Genotoxicity of the organochlorine pesticides 1,1-dichloro-2,2- bis(p-chlorophenyl)ethylene (DDE) and hexachlorobenzene (HCB) in cultured human lymphocytes

The possible genotoxic potential of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), which is a metabolite of dichlorobiphenyltrichloroetane (DDT), and hexachlorobenzene (HCB), which are organochlorine pesticides have been evaluated in vitro by using human lymphocytes as test system. Genetic damage was determined by scoring the frequency of micronuclei (MN) in primary lymphocyte cultures obtained from different donors. The results indicated that, under the experimental conditions used, the DDT metabolite DDE was able to induce significant increases in the frequency of micronucleated cells, which indicate a certain clastogenic and/or aneugenic potential. DDE was tested in the range of 10-80 mM, but the only concentration producing a significant genotoxic effect was 80 mM. On the other hand, HCB was unable to induce a significant increase in the MN frequency in the range of concentrations assayed, from 0.005 to 0.1mM. The selected concentrations of DDE and HCB were chosen according to their toxicity in cell blood cultures; higher concentrations reduced significantly cell proliferation and produced a low frequency of binucleated cells. In conclusion, the results indicate that a genotoxic risk is associated with the exposure to DDE at concentrations 80 mM and above.     

Role of organic acids in enhancing the desorption and uptake of weathered p,p'-DDE by Cucurbita pepo

Experiments were conducted to assess the effect of seven organic acids [succinic, tartaric, malic, malonic, oxalic, citric, ethylene-diaminetetraacetic (EDTA)] over a concentration range of two orders of magnitude (0.001-0.10 M) on the abiotic desorption of weathered p,p'-DDE and the extraction of polyvalent inorganic ions from soil. At 0.05 M all organic acids significantly increased contaminant desorption by 19-80%. Organic acids also increased the aqueous concentration of eight inorganic constituents extracted from soil, with at least a six-fold increase in the release of Al, Fe, Mn, and P at 0.001 M. Zucchini seedlings grown for 28 d in soil containing weathered p,p'-DDE (300 ng/g, dry weight) were periodically amended with distilled water, citric or oxalic acids (0.01 M). Plants receiving water removed 1.7% of the p,p'-DDE from the soil. Seedlings amended with citric or oxalic acids removed 2.1 and 1.9% of the contaminant, respectively, and contained up to 66% more contaminant in the shoot system than unamended vegetation. A second crop of untreated (distilled water) zucchini in the same soil removed more contaminant than the first crop (2.5%), although the addition of organic acids did not further enhance contaminant uptake. The data indicate that the addition of low molecular weight organic acids causes the partial dissolution of the soil structure through the chelation of inorganic structural ions, potentially enhancing bioavailability and having implications for the phytoremediation of persistent organic pollutants in soil.     

Cytogenetic status of human lymphocytes after exposure to low concentrations of p,p'-DDT, and its metabolites (p,p'-DDE, and p,p'-DDD) in vitro

Despite that the use of DDT has been restricted for more than 40 years to malaria affected areas, low doses of this pesticide and its metabolites DDE and DDD can be found in the environment around the world. Although it has been shown that these pollutants induce cell and DNA damage, the mechanisms of their cytogenotoxic activity remains largely unknown. This study looks into their possible genotoxic effects, at doses that can be found in body fluids, on human lymphocytes using the cytokinesis-block micronucleus assay and the comet assay. After exposure for 1, 6, and 24 h compounds p,p′-DDT (0.1 μg mL⁻¹), p,p′-DDE (4.1 μg mL⁻¹), and p,p′-DDD (3.9 μg mL⁻¹) showed increase in DNA damage. The most significant results were observed at exposure period of 24 h where number of micronucleated cells increased from control 2.5 ± 0.71 to 23.5 ± 3.54, 13.5 ± 0.71, and 16.5 ± 6.36 for DDT, DDE, and DDD, respectively. Similar effect was observed using comet test where the percentage of DNA in comets tail increased from control 1.81 ± 0.16 to 17.24 ± 0.55, 11.21 ± 0.56 and 9.28 ± 0.50 for each compound, respectively. At the same time Fpg-comet assay failed to report induction of oxidative DNA damage of these pollutants. Additionally, the type of cell death was determined using diffusion assay and necrosis dominated. Our findings suggest that even at low concentrations, these pesticides could induce cytogenetic damage to human peripheral blood lymphocytes and in that manner have the impact on human health as well.     

