Persistent organochlorine contaminants in human tissues of the Czech and Slovak populations

The persistence of lipophilic organochlorine substances leads to their incorporation into the food chain and subsequent uptake by humans. Due to their use in the past, Czech and Slovak countries belong to the countries with a relatively high body burden of organochlorines. Levels of PCBs in human tissues based on the congener‐specific analysis are reported in this paper. Samples were analysed for the most abundant PCB congeners. Prevalent persistent organochlorine pesticides and their isomers/metabolites have also been included. The present study is focused on following areas: i) distribution of analysed substances in the various human tissue samples from selected regions of the Czech and Slovak Republic and ii) comparison with the results from other foreign and local studies.     

Toxicokinetic-toxicodynamic modelling in an individual based context—Consequences of parameter variability

Toxicokinetic-toxicodynamic (TKTD) models simulate the time-course of toxicant concentration in the organism and toxicity at the level of the organism. A link between TKTD models that simulate survival and individual based models for populations (IBMs) is proposed which allows TKTD parameters to vary between individuals. The TKTD-IBM predicts different survival in response to toxicants when TKTD parameters vary amongst individuals compared to the survival predicted with fixed TKTD parameters. The model with fixed parameters represents the concept of stochastic death whereas the model with variable parameters behaves, at least partly, according to the individual tolerance distribution concept. The whole set of TKTD parameters of an individual can be interpreted as constituting “individual tolerance”.     

Investigation of odors in the fragrance industry

Scents form the basis for the fragrance industry and various research activities have been developed in different scientific disciplines all being linked by a common interest in odors and odor perception. In this paper, four different topics have been selected for a short discussion. Following a short overview on the history of perfumery, the first topic (Natural scents) is providing some insight into the investigation of natural scents and how this work has strongly stimulated fragrance creation as well as the quest to find new odoriferous substances for the perfumer’s palette. The second subject (Fragrance chemistry) gives a historical overview over the chemistry of fragrances and briefly describes the rational behind the synthesis and composition of new scents. Body odors and their biochemical formation concern the third topic (Body odor biochemistry) which describes our current understanding of this scientifically interesting field and how knowledge may find use to improve future deodorant products. The fourth subject (Olfactory mechanisms) deals with the biochemistry in the human nose when odorants are activating olfactory receptors and enzymes appear to rapidly metabolize the inhaled odorous stimuli. This review does not attempt to be comprehensive, but it describes selected successes in the fragrance industry and the motivation behind conducting various types of research. Ultimately, the activities are aiming to bring new ingredients onto the market and improve the quality of scented products but also to advance our understanding of the power of communication through fragrance.     

Investigation of PCDD/Fs and dl-PCBs in fish from the southern Baltic Sea during the 2002–2006 period

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the southern Baltic herring (Clupea harengus), sprat (Sprattus sprattus), and salmon (Salmo salar) are reported.The significant interspecies and season-specific differences in PCDD/Fs and dl-PCBs concentrations were observed. The contribution of dl-PCBs to the total toxicity equivalents (TEQs) ranged between 50% and 70%, dependently on fish species. In all samples, concentrations of PCDF were higher in comparison with that of PCDD.The permissible limits of the content of PCDD/Fs and dl-PCBs (8 pg g⁻¹ fresh weight for the sum of PCDD/Fs and dl-PCBs, and 4 pg g⁻¹ fresh weight for the PCDD/Fs) were exceeded mainly in salmon samples (in 80% of salmon samples studied). The elevated levels of PCDD/F and dl-PCB were observed only in two of seventy two herring samples, and in ten of 62 sprat samples.The multiple regression analysis revealed that fish lipid content, and concentration of PCB 153, used simultaneously, might be useful in the prediction of TEQ values of fish samples. These two variables explained more than 80% of total variance. For all fish species studied, the correlation coefficients obtained with the multiple regression analysis were higher than that obtained with the regression analysis involving total TEQ values, and only one independent variable: fish lipid content.     

Untersuchungen zum ?kotoxikologischen Sch?digungspotenzial und Erosionsrisiko von kontaminierten Sedimenten in staugeregelten Flüssen

Schwebstoffgebundene Schadstoffe werden durch Sedimentation der Wasserphase und damit der Verfügbarkeit für viele aquatischen Organismen entzogen. W?hrend bei durchschnittlichen hydrologischen. Verh?ltnissen die Freisetzung von Schadstoffen aus stabil gelagerten Sedimenten meist weitgehend unterbunden wird, besteht bei Hochwassereignissen die Gefahr einer Remobilisierung von kontaminierten Ablagerungen. In diesem Beitrag wird ein kombiniertes ?kotoxikologisches und hydraulisches Untersuchungssystem zur Untersuchung der ?kotoxikologischen Belastung und des Erosionsrisikos von Sedimenten vorgestellt. Der integrierte Ansatz wurde am staugeregelten Neckar angewendet, um das Sch?digungspotenzial und die Gefahr einer Remobilisierung an Sedimentbohrkernen der Stauhaltung Lauffen sowie an Schwebstoffen zweier extremer Hochwasser zu überprüfen. Für die Bohrkernsegmente unterhalb einer Erosionsdiskordanz konnte eine sprunghafte Zunahme der ?kotoxikologischen Belastung ermittelt werden. Bei Hochwasserereignissen mit einer 5-j?hrlichen Wiederkehrwahrscheinlichkeit (=HQ₅) k?nnen prinzipiell alle Sedimente, auch die st?rker kontaminierten und erosionsresistenteren Altsedimente, remobilisiert werden. W?hrend der Hochwasserereignisse (HQ₁₅ bis HQ₂₀) kam es zu einer deutlichen Erh?hung des cytotoxischen und mutagenen Sch?digungspotenzials der Schwebstoffe im Vergleich zu einem mittleren Hochwasser im Jahre 1995/96 (HQ₁) Dies schien zumindest teilweise auf die Remobilisierung hochkontaminierter Altsedimente zurückzuführen zu sein.     

