Showing papers in "Archives of Environmental Contamination and Toxicology in 2010"
TL;DR: In this paper, the authors presented rodenticide residue information on the livers from 164 strigiformes including barn owls, barred owls and great horned owls collected from the province of British Columbia and the Yukon Territory, Canada.
Abstract: Anticoagulant rodenticides are widely used to control rodent infestations. Previous studies have shown that nontarget organisms, such as birds, are at risk for both primary and secondary poisoning. This paper presents rodenticide residue information on the livers from 164 strigiformes which included barn owls (Tyto alba), barred owls (Strix varia), and great horned owls (Bubo virginianus), collected from 1988 to 2003 in the province of British Columbia and the Yukon Territory, Canada. Livers were analyzed for brodifacoum, bromadiolone, chlorophacinone, diphacinone, difethialone, and warfarin. Our results show that, of the 164 owl livers analyzed, 70% had residues of at least one rodenticide, and of these 41% had more than one rodenticide detected. Of the three species of owls examined, barred owls were most frequently exposed (92%, n = 23); brodifacoum and bromadiolone were most often detected, with liver concentrations ranging from 0.001 to 0.927 mg/kg brodifacoum, and 0.002 to 1.012 mg/kg bromadiolone. Six of the owls (three barred owls, two barn owls, and one great horned owl) were diagnosed as having died from anticoagulant poisoning; all six owls had brodifacoum residues in the liver.
150 citations
TL;DR: The results suggest that atrazine impairs reproductive function and elicits a depletion of the antioxidant defense system in the testis and epididymis, indicating the induction of oxidative stress.
Abstract: To study the effects of atrazine on reproductive functions and testicular and epididymal antioxidant defense, rats were exposed to 0, 120, or 200 mg/kg body weight atrazine orally for 7 and 16 days. Animals exposed to the high-dose atrazine had their body weights, feed intake, and reproductive organs weights significantly reduced, whereas testicular weights remain unaffected independent of the dose used. In comparison to control, glutathione (GSH) and glutathione-S-transferase (GST) activities were elevated in the high-dose group, whereas the activity of superoxide dismutase (SOD), catalase (CAT); ascorbate (AA), and malondialdehyde (MDA) levels and hydrogen peroxide production were unchanged in the testis during the 7-day-exposure protocol. When atrazine treatment was increased to 16 days, GSH levels remained unchanged, but lipid peroxidation levels were significantly increased in both the testes and epididymides. This corresponded to the significant diminution in the activities of GST and SOD. CAT activities were unaffected in the testes and then dropped in the epididymides. γ-Glutamyl transferase (γ-GT) activities increased during both studies, whereas AA levels remained unaffected (p < 0.05). Atrazine exposure has a dose-dependent adverse effect on the testicular and epididymal sperm numbers, motility, viability, morphology, and daily sperm production. Although the testes of the atrazine-treated animals appear normal, few tubules had mild degeneration with the presence of defoliated cells. Likewise, no perceptible morphological changes were observed in the epididymis. The results suggest that atrazine impairs reproductive function and elicits a depletion of the antioxidant defense system in the testis and epididymis, indicating the induction of oxidative stress.
135 citations
TL;DR: Stepwise multiple regression analysis showed that human bioaccessibility was also affected by some physico-chemical soil parameters (i.e. total nitrogen, carbonates, clay contents and pH).
Abstract: Ingestion of dust or soil particles could pose a potential health risk due to long-term metal trace element (MTE) exposure. Twenty-seven urban topsoil samples (kitchen garden and lawn) were collected and analyzed for Cd, Pb and Zn using the unified Bioaccessibility Research Group of Europe (BARGE) method (UBM) test to estimate the human bioaccessibility of these elements. The quantities of Cd, Pb and Zn extracted from soils indicated, on average, 68, 62 and 47% bioaccessibility, respectively, in the gastric phase and 31, 32 and 23% bioaccessibility, respectively, in the gastro-intestinal phase. Significant positive correlations were observed between concentrations extracted with UBM and total MTE contents. Stepwise multiple regression analysis showed that human bioaccessibility was also affected by some physico-chemical soil parameters (i.e. total nitrogen, carbonates, clay contents and pH). The unified test presents some valuable data for risk assessment. Indeed, the incorporation of oral bioaccessible concentrations into risk estimations could give more realistic information for health risk assessment.