Differences in p,p'-DDE bioaccumulation from compost and soil by the plants Cucurbita pepo and Cucurbita maxima and the earthworms Eisenia fetida and Lumbricus terrestris

Two plant species, Cucurbita pepo and Cucurbita maxima, and two earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to soil and compost with equivalent p,p'-DDE contamination. Pollutant bioconcentration was equal in plant roots in both media, but translocation was higher in C. pepo. Bioaccumulation by E. fetida was approximately 6- and 3-fold higher than that by L. terrestris in the soil and compost, respectively. For all species, p,p'-DDE uptake was significantly greater from soil than from compost; 7- to 8-fold higher for plant roots and 3- to 7-fold higher for worms. Abiotic desorption from soil was approximately twice that from the compost. When all the data are normalized for organic-carbon content of the media, the contaminant is more tightly bound by soil than compost. Although the risk associated with p,p'-DDE is higher in soil than compost, important mechanistic differences exist in contaminant binding to organic carbon in the two media.     

The interactions of Cr (VI) concentrations and amendments (biochar and manure) on growth and metal accumulation of two species of Salicornia in contaminated soil

Environmental Science and Pollution Research - Heavy metals are among the most dangerous contaminants in the environment. Organic components and plant species that can accumulate and stabilize...     

Scandium,yttrium, and lanthanide contents in soil from Serbia and their accumulation in the mushroom Macrolepiota procera (Scop.) Singer

The mobility (fractionation) of rare earth elements (REEs) and their possible impacts on ecosystems are still relatively unknown. Soil samples were collected from two sites in central Serbia, an unpolluted mountain region (site 1) and a forest near a city (site 2). In order to investigate REE fractions (acid-soluble/exchangeable, reducible, oxidizable, and residual) in soils, BCR sequential extraction was performed. Additionally, the content of REEs was also determined in stipes and caps of the mushroom Macrolepiota procera, growing in the observed sites. Sc, Y, and lanthanide contents were determined by inductively coupled plasma mass spectrometry (ICP-MS), and results were subjected to multivariate data analysis. Application of pattern recognition technique revealed the existence of two distinguished clusters belonging to different geographical sites and determined by greater levels of Sc, Y, and lanthanides in Go? soil compared to Trstenik soil. Additionally, PCA analysis showed that REEs in soil were concentrated in two groups: the first consisted of elements belonging to light REEs and the second contained heavy REEs. These results suggest that the distribution of REEs in soils could indicate the geographical origin and type of soil. The bioconcentration factors and translocation factors for each REE were also calculated. This study provides baseline data on the rare earth element levels in the wild edible mushroom M. procera, growing in Serbia. In terms of bioconcentration and bioexclusion concept, Sc, Y, and REEs were bioexcluded in M. procera for both studied sites.

     

Heavy metal accumulation and histomorphological alterations in Aphanius fasciatus (Pisces,Cyprinodontidae) from the Gulf of Gabes (Tunisia)

The present study illustrates an analysis of histological changes; cadmium (Cd), copper (Cu) and zinc (Zn) accumulation; and metallothionein (MT) levels in normal and deformed Mediterranean killifish, Aphanius fasciatus (Pisces, Cyprinodontidae), collected from unpolluted (S1) and polluted areas (S2) in the Gulf of Gabes in Tunisia. Metal determination in water and sediment showed that the concentrations were significantly higher (p?Histopathological investigations revealed greater changes in gills, kidney, liver, and bone tissues of fish from the polluted area than those recorded in fish from the reference area. In comparison to normal fish of the polluted area (S2), tissue alterations were more developed in deformed specimens of this site. A possible relationship between metallic pollution, incidence of spinal deformities, and histological changes in A. fasciatus in the polluted site was discussed.     

