During production of γ-hexachlorocyclohexane (γ-HCH), thousands of tons of other isomers were synthesized as byproducts, and after dumping represent sources of contamination for the environment. Several microbes have the potential for aerobic and anaerobic degradation of HCHs, and zero-valent iron is an effective remediation agent for abiotic dechlorination of HCHs, whereas the combination of the processes has not yet been explored. In this study, a sequence of anoxic/oxic chemico-biological treatments for the degradation of HCHs in a real extremely contaminated soil (10-30 g/kg) was applied. Approximately 1500 kg of the soil was employed, and various combinations of reducing and oxygen-releasing chemicals were used for setting up the aerobic and anaerobic phases. The best results were obtained with mZVI/nZVI, grass cuttings, and oxygen-releasing compounds. In this case, 80 % removal of HCHs was achieved in 129 days, and 98 % degradation was achieved after 1106 days. The analysis of HCHs and their transformation products proved active degradation when slight accumulation of the transformation product during the anaerobic phase was followed by aerobic degradation. The results document that switching between aerobic and anaerobic phases, together with the addition of grass, also created suitable conditions for the biodegradation of HCHs and monochlorobenzene/benzene by microbes.
Laboratory studies of pollutant uptake kinetics commonly start shortly after experimental soil contamination when it is not clear if the processes between soil and chemicals are equilibrated and stabilized. For instance, when the concentration in soil quickly decreases due to initial biodegradation, bioaccumulation may show a peak-shape accumulation curve instead of conventional first order kinetics with a plateau at the end. The results of such experiments with soil freshly contaminated in the laboratory are then hardly comparable to bioaccumulation observed in soils from historically contaminated sites. Therefore, our study focused on the uptake kinetics of four hydrophobic organic compounds (pyrene, lindane, p,p'-DDT and PCB 153) in two laboratory-contaminated natural soils with different soil properties (e.g. total organic carbon content of 1.6 and 9.3%) aged for 203 days to mimic long-term contamination. For pyrene, the results surprisingly showed peak-shape accumulation curves despite long aging. It seems compound biodegradation might be significant in aged soils when the conditions change (e.g. by distribution to the experimental vessels) and this should be also considered when testing historically contaminated soils. For lindane, longer aging seems to guarantee stability of the soil-compound-earthworm system and the steady state was reached after 5 days of exposure. Furthermore, although concentrations of p,p'-DDT and PCB 153 in earthworms after 11-15-day exposure did not statistically differ, which is a commonly-used indicator that a steady state was reached, they continuously increased until the end of the exposure. Therefore, despite the aging, longer exposure was probably needed to reach the true equilibrium between concentrations in earthworms and soil. In summary, aging does not warranty the conventional first order kinetic curve with the equilibrium at the end of the exposure but may have diverse effects for compounds with different environmental properties and should be taken into account in the bioaccumulation factor calculation and the risk assessment.
- MeSH
- DDT farmakokinetika MeSH
- hexachlorcyklohexan farmakokinetika MeSH
- hydrofobní a hydrofilní interakce MeSH
- kinetika MeSH
- látky znečišťující půdu chemie farmakokinetika MeSH
- Oligochaeta metabolismus MeSH
- polychlorované bifenyly farmakokinetika MeSH
- pyreny farmakokinetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Lindane (γ-hexachlorocyclohexane) and its isomers (HCH) are some of the most common and most easily detected organochlorine pesticides in the environment. The widespread distribution of lindane is due to its use as an insecticide, accompanied by its persistence and bioaccumulation, whereas HCH were disposed of as waste in unmanaged landfills. Unfortunately, certain HCH (especially the most reactive ones: γ- and α-HCH) are harmful to the central nervous system and to reproductive and endocrine systems, therefore development of suitable remediation methods is needed to remove them from contaminated soil and water. This paper provides a short history of the use of lindane and a description of the properties of HCH, as well as their determination methods. The main focus of the paper, however, is a review of oxidative and reductive treatment methods. Although these methods of HCH remediation are popular, there are no review papers summarising their principles, history, advantages and disadvantages. Furthermore, recent advances in the chemical treatment of HCH are discussed and risks concerning these processes are given.