128 citations
TL;DR: A comparison of the extent of DNA damage among the tissues showed the sensitivity of gill tissue to malathion, which exhibited a concentration-dependent increase in DNA damage up to day 3, followed by a nonlinear decrease with the duration of exposure.
Abstract: Malathion [S-(1,2-dicarboethoxyethyl) O, O-dimethyl phosphorodithioate] is a widely used organophosphorus insecticide throughout the world. However, limited efforts have made to study its genotoxic effect in different fish tissues. The present investigation was aimed to assess the genotoxic potential of the pesticide to the freshwater teleost fish Channa punctatus at sublethal concentrations using the micronucleus test and comet assay. Initially, the 96-h LC50 value of commercial-grade malathion (50% EC) was determined as 5.93 ppm in a semistatic system. Based on LC50, three test concentrations (viz. sublethal I, sublethal II, and sublethal III) were determined to be 1.48, 0.74, and 0.59 ppm, respectively, and the fish specimens were exposed to these concentrations. Tissue samplings were done on days 0, 1, 3, 7, 15, 22 and 29 of malathion exposure for assessment of the induction of micronuclei (MN) frequency and DNA damage. The MN formation in the peripheral blood cells was found to be significantly higher (p < 0.05) in the treated specimens at all sampling intervals compared to the control. The MN frequency reached maximum on days 3 and 7 at sublethal I and II concentrations, respectively, followed by a nonlinear decline with the progression of the experiment. Similarly, significant effects (p < 0.05) of both concentration and time of exposure were observed on DNA damage in the gill, kidney, and lymphocytes. All of the tissues exhibited a concentration-dependent increase in DNA damage up to day 3, followed by a nonlinear decrease with the duration of exposure. A comparison of the extent of DNA damage among the tissues showed the sensitivity of gill tissue to malathion.
127 citations
TL;DR: It is suggested that long-term exposure to Roundup causes metabolic disruption in Leporinus obtusidens, a teleost fish exposed to different concentrations of Roundup, a commercial herbicide formulation containing glyphosate for 90 days.
Abstract: The teleost fish Leporinus obtusidens (piava) was exposed to different concentrations of Roundup, a commercial herbicide formulation containing glyphosate (0, 1, or 5 mg L−1), for 90 days. Acetylcholinesterase (AChE) activity was verified in brain and muscle. Hepatic and muscular metabolic parameters as well as some hematological parameters were determined. The results showed that brain AChE activity was significantly decreased in fish exposed to 5 mg L−1 Roundup, whereas muscular AChE activity was not altered. Both Roundup concentrations significantly decreased liver glycogen without altering the muscle glycogen content. Hepatic glucose levels were reduced only in fish exposed to 5 mg L−1 Roundup. Lactate levels in the liver and muscle significantly increased in fish exposed to both Roundup concentrations. Hepatic protein content remained constant at 1 mg L−1 but increased at 5 mg L−1 Roundup. In the muscle however, protein content decreased with increasing exposure concentration. The herbicide exposure produced a decrease in hematological parameters at both concentrations tested. The majority of observed effects occur at environmental relevant concentrations, and in summary, the results show that Roundup affects brain AChE activity as well as metabolic and hematologic parameters of piavas. Thus, we can suggest that long-term exposure to Roundup causes metabolic disruption in Leporinus obtusidens.
123 citations
TL;DR: Water samples collected from 15 locations in 13 provinces and municipalities were analyzed for the presence of perchlorate and other inorganic anions that commonly occur in water and the disinfection byproducts, bromate, chlorate, and chlorite were determined by high-performance liquid chromatography interfaced with tandem mass spectrometry.
Abstract: Perchlorate is a potent thyroid hormone–disrupting compound. Drinking water is one of the major sources of human exposure to perchlorate. Little is known about the occurrence of perchlorate in waters from China. In this study, water samples (n = 300) collected from 15 locations in 13 provinces and municipalities were analyzed for the presence of perchlorate. In addition, other inorganic anions that commonly occur in water—iodide, bromide, and nitrate—and the disinfection byproducts, bromate, chlorate, and chlorite were determined by high-performance liquid chromatography interfaced with tandem mass spectrometry. Perchlorate was detected in 86% of the samples analyzed, at concentrations ranging from <0.02 to 54.4 μg l−1 (mean ± SD 2.20 ± 6.39 μg l−1; median 0.62 μg l−1). Mean concentrations of perchlorate in tap water, groundwater, surface waters, and bottled water were 2.46, 3.04, 2.82, and 0.22 μg l−1, respectively. Significant positive correlations were found between the concentrations of perchlorate and nitrate, perchlorate and chlorate, bromide and iodide, and nitrate and iodide.
