Cities of the future—bionic systems of new urban environment

Environmental Science and Pollution Research - The concepts of the cities we know nowadays, and which we are accustomed to, change at a very rapid pace. The philosophy of their design is also...     

Optimized yeast-based in vitro bioassay for determination of estrogenic and androgenic activity of hydroxylated / methoxylated metabolites of BDEs / CBs and related lipophilic organic pollutants

ABSTRACT

Persistent organic pollutants (POPs) are known to show endocrine disrupting (ED) activity, including interactions with hormone receptors. The aim of this work was to develop a bioassay applicable for evaluation of ED potency of highly lipophilic metabolites of POPs. To that end, a yeast-based bio-assay protocol was used. Estrogenic / androgenic activity of some native brominated biphenyl ethers (BDEs) / chlorinated biphenyls (CBs), and their hydroxylated / methoxylated metabolites was assessed. Since data (including potency compared to reference native hormones) obtained using different protocols vary, the possibility that yeast transforms POPs into some more potent compounds was first checked; it seems that no such transformation is important from the test applicability standpoint. The developed method was sensitive with EC50 values 6.5*10^?11 M and 4.5*10^?9 M calculated for E2 and DHT, respectively. Both CBs and BDEs show weak estrogenic activity negatively correlated with the degree of their halogenation, but their metabolites are significantly more potent xenohormones. 4-OH-2,2′,4′,6′-TeCB was the most potent estrogen receptor (ER) agonist among all tested compounds; its activity was only 1,000 times lower than that of native E2.     

Remediation capacity of Cd and Pb ions by mycelia of Imleria badia,Laetiporus sulphureus,and Agaricus bisporus in vitro cultures

The goal of this study was to evaluate cadmium and lead accumulation ability of in vitro cultures biomass containing selected edible mushroom species derived from the environment (Laetiporus sulphureus, Imleria badia) and those of commercial origin (Agaricus bisporus). Atomic absorption spectrometry was used to evaluate the content of Cd(II) and Pb(II) on the medium supplemented with Cd(II) or Pb(II), each of them at the same concentration of 5·10^?5 M. The highest concentration of Cd(II) ions was determined in the biomass from L. sulphureus in vitro cultures, while the highest concentration of Pb(II) ions was found in the biomass from A. bisporus in vitro cultures. The greatest Cd(II) and Pb(II) accumulation ability in mycelium per dry weight was shown for L. sulphureus. Among the test species, biomass of A. bisporus showed the lowest ability for the bioaccumulation of Cd(II); however, comparable ability for the remediation of Pb(II) was provided by the biomasses from A. bisporus and I. badia in vitro cultures. The results confirm the possibility of using these mushroom species for remediation and indicate the relationship between bioaccumulation of heavy metals and the test species.     

Profile of trace elements in Parasol Mushroom (Macrolepiota procera) from Tucholskie Forest

The aim of this study was to determine 19 elements contents and bioconcentration potential in fruiting bodies of Parasol Mushroom (Macrolepiota procera) collected from the Tucholskie Forest complex in Poland. Also discussed were Cd, Pb and Hg contents of edible caps in relation to the current regulatory standards. K, P and Mg were particularly abundant in caps and stipes, median values were 38-49, 13, and 1.6-1.6 mg/g dry weight, and followed by Ca, Na and Rb at 110-540, 44-240 and 20-50 μg/g dw, respectively. Concentrations of Al, Fe, Zn, Cu and Mn were from less than 50 to 180 μg/g dw, while concentrations of other elements were ～l.0?μg/g dw or less. Cu, K, Ag, Cd, Na, Rb, Zn and Hg were bioconcentrated (BCF >1), while Al, Ba, Fe, Mn, Co, Sr, Pb and Cr were not bioaccumulated (BCF <1). Cd and Pb content of Parasol Mushroom's edible caps collected from some sites in the Tucholskie Forest exceed the maximum levels set in the EU for cultivated mushrooms.     

