9 research outputs found
Wildlife Toxicology: Environmental Contaminants and Their National and International Regulation
Wildlife toxicology is the study of potentially harmful effects of toxic agents in wild animals, focusing on amphibians, reptiles, birds, and mammals. Fish and aquatic invertebrates are not usually included as part of wildlife toxicology since they fall within the field of aquatic toxicology, but collectively both disciplines often provide inSight into one another and both are integral parts of ecotoxicology (Hoffman et al. 2003). It entails monitoring, hypothesis testing, forensics, and risk assessment; encompasses molecular through ecosystem responses and various research venues (laboratory, mesocosm, field); and has been shaped by chemical use and misuse, ecological mishaps, and biomedical research. While human toxicology can be traced to ancient Egypt, wildlife toxicology dates back to the late 19th century, when unintentional poisoning of birds from ingestion oflead shot and predator control agents, alkali poisoning, and die-offs from oil spills appeared in the popular and scientific literature (Rattner 2009)
Wildlife Toxicology: Environmental Contaminants and Their National and International Regulation
Wildlife toxicology is the study of potentially harmful effects of toxic agents in wild animals, focusing on amphibians, reptiles, birds, and mammals. Fish and aquatic invertebrates are not usually included as part of wildlife toxicology since they fall within the field of aquatic toxicology, but collectively both disciplines often provide inSight into one another and both are integral parts of ecotoxicology (Hoffman et al. 2003). It entails monitoring, hypothesis testing, forensics, and risk assessment; encompasses molecular through ecosystem responses and various research venues (laboratory, mesocosm, field); and has been shaped by chemical use and misuse, ecological mishaps, and biomedical research. While human toxicology can be traced to ancient Egypt, wildlife toxicology dates back to the late 19th century, when unintentional poisoning of birds from ingestion oflead shot and predator control agents, alkali poisoning, and die-offs from oil spills appeared in the popular and scientific literature (Rattner 2009)
Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA
Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (\u3c 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was \u3c 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor local- ized contamination
Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA
Northern Cardinal eggs from six neighborhoods near Washington DC were analyzed for organochlorine pesticides and PCBs. All compounds were detected more frequently and at higher concentrations in more heavily urbanized neighborhoods. DDT (mostly as p,pʹ-DDE) was detected in all neighborhoods. p,pʹ-DDT was typically 0.5‒16 ng/g (ww) in most suburban neighborhoods but was not detected (\u3c 0.1 ng/g) in more rural areas; however, p,pʹ-DDT was 127‒1130 ng/g in eggs from two suburban Maryland nests and comprised 65.7% of total p,pʹ-DDT isomers in the most contaminated sample, indicating recent exposure to un-weathered DDT. Total chlordane (sum of 5 compounds) was 2‒70 ng/g; concentrations were greatest in older suburban neighborhoods. Total PCB (sum of detected congeners) was \u3c 5‒21 ng/g. Congener patterns were similar in all neighborhoods and resembled those typical of weathered mixtures. Results indicate that wildlife remains exposed to low concentrations of legacy contaminants in suburban neighborhoods and that cardinal eggs can be used to monitor local- ized contamination
Intersex in Japanese Medaka (\u3ci\u3eOryzias latipes\u3c/i\u3e) Used As Negative Controls In Toxicologic Bioassays: A Review of 54 Cases From 41 Studies
Histologic assessment of the gonads to detect intersex has become a valuable end point in reproductive toxicologic testing for fish, and many studies have solidly linked intersex with exposure to endocrine active substances (EAS). An assumption in such studies is that spontaneous intersex does not occur in control fish. Using historical data derived from toxicologic tests with Japanese medaka (Oryzias latipes), we report a retrospective study in which we identified 54 individual instances of intersex (testicular oocytes or ovarian testicular tissue) in control medaka from 15 of 41 selected toxicologic studies. These studies, comprised of previously unpublished data, had been conducted at three geographically distant laboratories, each of which utilized unique water sources, employed somewhat different culture protocols, and maintained distinct medaka breeding colonies. During our histologic examinations, we also identified three germ cell neoplasms that had been inadvertently diagnosed as intersex. In the present report, we review potential causes of intersex, discuss possible reasons why spontaneous intersex has rarely been reported, and propose suggestions for the judicious interpretation of intersex results in medaka studies involving EAS
Correction to: Organochlorine Chemical Residues in Northern Cardinal (Cardinalis cardinalis) Eggs from Greater Washington, DC USA
The original version of this article contained a mistake. Author name in the text citation and reference in section should be Maldonado et al (2016), it was incorrectly spelled as Maldinado et al (2015)
Measuring the Effects of an Ever-Changing Environment on Malaria Control
The effectiveness of malaria control measures depends not only on the potency of the control measures themselves but also upon the influence of variables associated with the environment. Environmental variables have the capacity either to enhance or to impair the desired outcome. An optimal outcome in the field, which is ultimately the real goal of vaccine research, will result from prior knowledge of both the potency of the control measures and the role of environmental variables. Here we describe both the potential effectiveness of control measures and the problems associated with testing in an area of endemicity. We placed canaries with different immunologic backgrounds (e.g., naïve to malaria infection, vaccinated naïve, and immune) directly into an area where avian malaria, Plasmodium relictum, is endemic. In our study setting, canaries that are naïve to malaria infection routinely suffer approximately 50% mortality during their first period of exposure to the disease. In comparison, birds vaccinated and boosted with a DNA vaccine plasmid encoding the circumsporozoite protein of P. relictum exhibited a moderate degree of protection against natural infection (P < 0.01). In the second year we followed the fate of all surviving birds with no further manipulation. The vaccinated birds from the first year were no longer statistically distinguishable for protection against malaria from cages of naïve birds. During this period, 36% of vaccinated birds died of malaria. We postulate that the vaccine-induced protective immune responses prevented the acquisition of natural immunity similar to that concurrently acquired by birds in a neighboring cage. These results indicate that dominant environmental parameters associated with malaria deaths can be addressed before their application to a less malleable human system
Results of a Wildlife Toxicology Workshop held by Smithsonian Institution: Identification & Prioritization of Problem Statements
*Background/Question/Methods*
On March 13-15, 2007 nearly 50 scientists and administrators from the US and Canada participated in a Smithsonian-sponsored Wildlife Toxicology Workshop. Invitees were from academic, government, conservation and private organizations and were selected to represent the diverse disciplines that encompass wildlife toxicology. The workshop addressed scientific and policy issues, strengths and weaknesses of current research strategies, interdisciplinary and science-based approaches in the study of complex contaminant issues, mechanisms for disseminating data to policy-makers, and the development of a partner network to meet the challenges facing wildlife toxicology over the next decade. Prior to the meeting, participants were asked to submit issues deemed to be of highest concern which shaped four thematic groups for discussion: Wildlife Toxicology in Education, Risk Assessment, Multiple Stressors/Complex Mixtures, and Sub-Lethal and Population-Level Effects.

*Results/Conclusions*
From these discussion groups, 18 problem statements were developed and prioritized outlining the most important issues to address now and into the future. Along with each problem statement participants developed potential solutions and action steps geared to move each issue forward. The workshop served as a stepping-stone for action in the field of wildlife toxicology. These problem statements and the resulting action items are presented to the inter-disciplinary wildlife toxicology community for adoption, and future work and action items in these areas are encouraged. For example, it was found that ecologists would be essential in addressing the implications of sublethal or lethal effects of contaminants on wildlife at the population, community and ecosystem scales. The workshop outcome looks to generate conversation and collaboration that will lead to the development of innovative research, future mechanisms for funding, workshops, working groups, and listserves within the wildlife toxicology community.