117 citations
TL;DR: Concentrations of TCS and TCC in water and sediment were greater in the Vernon River, followed by the Savannah River and the Ogeechee River.
Abstract: Triclosan (TCS) and triclocarbon (TCC) are bactericides used in various consumer and personal-care products. Recent studies have revealed considerable levels of these bactericides in wastewater, aquatic wildlife, and human samples. Consequently, in this study we measured TCS and TCC in influent and effluent, sludge, and pond water/sediment samples from four wastewater treatment plants (WWTPs) and three major rivers in Savannah, Georgia (USA). Among these treatment plants, the Wilshire plant showed elevated concentrations of TCS (influent, 86,161; effluent, 5370 ng/L), whereas TCC was greater in the Georgetown plant (influent, 36,221) and the Wilshire plant effluent (3045 ng/L). Clearance of TCS and TCC were 95 and 92%, respectively, in the President Street plant, 94 and 85%, respectively, in the Wilshire plant, 99 and 80%, respectively, in the Travis Field plant, and 99 and 99%, respectively, in the Georgetown plant. Based on the mass flow estimate, 138 g/day of TCS and 214 g/day TCC are released into the Savannah River from the President Street, Travis Field, and Wilshire plants and 1.60 g/day TCS and 1.64 g/day TCC are released to the Ogeechee River from the Georgetown plant. Based on the sludge data, the loading estimate can be calculated that 32 and 0.004 g/day TCS and 53 and 0.01 g/day TCC (nonincinerated and incinerated, respectively) are deposited in landfill from the President Street plant alone, whereas 4.6, 26, and 6.8 g/day TCS and 3.8, 23, and 5.9 g/day TCC (wet sludge) were produced and dumped in landfill from the rest of the WWTPs. Incineration of wet sludge can eliminate 99.99% of TCS and TCC. Concentrations of TCS and TCC in water and sediment were greater in the Vernon River, followed by the Savannah River and the Ogeechee River.
109 citations
TL;DR: Biochemical parameters in fish blood can be used as an indicator of heavy-metal toxicity in fish exposed to metals individually or in combination.
Abstract: Changes in serum biochemistry in response to single- and combined-metal exposure were studied in a freshwater fish Oreochromis niloticus. Fish were exposed to 5.0 mg/L Zn, 1.0 mg/L Cd, and 5.0 mg/L Zn+1.0 mg/L Cd mixtures for 7 and 14 days to determine levels of biochemical parameters and metals in blood serum. The individual and combined effects of metals caused an increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and in levels of albumin, transferrin, ceruloplasmin, cortisol, glucose, and total protein, whereas they caused a decrease in cholesterol levels. At both exposure periods, increased ALT activity of fish exposed to Cd was higher compared with the Zn and Zn+Cd groups, respectively. The decreased cholesterol level was higher in the Cd alone, and for Cd in combination with Zn, than in Zn alone at 14 days. Zn or Cd levels increased in the blood serum of fish exposed to metals individually or in combination. When fish were exposed to the mixtures of Zn+Cd, concentrations of these metals in their serum were lower than in fish exposed to individual metals. One metal blocks or even antagonizes the gill epithelium absorption of the other and thereby limits the distribution of the metal in blood. The results indicate that biochemical parameters in fish blood can be used as an indicator of heavy-metal toxicity.
104 citations
TL;DR: Female birds displayed higher concentrations in liver and feathers than did male birds, and Cd accumulation increased with age, whereas Pb levels in feathers were lower in adult birds in connection with moulting, as was influenced by sex.
Abstract: Trace elements (mercury [Hg], cadmium [Cd], copper [Cu], zinc [Zn], lead [Pb], aluminium [Al], nickel [Ni], arsenic [As], and selenium [Se]) were investigated using inductively coupled plasma-mass spectrometry in liver, kidney, muscle, and feather of aquatic birds wintering or inhabiting the wetlands situated on the Southwest Atlantic coast of France. A majority of greylag geese, red knots, and grey plovers were collected from among hunter-shot animals. The relation between residue concentrations, age (juvenile vs. adult), and sex was investigated. Trace elements were lower than threshold levels of toxicity, except for Pb. Greylag geese sampled could be considered Pb-poisoned. These consequential levels of contamination could be the result of the ingestion of Pb-shot from ammunition used in hunting areas they crossed during migration. Cd accumulation increased with age, whereas Pb levels in feathers were lower in adult birds in connection with moulting. As was influenced by sex. Female birds displayed higher concentrations in liver and feathers than did male birds.
