCB level was lower (900-3900 micrograms/kg ww). The PCB level corresponds to the level found in human adipose tissue determined with a similar quantification technique. The lowest levels reported for mammals correspond to walrus blubber, the sum of PCBs and DDTs being in the ranges of 180-360 micrograms/kg ww and 50-90 micrograms/kg ww, respectively. The content of PCBs in scallops was found to be 3 micrograms/kg ww near the Thule Air base.     

Pb-Al relationships in waterfowl feces discriminate between sources of Pb exposure

Hunted mallards (n = 56) were collected in the Ebro Delta (Spain) in 2007-08 to evaluate the use of feces as a non-invasive monitoring method to study lead shot ingestion. The prevalence of Pb shot ingestion in these birds was 28.6%, and similar to that reported before a ban on Pb shot use in 2003. Lead concentrations in terminal intestinal contents were higher in mallards with Pb shot in their gizzard. Feces Pb concentrations >34 μg/g d.w were indicative of Pb shot ingestion, and background Pb levels were <12.5 μg/g d.w. To discriminate between birds ingesting soil Pb, and those ingesting Pb shot, we correlated Al and Pb levels and showed that mallards with ingested Pb shot in the gizzard stood out as outliers within the regression. Feces Pb-Al relationships can be used as a simple non-invasive tool in monitoring programs regarding Pb shot ingestion in birds.     

Exposure of migrant bald eagles to lead in prairie Canada

The prevalence of elevated exposure to lead was assessed in a migrant population of bald eagles (Haliaeetus leucocephalus) at a waterfowl staging area in the southern portion of the Canadian prairies, from September to November, 1992-1995. Of 103 eagles, 8% exhibited blood lead (PbB) concentrations suggestive of elevated exposure to lead (> or = 0.200 microgram ml-1 wet wt.). PbB concentrations in eagles from the study area ranged from < 0.01 to 0.585 microgram ml-1, while those of nestling eagles from a reference site indicated normal or background exposure (< 0.01 microgram ml-1). No differences in the prevalence of elevated exposure were detected among genders or age classes (0.5- and > or = 1.5-year-old birds) (P > 0.05). The prevalence of elevated exposure was significantly greater in November than in October (21.7 vs. 3.8%) (all years: chi 2Y = 5.75, P = 0.017). Eagles with shotshell pellets in the digestive tract did not have accompanying high PbB concentrations. The prevalence of elevated lead exposure in this study was low in comparison to other areas in North America. Potential biases in the trapping technique as they relate to interpreting the results are addressed.     

Mute swans, Cygnus olor, killed from collision with electrical wires, a study of two situations in Sweden

Different studies indicate that 19-38% of the Swedish ringed Mute Swans (Cygnus olor) are killed by collision with electrical wires. The relative frequency of killed swans is not related to the density or type of electrical wires in the landscape, but to where in the landscape the wires are constructed, and to the time when mass movements of swans occur. Experience (age), bodyweight ("too heavy to raise"), breast muscle weakening ("engine problems") and heavy metal (lead) loads strongly affect the chances of birds avoiding collision; but, swans not belonging to these risk-groups are also killed. Different skeletal injuries were found in dead birds after collision but many of them were not lethal. It was proved, however, that most collision-birds ultimately died from liver damage, probably caused by their heavy bodies hitting the ground.     

Mortality factors, helminth burden, and contaminant residues in white-tailed sea eagles (Haliaeetus albicilla) from Finland

Eleven white-tailed sea eagles (WSEs) (Haliaeetus albicilla) collected in Finland between 1994 and 2001 were examined for their causes of death, including analyses of ubiquitous environmental contaminants and parasites. Four WSEs died due to electrocution. Two were lead poisoned and another had fragments of a lead bullet in its gizzard. An 11-year-old female drowned entangled in fishing gear, but also had mercury levels in its liver and kidneys known for detrimental physiological effects. One WSE was evidently killed by an intraspecific conflict, which was also assumed to be with another bird. The mortality factors of two WSEs could not be clarified, but one had a lead level of 4.604 microg g(-1) in its liver, indicating high lead exposure at a clinically relevant concentration. All organ levels of chlorinated pesticides, polychlorinated biphenyls, and cadmium were moderate and not harmful for birds of prey. Seven helminth species, but no ectoparasites or coccidians, were found in 8 of 10 WSEs investigated for parasites. The highest prevalence of 40% was found for the liver fluke Metorchis billis, but no severe parasitosis was diagnosed for the eagles. The two acanthocephalan species Corynosoma semerme and Polymorphus meyeri are both new records for WSEs.     

