RESUMEN
Research has demonstrated that intramuscularly embedded lead in humans and rats may cause direct plumbism, albeit rarely, and has identified risk factors to this end. To the authors' knowledge, this has not been investigated in wildlife, despite a high incidence of embedded lead in these animals secondary to cynegetic activities. Fourteen wildlife cases submitted to the National Fish and Wildlife Forensics Laboratory for cause-of-death determination had chronically embedded lead projectiles that were unrelated to the cause of death. Tissue lead levels were measured in all cases and revealed clinically significant hepatic lead levels in two cases. The results corroborate comparative literature and suggest that embedded lead fragments carry a low risk for direct plumbism, even in the face of risk factors such as fractures, inflammation, and projectile fragmentation. Wildlife morbidity and mortality from embedded lead is more commonly realized secondary to incidental ingestion and ballistic trauma rather than by direct toxicity.
Asunto(s)
Animales Salvajes , Enfermedades de las Aves/inducido químicamente , Cuerpos Extraños , Intoxicación por Plomo/veterinaria , Plomo/toxicidad , Lobos , Animales , Aves , Intoxicación por Plomo/etiología , Heridas por Arma de Fuego/veterinariaRESUMEN
Potential effects of pesticides on stream algae occur alongside complex environmental influences; in situ studies examining these effects together are few, and have not typically controlled for collinearity of variables. We monitored the dynamics of periphyton, phytoplankton, and environmental factors including atrazine, and other water chemistry variables at 6 agricultural streams in the Midwest US from spring to summer of 2011 and 2012, and used variation partitioning of community models to determine the community inertia that is explained uniquely and/or jointly by atrazine and other environmental factors or groups of factors. Periphyton and phytoplankton assemblages were significantly structured by year, day of year, and site, and exhibited dynamic synchrony both between site-years and between periphyton and phytoplankton in the same site-year. The majority of inertia in the models (55.4% for periphyton, 68.4% for phytoplankton) was unexplained. The explained inertia in the models was predominantly shared (confounded) between variables and variable groups (13.3, 30.9%); the magnitude of inertia that was explained uniquely by variable groups (15.1, 18.3%) was of the order hydroclimate>chemistry>geography>atrazine for periphyton, and chemistry>hydroclimate>geography>atrazine for phytoplankton. The variables most influential to the assemblage structure included flow and velocity variables, and time since pulses above certain thresholds of nitrate+nitrite, total phosphorus, total suspended solids, and atrazine. Time since a ≥30 µg/L atrazine pulse uniquely explained more inertia than time since pulses ≥ 10 µg/L or daily or historic atrazine concentrations; this result is consistent with studies concluding that the effects of atrazine on algae typically only occur at ≥30 µg/L and are recovered from.
Asunto(s)
Atrazina/toxicidad , Monitoreo del Ambiente/métodos , Herbicidas/toxicidad , Microalgas/crecimiento & desarrollo , Agricultura , Atrazina/análisis , Herbicidas/análisis , Microalgas/clasificación , Medio Oeste de Estados Unidos , Fitoplancton/clasificación , Fitoplancton/crecimiento & desarrollo , Ríos/química , Análisis Espacio-Temporal , Contaminantes Químicos del Agua/toxicidadRESUMEN
Numerous studies characterizing the potential effects of atrazine on algal assemblages have been conducted using micro- or mesocosms; however, few evaluations focused on in situ lotic algal communities, potentially confounding risk assessment conclusions. This exploratory study, conducted at several sites in the midwestern United States where atrazine is commonly used, presents in situ observations of native algal communities relative to atrazine exposure and other parameters. Planktonic and periphytic algae from three streams in three Midwestern states, having historically differing atrazine levels, were sampled over a 16-week period in 2011 encompassing atrazine applications and the summer algal growth period at each site. Changes in abundance, diversity, and composition of algal communities were placed in the context of hydrological, climatic, and water quality parameters (including components sometimes present in agricultural runoff) also collected during the study. Diatoms dominated communities at each of the three sites and periphyton was much more abundant than phytoplankton. As expected, significant variations in algal community and environmental parameters were observed between sites. However, correspondence analysis plots revealed that patterns of temporal variation in algal communities at each site and in periphyton or phytoplankton were dominated by seasonal environmental gradients. Significant concordance in these seasonal patterns was detected among sites and between phytoplankton and periphyton communities (via procrustes Protest analysis), suggesting synchronicity of algal communities across a regional scale. While atrazine concentrations generally exhibited seasonal trends at the study watersheds; no effects on algal abundance, diversity or assemblage structure were observed as a result of atrazine pulses. This lack of response may be due to exposure events of insufficient concentration or duration (consistent with previously reported results) or the composition of the algal assemblages present. This was in contrast to the effects of elevated flow events, which were associated with significant changes in periphyton abundance, diversity and assemblage.
Asunto(s)
Diatomeas/crecimiento & desarrollo , Ecosistema , Fitoplancton/crecimiento & desarrollo , Ríos/microbiología , Estaciones del Año , Biomasa , Clorofila/análisis , Clorofila A , Conductividad Eléctrica , Concentración de Iones de Hidrógeno , Illinois , Iowa , Missouri , Nitratos/análisis , Oxígeno/análisis , Dinámica Poblacional , Ríos/química , TemperaturaRESUMEN
Fourier-transform infrared spectroscopy (FTIR), discriminate analysis, X-ray fluorescence spectrometry (XRF), and stereoscopic microscopy were used to separate black coral forensic evidence items from similarly appearing items manufactured from plastics, bovid keratin, and mangrove wood. In addition, novel observations were made of bromine and iodine relationships in black coral that have not been previously reported.
Asunto(s)
Antozoos/química , Animales , Bromo/análisis , Caseínas , Comercio/legislación & jurisprudencia , Conservación de los Recursos Naturales/legislación & jurisprudencia , Análisis Discriminante , Fraude/legislación & jurisprudencia , Yodo/análisis , Queratinas , Microscopía , Plásticos , Espectrometría por Rayos X , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Given the well-recognized association of radiation and thyroid cancer, the objective of this study was to assess the frequency of radiation overlap at the level of the thyroid gland as part of standard protocols for computed tomography (CT) assessment of trauma, incorporating both cervical spine and chest images. A survey was sent to physician members of the American Society of Emergency Radiology. Among other questions, the respondents were asked to indicate their CT protocol with respect to the lower boundary of their cervical spine series and the upper boundary of their chest CT series. Forty-one surveys were returned. Of these, 83% reported overlap of the contiguous margins of the two CT studies resulting in partial or total double radiation deposition to the thyroid gland, which typically extends from vertebral levels C5 to T1. Sixty-one percent reported overlapping at T1 only, 15% at C7 to T1, 4.9% at C6 to T1, and 2.4% at C5 to T1. These data reveal that the predominant practice among the respondents is to include the thyroid gland in coincident CT studies of the cervical spine and chest in trauma protocols.