98 citations
TL;DR: Calculations indicate that dust ingestion by children account for, on average, 15–18% of the tolerable daily intake proposed by the World Health Organization (WHO).
Abstract: Organotin compounds (OTs) have been used in a wide variety of consumer products. Despite this, very few studies have reported the occurrence of OTs in house dust or exposure of humans to OTs through the ingestion of house dust. In the present study, concentrations of monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monooctyltin (MOT), dioctyltin (DOT), trioctyltin (TOT), diphenyltin (DPT), and triphenyltin (TPT) were measured in dust collected from 24 houses in Albany, New York, USA. In addition, a few household products, such as wallpaper, floor tile, vinyl window blinds, and handbags were analyzed for the presence of OTs. Organotins were found in all of the house dust samples analyzed, and total OT concentrations varied from 390 to 28,000 ng/g (mean ± SD: 6700 ± 6200; median: 5000). Relative abundances of OTs in house dust were in the order MBT >MOT >DBT >DOT >TBT. TOT, DPT, and TPT were not found in any of the samples at concentrations above their corresponding detection limits. MBT accounted for, on average, 51% of the total OT concentrations. Mean concentrations of total OTs found in house dust samples from our study were two to five times higher than concentrations that have been reported for dust samples from several European countries. Calculations indicate that dust ingestion by children account for, on average, 15–18% of the tolerable daily intake proposed by the World Health Organization (WHO). The estimated rates of OT intake by children via dust ingestion were, on average, eightfold higher than the intake rates calculated for adults. Household products, such as wallpaper, contained total OT concentrations as high as 780,000 ng/g.
89 citations
TL;DR: The sediment and the herbivorous fish O. niloticus and the crayfish had much higher biota-sediment accumulation factors (BSAF) for Cu, Zn, and Cd relative to Cr, Co, Pb, and Ni.
Abstract: We measured the level of heavy metal accumulation in lake sediments, herbivorous (Oreochromis niloticus) and carnivorous (Serranochromis thumbergi) fish, and crayfish (Cherax quadricarinatus) from Lake Itezhi-tezhi (ITT) and Lake Kariba. We used atomic absorption spectrophotometry to quantify the levels of seven heavy metals (Cr, Co, Cu, Zn, Cd, Pb, and Ni). The sediment and the herbivorous fish O. niloticus accumulated a very high concentration of Cu in Lake ITT, most likely due to the discharge of Cu waste from a mining area 450 km upstream. The aquatic species we sampled in Lake Kariba had higher concentrations of Cr, Ni, and Pb relative to those in Lake ITT. This is most likely due to anthropogenic activities, such as the use of leaded petrol and antifouling agents in marine paints. Interestingly, we observed a negative correlation between the coefficient of condition (K) and Ni concentration in the crayfish hepatopancreas. Both O. niloticus and the crayfish had much higher biota-sediment accumulation factors (BSAF) for Cu, Zn, and Cd relative to Cr, Co, Pb, and Ni. The rank of BSAF values for O. niloticus (Cu > Cd > Zn) and C. quadricarinatus (Zn > Cd > Cu) differed from the expected ranks based on the general order of affinity of metals (Cd >> Zn > Cu).
TL;DR: Because increased levels of heavy metals and pesticide residues found in plant products could pose a risk to consumers’ health, their continual monitoring before product distribution to city markets is indispensable.
