The Link Between Human Menstruation and Placental Delivery: A Novel Evolutionary Interpretation: Menstruation and fetal placental detachment share common evolved physiological processes dependent on progesterone withdrawal.

A new interpretation of human menstruation is presented, resulting from a cross-disciplinary investigation of evolution, developmental biology, and physiology. A process evolutionarily associated with childbirth expresses itself as menstruation in women for whom frequent and continual failure to conceive has become the default situation. In humans and Old World primates, contractile uterine spiral arterioles evolved as the complement of the highly invasive hemochorionic placenta and is the selected phenotype. Placental progesterone withdrawal during the last stage of birth leads to arrested blood flow through maternal spiral arterioles, allowing detachment of the deciduous placenta with minimal maternal hemorrhage. In nonpregnant females, progesterone withdrawal from a degenerating corpus luteum initiates menstruation and stops blood flow through uterine spiral arterioles. Both events share similar physiological mechanisms and sequences. This explanation may improve our understanding of a recurrent event experienced by half of the human population and for a quarter of their adult reproductive life.

DNA-based identification of invasive alien species in relation to Canadian federal policy and law, and the basis of rapid-response management.

Managing invasive alien species in Canada requires reliable taxonomic identification as the basis of rapid-response management. This can be challenging, especially when organisms are small and lack morphological diagnostic features. DNA-based techniques, such as DNA barcoding, offer a reliable, rapid, and inexpensive toolkit for taxonomic identification of individual or bulk samples, forensic remains, and even environmental DNA. Well suited for this requirement, they could be more broadly deployed and incorporated into the operating policy and practices of Canadian federal departments and should be authorized under these agencies' articles of law. These include Fisheries and Oceans Canada, Canadian Food Inspection Agency, Transport Canada, Environment Canada, Parks Canada, and Health Canada. These efforts should be harmonized with the appropriate provisions of provincial jurisdictions, for example, the Ontario Invasive Species Act. This approach necessitates that a network of accredited, certified laboratories exists, and that updated DNA reference libraries are readily accessible. Harmonizing this approach is vital among Canadian federal agencies, and between the federal and provincial levels of government. Canadian policy and law must also be harmonized with that of the USA when detecting, and responding to, invasive species in contiguous lands and waters. Creating capacity in legislation for use of DNA-based identifications brings the authority to fund, train, deploy, and certify staff, and to refine further developments in this molecular technology.

Promoting enforcement of non-lead hunting ammunition regulations and compliance in Europe and North America.

The direct regulation of lead ammunition in North America and Europe has been mainly for hunting in wetlands. Little support among hunters and the ammunition makers exists for further regulation despite suitable lead substitutes and much education about the known risks to wildlife and human health from ingested lead. In the absence of personnel to detect use of lead ammunition and enforce regulations, hunter compliance is low. Identification of non-lead ammunition using existing electronic technology and an international protocol on the identification of non-lead rifle bullets is proposed to aid enforcement. An explicit definition of the chemical composition of lead substitutes is required in European Union legislation together with a more enforceable distinction between 'possession during hunting' and 'ownership' of lead ammunition. A more transdisciplinary regulatory approach to transitioning to non-lead ammunition is advised. It comprises widespread public health advisories, setting a maximum allowable lead level in commercial game meats in EU legislation, and public communication that emphasizes the benefits of non-lead ammunition use to all categories of wildlife and the public perception of hunting, whether in North America or Europe.

Setting maximum levels for lead in game meat in EC regulations: An adjunct to replacement of lead ammunition.

Each year, hunters from 12 of the 27 European Union (EU) countries and the UK shoot over 6 million large game mammals, 12 million rabbits and hares and over 80 million birds. They support an international game meat market worth over 1.1 thousand million Euros. Animals shot with lead ammunition frequently contain lead fragments in the carcass which contaminate meals made from game meat with concentrations of lead substantially above the maximum allowable level (ML) set by European Commission Regulation EC1881/2006 for meat from domesticated animals. This poses a health risk to frequent consumers of wild-shot game meat, with children and pregnant women being particularly vulnerable. Total replacement of lead rifle and shotgun ammunition with available non-toxic alternatives is needed for all hunting in EU nations to prevent exposure of humans and wildlife to ammunition-derived lead and to allow the depletion of the long-term environmental legacy of lead from spent ammunition. We propose that EC1881/2006 is amended to incorporate an ML for game meats as a supplementary measure to the replacement of lead ammunition. This would harmonise food safety standards for lead in meats traded across and imported into the EU.