Lethal critical body residues as measures of Cd, Pb, and Zn bioavailability and toxicity in the earthwormEisenia fetida

Background  

Earthworm heavy metal concentrations (critical body residues, CBRs) may be the most relevant measures of heavy metal bioavailability in soils and may be linkable to toxic effects in order to better assess soil ecotoxicity. However, as earthworms possess physiological mechanisms to secrete and/or sequester absorbed metals as toxicologically inactive forms, total earthworm metal concentrations may not relate well with toxicity.     

Electrochemical remediation of copper contaminated kaolinite by conditioning anolyte and catholyte pH simultaneously

This report examined electrochemical remediation of copper contaminated kaojinite by controlling electrolytes‘ pH for both of anolyte and catholyte simultaneously.Results showed the electrokinetic process and remediation efficiency varied obviously when different buffer systems,including citric acid(test 1),nitric acid EDTA(test 2)and nitric acid(test 3),were used to control catholyte pH AND Na2CO3 was used at the same time to control all anolyte one.It was found that under such pH condition soil‘s pH in soil column kept at 3.0-7.0 successfully,and correspondingly no copper precipitation and decrease of soil electroconductivity appeared.which are usually observed in electrokinetic process due to OH^- introduction into soil cojumn by electrochemical reaction occurred in cathode.Electroosmosis flow rates were almost equal for these three tests,indicating that these buffers did not affect Zeta-potential of kaolinite within the examined duration.More acid and basic solution was added into electrokinetic cell when nitric acid was used as buffer than when nitric acid EDTA and then citric acid were used.Due to introduction of large amounts of ions into soil column,significant higher current was observed for test 3 than other two.Analysis of copper speciation and total quantity in kaolinite indicated that 22.5%,23.74%and 55.65% Cu were removed from kaolinite for test 1,test 2 and test 3 respectively after only 10 days‘ electrokinetic remediation.     

Pheromone-modulated behavioral suites influence colony growth in the honey bee (<Emphasis Type="Italic">Apis mellifera</Emphasis>)

The success of a species depends on its ability to assess its environment and to decide accordingly which behaviors are most appropriate. Many animal species, from bacteria to mammals, are able to communicate using interspecies chemicals called pheromones. In addition to exerting physiological effects on individuals, for social species, pheromones communicate group social structure. Communication of social structure is important to social insects for the allocation of its working members into coordinated suites of behaviors. We tested effects of long-term treatment with brood pheromone on suites of honey bee brood rearing and foraging behaviors. Pheromone-treated colonies reared significantly greater brood areas and more adults than controls, while amounts of stored pollen and honey remained statistically similar. Brood pheromone increased the number of pollen foragers and the pollen load weights they returned. It appeared that the pheromone-induced increase in pollen intake was directly canalized into more brood rearing. A two-way pheromone priming effect was observed, such that some workers from the same age cohorts showed an increased and extended capacity to rear larvae, while others were recruited at significantly younger ages into pollen-specific foraging. Brood pheromone affected suites of nursing and foraging behaviors allocating worker and pollen resources associated with an important fitness trait, colony growth.     

Vocal alliances in Chacma baboons (<Emphasis Type="Italic">Papio hamadryas ursinus</Emphasis>)

Theory predicts that females in species with matrilineal dominance hierarchies should use nepotistic support systems to maintain their family’s rank. Female Old World monkeys, however, form alliances against other females at surprisingly low rates. Nonetheless, in many species, females utter threat vocalizations when observing others’ disputes, suggesting that these vocalizations may function as ‘vocal alliances’. We describe a playback experiment testing the efficacy of vocal alliances in free-ranging female baboons. Subjects were played the same female’s threat-grunts under three separate conditions: after being threatened by the signaller’s close relative to mimic kin support, after being threatened by a female maternally unrelated to the signaller to mimic non-kin support, and after a friendly interaction with the signaller’s close relative as a control. Subjects responded more strongly to the playback and avoided the signaller and her matrilineal relatives for a longer period of time in kin support trials than in either non-kin support or no aggression trials. In contrast, there was no difference in subjects’ behaviour between non-kin support and no aggression trials. These results corroborate observational data showing that vocal support occurs at a higher rate than physical support in female baboons, and that kin are more likely to provide vocal support than non-kin. We conclude that vocal support plays a similar role as physical support in the alliances of female baboons.