Copper and zinc content in wild game shot with lead or non-lead ammunition - implications for consumer health protection

Lead poisoning of raptors: state of the science and cross-discipline mitigation options for a global problem

Lead poisoning is an important global conservation problem for many species of wildlife, especially raptors. Despite the increasing number of individual studies and regional reviews of lead poisoning of raptors, it has been over a decade since this information has been compiled into a comprehensive global review. Here, we summarize the state of knowledge of lead poisoning of raptors, we review developments in manufacturing of non-lead ammunition, the use of which can reduce the most pervasive source of lead these birds encounter, and we compile data on voluntary and regulatory mitigation options and their associated sociological context. We support our literature review with case studies of mitigation actions, largely provided by the conservation practitioners who study or manage these efforts. Our review illustrates the growing awareness and understanding of lead exposure of raptors, and it shows that the science underpinning this understanding has expanded considerably in recent years. We also show that the political and social appetite for managing lead ammunition appears to vary substantially across administrative regions, countries, and continents. Improved understanding of the drivers of this variation could support more effective mitigation of lead exposure of wildlife. This review also shows that mitigation strategies are likely to be most effective when they are outcome driven, consider behavioural theory, local cultures, and environmental conditions, effectively monitor participation, compliance, and levels of raptor exposure, and support both environmental and human health.

Microecological characteristics of water bodies/sediments and microbial remediation strategies after 50 years of pollution exposure in ammunition destruction sites in China

The effects of long-term ammunition pollution on microecological characteristics were analyzed to formulate microbial remediation strategies. Specifically, the response of enzyme systems, N/O stable isotopes, ion networks, and microbial community structure/function levels were analyzed in long-term (50 years) ammunition-contaminated water/sediments from a contamination site, and a compound bacterial agent capable of efficiently degrading trinitrotoluene (TNT) while tolerating many heavy metals was selected to remediate the ammunition-contaminated soil. The basic physical and chemical properties of the water/sediment (pH (up: 0.57-0.64), nitrate (up: 1.31-4.28 times), nitrite (up: 1.51-5.03 times), and ammonium (up: 7.06-70.93 times)) were changed significantly, and the significant differences in stable isotope ratios of N and O (nitrate nitrogen) confirmed the degradability of TNT by indigenous microorganisms exposed to long-term pollution. Heavy metals, such as Pb, Zn, Cu, Cd, Cs, and Sb, have synergistic toxic effects in ammunition-contaminated sites, and significantly decreased the microbial diversity and richness in the core pollution area. However, long-term exposure in the edge pollution area induced microorganisms to use TNT as a carbon and nitrogen sources for life activities and growth and development. The Bacteroidales microbial group was significantly inhibited by ammunition contamination, whereas microorganisms such as Proteobacteria, Acidobacteriota, and Comamonadaceae gradually adapted to this environmental stress by regulating their development and stress responses. Ammunition pollution significantly affected DNA replication and gene regulation in the microecological genetic networks and increased the risk to human health. Mg and K were significantly involved in the internal mechanism of microbial transport, enrichment, and metabolism of TNT. Nine strains of TNT-utilizing microbes were screened for efficient TNT degradation and tolerance to typical heavy metals (copper, zinc and lead) found in contaminated sites, and a compound bacterial agent prepared for effective repair of ammunition-contaminated soil significantly improved the soil ecological environment.

Lead contamination in Australian game meat

Lead-based ammunition (gunshot and bullets) frequently leaves small lead fragments embedded in the meat of wild-shot game animals. Australia produces several commercial game meat products from wild animals harvested with lead-based ammunition and has a growing population of recreational hunters. However, no studies have previously investigated the frequency of lead fragments or lead concentrations in Australian game meat. We examined 133 Australian minced game meat items of four types for evidence of lead contamination. Samples were meat from kangaroos (Macropus and Osphranter spp.; n=36) and Bennett's wallabies (Notamacropus rufogriseus; n=28) sold for human consumption, and deer ('venison'; multiple spp.; n=32) and stubble quail (Coturnix pectoralis; n=37) harvested for private consumption by recreational hunters. All packages were studied by digital radiography to detect the presence of radio-dense fragments, assumed to be lead fragments from ammunition. Visible fragments were absent in commercially available kangaroo products, but were present in 4%, 28% and 35% of wallaby, venison and quail, respectively. Mean meat lead concentrations (mg/kg wet weight) were 0.01 ± 0.01 for kangaroo, 0.02 ± 0.01 for wallaby, 0.12 ± 0.07 for venison, and 1.76 ± 3.76 for quail. The Australian food standards threshold for livestock meat (0.1 mg/kg w.w.) was not exceeded by any kangaroo or wallaby products but was exceeded by 53% and 86% of venison and quail, respectively. Radiography only detected 35% of samples that were above the food safety threshold. While average lead concentrations in commercially available macropod (kangaroo and wallaby) meat were low, those in recreationally harvested game meat may pose health risks for hunters and associated consumers.