Assessment of the environmental toxicity and carcinogenicity of tungsten-based shot.

The toxicity of elemental tungsten released from discharged shot was assessed against previous studies that established a 1% toxic threshold for soil organisms. Extremely heavy theoretical shot loadings of 69,000shot/ha were used to generate estimated environmental concentrations (EEC) for two brands of tungsten-based shot containing 51% and 95% tungsten. The corresponding tungsten EEC values were 6.5-13.5mg W/kg soil, far below the 1% toxic threshold. The same shot loading in water produced tungsten EEC values of 2.1-4.4mg W/L, levels that are not toxic under experimental conditions. Pure tungsten has not been shown to exhibit carcinogenic properties when ingested or embedded in animal tissues, but nickel, with which it is often alloyed, has known carcinogenicity. Given the large number of waterfowl that carry shot embedded in their body, it is advisable to screen lead shot substitutes for their carcinogenic potential through intra-muscular implantation.

Rationale for the regulated transition to non-lead products in Canada: A policy discussion paper.

Lead gunshot, rifle bullets, and fishing weights are still allowed in Canadian provincially-regulated hunting and fishing, despite the contribution to lead exposure in humans, wildlife, and the environment. Non-lead gunshot and fishing weights are required in Canada only for waterfowl hunting, and angling in national parks and national wildlife areas. Lead wheel weights are also allowed and comprise a majority of the Canadian market. Effective non-lead substitutes for these products exist, and are already required in various American and European jurisdictions. Several analyses commissioned by the Canadian government in 2018 identified the problems of lead exposure attributable to these four lead products. Lead is already listed under Schedule 1 of the Canadian Environmental Protection Act (CEPA) that authorizes the government to undertake measures to reduce exposure. CEPA could require, simultaneously, use of non-lead ammunition, fishing weights and wheel weights at the national level, following an appropriate phase-in period. The low provincial and territorial licence fees for hunting and fishing in Canada would offset any costs associated with use of lead substitutes. Costs for non-lead wheel weights would comprise a small percentage of the costs of new vehicles and new tire purchases. This regulatory initiative would complement other Canadian national bans on lead products. Because there is no safe threshold level for blood lead, use of non-lead products would benefit the health of humans, scavengers, upland game species, and fish-eating birds.

Chemical compositional standards for non-lead hunting ammunition and fishing weights.

The chemical composition of non-lead, non-toxic, gunshot used for hunting waterfowl is regulated only in Canada and the USA. No nation regulates the composition of non-lead fishing weights, rifle bullets, and gunshot used for upland game hunting. Compositional criteria for these non-lead products are proposed here, based on established experimental toxicity protocols. Because of the demonstrated acute toxicity of ingested zinc shot to birds, fishing weights and gunshot should never be made of this pure metal. Nickel should be avoided as an incidental component of gunshot because of potential carcinogenicity concerns about such embedded shot in birds and other animals. These compositional criteria could be adopted by all nations undertaking the transition to non-lead fishing weights and hunting ammunition. The listed criteria would facilitate production and international trade in non-lead products, and promote easier enforcement and user compliance with non-lead standards.

Availability and prices of non-lead gunshot cartridges in the European retail market.

To analyse those factors that inhibit or facilitate the shift from lead to non-lead ammunition, it is important to evaluate the extent to which hunters can purchase suitable non-lead products. Based on an Internet search, we identified 22 European and 6 North American manufactures of non-lead shot cartridges distributed in 10 different countries. During the web search, we found non-lead shot cartridges available in retail stores with online sales of these products in 22 of 29 European countries. The most common non-lead shot type was steel shot, although bismuth, tungsten and copper were available in some countries. We conclude that non-lead shot cartridges are available to purchasers in most European countries, but in a limited variety. Availability of non-lead ammunition is not limited by production but by the demand at the national, regional, and local levels. Multiple manufacturers provide such ammunition, and their products may become available in any member state, regionally and locally, once the demand is established. The collective experience of Denmark, Canada, and the USA indicate that the demand for non-lead products will be stimulated by any intergovernmental initiatives to regulate lead ammunition for hunting and target shooting, especially when such initiatives are accomplished through well-enforced national regulation.

