Accumulation of artificial and natural radionuclides in the chains of food webs leading to non-predatory and piscivorous fish of the Yenisei River was investigated during one year before and three years after the shutdown of a nuclear power plant at the Mining-and-Chemical Combine (2009-2012). The activity of artificial radionuclides in the samples of biota ofthe Yenisei River (aquatic moss, gammarids, dace, grayling, pike) was estimated. The concentration of radionuclides with induced activity (51Cr, 54Mn, 58Co, 60Co, 65Zn, 141, 144Ce, 152, 154Eu, 239Np) decreased in the biomass of biota after the shutdown of the nuclear power plant; the concentration of 137Cs did not. Analysis of the accumulation factors (C(F)) allows us to expect the effective accumulation of 137Cs in the terminal level of the food web of the Yenisei River--pike (C(F) = 2.0-9.4), i.e. biomagnifications of radiocesium. Accumulation of artificial, radionuclides in non-predatory fish from gammarids was not effective (C(F)
Novel solutions for sulfide-mine tailings remediation were evaluated in field-scale experiments on a former tailings repository in northern Sweden. Uncovered sulfide-tailings were compared to sewage-sludge biosolid amended tailings over 2 years. An application of a 0.2m single-layer sewage-sludge amendment was unsuccessful at preventing oxygen ingress to underlying tailings. It merely slowed the sulfide-oxidation rate by 20%. In addition, sludge-derived metals (Cu, Ni, Fe, and Zn) migrated and precipitated at the tailings-to-sludge interface. By using an additional 0.6m thick fly-ash sealing layer underlying the sewage sludge layer, a solution to mitigate oxygen transport to the underlying tailings and minimize sulfide-oxidation was found. The fly-ash acted as a hardened physical barrier that prevented oxygen diffusion and provided a trap for sludge-borne metals. Nevertheless, the biosolid application hampered the application, despite the advances in the effectiveness of the fly-ash layer, as sludge-borne nitrate leached through the cover system into the underlying tailings, oxidizing pyrite. This created a 0.3m deep oxidized zone in 6-years. This study highlights that using sewage sludge in unconventional cover systems is not always a practical solution for the remediation of sulfide-bearing mine tailings to mitigate against sulfide weathering and acid rock drainage formation.
In 1985, the human exposure from a site of PCB (Aroclor 1260) contamination in a Toronto community was assessed. The primary source of potential exposure was soil. Extensive surface soil sampling revealed levels greater than expected (geometric mean level = 0.19 ppm). Children under age 6 were considered to be at greatest risk of exposure as they may absorb PCBs from ingested soil or skin contact. A sample of children aged 1-5 was recruited from the community (n = 30) and from a socio-demographically similar control area (n = 23) that had significantly lower but detectable soil PCB levels (geometric mean level = 0.12 ppm). Exposure to PCBs from breastfeeding, food consumption, contact with soil, and parental occupation was comparable in the two groups. Geometric mean blood PCB levels did not differ significantly between the study (1.5 ppb) and control (1.9 ppb) group. Levels ranged up to 5 ppb in both groups and are comparable to those described in children elsewhere in North America.
Antibiotic-resistant organisms enter into water environments from human and animal sources. These bacteria are able to spread their genes into water-indigenous microbes, which also contain resistance genes. On the contrary, many antibiotics from industrial origin circulate in water environments, potentially altering microbial ecosystems. Risk assessment protocols for antibiotics and resistant bacteria in water, based on better systems for antibiotics detection and antibiotic-resistance microbial source tracking, are starting to be discussed. Methods to reduce resistant bacterial load in wastewaters, and the amount of antimicrobial agents, in most cases originated in hospitals and farms, include optimization of disinfection procedures and management of wastewater and manure. A policy for preventing mixing human-originated and animal-originated bacteria with environmental organisms seems advisable.
Ants accumulate heavy metals and respond to pollution with modification in species composition, community structure, altered behaviour and immunity. However, the levels of heavy metals in ants' nests and explicit individual-level responses towards heavy metals have not been revealed. We found that red wood ants Formica lugubris accumulate high and correlated values of such heavy metals as Al, Cd, Co, Cu, Fe, Ni, Pb and Zn both in ants and nest material near cobalt smelter in Finland. Relative differences in metal concentrations were higher in nests than in ants. The highest values were obtained for elements such as Co (36.6), Zn (14.9), Cd (9.7), Pb (8.5), Cu (7.4), Ni (6.4), As (4.7), Cr (2.9) and Fe (2.4) in nest material, and Co (32.7), Cd (6.3), Pb (6), Fe (2.8), Ni (2.9) and Zn (2.1) in ants. In industrial and reference areas, ants have no differences in size, but differed in dry and residual body mass. In polluted areas, F. lugubris had less melanised heads, but not thoraxes. The sensitivity of cuticular colouration in red wood ants subjected to heavy metal pollution might be related to metal-binding properties of melanins. The overall results are useful for the improvement of biomonitoring techniques using ants as indicators of industrial contamination and for further discovery of novel ecotoxicological biomarkers.