Trace element (Cd, Cu, Hg, Se, Zn) accumulation and tissue distribution in loggerhead turtles (Caretta caretta) from the Western Mediterranean Sea (southern Italy)

Cadmium (Cd), copper (Cu), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the liver, kidney and muscle of 29 loggerhead turtles, Caretta caretta, from the South Tyrrhenian Sea (Western Mediterranean). No significant differences (p>0.05) were detected between males and females. Trace element concentrations were not influenced by the size of the specimen except Se in the liver, which was negatively correlated with the curved carapace length (p<0.001). Muscles generally displayed the lowest trace element burdens, with the exception of Zn which contained concentrations as high as 176 microgg-1dwt. Kidneys displayed the highest Cd and Se mean concentrations (57.2+/-34.6 and 15.5+/-9.1 microgg-1dwt, respectively), while liver exhibited the highest Cu and Hg levels (37.3+/-8.7 and 1.1+/-1.7 microgg-1dwt, respectively). Whichever tissue is considered, the toxic elements had elevated coefficients of variation (i.e. from 60% to 177%) compared to those of the essential ones (i.e. from 14% to 65%), which is a consequence of homeostatic processes for Cu, Se and Zn. Globally, the concentrations of Hg remained low in all the considered tissues, possibly the result of low trophic level in sea turtles. In contrast, the diet of loggerhead turtles would result in a significant exposure to Cd. Highly significant correlations between Cd and Cu and Zn in the liver and kidney suggest that efficient detoxification processes involving MT occur which prevent Cd toxicity in loggerhead turtles.     

Effects of soil properties on food web accumulation of heavy metals to the wood mouse (Apodemus sylvaticus)

Effects of soil properties on the accumulation of metals to wood mice (Apodemus sylvaticus) were evaluated at two sites with different pH and organic matter content of the soil. pH and organic matter content significantly affected accumulation of Cd, Cu, Pb and Zn in earthworms and vegetation. For Cd, Cu and Zn these effects propagated through the food web to the wood mouse. Soil-to-kidney ratios differed between sites: Cd: 0.15 versus 3.52, Cu: 0.37 versus 1.30 and Zn: 0.33-0.83. This was confirmed in model calculations for Cd and Zn. Results indicate that total soil concentrations may be unsuitable indicators for risks that metals pose to wildlife. Furthermore, environmental managers may, unintentionally, change soil properties while taking specific environmental measures. In this way they may affect risks of metals to wildlife, even without changes in total soil concentrations.     

Wild fire impact on copper, zinc, lead and cadmium distribution in soil and relation with abundance in selected plants of Lamiaceae family from Vidlic Mountain (Serbia)

Fire has been considered as an improving factor in soil quality, but only if it is controlled. Severe wild fire occurred in the summer 2007 on the Vidlic Mountain (Serbia) overspreading a huge area of meadows and forests.Main soil characteristics and content of heavy metals (Cu, Pb, Cd, Zn) in different fractions obtained after sequential extraction of soil from post-fire areas and from fire non disturbed areas were studied. In four plant species of Lamiaceae family (Ajuga genevensis L., Lamium galeobdolon (L.) L., Teucrium chamaedrys L., Acinos alpinus (L.) Moench.), that grow in typical habitats of the mountain, distribution of heavy metals in aerial parts and roots was investigated too.For all samples from post-fire area cation exchange capacity and soil organic matter content are increased while rH is decreased. Fire caused slightly increased bioavailability of the observed metals but more significant rise happened in metal amounts bound to oxides and organics. The plants showed variable behavior. T. chamaedrys collected on the post-fire area contained elevated concentrations of all analyzed metals. A. alpinus showed higher phytoaccumulation for Zn and Cd, while the other two plant species for Pb and Cd in the post-fire areas.     

