Accumulation of trace elements (including heavy metals) in soil from usage of superphosphate fertilisers induces resistance of soil bacteria to trace elements of environmental concern (TEoEC) and may co-select for resistance to antibiotics (Ab). This study aimed to investigate selection of co-resistance of soil bacteria to Cd, Zn and Hg, and Ab in soils with varied management histories. Genetic diversity of these bacteria and horizontal transfer of Cd resistance genes (cadA and czcA) were also investigated. Soils with either pastoral and arable management histories and either high levels of Cd and Zn, or indigenous bush with background levels of these TEoEC from the Waikato region, New Zealand were sampled. Plate culturing with a range of TEoEC and Ab concentrations, Pollution Induced Community Tolerance (PICT) assay, antibiotic sensitivity, terminal restriction fragment length polymorphism (TRFLP) and horizontal gene transfer (HGT) analyses were employed to investigate co-selection of TEoEC and Ab resistance. Higher levels of bacterial resistance to TEoEC and Ab correlated with higher levels of TEoEC in soil. Bacterial community structures were altered in soils with high TEoEC levels. Cd resistance genes were transferred from donor bacterial isolates, to recipients and the transconjugants also had resistance to Zn and/or Hg and a range of Ab.
A study was conducted of potential vapor phase interferents which could be present on human breath and also be capable of inducing a false-positive response for ethanol on the evidential infrared-based breath testing device, the Intoxilyzer-5000. This involved preparation and validation of a range of vapor standards, which were introduced to the instrument using a dynamic flow double-bubbler system. Potential interferents were chosen on the basis of both their infrared signatures and their general availability, and included toluene, m-xylene, o-xylene, methanol and isopropanol. All compounds tested were found to be capable of inducing false-positive readings for ethanol in a highly reproducible manner, as a result of which it has been possible to derive precise least-squares equations describing the ethanol readout expected for any given blood concentration of toluene, m-xylene, o-xylene, methanol and isopropanol. The likelihood of an interference compromising the integrity of the analysis is related to both the toxicological significance and prevalence of a given blood concentration of each solvent, and the point at which the instrumental interference light is triggered in each case.
Abstract-The effects of point-source and diffuse discharges on resident populations of brown bullhead catfish (Ameiurus nebulosus (LeSueur, 1819)) in the Waikato River (New Zealand) were assessed at sites both upstream and downstream of point-source discharges. At each site, the population parameters, relative abundance, age structure, and individual indices, such as condition factor, organ (gonad, liver, and spleen) to somatic weight ratios, and number and size of follicles per female, were assessed. Physiological (blood), biochemical (hepatic ethoxyresorufin-O-deethylase [EROD] and plasma steroids), and other indicators (bile chemistry and liver metals) of exposure or response also were measured. No impacts on brown bullhead health were obvious at individual geothermal, municipal sewage, or thermal discharge sites or cumulatively along the river. Brown bullhead from the bleached kraft mill effluent site showed elevated levels of EROD, decreased numbers of red blood cells, increased numbers of white blood cells, and depressed levels of sex steroids. However, growth rates, condition factor, age structure, and gonadosomatic index suggest that discharges with significant heat or nutrients benefit catfish despite physiological impairment at one site. Consideration of brown bullhead population-level responses to discharges in a monitoring framework revealed three different populationlevel response patterns resulting from the point-source discharges.
Background and Objectives: This study assessed the nutritional status among householders in urban South Tarawa and rural Butaritari in Kiribati. Methods and Study Design: In this cross-sectional study, we assessed energy and nutrient intakes, food variety scores, and dietary diversity scores of men and women from 468 households randomly selected in South Tarawa (n = 161) and Butaritari (n = 307) using a 24-hour dietary recall. Nutrient adequacy ratios and mean adequacy ratios of selected nutrients were also determined from 3-day weighed food records collected among participants living in a further 28 households from South Tarawa (n = 29) and Butaritari (n = 44). Results: Based on the 24-hour dietary recall, the average energy intake for men and women was 2536 kcals and 2068 kcals, respectively. Carbohydrate (CHO), fat, and protein intakes for men and women were 332.5 g, 76.5 g, and 130.4 g and 291.7 g, 55.1 g, and 103.5 g, respectively. The mean and standard deviation of household Food Variety Score and Dietary Diversity Score was 3.90 ± 1.25 and 5.44 ± 1.92, respectively. Intakes of vitamin A, calcium, and iron, and zinc were notably deficient in both locations, with the urban participants having lower intakes of vitamin B-1, vitamin B-2, magnesium, and potassium than their rural counterparts. Mean sodium intakes exceeded recommendations for all age groups in South Tarawa except children aged 4 to 6 years. Conclusions: Food consumption patterns of the households in South Tarawa and Butaritari reflected high consumption of nontraditional diets and refined foods, which manifested in inadequate micronutrient intake estimates and low dietary diversity: strong risk factors for noncommunicable diseases such as obesity and diabetes.
Adsorption of 10-100 ppb lead and thallium by borosilicate glass and polypropylene surfaces was studied. No thallium was adsorbed by either substrate at pH 7.0. About 50-60% of the lead was adsorbed by borosilicate glass at pH 5.5 and pH 7.0, with statistically indistinguishable conditional equilibrium constants (K* values) of 1.47±0.40 mL cm and 1.80±0.11 mL cm, respectively. Polypropylene adsorbed significantly more lead than borosilicate glass at pH 7.0 (80.9%, K* =5.33±0.45 mL cm), and substantially less at pH 5.5 (16.7%, K* = 0.27±0.03 mL cm), indicating a fundamental change in the nature of the polypropylene surface. All adsorption data fitted Freundlich plots. Preliminary experiments indicate that at pH 5.5, a fraction of the lead sequestered by the borosilicate glass may be bound irreversibly by migrating into the glass matrix. The results suggest that tectosilicates and silicate glasses may represent important adsorbents of some heavy metals in soils, despite showing very low intrinsic cation exchange capacities.
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