Abstract: This study was aimed to assess the levels of selected heavy metals and pesticides in soil and plant products from an agricultural area of Belgrade, Serbia and to indicate possible sources and risks of contamination. Soil, vegetable, and fruit samples from the most important agricultural city areas were collected from July to November of 2006. Metal contents were determined by atomic absorption spectrometry, whereas pesticide residues were analyzed by gas chromatography-mass spectrometry after extraction performed using solid-phase microextraction technique. Soil characterization based on the determination of selected physical and chemical properties revealed heterogeneous soils belonging to different soil groups. The concentrations of lead, cadmium, copper, and zinc in soil samples do not exceed the limits established by national and international regulations. Residues of the herbicide atrazine were detected in three soil samples, with levels lower than the relevant limit. The presence of other herbicides, namely prometryn, chloridazon, acetochlor, flurochloridone, and napropamide, was registered in some soil samples as well. Among the insecticides investigated in the soil, fenitrothion and chlorpyrifos were the only ones detected. In most of the investigated vegetable samples from the Obrenovac area, Pb and Cd contents are higher in comparison with the maximum levels, indicating the emission of coal combustion products from local thermal power plants as a possible source of contamination. Residue levels of some herbicides and insecticides (metribuzin, trifluralin, pendimethalin, bifenthrin, chlorpyrifos, and cypermethrin) determined in tomato, pepper, potato, and onion samples from Slanci, Ovca, and Obrenovac areas are even several times higher than the maximum residue levels. Inappropriate use of these plant protection products is considered to be the most probable reason of contamination. Because increased levels of heavy metals and pesticide residues found in plant products could pose a risk to consumers' health, their continual monitoring before product distribution to city markets is indispensable.
TL;DR: It is suggested that road salt contributes to the degradation of stormwater pond habitat quality for amphibian reproduction and that future research should focus on understanding interactions among road salts and other pollutants and stressors characteristic of urban environments.
Abstract: Stormwater ponds are common features of modern stormwater management practices. Stormwater ponds often retain standing water for extended periods of time, develop vegetative characteristics similar to natural wetlands, and attract wildlife. However, because stormwater ponds are designed to capture pollutants, wildlife that utilize ponds might be exposed to pollutants and suffer toxicological effects. To investigate the toxicity of stormwater pond sediments to Hyla versicolor, an anuran commonly found using retention ponds for breeding, we exposed embryos and larvae to sediments in laboratory microcosms. Exposure to pond sediments reduced survival of embryos by approximately 50% but did not affect larval survival. Larvae exposed to stormwater pond sediment developed significantly faster (x = 39 days compared to 42 days; p = 0.005) and were significantly larger at metamorphosis (x = 0.49 g compared to 0.36 g; p < 0.001) than controls that were exposed to clean sand. Substantial amounts (712-2215 mg/l) of chloride leached from pond sediments into the water column of treatment microcosms; subsequently, survival of embryos was negatively correlated (r (2) = 0.50; p < 0.001) with water conductivity during development. Our results, along with the limited number of other toxicological studies of stormwater ponds, suggest that road salt contributes to the degradation of stormwater pond habitat quality for amphibian reproduction and that future research should focus on understanding interactions among road salts and other pollutants and stressors characteristic of urban environments.
TL;DR: A good correlation existed between the benzo[a]pyrene level and the total PAH concentrations, making this compound a potential molecular marker for PAH pollution.
Abstract: The distribution and potential sources of 16 polycyclic aromatic hydrocarbons (PAHs) in sediment cores (<63 microm particle size) of the Sundarban mangrove wetland, northeastern coast of Bay of Bengal (India), were investigated by gas chromatography coupled to mass spectrometry. The total concentrations of 16 PAHs ( summation operator(16)PAHs) ranged from 132 to 2938 ng/g, with a mean of 634 ng/g, and the sum of 10 out of 16 priority PAHs ( summation operator(10)PAH) varied from 123 to 2441 ng/g, with a mean of 555 ng/g, and the 5 carcinogenic PAHs (benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, and dibenz[a,h]anthracene) accounted for 68-73% of the priority PAHs. Maximum concentrations of the sediment core were obtained at subsoil depth of 12-16 cm. The prevalence of four to six aromatic ring PAHs and cross-plots of specific isomer ratios such as phenanthrene/anthracene, fluoranthene/pyrene, and methylphenanthrenes/phenanthrene suggested the predominance of wood and coal combustion sources, the atmospheric deposition, and surface runoff to be the major transport pathways. A good correlation existed between the benzo[a]pyrene level and the total PAH concentrations, making this compound a potential molecular marker for PAH pollution. Total TEQ (S) (carc) values calculated for samples varied from 6.95 ng/g TEQ (S) (carc) to 119 ng/g TEQ (S) (carc) , with an average of 59 ng/g dry weight TEQ (S) (carc) . The baseline data can be used for regular monitoring, considering the industrial and agricultural growth around this coastal environment.
TL;DR: This study suggests that upregulation of the antioxidant enzyme activities, elevation of LPO, and the reduction in GSH content is related to oxidative stress in this species that could be useful as biomarkers for the evaluation of contaminated terrestrial ecosystems.