The study of the soil microbial community represents an important step in better understanding the environmental context. Therefore, biological characterisation and physicochemical integration are keys when defining contaminated sites. Fungi play a fundamental role in the soil, by providing and supporting ecological services for ecosystems and human wellbeing. In this research, 52 soil fungal taxa were isolated from in situ pilot reactors installed to a contaminated site in Czech Republic with a high concentration of hexachlorocyclohexane (HCH). Among the identified isolates, 12 strains were selected to evaluate their tolerance to different isomers of HCH by using specific indices (Rt:Rc; T.I.) and to test their potential in xenobiotic biotransformation. Most of the selected taxa was not significantly affected by exposure to HCH, underlining the elevated tolerance of all the tested fungal taxa, and different metabolic intermediates of HCH dechlorination were observed. The oxidative stress responses to HCH for two selected species, Penicillium simplicissimum and Trichoderma harzianum, were investigated in order to explore their toxic responses and to evaluate their potential functioning in bioremediation of contaminated environments. This research suggests that the isolated fungal species may provide opportunities for new eco-friendly, integrated and cost-effective solutions for environmental management and remediation, considering their efficient adaptation to stressful conditions.
- MeSH
- biodegradace MeSH
- biotransformace * MeSH
- ekosystém MeSH
- hexachlorcyklohexan analýza metabolismus MeSH
- houby metabolismus MeSH
- isomerie MeSH
- látky znečišťující půdu analýza metabolismus MeSH
- oxidační stres MeSH
- Penicillium metabolismus MeSH
- půda MeSH
- půdní mikrobiologie * MeSH
- tolerance léku MeSH
- Trichoderma metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Toxicity of mine dump effluent containing five hexachlorocyclohexane (α, β, γ, δ and ε-HCH, sum 159.4 μg/L) and two trichlorobenzene (TCB, sum 65.2 μg/L) isomers to two microalgae (Scenedesmus quadricauda and Coccomyxa subellipsoidea) was studied over 24 h exposure and also with 2- and 10-fold diluted stock solution (i.e. 1×, 0.5× and 0.1× strength). Individual isomers revealed rather dose-dependent accumulation typically higher in Scenedesmus than in Coccomyxa (max. sum of HCH 14.99 μg/g DW with bioaccumulation factor 94) and δ-HCH was dominant isomer. TCB isomers showed low accumulation in algae. 0.1× dose elevated chlorophylls and carotenoids in Coccomyxa while enzymatic activities (SOD, CAT, and APX), thiols (glutathione and phytochelatin 2) and ascorbic acid were rather elevated by 1× dose in both species. Malic acid, rather than citric acid, increased in response to 0.5× and 1× concentration. Sum of fatty acids was higher in Coccomyxa than in Scenedesmus with palmitic, oleic, linoleic and α-linolenic acids being dominant compounds in both species. Detailed profiling revealed that saturated and monounsaturated fatty acids increased in Coccomyxa while polyunsaturated fatty acids in Scenedesmus in response to increasing dose of organochlorines. Accumulation of organochlorines and metabolic responses in algae are reported here for the first time.
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- chlorbenzeny toxicita MeSH
- Chlorophyta účinky léků metabolismus MeSH
- hexachlorcyklohexan toxicita MeSH
- hornictví MeSH
- mastné kyseliny metabolismus MeSH
- mikrořasy účinky léků metabolismus MeSH
- průmyslový odpad MeSH
- sulfhydrylové sloučeniny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
A special initiative in the Global Atmospheric Passive Sampling (GAPS) Network was implemented to provide information on new and emerging persistent organic pollutants (POPs) in the Group of Latin America and Caribbean (GRULAC) region. Regional-scale atmospheric concentrations of the new and emerging POPs hexachlorobutadiene (HCBD), pentachloroanisole (PCA) and dicofol indicators (breakdown products) are reported for the first time. HCBD was detected in similar concentrations at all location types (<20-120 pg/m3). PCA had elevated concentrations at the urban site Concepción (Chile) of 49-222 pg/m3, with concentrations ranging <1-8.5 pg/m3 at the other sites in this study. Dicofol indicators were detected at the agricultural site of Sonora (Mexico) at concentrations ranging 30-117 pg/m3. Legacy POPs, including a range of organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were also monitored to compare regional atmospheric concentrations over a decade of monitoring under the GAPS Network. γ-hexachlorocyclohexane (HCH) and the endosulfans significantly decreased (p < 0.05) from 2005 to 2015, suggesting regional levels are decreasing. However, there were no significant changes for the other legacy POPs monitored, likely a reflection of the persistency and slow decline of environmental levels of these POPs. For the more volatile OCs, atmospheric concentrations derived from polyurethane foam (PUF) (acting as an equilibrium sampler) and sorbent impregnated PUF (SIP) (acting as a linear phase sampler), were compared. The complimentary methods show a good agreement of within a factor of 2-3, and areas for future studies to improve this agreement are further discussed.