PCDDs, PCDFs, and PCBs concentrations in breast milk from two areas in Korea: body burden of mothers and implications for feeding infants

We determined breast milk concentration of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in 24 mothers living in Korea, and assessed the maternal body burden based on PCDDs/PCDFs and PCBs concentrations in breast milk and an infant intake rate through breast-feeding based on their concentration in breast milk. PCDDs/PCDFs and PCBs levels in breast milk from primipara mothers were found to be higher than those from multipara mothers. For total PCDDs/PCDFs TEQ level, 2,3,4,7,8-PeCDD was the predominant congener, and the proportion of 2,3,7,8-TCDD was less than 3% of total PCDDs/PCDFs TEQ level. For PCBs TEQ level, PCB-126 was the predominant congener. Maternal body burden levels of PCDDs/PCDFs and PCBs based on their concentrations in breast milk were 268-622 TEQ ng. The daily dioxin intakes of mothers were predicted to be 0.78-2.18 TEQ pg/kg/day for PCDDs/PCDFs and 0.34-0.66 TEQ pg/kg/ day for PCBs. For the first year, the body burden of an infant was predicted to be 212 TEQ ng and the daily intake of an infant was predicted to be 85 TEQ pg/kg/day, assuming the mean dioxin-related compounds concentration (27.54 TEQ pg/g fat).     

Investigation into the effects of ingestion of zinc shot by Mallard Ducks (Anas platyrhynchos)

Lead fishing weights and gun shot have been identified as a widespread cause of poisoning of swans and other wildfowl (order Anseriformes). As part of the efforts to find environmentally acceptable substitutes for lead, this paper describes the results obtained from a trial which involved the feeding of zinc shot to groups of mallard (Anas platyrhynchos). Observations of the mallard during the experimental period, post mortem examination, histo-pathological examination and also chemical analysis of liver, kidney and feathers, revealed no ill effects to the dosed birds and indicated that zinc metal in shot from probably presents no detectable health threat to wild birds if ingested.     

Mute swans, Cygnus olor, killed from collision with electrical wires, a study of two situations in Sweden

Different studies indicate that 19–38% of the Swedish ringed Mute Swans (Cygnus olor) are killed by collision with electrical wires. The relative frequency of killed swans is not related to the density or type of electrical wires in the landscape, but to where in the landscape the wires are constructed, and to the time when mass movements of swans occur. Experience (age), bodyweight (“too heavy to raise”), breast muscle weakening (“engine problems”) and heavy metal (lead) loads strongly affect the chances of birds avoiding collision; but, swans not belonging to these risk-groups are also killed. Different skeletal injuries were found in dead birds after collision but many of them were not lethal. It was proved, however, that most collision-birds ultimately died from liver damage, probably caused by their heavy bodies hitting the ground.     

Lead shot ingestion by waterbirds in the Camargue, france: an investigation of levels and interspecific differences

Between January 1988 and February 1989, gizzards were collected from 1155 birds from the groups; Anatidae, Charadriidae, Scolopacidae and Rallidae, shot in the Camargue, and examined for the presence of ingested lead shot. Shot was found in nine out of ten Anatidae species, three of 15 Scolopacidae species and all of three Rallidae species. Twenty-seven per cent of Anatidae sampled had ingested shot, 13.8% had one shot present and 6.3% had more than five. Shot ingestion levels ranged from 3-60% of birds examined according to species. The incidence of shot ingestion did not appear to vary seasonally. In Anatidae, a strong interspecific relationship was found between the grit size ingested and susceptibility to ingest shot (r = 0.94). In Scolopacidae, shot ingestion may have been related to grit size ingested, feeding method and bill length. The levels of shot ingestion presented are for most species higher than have been reported elsewhere in the world. This may result from the absence of grit and presence of high shot densities in Camargue marshes.     