Risk Assessment of Cd, Cu, and Pb from the consumption of hunted meat: red-legged partridge and wild rabbit

The objective was to assess that potential health risk from Cd, Cu, and Pb, through the consumption of hunted red-legged partridge and wild rabbit meat, with special focus on the population of hunters and their relatives. Mineral content was analyzed by atomic absorption methods (F-AAS for Cu and GF-AAS for Cd and Pb) after microwave digestion of lyophilized samples. The average concentrations of these elements were 0.008 and 0.01 mg/kg for Cd; 1.41 and 1.63 mg/kg for Cu and 0.98 and 1.28 mg/kg for Pb in wild rabbit and red-legged partridge meat respectively. The dietary, risk assessment was performed by assuming two intake scenarios based on the obtained results of the survey on game meat consumption and the current maximum recommended intakes of Cd, Cu, and Pb, and then, the hazard quotients (THQ and TTHQ) were calculated. The data show that exposure to these metals from eating red-legged partridge and wild rabbit meat from a hunting provenance is relatively low and generally greater in the hunter population. The risk assessment revealed that moderate or low consumption of meat of these species does not offer a significant public health risk. Moreover, hazard quotients values for these metals of red-legged partridge and rabbit meat consumption in hunters and nonhunters are below 1. However, a high Pb content in the meat of these species and a high consumption may pose a greater health risk to hunters.

Trace Element Concentrations in Migratory Game Bird Meat: Contribution to Reference Intakes Through a Probabilistic Assessment

The aim of this study was to determine Co, Cr, Cu, Fe, and Zn content in migratory game bird meat and its contribution to DRI through a probabilistic assessment. A total of 89 wild birds of three species, woodpigeon (Columba palumbus) (n = 25), common turtledove (Streptopelia turtur) (n = 19), and thrush (Turdus philomelos) (n = 45), were analyzed. Concentrations ranged between the following values: Fe: 35.6-39.6 mg/kg ww; Cu: 2.3-4.0 mg/kg ww; Zn: 11.0-18.6 mg/kg ww; and Cr: 43-51 μg/kg ww. Co content in this kind of meat was negligible. Significant differences were found for Cu and Zn content among species and for Cu, Fe, and Zn between breast and thigh muscle. Breast was the muscle with the highest Cu and Fe content, and thigh recorded the highest Zn levels for all species. Finally, a probabilistic assessment showed that consumption of a serving size between 100 and 200 g of game bird meat (80% breast + 20% thigh) that could meet the DRIs of Cu and Fe for 95th percentile. Then, game meat of these species could be considered as part of a healthy diet and a food with a high nutritional value.

D-Penicillamine prolongs survival and lessens copper-induced toxicity in Drosophila melanogaster

D-penicillamine (DPA) is an amino-thiol that has been established as a copper chelating agent for the treatment of Wilson's disease. DPA reacts with metals to form complexes and/or chelates. Here, we investigated the survival rate extension capacity and modulatory role of DPA on Cu²⁺-induced toxicity in Drosophila melanogaster. Adult Wild type (Harwich strain) flies were exposed to Cu²⁺ (1 mM) and/or DPA (50 μM) in the diet for 7 days. Additionally, flies were exposed to acute Cu²⁺ (10 mM) for 24 h, followed by DPA (50 μM) treatment for 4 days. Thereafter, the antioxidant status [total thiol (T-SH) and glutathione (GSH) levels and glutathione S-transferase and catalase activities] as well as hydrogen peroxide (H₂O₂) level and acetylcholinesterase activity were evaluated. The results showed that DPA treatment prolongs the survival rate of D. melanogaster by protecting against Cu²⁺-induced lethality. Further, DPA restored Cu²⁺-induced depletion of T-SH level compared to the control (P < 0.05). DPA also protected against Cu²⁺ (1 mM)-induced inhibition of catalase activity. In addition, DPA ameliorated Cu²⁺-induced elevation of acetylcholinesterase activity in the flies. The study may therefore have health implications in neurodegenerative diseases involving oxidative stress such as Alzheimer's disease.