Specific accumulation of arsenic compounds in green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Ishigaki Island, Japan

Concentrations of total arsenic (As) and individual compounds were determined in green and hawksbill turtles from Ishigaki Island, Japan. In both species, total As concentrations were highest in muscle among the tissues. Arsenobetaine was a major compound in most tissues of both turtles. High concentrations of trimethylarsine oxide were detected in hawksbill turtles. A significant negative correlation between standard carapace length (SCL), an indicator of age, and total As levels in green turtles was found. In contrast, the levels increased with SCL of hawksbill turtles. Shifts in feeding habitats with growth may account for such a growth-dependent accumulation of As. Although concentrations of As in marine sponges, the major food of hawksbill turtles are not high compared to those in algae eaten by green turtles, As concentrations in hawksbill turtles were higher than those in green turtles, indicating that hawksbill turtles may have a specific accumulation mechanism for As.     

Degradation of three phenylurea herbicides (chlortoluron, isoproturon and diuron) by micromycetes isolated from soil

As part of a study conducted on the fate of xenobiotics in the environment, a selection of 100 strains of micromycetes (Ascomycetes, Basidiomycetes and Yeasts) have been cultivated in liquid synthetic medium with 3 phenylurea herbicides: chlortoluron and isoproturon (100mg L-1) and diuron (20mg L-1). While 17 strains depleted isoproturon over 50% only 4 depleted diuron and 2 chlortoluron at the same level. The best results were obtained with Bjerkandera adusta and Oxysporus sp which were the most efficient towards the 3 substrates. After 2 weeks Bjerkandera adusta depleted chlortoluron 98%, diuron 92% and isoproturon 88%.     

Altitude dependence of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in surface soil from Tibetan Plateau, China

Remote mountain areas besides high latitude regions are beginning to receive increased attention in studying the transport and behavior of persistent organic pollutants (POPs). In the present work, surface soil samples were collected from the Tibetan Plateau, the highest plateau in the world which includes the northern slope of Mt. Qomolangma, to investigate the levels and trends of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) along the altitudinal gradient. The average PCB and PBDE concentrations were 185.6 ng kg⁻¹ dry weight (dw) (range 47.1–422.6 ng kg⁻¹ dw) and 11.1 ng kg⁻¹ dw (range 4.3–34.9 ng kg⁻¹ dw), respectively. Regression analysis between the log-transformed TOC-normalized concentrations and the altitudes of the sampling sites showed two opposite trends with regard to altitude dependence: negative relationship with altitude below about 4500 m followed by a positive altitude dependence above this point. Considering minimum anthropogenic activities and very sparse precipitation in the north of Himalayas, the trends above 4500 m imply that the significant altitude dependence of these two groups of POPs were irrespective of pollution sources, but could be predicted by the global distillation effect involving cold condensation in high altitude mountain areas. Increasing levels of heavier congeners were found in higher altitude sites, although the lighter congeners were the main contributors to the total amount, suggesting that less volatile congeners seem to become enriched easier than those more volatile at higher altitudes in this region.     

Occurrence,impact, and elimination of contaminants of emerging concern (CECs) in soil,water, and air streams: advances and challenges in Ibero-American countries

Environmental Science and Pollution Research -     

Sorption kinetics and leachability of heavy metal from the contaminated soil amended with immobilizing agent (humus soil and hydroxyapatite)

Release of heavy metals onto the soil as a result of agricultural and industrial activities may pose a serious threat to the environment. This study investigated the kinetics of sorption of heavy metals on the non-humus soil amended with (1:3) humus soil and 1% hydroxyapatite used for in situ immobilization and leachability of heavy metals from these soils. For this, a batch equilibrium experiment was performed to evaluate metal sorption in the presence of 0.05 M KNO(3) background electrolyte solutions. The Langmuir isotherms applied for sorption studies showed that the amount of metal sorbed on the amended soil decreased in the order of Pb(2+)>Zn(2+)>Cd(2+). The data suggested the possibility of immobilization of Pb due to sorption process and immobilization of Zn and Cd by other processes like co-precipitation and ion exchange. The sorption kinetics data showed the pseudo-second-order reaction kinetics rather than pseudo-first-order kinetics. Leachability study was performed at various pHs (ranging from 3 to 10). Leachability rate was slowest for the Pb(2+) followed by Zn(2+) and Cd(2+). Out of the metal adsorbed on the soil only 6.1-21.6% of Pb, 7.3-39% of Zn and 9.3-44.3% of Cd leached out from the amended soil.     

