Effect of chemophytostabilization practices on arbuscular mycorrhiza colonization of Deschampsia cespitosa ecotype Waryński at different soil depths

The effects of chemophytostabilization practices on arbuscular mycorrhiza (AM) of Deschampsia cespitosa roots at different depths in soils highly contaminated with heavy metals were studied in field trials. Mycorrhizal parameters, including frequency of mycorrhization, intensity of root cortex colonization and arbuscule abundance were studied. Correlations between concentration of bioavailable Cd, Zn, Pb and Cu in soil and mycorrhizal parameters were estimated. An increase in AM colonization with increasing soil depth was observed in soils with spontaneously growing D. cespitosa. A positive effect of chemophytostabilization amendments (calcium phosphate, lignite) on AM colonization was found in the soil layers to which the amendments were applied. Negative correlation coefficients between mycorrhizal parameters and concentration of bioavailable Cd and Zn in soil were obtained. Our results demonstrated that chemophytostabilization practices enhance AM colonization in D. cespitosa roots, even in soils fertilized with high rates of phosphorus.     

Acid-base responses to lethal aquatic hypercapnia in three marine fishes

Ocean sequestration of CO₂ is proposed as a possible measure to mitigate environmental changes due to the increasing atmospheric concentration of the gas. However, toxic effects of CO₂ on marine organisms are poorly understood. We therefore studied acid–base responses and mortality during exposure to fatal levels of CO₂ in three marine fishes (Japanese flounder, Paralichthys olivaceus; yellowtail, Seriola quinqueradiata; and starspotted dogfish, Mustelus manazo). The teleosts died during exposure to seawater equilibrated with a gas mixture containing 5% CO₂ (water PCO₂ 4.95 kPa); 100% mortality occurred within 8 h for yellowtail and within 48 h for flounder. Only 20% mortality was recorded at 72 h for the dogfish during exposure to 7% CO₂ (water PCO₂ 6.96 kPa). Arterial pH (pH_a) initially decreased, but completely recovered within 1–24 h for the teleosts at 1% and 3%, although the recovery was slower and complete only at 1% (water PCO₂ 0.99 kPa) for the dogfish. During exposure to 5%, the flounder died after the pH_a had been completely restored, suggesting that the mortality was not due to plasma acidosis. During exposure to 1% hypercapnia, plasma [Cl^–] appeared to be the main counter ion to balance increases in plasma [HCO₃^-]. There was a 1:1 stoichiometry for the rise in [HCO₃^-] and the fall in [Cl^–] for the teleosts, whereas the ratio was 1:0.4 for the dogfish at 1% CO₂. At the higher levels of hypercapnia, the rise in [HCO₃^-] consistently exceeded the fall in [Cl^–], and plasma [Na⁺] significantly increased.These results do not agree with the generally accepted model for acid–base regulation in marine fish in which Na⁺/H⁺ exchangers are assumed to play a predominant role, and indicate that an acid–base regulatory mechanism differs between teleost and elasmobranch fishes, as well as the intensity of acidic stress.Communicated by T. Ikeda, Hakodate     

Low-carbon transitions in world regions: comparison of technological mitigation potential and costs in 2020 and 2030 through bottom-up analyses

This study focuses on low-carbon transitions in the mid-term and analyzes mitigation potentials of greenhouse gas (GHG) emissions in 2020 and 2030 in a comparison based on bottom-up-type models. The study provides in-depth analyses of technological mitigation potentials and costs by sector and analyzes marginal abatement cost (MAC) curves from 0 to 200 US $/tCO₂ eq in major countries. An advantage of this study is that the technological feasibility of reducing GHG emissions is identified explicitly through looking at distinct technological options. However, the results of MAC curves using the bottom-up approach vary widely according to region and model due to the various differing assumptions. Thus, this study focuses on some comparable variables in order to analyze the differences between MAC curves. For example, reduction ratios relative to 2005 in Annex I range from 9 % to 31 % and 17 % to 34 % at 50 US $/tCO₂ eq in major countries. An advantage of this study is that the technological feasibility of reducing GHG emissions is identified explicitly through looking at distinct technological options. However, the results of MAC curves using the bottom-up approach vary widely according to region and model due to the various differing assumptions. Thus, this study focuses on some comparable variables in order to analyze the differences between MAC curves. For example, reduction ratios relative to 2005 in Annex I range from 9 % to 31 % and 17 % to 34 % at 50 US /tCO₂ eq in 2020 and 2030, respectively. In China and India, results of GHG emissions relative to 2005 vary very widely due to the difference in baseline emissions as well as the diffusion rate of mitigation technologies. Future portfolios of advanced technologies and energy resources, especially nuclear and renewable energies, are the most prominent reasons for the difference in MAC curves. Transitions toward a low-carbon society are not in line with current trends, and will require drastic GHG reductions, hence it is important to discuss how to overcome various existing barriers such as energy security constraints and technological restrictions.     