- MeSH
- chlorované uhlovodíky analýza MeSH
- endosulfan MeSH
- hexachlorcyklohexan MeSH
- látky znečišťující vzduch analýza MeSH
- látky znečišťující životní prostředí analýza MeSH
- monitorování životního prostředí * MeSH
- pesticidy analýza MeSH
- polychlorované bifenyly analýza MeSH
- polyurethany analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Chile MeSH
- karibský region MeSH
- Latinská Amerika MeSH
- Mexiko MeSH
The main topic of this study is a human health risk assessment of a defined exposure scenario in the floodplain soils of the headwater areas of the central European watershed, with the aim of exploring both multivariate and regional data structures. Flood-prone areas are recognized worldwide to be susceptible to contamination and its redistribution. Contributions of various classes of toxic compounds (organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs)) to human health risks were assessed in a screening risk assessment. However, due to the relative nature of our data and a high PAH dominancy over the data ensemble, reliance solely on the standard statistical processing of raw data might lead to incomplete insight into the structure of the multivariate data. Explanatory analysis of the data structure using the compositional approach was found to be beneficial to elucidating human health risk profiles and provided robust evidence that a contrast between agricultural and airborne industrial pollution controlled the whole human toxicological variation of persistent organic pollutants (POPs) in floodplain soils. These results were effectively quantified with the subcomposition of benzo(a)pyrene, DDT, and alpha-hexachlorocyclohexane (aHCH), allowing for an interpretation of structural differences in regional pollution patterns, which conferred different extents and compositions of human health risks in floodplain soils.
- MeSH
- algoritmy MeSH
- chlorované uhlovodíky analýza MeSH
- hexachlorcyklohexan analýza MeSH
- látky znečišťující půdu analýza MeSH
- látky znečišťující životní prostředí analýza MeSH
- lidé MeSH
- monitorování životního prostředí * MeSH
- pesticidy analýza MeSH
- polychlorované bifenyly analýza MeSH
- polycyklické aromatické uhlovodíky analýza MeSH
- půda chemie MeSH
- záplavy * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Polyurethane foam (PUF) disk passive air samplers were deployed concurrently at five sites across Kolkata megacity and the rural mangrove wetland of Sundarban (UNESCO World Heritage Site) between January-March in 2014. Samples were analyzed for hexachlorocyclohexanes (HCHs), dichlorodiphenyltricholoroethanes (DDTs), polychlorinated biphenyls (PCBs) and, polybrominated diphenyl ethers (PBDEs) using gas chromatography and mass spectrometry (GC-MS). Derived air concentrations (pg/m(3)) for Kolkata ranged: for ∑α- and γ-HCH between 70 and 207 (114 ± 62), ∑6DDTs: 127-216 (161 ± 36), ∑7PCBs: 53-213 (141 ± 64), and ∑10PBDEs: 0.30-23 (11 ± 9). Low values for all the studied POPs were recorded in the remote area of the Sundarban site (with the exception of DDTs: o,p'-DDT and p,p'-DDT), where ∑4DDTs was 161 ± 36. In particular, the site of Ballygunge, located in the southern part of Kolkata, showed the highest level of all the metabolites/congeners of POPs, suggesting a potential hot spot of usage and emissions. From HCHs, α-/γ-HCH isomers ratio was low (0.67-1.96) indicating a possible sporadic source of lindane. γ-HCH dominated the HCH signal (at 3 sites) reflecting wide spread use of lindane both in Kolkata and the Sundarban region; however, isomeric composition in Kolkata also suggests potential technical HCHs use. Among DDT metabolites, both o,p'-DDT and p,p'-DDT shared the dominant percentages accounting for ∼26-46% of total DDTs followed by p,p'-DDE (∼12-19%). The PCB congener profile was dominated by tri- and tetra-Cl at the southern and eastern part of Kolkata. These results are one of the few contributions that reports air concentrations of POPs, concurrently, at urban and remote villages in India. These data are useful to assess atmospheric pollution levels and to motivate local and regional authorities to better understand the potential human exposure risk associated to urban areas in India.