Level, sources and toxicity of polychlorinated biphenyls in the Italian diet

We used the duplicate portion method to measure the daily dietary intake of total and congener-specific polychlorinated biphenyls (PCB) and to assess their potential toxicity in a group of 20 subjects consuming a typical Italian diet. The mean +/- SD intake of total PCB, measured by GC-MS, was 3.72 +/- 1.51 micrograms/person/day, comparable to values reported in similar studies world-wide, with individual intakes varying within one order of magnitude, from 0.97 to 10.59 micrograms/person/day. The di-ortho congeners 153, 18 and 138 were the PCB found in the highest concentrations (respectively 13.8%, 11.4% and 10.9% of the total) while the non-ortho coplanar congeners (77, 126 and 169) amounted to 0.5% of the total. The corresponding levels of toxicity (TCDD-like TEQ values ascribable to PCB) ranged from 4.6 up to 119 pg/person/day of TCDD-equivalents in 18 subjects, i.e. presumed no-risk levels, but with peaks of 2109 and 4553 pg/person/day in two subjects with significant intakes of the congener 126. Principal components analysis and redundancy analysis showed dairy products, meat and fish were the principal sources of PCB, and vegetables those with the highest toxicity index in the Italian diet.     

Source-pathway-receptor investigation of the fate of trace elements derived from shotgun pellets discharged in terrestrial ecosystems managed for game shooting

Spent shotgun pellets may contaminate terrestrial ecosystems. We examined the fate of elements originating from shotgun pellets in pasture and woodland ecosystems. Two source-receptor pathways: i) soil-soil pore water-plant and ii) whole earthworm/worm gut contents - washed and unwashed small mammal hair were investigated. Concentrations of Pb and associated contaminants were higher in soils from shot areas than controls. Arsenic and lead concentrations were positively correlated in soils, soil pore water and associated biota. Element concentrations in biota were below statutory levels in all locations. Bioavailability of lead to small mammals, based on concentrations in washed body hair was low. Lead movement from soil water to higher trophic levels was minor compared to lead adsorbed onto body surfaces. Lead was concentrated in earthworm gut and some plants. Results indicate that managed game shooting presents minimal risk in terms of element transfer to soils and their associated biota.     

The history of seabird colonies and the North Water ecosystem: Contributions from palaeoecological and archaeological evidence

The North Water (NOW) polynya is one of the most productive marine areas of the Arctic and an important breeding area for millions of seabirds. There is, however, little information on the dynamics of the polynya or the bird populations over the long term. Here, we used sediment archives from a lake and peat deposits along the Greenland coast of the NOW polynya to track long-term patterns in the dynamics of the seabird populations. Radiocarbon dates show that the thick-billed murre (Uria lomvia) and the common eider (Somateria mollissima) have been present for at least 5500 cal. years. The first recorded arrival of the little auk (Alle alle) was around 4400 cal. years bp at Annikitsoq, with arrival at Qeqertaq (Salve Ø) colony dated to 3600 cal. years bp. Concentrations of cadmium and phosphorus (both abundant in little auk guano) in the lake and peat cores suggest that there was a period of large variation in bird numbers between 2500 and 1500 cal. years bp. The little auk arrival times show a strong accord with past periods of colder climate and with some aspects of human settlement in the area.     

Preliminary screening of perfluorooctane sulfonate (PFOS) and other fluorochemicals in fish, birds and marine mammals from Greenland and the Faroe Islands

Extensive screening analyses of perfluorooctane sulfonate (PFOS) and related perfluorinated compounds in biota samples from all over the world have identified PFOS as a global pollutant and have shown its bioaccumulation into higher trophic levels in the food chain. Perfluorinated compounds have been found in remote areas as the Arctic. In this study a preliminary screening of PFOS and related compounds has been performed in liver samples of fish, birds and marine mammals from Greenland and the Faroe Islands. PFOS was the predominant fluorochemical in the biota analyzed, followed by perfluorooctane sulfonamide (PFOSA). PFOS was found at concentrations above LOQ (10 ng/g wet weight) in 13 out of 16 samples from Greenland and in all samples from the Faroe Islands. The results from Greenland showed a biomagnification of PFOS along the marine food chain (shorthorn sculpin < ringed seal < polar bear). The greatest concentration of PFOS was found in liver of polar bear from east Greenland (mean: 1285 ng/g wet weight, n = 2). The geographical distribution of perfluorinated compounds in Greenland was similar to that of persistent organohalogenated compounds (OHCs), with the highest concentrations in east Greenland, indicating a similar geographical distribution to that of OHCs, with higher concentrations in east Greenland than in west Greenland.