The transition to non-lead sporting ammunition and fishing weights: Review of progress and barriers to implementation.

This review presents evidence of lead exposure and toxicity to wildlife and humans from spent shotgun and rifle ammunition and fishing weights, and the barriers and bridges to completing the transition to non-lead products. Despite the international availability of effective non-lead substitutes, and that more jurisdictions are adopting suitable policies and regulations, a broader transition to non-lead alternatives is prevented because resolution remains divided among disparate human user constituencies. Progress has occurred only where evidence is most compelling or where a responsible public authority with statutory powers has managed to change mindsets in the wider public interest. Arguments opposing lead bans are shown to lack validity. Differing national regulations impede progress, requiring analysis to achieve better regulation. Evidence that lead bans have reduced wildlife exposure should be used more to promote sustainable hunting and fishing. Evidence of the lead contribution from hunted game to human exposure should shape policy and regulation to end lead ammunition use. The Special Issue presents evidence that a transition to non-lead products is both warranted and feasible.

Dissolution of copper, tin, and iron from sintered tungsten-bronze spheres in a simulated avian gizzard, and an assessment of their potential toxicity to birds.

The rates of dissolution of copper, tin, and iron from sintered tungsten-bronze spheres (51.1%W, 44.4%Cu, 3.9%Sn, 0.6%Fe, by mass) were measured in an in vitro simulated avian gizzard at pH 2.0, and 42C. Most of the spheres had disintegrated completely to a fine powder by day 14. Dissolution of copper, tin, and iron from the spheres was linear over time; all r>0.974; all P<0.001. The mean rate of release of copper, tin, and iron was 30.4 mg, 2.74 mg, and 0.38 mg per g tungsten-bronze per day, respectively. These rates of metal release were compared to those in published studies to determine whether the simultaneous ingestion of eight spheres of 3.48 mm diameter would pose a toxic risk to birds. The potential absorption rates of iron and tin (0.54 mg Fe/day, and 3.89 mg Sn/day) from eight tungsten-bronze spheres of total mass 1.42 g would not prove toxic, based on empirical studies of tin and iron ingestion in waterfowl. The release of 43.17 mg copper/day from eight tungsten-bronze spheres, while exceeding the daily copper requirements of domesticated birds, is far below the levels of copper known to cause copper toxicosis in birds. We conclude that sintered tungsten-bronze material made into gunshot, fishing weights, or wheel balance weights, would not pose a toxic risk to wild birds when ingested.

Release of copper from sintered tungsten-bronze shot under different pH conditions and its potential toxicity to aquatic organisms.

Sintered tungsten-bronze is a new substitute for lead shot, and is about to be deposited in and around the wetlands of North America. This material contains copper in the alloyed form of bronze. This in vitro study was performed according to U.S. Fish and Wildlife Service criteria to determine the dissolution rate of copper from the shot, and to assess the toxic risk that it may present to aquatic organisms. The dissolution of copper from tungsten-bronze shot, pure copper shot, and glass beads was measured in a buffered, moderately hard, synthetic water of pH 5.5, 6.6, and 7.8 over a 28-day period. The dissolution of copper from both the control copper shot and the tungsten-bronze shot was affected significantly by the pH of the water and the duration of dissolution (all p values<0.000). The rate of copper release from tungsten bronze shot was 30 to 50 times lower than that from the copper shot, depending on pH (p<0.0000). The observed expected environmental concentration of copper released from tungsten-bronze shot after 28 days was 0.02 microg/L at pH 7.8, and 0.4 microg/L at pH 5.6, using a loading and exposure scenario specific in a U.S. Fish and Wildlife Service protocol. Ratio Quotient values derived from the highest EEC observed in this study (0.4 microg/L), and the copper toxic effect levels for all aquatic species listed in the U.S. Environmental Protection Agency ambient water quality criteria database, were all far less than the 0.1 criterion value. Given the conditions stipulated by the U.S. Fish and Wildlife Service and the U.S. Environmental Protection Agency, heavy loading from discharged tungsten-bronze shot would not pose a toxic risk to potable water, or to soil. Consequently, it would appear that no toxic risks to aquatic organisms will attend the use of tungsten-bronze shot of the approved composition. Given the likelihood that sintered tungsten-bronze of the same formula will be used for fishing weights, bullets, and wheel balance weights, it is expected that the use of this new material in these applications will not be associated with toxic risks to aquatic life.

