Evaluating Non-toxic Substitutes for Lead Shot and Fishing Weights
Bibliographic record
Abstract
* Vernon Thomas is a professor of wildlife biology and management in the Department of Zoology, University of Guelph, Guelph, Ontario, Canada, specialising in the extension of science to policy and legislative issues in conservation. He has been involved with the problem of lead poisoning of wildlife and its resolution for the past 12 years. E-mail; vthomas@uoguelph.ca. ** Raimon Guitart is a professor of toxicology at the Veterinary Faculty, Autonomous University of Barcelona, Bellaterra, Spain. His research involves the problems of lead poisoning of Spanish wildlife and people. E-mail: raimon.guitart@ uab.es. Introduction Avian lead toxicosis from spent lead shot and lost fishing weights occurs throughout the world, constituting a serious risk to wildlife in both wetland and upland regions (Scheuhammer and Norris 1995; Twiss and Thomas 1998; Guitart et al. 1999). Concerns over the scale of mortality of waterbirds and raptors arising from lead toxicosis (Kendall et al. 1996; Mateo et al. 1997, 2001) have led to the development of lead substitutes. However, national regulatory actions dealing with this toxic risk range from total, regional and/or local bans on the use of lead shot and fishing weights to no action on the issue (Thomas 1995, 1997; Thomas and Owen 1996; Beintema 2001). Substitutes for lead products must be non-toxic to all wildlife (in all kingdoms), which assumes that criteria exist for the evaluation of their toxicity. Since 1991, eight countries have banned the use of lead shot for hunting in wetlands. However, only the USA and Canada have regulations which define the criteria that must be satisfied before shot may be approved, legally, as non-toxic for the hunting of migratory birds (CWS 1993; USFWS 1997). These North American regulations apply only to substitutes for shot: no regulations exist in any country for determining the non-toxicity of substitutes for lead fishing weights (Thomas 1995), even though they are required by law in certain regions of Canada and the USA (Twiss and Thomas 1998). As more nations begin to restrict the use of lead shot and lead fishing weights (Beintema 2001), it is advisable for reasons of environmental protection, regulative expediency and international trade to have regulations that define the allowable lead substitutes. At present, no initiatives exist at the international level to regulate substitutes for lead shot, and especially lead fishing weights. Nations could follow the decisions of the USA and Canada on what are legally approved substitutes, or they could introduce their own criteria of toxicity and testing protocols. The latter could result in an international mosaic of differing regulations and varying rigours of testing. That could delay a transition to use of lead-free products and impede international trade in non-toxic shot and fishing weights. Therefore, we recommend a harmonised approach to the approval process (similar to that proposed for the three North American countries by Thomas 2003) based on common international policy and regulations, including a broadly accepted definition of non-toxic shot and sinkers, which would facilitate the phase-out of lead products. The European Commission and the Organisation for Economic Cooperation and Development are examined as potential agencies for issuing such regulations. The US Protocol for assessing lead shot substitutes (USFWS 1997) has strengths and limitations. We identify the strengths of this protocol that could be incorporated into a broader evaluation of lead substitutes and address the limitations. We propose an alternate protocol for assessing the potential toxicity of a candidate material that does not involve testing with waterfowl under outdoor winter conditions, and that is both faster and less costly. Furthermore, the extension of testing proposed substitutes for lead beyond the present narrow focus on birds is advised, to encompass better components of the natural and human environment.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".