Volatile organohalogen compounds in human urine: the effect of environmental exposure

The paper presents the results of determination of volatile organohalogen compounds (VOX) in urine samples from subjects exposed to these compounds in their workplaces and through consumption of chlorinated tap water. The analytes were isolated and preconcentrated from the complex urine samples using the thin layer headspace (TLHS) technique with autogenous generation of the liquid sorbent. Final gas chromatographic determination was carried out by direct aqueous injection with electron capture detection (DAI-ECD). The results indicate that only a small fraction (<4%) of the VOX input is excreted with urine in the non-metabolized form. A positive correlation was found between the occupational levels of VOX in the workplace and their levels in urine. VOX levels in the urine of subjects not exposed to them in the workplace were significantly lower. Their presence in the organisms was most probably related to consumption of tap water produced by chlorination of surface waters.     

SEC-ICP-MS studies for elements binding to different molecular weight fractions of humic substances in compost extract obtained from urban solid waste

In this work, the speciation of elements in compost was studied with emphasis on their binding to humic substances. In order to assess the distribution of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, U, Th and Zn among molecular weight fractions of humic substances, the compost extract (extracted by 0.1 mol l(-1) sodium pyrophosphate) was analyzed by size exclusion chromatography coupled on-line with UV-Vis spectrophotometric and ICP-MS detection. Similar chromatograms were obtained for standard humic acid (Fluka) and for compost extract (254 nm, 400 nm) and three size fractions were operationally defined that corresponded to the apparent molecular weight ranges > 15 kDa, 1-15 kDa and < 1 kDa. The percentage of total element content in compost that was leached to the extract ranged from 30% up to 100% for different elements. The elution profiles of Co, Cr, Cu, Ni and Pb (ICP-MS) followed that of humic substances, while for other elements the bulk elution peak matched the retention time observed for the element in the absence of compost extract. Spiking experiments were carried out to confirm elements' binding and to estimate the affinity of individual elements for humic substances derived from compost. The results obtained indicated the following order of decreasing affinity: Cu > Ni > Co > Pb > Cd > (Cr, U, Th) > (As, Mn, Mo, Zn). After standard addition, further binding of Cu, Ni and Co with the two molecular weight fractions of humic substances was observed, indicating that humic substances derived from compost were not saturated with these elements.     

Nineteenth-century land-use legacies affect contemporary land abandonment in the Carpathians

Regional Environmental Change - Historical land use may shape landscapes for centuries into the future, but it remains unclear how much land-use legacies affect contemporary land use. Knowing for...     

Classification of the Substances on the Basis of the Acute-Toxic-Class Method (ATC)

The acute-toxic-class method (ATC) is an alternative to the classical LD₅₀ test. Four substances were tested with an ATC testing procedure. The results were compared with LD₅₀ data obtained from the literature. Great importance was attached to the observations of toxic signs following administration. The results of this study have shown that the ATC method allows allocation to toxicity classes in the same manner as on the basis of the classical LD₅₀ tests. The ATC method uses fewer animals and yields the same information on toxic signs. Introducing the ATC method into the quality system allows estimating the acute oral toxicity of chemicals according to the Organisation for Economic Cooperation and Development (OECD; OECD, 1992, 1996).     

Nitrogen removal from wastewater and bacterial diversity in activated sludge at different COD/N ratios and dissolved oxygen concentrations

The impact of the organic carbon to nitrogen ratio (chemical oxygen demand (COD)/N) in wastewater and dissolved oxygen (DO) concentration on carbon and nitrogen removal efficiency, and total bacteria and ammonia-oxidizing bacteria (AOB) communities in activated sludge in constantly aerated sequencing batch reactors (SBRs) was determined. At DO of 0.5 and 1.5 mg O₂/L during the aeration phase, the efficiency of ammonia oxidation exceeded 90%, with nitrates as the main product. Nitrification and denitrification achieved under the same operating conditions suggested the simultaneous course of these processes. The most effective nitrogen elimination (above 50%) was obtained at the COD/N ratio of 6.8 and DO of 0.5 mg O₂/L. Total bacterial diversity was similar in all experimental series, however, for both COD/N ratios of 6.8 and 0.7, higher values were observed at DO of 0.5 mg O₂/L. The diversity and abundance of AOB were higher in the reactors with the COD/N ratio of 0.7 in comparison with the reactors with the COD/N of 6.8. For both COD/N ratios applied, the AOB population was not affected by oxygen concentration. Amplicons with sequences indicating membership of the genus Nitrosospira were the determinants of variable technological conditions.