- MeSH
- DDT analýza MeSH
- halogenované difenylethery analýza MeSH
- hexachlorcyklohexan analýza MeSH
- látky znečišťující vzduch analýza MeSH
- mokřady MeSH
- monitorování životního prostředí MeSH
- polychlorované bifenyly analýza MeSH
- velkoměsta MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Indie MeSH
- velkoměsta MeSH
Concentrations of persistent organic pollutants (POPs) were measured for an entire year in the region of Tuscany, Italy. Passive air samplers consisting of polyurethane foam (PUF) disks were deployed over four sampling periods of 3-5 months from April 2008 to July 2009 in urban (n = 6) and rural (n = 4) sites. The aim of the study was to characterize the spatial and seasonal variations in selected POPs. The POP concentrations (pg m(-3)) in the air were dominated by dichlorodiphenyltrichloroethane and metabolites (DDTs) and polychlorinated biphenyls (∑7PCBs). DDTs, and ∑7PCBs showed a clear decreasing urban > rural gradient. The concentrations of DDTs and PCBs were up to 10 and 6 times higher, respectively, in urban sites than in rural sites. ∑7PCBs showed a significant correlation with the urbanized areas located <5 km around the sampling sites. For hexachlorocyclohexanes (HCHs), α-HCH concentrations were similar at both sampling sites and were found to be quite uniform during the four sampling periods. Seasonal fluctuations were observed for DDTs, and ∑7PCBs, with the highest concentrations observed during period 4 (summer-spring); this is most likely due to a temperature-driven re-emission from local sources. These findings were also supported by an air back trajectory analysis in the study area. This study contributes new information about POP levels in the Italian atmosphere and demonstrates the feasibility of using PUF disks to simultaneously assess seasonal concentrations at different sampling sites.
- MeSH
- chlorované uhlovodíky analýza chemie MeSH
- DDT analýza chemie MeSH
- hexachlorcyklohexan analýza chemie MeSH
- látky znečišťující vzduch analýza chemie MeSH
- monitorování životního prostředí metody MeSH
- polychlorované bifenyly analýza chemie MeSH
- polyurethany chemie MeSH
- roční období * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Itálie MeSH
Svrab je epidemická ektoparazitóza vyvolaná zákožkou svrabovou. Zdrojem nákazy je nemocný člověk. K přenosu infekce dochází buď přímo, nebo nepřímo. Inkubační doba je 2–3 týdny. Onemocnění charakterizuje intenzivní noční pruritus. V dětském věku se toto onemocnění vyskytuje velmi často. Diagnostika choroby je založená na pozitivní anamnéze nočního pruritu, klinickém obraze a průkazu zákožky v kůži nemocného. Metodou první volby v terapii choroby u dětí je permethrin a síra. Svrab podléhá povinnému epidemiologickému hlášení. V článku popisujeme etiologii, patogenezi, diagnostiku, diferenciální diagnostiku a terapii choroby včetně současné legislativy a protiepidemických opatření.
Scabies is epidemic ectoparasitosis caused by human parasite Sarcoptes scabiei, var. hominis. The reservoir of a contagion is the man. The transmission of the disease is caused by direct or indirect contact. The incubation period ranges from two to three weeks. The disease is characterised by an intensive night pruritus. In childhood age we can find this disease very frequently. Diagnostics is based on positive night pruritus, clinical picture and demonstration of Sarcoptes scabiei in skin of ill person. The method of the first alternative at children there is permethrin and sulphur. Scabies is subordinated to the obligatory epidemiologic announcement. In the article we describe aetiology, pathogenesis, diagnostics, differential diagnostics, treatment and present legislation with precaution.
- MeSH
- antiparazitární látky aplikace a dávkování MeSH
- benzoáty terapeutické užití MeSH
- diferenciální diagnóza MeSH
- dítě MeSH
- hexachlorcyklohexan aplikace a dávkování MeSH
- hlášení nemocí normy statistika a číselné údaje MeSH
- ivermektin aplikace a dávkování MeSH
- lidé MeSH
- permethrin aplikace a dávkování MeSH
- síra terapeutické užití MeSH
- svrab * diagnóza farmakoterapie prevence a kontrola přenos MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
