Organochlorine and heavy metal contaminants in wild mink in western Northwest Territories, Canada.

The mink (Mustela vision) is a top trophic level species that readily bioaccumulates environmental pollutants and is considered to be a sensitive indicator of ecosystem health. Spatial trends in levels of organochlorine and heavy metal contaminant burdens were determined from 1991 to 1995 for wild mink from western Northwest Territories (NWT), Canada. Tissue samples from 207 mink from seven communities were analyzed for residues of 63 organochlorines and 10 heavy metals. All groups of organochlorines were detected in mink livers at relatively low levels; maximum community means were 9.52 ng/g sigma DDT and 73.07 ng/g sigma PCB (sum of 43 congeners). There was a general trend of decreasing organochlorine burdens along a northerly or westerly gradient for some groups of compounds, primarily sigma DDT, sigma PCB, sigma chlordane and dieldrin. Toxic equivalents (TEQs) of mink liver tissue were low, with the maximum community mean of 0.28 pg/g wet weight (5.5 pg/g lipid weight). Levels of heavy metal burdens in liver and kidney tissues were found to be relatively low, with the exception of Hg, which was found at moderate levels. There was no obvious geographic trend to the pattern of heavy metal burdens. The available evidence suggests that long-range atmospheric transport is the main source of the organochlorine contaminants observed. Local conditions (geology, water and soil chemistry, diet, etc.) may determine heavy metal burdens. Levels of contaminants in NWT mink appear to be one to two orders of magnitude lower than levels observed to cause reproductive impairment, reduced survival of kits, or lethality in adult mink. In the western NWT mink may be the best indicator to assess trends in environmental contaminants and ecosystem health; periodic monitoring is recommended.

Performance and limitations of electron probe microanalysis applied to the characterization of coatings and layered structures.

Electron probe microanalysis (EPMA) at low electron energies (typically 3-10 keV) has been used to study the composition of coatings with a film thickness of 0.1-1.3 microm ("bulk" analysis). The accuracy of quantification, including the most critical situation of low atomic number elements (boron-oxygen), is about 5% relative by use of pure element or arbitrary compound standards. A special procedure of data processing ("thin film" analysis) enables the simultaneous determination of film thickness and composition, provided that the substrate is known. The film thickness may be in the range of 2 nm to 5 microm. EPMA can be also applied in the mode of "non-destructive in-depth analysis", which is based on the combined evaluation of experiments at different electron energies. The quantitative characterization of layered structures and implantation zones is demonstrated.

Environmental contaminants in caribou in the Northwest Territories, Canada.

Caribou (Rangifer tarandus) are strict herbivores with a winter diet consisting primarily of lichen. This simple food chain makes caribou a good species for monitoring changes in arctic terrestrial ecosystem contamination. The defined ranges of herds across the Northwest Territories (NWT) also enables examination of spatial trends in contaminant exposure. Caribou were collected from five locations in the first half of a study designed to examine levels of a broad spectrum of organochlorine, heavy metal, and radionuclide contaminants. A wide range of contaminants were detected, with most compounds found at relatively low levels. In general, organochlorine residues were significantly lower in caribou from the mainland Bathurst and Qamanirjuaq (Arviat) and the Southampton Island herds than in caribou from Cape Dorset and Lake Harbour on southern Baffin Island. Moderate levels of hexachlorobenzene (HCB) and alpha-hexachlorocyclohexane (alpha-HCH) were detected at all five study sites. HCB residues ranged from a lipid corrected mean of 32.83 ng/g in fat of Bathurst caribou to 129.41 ng/g in Lake Harbour animals. Alpha-HCH levels ranged from 8.11 ng/g in Bathurst animals to 37.9 ng/g in Cape Dorset caribou. Total polychlorinated biphenyl (sigma PCB) residues ranged from 6.24 ng/g in fat of Arviat caribou to 31.68 ng/g in Cape Dorset animals. Congeners 153 and 138 were the most dominant of the 43 congeners tested. Metal levels were also relatively low with the exception of cadmium, which had community means of 9.68- 33.87 micrograms/g in kidney tissue and 1.96-4.39 micrograms/g in liver tissue. Moderate levels of cesium-137 were detected, with community means of 33.2-184.1 Bq/kg in muscle tissue. Long-range atmospheric transport appears to be the primary source of the contaminants detected in this study.

Environmental contaminants in wild mink in the Northwest Territories, Canada.

As a top trophic level species that readily bioaccumulates environmental pollutants, the mink (Mustela vison) is considered to be a sensitive indicator of ecosystem health. Here we report on the first 2 years of a 4-year program established to examine organochlorine and heavy metal residues in wild mink from western Northwest Territories (NWT), Canada. Tissue samples taken from up to 24 mink harvested from each of five sites in 1991-92 and 1992-93 were analyzed for residues of a suite of 63 organochlorines in fat and liver samples, including 43 polychlorinated biphenyl (PCB) congeners and 20 pesticides, and residues of 10 heavy metals in liver and kidney samples. Overall, contaminant levels were low in comparison with levels in other mink studied in North America. Sigma PCB residues (sum of 43 congeners) ranged from a mean of 5.32 ng/g wet weight in the livers of Inuvik mink (the most northerly collection site) to 27.67 ng/g in mink from Fort Smith (the most southerly collection site). There appeared to be no differences in organochlorine burden between sexes. Heavy metal residues were also comparatively low, with the exception of total mercury, which was at moderate levels (community means of 1.16-3.30 micrograms/g wet wt. in liver samples). There was a distinct trend of decreasing organochlorine contaminant burdens with increasing latitude, but no trend in heavy metal burdens was evident. There was a doubling of mean sigma PCB levels in Inuvik mink from 5.32 ng/g wet weight in 1991-92 to 10.69 ng/g in 1992-93. Population indices derived from age and sex ratios of the harvest, coupled with comparatively low levels of contaminants, suggest little or no effects on mink reproduction or population health as a result of these contaminants. Long-range atmospheric transport is probably the major source of most of the contaminants. Additional collections will further elucidate spatial and temporal trends in contaminant levels in NWT mink.