The contributors propose a selective photometric technique for detection of sodium and potassium cyanides in different washings, sewage, overalls extraction. The technique was based on the formation of a polymetyne dye, and barbituric acid and pyridine reactions. It proved efficient in detecting the cyanides within 0.01-0.054 mg/dm3, 1-100 mg/l, 0.08-1.24 mg/dm3 with deviations not exceeding 23%. Duration of the test was limited to 25-30 min.
To examine the influence of the sampling method on beryllium (Be) exposure assessment, a study was conducted in foundries and smelters to contrast the performance of five different dust sampling devices. Six sampling surveys were conducted in four different settings, and both personal and fixed station samples were collected using the following sampling heads: IOM samplers (inhalable dust), 35-mm plastic cassettes (total dust), aluminum SKC cyclones (respirable dust), 8-stage Sierra cascade impactors, and 12-stage MOUDI impactors. In total, beryllium concentrations were determined for 66/68 inhalable dust samples, 62/62 total dust samples, 56/57 respirable dust samples, 54/64 8-stage Sierra samples, and 19/25 12-stage MOUDI samples. In the magnesium foundry and aluminum smelters, the concentrations obtained during specific tasks could exceed the actual permissible exposure limit of the province of Quebec (0.15 microg/m(3)) or of the ACGIH threshold limit value (TLV) (0.05 microg/m(3)). The median of median dust concentration ratios computed from the sampling heads at the fixed station decreased as follows: IOM (1.00) > Sierra (0.76) > 37-mm cassette (0.61) > MOUDI (0.48) > respirable (0.12). The same trends were observed with the ratios of the median of median Be concentrations at the fixed station but with a larger scattering within sampling heads as follows: IOM (1.00) > Sierra (0.69) > 37-mm cassette (0.64) > MOUDI (0.54) > respirable (0.19). The median of median ratios of dust (IOM (1.00) > Sierra (0.56) > 37-mm cassette (0.35) > respirable (0.06)) and Be (IOM (1.00) > Sierra (0.66) > 37-mm cassette (0.48) > respirable (0.11)) in dust were lower, and there was less scattering for the 37-mm cassette and SKC cyclone used during breathing zone sampling than for the same sampling heads at the fixed station. Inhalable aerosol measurements should remain the tool for estimating the risk of exposure to beryllium in these settings until a clear dose response is established for these sampling heads.
Barley husks, rye bran, and a fiber residue from oat milk production were processed by heat pretreatment, various separation steps, and treatment with an endoxylanase in order to improve the prebiotic potential of these cereal byproducts. Metabolic functions were intended to improve along with improved microbial activity. The products obtained were included in a high-fat mouse diet so that all diets contained 5% dietary fiber. In addition, high-fat and low-fat controls as well as partially hydrolyzed guar gum were included in the study. The soluble fiber product obtained from rye bran caused a significant increase in the bifidobacteria (log copies of 16S rRNA genes; median (25-75 percentile): 6.38 (6.04-6.66) and 7.47 (7.30-7.74), respectively; p
Manure is one of the most common substrates for biogas production. Manure from dairy- and swine animals are often considered to stabilize the biogas process by contributing nutrients and trace elements needed for the biogas process. In this study two lab-scale reactors were used to evaluate the effects of trace element addition during co-digestion of manure from swine- and dairy animals with industrial waste. The substrate used contained high background concentrations of both cobalt and nickel, which are considered to be the most important trace elements. In the reactor receiving additional trace elements, the volatile fatty acids (VFA) concentration was 89% lower than in the control reactor. The lower VFA concentration contributed to a more digested digestate, and thus lower methane emissions in the subsequent storage. Also, the biogas production rate increased with 24% and the biogas production yield with 10%, both as a result of the additional trace elements at high organic loading rates. All in all, even though 50% of the feedstock consisted of manure, trace element addition resulted in multiple positive effects and a more reliable process with stable and high yield.
Hydrolyzed protein-rich byproducts from food production may find a variety of applications, for example, as rich ingredients of fermentation media. We have conducted a study of the enzymatic hydrolysis of three byproducts from Norwegian food industries: chicken byproducts, mixed pork and beef byproducts, and salmon viscera. The efficiency and optimization of the enzymatic hydrolysis were evaluated using endogenous enzymes alone and in combination with commercial proteases. Hydrolysis reactions were conducted with freshly thawed raw materials using short incubation times and including an initial temperature gradient from 4 to 60 °C to both harness the power of endogenous enzymes and minimize microbial contamination. Subsequently, hydrolysates were characterized by analyzing the total recovery of protein, the peptide molecular-weight distribution, and the composition of total and free amino acids. The action of endogenous enzymes played an important role in raw-material hydrolysis, particularly when hydrolyzing salmon viscera but less so when hydrolyzing chicken byproducts. For pork-beef and chicken byproducts, the addition of Alcalase or Papain improved protein recovery, reaching levels up to 90%. Next to showing efficient hydrolysis protocols, the present data also provide a comparison of the amino acid compositions of hydrolysates derived from these three different protein-rich byproducts. Growth studies showed that the obtained protein-rich hydrolysates from meat and fish industries are a promising alternative for expensive nitrogen sources that are commonly used for fermenting yeasts.