Fragmentation of lead-free and lead-based hunting rifle bullets under real life hunting conditions in Germany

As lead is a heavy metal showing high toxicity for many organisms, its entry in the ecosystem should be minimised. Nevertheless, considerable quantities are deposited in the environment via hunting ammunition. Such practice is responsible for the occurrence of lead poisoning in many wildlife species and represents a health risk to humans. We assess the differences in the fragmentation patterns of lead-based and lead-free hunting rifle bullets using the radiographic characteristics of gunshot wounds. We took radiographs of 297 wild ungulates shot during regular hunting events in Germany. Compared to lead-free ammunition, both the number of bullet fragments and the maximal distance between fragments and the wound channel increased when bullets were lead-based. Under normal German hunting conditions, the use of lead-based bullets causes a broad contamination of the carcass and the viscera with bullet material. The wide-spread substitution of lead-based bullets through non-lead alternatives should therefore be further encouraged.

Biochemical CuSO4 Toxicity in Drosophila melanogaster Depends on Sex and Developmental Stage of Exposure

Copper is a transition metal that exists in different chemical forms (e.g., Cu²⁺,Cu⁺, and Cu⁰) and at high concentrations it is toxic. Here, we investigated the Cu²⁺-induced toxicity in Drosophila melanogaster, evaluating the survival, locomotion, and the activity of acetylcholinesterase (AChE) and glutathione S-transferase (GST) enzymes. Flies were exposed to Cu²⁺(0.1-1 mmol CuSO₄/kg of diet or approximately 0.1-1 mM Cu²⁺) and allowed to mate during 24 h. GST and AChE enzymes were evaluated in the larvae and in the head and the body (thorax + abdomen) of the adult male and females flies. The total number of adult females (0.4-1 mM) and males (0.75 and 1 mM) was decreased by CuSO₄. The climbing ability was hampered in flies exposed to 1 mM Cu²⁺. In larvae, Cu²⁺(0.4-1 mM) increased AChE activity (P < 0.002). In males' heads, 0.4 mM Cu²⁺ increased the AChE activity (P < 0.01). In adults' bodies, Cu²⁺inhibited the activity in both sexes, but with greater effectiveness in males (0.1 to 1 mM) than in females (1 mM). Regarding GST activity, 0.1 mM Cu²⁺increased, but 1 mM decrease GST in larvae. In the head of flies, Cu²⁺decreased the GST activity at intermediate (0.4 mM) and increased GST at the highest concentration (1 mM) in males. In the bodies, the effect of Cu²⁺was similar. In conclusion, Cu²⁺exposure in D. melanogaster disrupted locomotion and enzymatic parameters that can be related to changes in AChE and in the detoxifying GST enzyme.

Lead and copper in hunted wild boars and radiographic evaluation of bullet fragmentation between ammunitions

The purpose of the present study was to evaluate the content of lead in carcasses of wild boars shot with lead bullets, in comparison with that of copper caused by lead-free ammunitions. Radiographic images of hunted boars were obtained in order to assess the degree of bullet fragmentation in the carcasses. Samples of meat were collected from different body areas at increasing distance from bullet trajectory, to be analysed by ICP-MS for lead and copper levels. In wild boars shot with lead ammunitions, a massive dispersion of bullet fragments and very high lead levels were detected. By contrast, in wild boars killed with copper ammunitions no radiographic signs of bullet fragmentation were observed. Copper ammunitions seem therefore a safer alternative to standard lead-core ones, due to their minimal fragmentation and the relatively low toxicity of this metal.

Meat quality of farmed red deer fed a balanced diet: effects of supplementation with copper bolus on different muscles

