Chlorobiphenyls (CBs) and organochlorine pesticides (OCPs) have been determined in the blubber of 17 Atlantic white-sided dolphins stranded at Killala Bay, Co Mayo, Ireland and five from the Scottish coast. The concentrations of the contaminants measured range from 773 to 63,400 microg kg(-1) for sigmaCB and from 160 to 54,600 microg kg(-1) for sigmaDDT. The concentrations of the CBs and OCPs is highly dependent on the age, sex, reproductive state and nutritional condition of the animals in addition to the intake via the food web. Principal Components Analysis (PCA) has been used to study the variation of chemical patterns (data ratioed to CB 153). Immature animals (< 6 years), mature males and primogravid females, and lactating females could be distinguished on the basis of their contaminant patterns. This paper describes the different processes of bioaccumulation and metabolism of organochlorine contaminants (OCs) in this species. 相似文献
The aim of this paper was to assess the endogenous release of lead from bone to blood, in 204 exposed subjects. resuming their duties after a 10-month strike in a primary lead smelter in 1991. In vivo 109Cd K X-ray Fluorescence (109Cd K XRF) was used to measure the bone lead concentration in tibia and calcaneus in the smelter, in 1994 and five years later. The 1994 data were used to derive the post-strike bone lead concentrations retrospectively from the significant association between bone lead and the cumulative blood lead index (CBLI). When a linear model was used to predict the current blood lead upon the level of lead in bone, structural analysis of the data produced slopes for tibia (2.0, 95% CI 1.66-2.54) and calcaneus (0.19, 95% CI 0.16-0.23) that were significantly higher than those predicted by the commonly used simple linear regression method, for tibia (0.73, 95%, CI 0.58-0.88) and calcaneus (0.08, 95% CI 0.06-0.09). This suggests that more lead than previously predicted by regression is released from bone to blood. Furthermore, the structural analysis of the data produced an estimation of the contribution of the bone lead stores to the bloodstream that was more consistent with the 1999 epidemiological data than did the regression estimation. Moreover, a non-linear relationship between tibia lead and blood lead was suggested from the assumption checking procedures for regression. When a non-linear regression model was fit to the data, the method produced estimates of important parameters in human lead kinetics, namely the blood lead saturation constant, showing a good agreement with current knowledge of lead metabolism. Finally, the likelihood of a non-linear bone lead release seems to be supported by the recently described dependence of the half-life of lead in bone on age and intensity of occupational exposure. 相似文献
This paper demonstrates the relative non-engagement of universities in regional sustainability initiatives through a case study of Cardiff University in Wales. It is argued that the turbulent and often complicated political and administrative context along with divergent goals and performance targets means that synergies are less readily achieved. A case study of automotive industry alternative technology new cluster development is given to illustrate the arguments. In so doing, the paper presents the view that we need to move beyond mere optimism in order to address fundamental underlying issues. 相似文献
A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.
In the mid-1980s, the first formal seat-belt enforcement program in the United States was conducted in Elmira, NY. Front seat-belt use increased from 49% to 80%, and the Elmira program became a model for other such programs. In the spring of 1999, the New York State Police launched a statewide seat-belt enforcement campaign, and the Elmira program was revived as part of this effort. This 3-week program was coordinated by the Chemung County Sheriff's Office, and carried out in cooperation with local police departments as well as the state police. The earlier Elmira program emphasized the health and safety benefits of seat belts and warning periods prior to tickets being issued. The 1999 program featured a strong no-excuses, no-warning enforcement message, 32 belt-use checkpoints, and publicity about the enforcement through a variety of mechanisms, including feedback signs that informed motorists of current belt use rates. Front seat-belt use increased from 69% to 90%. Public opinion surveys indicated the program was well known to Elmira residents, and had the support of 79% of those polled. The 1999 Elmira program demonstrates that high-intensity enforcement programs can increase seat-belt use to very high levels with strong community support. 相似文献
Prey selection was investigated in wild, resident common bottlenose dolphins, Tursiops truncatus, during the summer months in Sarasota Bay, Florida, USA. Stomach content analyses of 15 dolphins with extensive sighting histories and well-documented distributions were used to determine prey use. Prey availability was assessed by purse seine surveys. We compared the relative abundances of prey available to estimates of prey use at closely matching spatial and temporal scales. G-tests determined that dolphins in this study significantly selected for prey at the species, family, and soniferous/non-soniferous prey levels (Gadj = 753.98–1,775.93, df = 1–21, p ≤ 0.01). While comprising only 6.3% of the total available prey, soniferous fishes accounted for 51.9% of the total prey consumed. Manly’s standardized forage ratios and 95% Bonferroni confidence intervals determined significant positive selection for soniferous prey and against non-soniferous prey (βS = 0.9461 vs. βNS = 0.0539). Dolphins selected against Gerridae, Clupeidae, and Sparidae (β ≤ 0.0014), as well as against all the species within those families (β ≤ 0.0190). It is likely that passive listening for soniferous prey provides an ecological or energetic advantage to cetaceans utilizing this specific foraging technique. 相似文献
Prey selection was investigated in wild, resident common bottlenose dolphins, Tursiops truncatus, during the summer months in Sarasota Bay, Florida, USA. Stomach content analyses of 15 dolphins with extensive sighting
histories and well-documented distributions were used to determine prey use. Prey availability was assessed by purse seine
surveys. We compared the relative abundances of prey available to estimates of prey use at closely matching spatial and temporal
scales. G-tests determined that dolphins in this study significantly selected for prey at the species, family, and soniferous/non-soniferous
prey levels (Gadj = 753.98–1,775.93, df = 1–21, p ≤ 0.01). While comprising only 6.3% of the total available prey, soniferous fishes accounted for 51.9% of the total prey
consumed. Manly’s standardized forage ratios and 95% Bonferroni confidence intervals determined significant positive selection
for soniferous prey and against non-soniferous prey (βS = 0.9461 vs. βNS = 0.0539). Dolphins selected against Gerridae, Clupeidae, and Sparidae (β ≤ 0.0014), as well as against all the species within those families (β ≤ 0.0190). It is likely that passive listening for soniferous prey provides an ecological or energetic advantage to cetaceans
utilizing this specific foraging technique. 相似文献