Effect of standing orders on paramedic scene time for trauma patients.

STUDY OBJECTIVE: To determine if a protocol change that allowed paramedics to perform certain procedures before base station contact (standing orders) would decrease scene time in trauma patients. DESIGN: Retrospective review of case series. SETTING: A single-tiered, all advanced life support emergency medical services system. INTERVENTION: Implementation with standing orders for invasive procedures. TYPE OF PARTICIPANTS: All physiologically unstable trauma patients transported to a Level I trauma center by ambulance. MEASUREMENTS AND MAIN RESULTS: One hundred ninety-seven patients met the inclusion criteria--87 before and 110 after the initiation of standing orders. Mean scene times for the control group (15.3 +/- 8.4 minutes) and for the standing orders group (15.1 +/- 7.6 minutes) were similar (P = .18). The power of the study to detect a two-minute difference in scene time was .92. Scene time was not influenced by mechanism of injury, and the number of procedures performed on patients was similar between the two groups. CONCLUSION: Standing orders did not decrease scene time in physiologically unstable trauma patients. Further study is necessary to delineate the factors that actually contribute to on-scene time and the factors that are important in determining whether standing orders or on-line medical contact should be used.

[Renal tolerance of combined treatment with cefotaxime and gentamicin (author's transl)]. / Nierenverträglichkeit der kombinierten Behandlung mit Cefotaxim und Gentamicin.

Treatment of 20 patients with 2 g cefotaxime intravenously and 80 mg gentamicin intramuscularly b.i.d. for various reasons before antibiograms were available showed no recognizable influence on renal function after one week. Patients were without renal disease and of both sexes on groups from 19-23, 36-59 and 63-69 years of age. No damage to the kidneys was evident when creatinine clearance, serum creatinine and urea concentrations and the usual urinalysis were considered.

[Penetration activities of cefoxitin into different human tissues. An experimental study (author's transl)]. / Experimentelle Untersuchungen über die Diffusionsrate von Cefoxitin in verschiedene menschliche Gewebe.

Subject of the following study was the penetration activity of cefoxitin into different human tissues. The authors obtained material of the cutis, subcutis, fascia, muscle, spongy bone and compact bone during orthopedic surgery on 20 patients. Cefoxitin was administered by means of a continual infusion of a dose of 45 mg per kg body weight per hour. Tissue and serum levels were studied after infusions lasting 15, 60, 90 and 120 minutes. Altogether the results of 215 specimens of serum and 132 specimens of tissue are recorded. The evaluation showed the following mean tissue levels of cefoxitin: 6.6 micrograms/g in compact bone; 14.4 micrograms/g in spongy bone; 23.3 micrograms/g in muscle; 64.2 micrograms/g in fascia, 69.9 micrograms/g in cutis and 21.7 micrograms/g in subcutis.

[Serum and tissue concentrations after a single dose of cefaclor]. / Serum- und Gewebespiegel nach einmaliger Cefaclorgabe.

Serum and tissue concentrations of cefaclor were determined a total of 155 and 96 times respectively in 16 volunteers after a single dose of 1 g. At this dosage peak concentrations of 13.5, 14.5 and 13.4 mcg/ml were measured after 60, 90 and 120 minutes respectively. Tissues in which concentrations were measured included cortical bone, spongy bone, muscle, fascia, cutis and subcutis. By measuring blood concentrations of the tissue samples, a division could be made for purposes of calculation into intravascular and extravascular active components. Low amounts of extravascular cefaclor could be established merely in the fascia and in the cutis. The cefaclor concentrations found in spongy bone, muscles and subcutis proved to be determined to a large extent by the intravascular antibiotic. No cefaclor could be detected in cortical bone at the given dosage.

[Studies on the diffusion rate of cefamandole in various human tissue (author's transl)]. / Untersuchungen über die Diffusionsrate von Cefamandol in verschiedene menschliche Gewebe.

The penetration activity of cefamandole into different human tissues was studied under experimental conditions. The authors obtained samples of corticalis, spongiosa, cutis, subcutis, fascia and muscle during surgery in 42 cases. Cefamandole was given i.v. by means of: 1. single injections of 40 mg/kg body weight. 2. multiple injections with an initial dose of 40 mg/kg body weight and reinjections of 20 mg/kg body weight after reaching half-life, 3. permanent infusions of 50 mg/kg body weight per hour during 70 min. The investigation is based upon 482 serum level and 330 tissue level determinations. In case of tissue levels the extra- and intravascular concentrations had to be separated so that the contamination of the investigated samples by blood could be quantified. This was done first by the usual way of measuring the hemoglobin concentration, and additionally by the dextran method which was used for control of the hemoglobin method for the first time. The cefamandole conentrations following single and multiple injection did not show any differences in all tissues studied. Distinctly higher concentrations were found after permanent infusions, though with a considerably higher total dose.