The transition to non-lead rifle ammunition in Denmark: National obligations and policy considerations.

The issue of Denmark regulating use of lead-free rifle ammunition because of potential risks of lead exposure in wildlife and humans was examined from a scientific and objective policy perspective. The consequences of adopting or rejecting such regulation were identified. Denmark is obliged to examine this topic because of its national policy on lead reduction, its being a Party to the UN Bonn Convention on Migratory Species, and its role in protecting White-tailed Sea Eagles (Haliaeetus albicilla), a species prone to lead poisoning from lead ingestion. Lead-free bullets suited for deer hunting are available at comparable cost to lead bullets, and have been demonstrated to be as effective. National adoption of lead-free bullets would complete the Danish transition to lead-free ammunition use. It would reduce the risk of lead exposure to scavenging wildlife, and humans who might eat lead-contaminated wild game meat. Opposition from hunting organizations would be expected.

Lead bioaccumulation in earthworms, Lumbricus terrestris, from exposure to lead compounds of differing solubility.

This study examined the relative effects of soluble and less soluble Pb compounds on Pb accumulation by Lumbricus terrestris. The earthworms were exposed to composted cattle manure contaminated with a range of concentrations of either soluble lead acetate trihydrate (PbAc) (14.5, 72.2, 137, 257, and 603 microg/g) or less soluble lead carbonate (Pb(CO(3))(2)) (5.09, 171, 575, and 710 microg/g). Relative Pb bioaccumulation rates in earthworms from the PbAc and Pb(CO(3))(2) lead carbonate trials were compared over time (0, 20, 40, and 60 days). The two molecular forms of Pb were heavily adsorbed onto the organic matter. Relative soluble Pb concentrations in the manure pore water were very low, at 0.049% and 0.022% of total Pb for PbAc and Pb(CO(3))(2), respectively. There was a significant uptake of lead by earthworms from both the readily soluble and less soluble forms of Pb. Regression surfaces relating organic matter total Pb concentration to exposure time and Pb body burden were compared. For the PbAc trial, the following equation was fitted: Body burden=2.3429+0.0014 x--0.0632 y+0.0008 xy (R(2)=0.8494, p<0.0001). For the Pb(CO(3))(2) trial, the equation was: Body burden=-2.0760--0.0067 x-0.2297 y-0.0038 y(2)+0.0003 xy (R(2)=0.5686, p<0.0001) (for x=organic matter Pb concentration in microg/g and y=time in days). The Pb bioaccumulation resulting from the PbAc exposure was significantly higher than that from Pb(CO(3))(2). Body burdens of earthworms exposed to PbAc were linearly related to exposure time and total Pb concentration. Worms exposed to Pb(CO(3))(2) had non-linear Pb accumulation over time that suggested a decrease in Pb bioavailability with increasing exposure time. The results indicate that L. terrestris feeding on detritus in the upper soil levels can mobilize and accumulate Pb from the principal transformation products of metallic Pb, as at shooting ranges and lead smelter sites.

[Is lead used in sports (hunting, shooting and angling) an underestimated public health problem?]. / Es el plomo empleado en deportes (caza, tiro y pesca deportiva) un problema de salud pública infravalorado?