Supplementation with copper (Cu) improves deer antler characteristics, but it could modify meat quality and increase its Cu content to levels potentially harmful for humans. Here, we studied the effects of Cu bolus supplementation by means on quality and composition of sternocephalicus (ST) and rectus abdominis (RA) muscles (n=13 for each one) from yearling male red deer fed with a balanced diet. Each intraruminal bolus, containing 3.4 g of Cu, was administered orally in the treatment group to compare with the control group. Meat traits studied were pH at 24 h postmortem (pH24), colour, chemical composition, cholesterol content, fatty acid (FA) composition, amino acid (AA) profile and mineral content. In addition, the effect of Cu supplementation on mineral composition of liver and serum (at 0 and 90 days of treatment) was analysed. No interactions between Cu supplementation and muscle were observed for any trait. Supplementation with Cu increased the protein content of meat (P&lt;0.01). However, Cu content of meat, liver and serum was not modified by supplementation. In fact, Cu content of meat (1.20 and 1.34 mg/kg for Cu supplemented and control deer, respectively) was much lower in both groups than 5 mg/kg of fresh weight allowed legally for food of animal origin. However, bolus of Cu tended to increase the meat content of zinc and significantly increased (P&lt;0.05) the hepatic contents of sodium and lead. Muscles studied had different composition and characteristics. The RA muscle had significantly higher protein content (P&lt;0.001), monounsaturated FA content (P&lt;0.05) and essential/non-essential AA ratio (P&lt;0.01) but lower pH24 (P&lt;0.01) and polyunsaturated FA content (P=0.001) than the ST muscle. In addition, RA muscle had 14.4% less cholesterol (P=0.001) than ST muscle. Also, mineral profile differed between muscles with higher content of iron, significantly higher (P&lt;0.001) content of zinc and lower content of calcium, magnesium and phosphorus (P&lt;0.05) for ST muscle compared with RA. Therefore, supplementation with Cu modified deer meat characteristics, but it did not increase its concentration to toxic levels, making it a safe practice from this perspective. Despite the lower content of polyunsaturated FA, quality was better for RA than for ST muscle based on its higher content of protein with more essential/non-essential AA ratio and lower pH24 and cholesterol content.

Lead content in wild game shot with lead or non-lead ammunition - Does "state of the art consumer health protection" require non-lead ammunition?

The toxicity of lead has been known for a long time, and no safe uptake level can be derived for humans. Consumers’ intake via food should therefore be kept as low as possible. Game meat can contain elevated levels of lead due to the use of lead ammunition for hunting. A risk assessment conducted in 2010 by the German Federal Institute for Risk Assessment including various consumption scenarios revealed a possible health risk for extreme consumers of game meat hunted with lead ammunition (i.e. hunters and members of hunters’ households). Babies, infants, children and women of childbearing age were identified as vulnerable group with regards to the developmental neurotoxicity of lead. It was noted, that a sound data base was required in order to refine the assessment. Therefore, the research project “Safety of game meat obtained through hunting” (LEMISI) has been conducted in Germany, with the aims of determining the concentrations of lead (as well as of copper and zinc) brought into the edible parts of game meat (roe deer (Capreolus capreolus) and wild boar (Sus scrofa)) due to using either lead or non-lead hunting ammunition, whilst concurrently taking geogenic (i.e. “background”) levels of lead into account. Compared to non-lead ammunition, lead ammunition significantly increased lead concentrations in the game meat. The use of both lead and non-lead ammunition deposited copper and zinc in the edible parts of game meat, and the concentrations were in the range of those detected regularly in meat of farm animals. For the average consumer of game meat in Germany the additional uptake of lead only makes a minor contribution to the average alimentary lead exposure. However, for consumers from hunters’ households the resulting uptake of lead–due to lead ammunition—can be several times higher than the average alimentary lead exposure. Non-lead bullets in combination with suitable game meat hygienic measures are therefore recommended in order to ensure “state of the art consumer health protection”.

Heads in the sand: public health and ecological risks of lead-based bullets for wildlife shooting in Australia

Lead (Pb) is a toxic element banned from fuel, paint and many other products in most developed countries. Nonetheless, it is still widely used in ammunition, including rifle bullets, and Pb-based bullets are almost universally used in Australia. For decades, poisoning from Pb shot (shotguns) has been recognised as a cause of disease in waterfowl and Pb shot has been subsequently banned for waterfowl hunting in many jurisdictions. However, the risks posed by Pb-based bullets (rifles) have not been similarly recognised in Australia. Pb-based rifle bullets frequently fragment, contaminating the tissue of shot animals. Consuming this Pb-contaminated tissue risks harmful Pb exposure and, thus, the health of wildlife scavengers (carrion eaters) and humans and their companion animals who consume harvested meat (game eaters). In Europe, North America and elsewhere, the environmental and human health risks of Pb-based bullets are widely recognised, and non-toxic alternatives (e.g. copper-based bullets) are increasingly being used. However, Australia has no comparable research despite widespread use of shooting, common scavenging by potentially susceptible wildlife species, and people regularly consuming shot meat. We conclude that Australia has its collective ‘head in the sand’ on this pressing worldwide One Health issue. We present the need for urgent research into this field in Australia.