Distribution and accumulation of elements (As, Cu, Fe, Hg, Mn, and Zn) in tissues of fish species from different trophic levels in the Danube River at the confluence with the Sava River (Serbia)

Pikeperch (Sander lucioperca), European catfish (Silurus glanis), common carp (Cyprinus carpio), and gobies (Neogobius gymnotrachelus, Neogobius melanostomus) were collected from the Danube River (Belgrade section), and samples of liver, muscle, or whole-body composites (in the case of gobies) were analyzed for As, Cu, Fe, Hg, Mn, and Zn with inductively coupled plasma optical spectrometry to find out if there was a correlation between accumulation of these elements in predatory and prey species, as well as in pairs of species with overlapping diets. Concentrations of all analyzed elements were either higher (Cu, Fe, Mn, Zn) in liver than in muscle, or equal (As, Hg), except for Hg in carp, which was higher in muscle. Mercury concentration in liver and muscle of predators (catfish, pikeperch) was significantly (<10^?4) higher than in prey fishes (carp and gobies). The results indicate that Hg concentration was biomagnified through the food chain. Concentrations of As, Fe, and Hg in carp liver and gobies whole-body composite were similar, but carp had significantly (<10^?4) higher values of Zn and Cu in liver. The regression analysis and trendline equations indicate that the concentrations of all tested elements, except for As in liver, and Mn and Fe in muscle, were similar in predatory fish (pikeperch and catfish), on one hand, and in prey fish (carp and gobies), on the other hand. Distinctly high Zn concentration in carp is very common in this species due to its physiology. Concentrations of Hg and Zn were higher than the maximum acceptable concentration due to the high pollution level in this section of the Danube River, accordingly posing a risk for the human consumption of these fish species.     

Characterization of bacteria with phenol-oxidase activity from soil in the La Laguna area (Spain)

A total of 168 bacterial strains isolated from soil of the La Laguna area (Tenerife Island, Spain) were characterized and assayed for phenol-oxidase enzymes (as an indicator of lignolytic capability).     

Trophic transfer of CuO nanoparticles from brine shrimp (Artemia salina) nauplii to convict cichlid (Amatitlania nigrofasciata) larvae: uptake,accumulation and elimination

Environmental Science and Pollution Research - We investigated the trophic transfer potential of CuO-NPs from Artemia salina to Amatitlania nigrofasciata. The Cu uptake was investigated by exposure...     

Effect of arbuscular mycorrhizal fungus (Glomus caledonium) on the accumulation and metabolism of atrazine in maize (Zea mays L.) and atrazine dissipation in soil

Effects of an arbuscular mycorrhizal (AM) fungus (Glomus caledonium) on accumulation and metabolism of atrazine in maize grown in soil contaminated with different concentrations of atrazine were investigated in a series of pot experiments. Roots of mycorrhizal plants accumulated more atrazine than non-mycorrhizal roots. In contrast, atrazine accumulation in shoot decreased in mycorrhizal compared with non-mycorrhizal plants. No atrazine derivatives were detected in the soil, either with or without mycorrhizal colonization. However, atrazine metabolites, deethylatrazine (DEA) and deisopropylatrazine (DIA), were detected in plant roots and the AM colonization enhanced the metabolism. After plant harvest atrazine concentrations decreased markedly in the soils compared to the initial concentrations. The decreases were the most in rhizosphere soil and then near-rhizosphere soil and the least in bulk soil. Mycorrhizal treatment enhanced atrazine dissipation in the near-rhizosphere and bulk soils irrespective of atrazine application rates.