Ammunition and fishing weights used in recreational hunting, shooting and fishing sports have been made traditionally with lead. In Spain, for example, hunters and shooters are responsible for the dispersion of some 6000 tonnes of the heavy metal yearly, into wetland and dryland areas, and an estimated 100 tonnes are contributed by anglers to the aquatic zones. The few legal measures that several countries have adopted banning the use of the lead in these sports are based on the irrefutable proof that every year millions of birds were poisoned lethally, due to the inadvertent ingestion of lead shot and sinkers found in their habitats. We analyzed whether the present conservationist approach to the problem is suitable, and if the evidence of damage to human beings is, or is not, sufficient to warrant even more prohibitive measures, especially because, in children, there is no safe exposure to lead. We conclude that in some areas adequate information already exists, although in others the toxicological-epidemiological studies are still scanty, suggesting that the topic has been given little attention. We are concerned that the Precautionary Principle has not been applied to solve this problem whose health effects will be more long-term than immediate, especially given the array of lead substitutes available.

The distribution of outdoor shooting ranges in Ontario and the potential for lead pollution of soil and water.

The distribution of outdoor shotgun shooting ranges in Ontario was determined to assess their potential for contributing to lead contamination of soil and water. Provincial soil maps were used to identify the soil type(s) occurring on each range, and to record their soil pH, organic matter content and clay content. Topographic maps (scale 1:50000) were used to identify any surface waters that existed on each range. At least 211 active shooting ranges exist in Ontario, of which 135 cater to shotgun sports. This number far exceeds earlier estimates. Soil pH data existed for 67 ranges, of which 50 had soil pH values >or=6.0, and 17 had pH values less than 6.0. Data for organic matter and or clay content were available for only 59 ranges. Approximately 10% of the ranges are on soils with low levels of both clay and organic matter. Seven of these ranges had a combination of low pH, and low clay and organic matter content, suggesting that they have a high potential for lead dissolution and mobilization. Surface waters that could potentially receive shot fall-out occurred on 94% of the ranges surveyed, although the precise location of the water with respect to the shot fall area at each range could not be determined. The majority of shooting ranges in the province occur on luvisolic soils: most of the ranges with a higher potential for lead solubilization occur on podzolic and brunisolic soils. This indirect approach to assessing the potential for lead pollution and mobility at shooting ranges allows a large number of ranges to be examined quickly, so that ranges with a high potential for lead contamination of soil and water can be selected for on-site measurements. This broad scale approach has allowed for the first time the point loading of metallic lead into the Ontario environment from shooting ranges to be determined, as well as the locations of ranges that may warrant investigation of lead pollution.

Bone lead levels and lead isotope ratios in red grouse from Scottish and Yorkshire moors.

Leg and foot bones of adult and juvenile red grouse (Lagopus lagopus scoticus) were collected from hunter-shot birds on two Scottish estates (Glendye and Invermark) and one Yorkshire estate in September, 2003. The lead content of bones was measured by atomic absorption spectrophotometry, and corresponding stable lead isotopes (Pb(204, 206, 207, 208)) by inductively coupled plasma mass spectrometry. At the Glendye (N=111) and Invermark (N=85) estates, relatively few birds (5.4% and 3.5%, respectively) had highly elevated bone lead concentrations (>20 microg/g dry weight). In bones of these highly exposed birds, a combination of Pb(206):Pb(207) and Pb(208):Pb(207)ratios was consistent with ingestion of lead gunshot available in Europe. By contrast, Yorkshire grouse experienced a high incidence (65.8%) of bone lead >20 microg/g. The Pb(206):Pb(207) and Pb(208):Pb(207)ratios in bones of these highly exposed birds were consistent with a combined exposure to ingested lead gunshot and lead from galena mining in the region. Lead isotope ratios also indicated that lead from UK gasoline combustion and fallout from atmospheric particles was not a likely source of elevated lead in bones of either Scottish or Yorkshire grouse. Suggested management options for the three moors include adopting nontoxic shot for all game shooting on the estates, allowing heather (Calluna vulgaris) vegetation to grow tall in lead shot fall-out zones to reduce physical access to high densities of lead shot already present, and provision of calcareous grit across moors to reduce lead assimilation from all ingested sources of lead.