Systematic analysis and overall toxicity evaluation of dioxins and hexachlorobenzene in human milk

A systematic method for analyzing dioxins (PCDDs, PCDFs and dioxin-like PCBs), hexachlorobenzene (HCB), heptachlor epoxide and beta-hexachlorocyclohexane (HCH) in human milk was developed to determine the residual amount of HCB in human milk and to evaluate the overall toxicity of both dioxins and HCB in human milk. The fractionation behavior of HCB on chromatography with silica gel, alumina, and activated carbon/silica gel, and the concentrated sulfuric acid decomposition method, which is widely used as a dioxin cleanup method, were studied in order to make the preprocessing operation for HCB measurement compatible with that for conventional dioxin measurement. HCB was found to be eluted in the 2% dichloromethane (DCM)/hexane 60 ml fraction from an alumina column. Heptachlor epoxide and a part of beta-HCH were eluted in the 10% DCM/hexane 50 ml fraction from a silica gel column, while the remaining beta-HCH was eluted in the 25% DCM/hexane 60 ml fraction from an activated carbon/silica gel column. Moreover, HCB showed significant correlation with dioxin congeners having high toxicity equivalence factors (TEFs). The results suggest that the exposure route to HCB and its accumulation behavior in the human body are similar to those of the dioxins.     

Analysis of selected fungi variation and its dependence on season and mountain range in southern Poland—key factors in drawing up trial guidelines for aeromycological monitoring

The aim of the study was to identify fungal spores, in particular plant pathogenic fungi, occurring in the air in selected mountain ranges. The results revealed not only the array of fungal species migrating with air currents from the Czech Republic and Slovakia but also how the season of the year affects the distribution of spores. Such studies may lay a foundation for future aeromycological monitoring, in accordance with the requirements for integrated plant protection. Aeromycological research was carried out between 2013 and 2016 at 3-month intervals in mountainous areas along the southern borders of Poland: the Bieszczady, the Pieniny, the Giant Mountains (Karkonosze) and the Babia Góra Massif. The research relied on impact method employing Air Ideal 3P sampler, which, by drawing in atmospheric air, also collects fungal spores. Regardless of altitudinal zonation, the changing weather conditions appeared to be the main reason for the variations in the number of the fungal spores under study in those years.     

Bioelements and mineral matter in human livers from the highly industrialized region of the Upper Silesia Coal Basin (Poland)

Contents of mineral substance, silica, and a range of bioelements and toxic elements (Mg, Na, K, Ca, Ba, Zn, Cr, P Al, Cd, Mn Cu, Ni, Pb, Sr, Fe) in 38 livers of donors from the Upper Silesia Coal Basin (southern Poland) are presented. Elements were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) with the exception of silica that was estimated colorimetrically. Concentrations, concentration variability, and correlations between selected liver components determined for the total population are related to donor age, gender, and lesion occurrence. Correlations between particular elements were found using correlation coefficient values and the Fisher transformation. Mineral substance in the livers lies in the range 0.40–5.03 wt%. With increasing donor age, mineral-matter content decreases to a minimum for the 40–60 years of age range. Microbioelement contents show a similar tendency, while microbioelements and toxic elements reach maximum contents in donors aged 60–80 years. All elements show content decreases in livers from the oldest group (>80 years). Silica contents increase with age. Variability of element contents is lowest in the older subpopulations. Livers with lesions show lower element contents and variability. The results are compared to literature data for regions of Poland assumed to be of low pollution and to data from comparable regions in Japan and Hungary. Up to our knowledge, this paper is the first work describing the total contents, as distinct from contents of selected elements, of mineral substance in human livers.