Abstract: The in vivo toxic effects of sublethal treatment of 40 and 80% of 48-h LD50 of topically applied trace metals [copper (Cu), lead (Pb), and zinc (Zn)] on oxidative stress biomarkers in the digestive gland of Theba pisana were examined. Oxidative individual perturbations were assessed by measuring nonenzymatic (glutathione; GSH) and enzymatic (catalase, CAT; glutathione peroxidase, GPx; and glutathione-S-transferase, GST) antioxidants in digestive gland of the snails. Lipid peroxidation (LPO) was also evaluated as a marker of cell damage. The results indicated that the copper ion was the most potent metal against this snail, followed by zinc and lead, for which the corresponding LD50 values were 37.88, 261.72, and 652.55 μg/snail, respectively. The no-observed effect concentration (NOEC) values for Cu, Zn, and Pb were 10, 50, and 500 μg/snail, respectively, and the corresponding lowest-observed effect concentration (LOEC) values were 50, 100, and 1000 μg/snail. All trace metals resulted in a significant increase in the level of LPO, whereas a significant decline in the content of GSH was observed when compared with untreated controls. Treatment with both sublethal doses of the metals caused significant increase in CAT activity, except in the case of 40% LD50 Zn and 80% LD50 Cu, which exhibited no alteration in CAT when compared to control animals. GPx was significantly increased in snails exposed to 40% LD50 Cu and Pb as well as 80% LD50 Cu. However, an opposite effect was observed in snails exposed to 80% LD50 Pb and in either 40 or 80% LD50 of Zn-intoxicated animals. Treatment with Pb at two sublethal doses significantly increased GST activity, whereas treatment the animal with Cu caused significant inhibition in this enzyme. Snails exposed to 40% LD50 Zn showed significant enhancement of GST, whereas snails exposed to 80% LD50 showed ignificantly reduced GST activity. Biphasic responses were observed for CAT, GPx, and GST activities in snails exposed to Cu, Pb, and Zn, respectively. This study suggests that upregulation of the antioxidant enzyme activities, elevation of LPO, and the reduction in GSH content is related to oxidative stress in this species that could be useful as biomarkers for the evaluation of contaminated terrestrial ecosystems.
TL;DR: The level and patterns of imbalance evolved by a single dose of 2 μg/L deltamethrin on the lipid peroxidation and the antioxidant defense system of Carassius auratus gibelio liver and intestine and the recovery dynamics of these parameters during a 14-day post-exposure period were assessed.
Abstract: Pyrethroids, such as deltamethrin, are toxic substances that lead to generation of reactive oxygen species, which harm living organisms. We assessed the level and patterns of imbalance evolved by a single dose of 2 μg/L deltamethrin on the lipid peroxidation (LPO) and the antioxidant defense system of Carassius auratus gibelio liver and intestine, and monitored the recovery dynamics of these parameters during a 14-day post-exposure period. LPO and antioxidative defense mechanisms displayed different responses in the investigated tissues. Sudden increase of LPO in the liver, persisting at this elevated level throughout the test period, was observed on the third day post-exposure, while in the intestine significant enhancement of this parameter was recorded from the seventh day. Reduced glutathione (GSH) showed a transient increase in the liver, and was depleted in the intestine by the second day of exposure, with signs of recovery by the end of the experimental tenure. In the liver of fish a temporary inhibition of superoxide dismutase (SOD) and catalase (CAT) activity, and activation of glutathione peroxidase (GPX), glutathione transferase (GST), and glutathione reductase (GR) enzymes was observed, with maximum thresholds recorded on the third and second days, respectively. In the intestine a relevant increase in CAT and GST activity up to the second day and almost complete recovery by the end of the experiment was recorded, while for GR a continuous enhancement was apparent.
TL;DR: Results suggest that W. arrhiza is a promising bioindicator of heavy-metal toxicity, and enzymatic and nonenzymatic antioxidant mechanisms activated in W.arrhiza plants exposed to Cd and Pb, especially at 10 μM.
Abstract: The present study investigated the biochemical response of aquatic plant Wolffia arrhiza (Lemnaceae) treated with lead (Pb) and cadmium (Cd) at a range of concentrations from 1 to 1000 μM. W. arrhiza has been identified as good scavenger of heavy metals from aqueous solution. Pb and Cd accumulation was found to be increased in a concentration- and duration-dependent manner. However, the highest biosorption of heavy metals was found in plants exposed to low levels (10 μM) of Cd and Pb in the nutrient medium. In observing the response to heavy-metal stress, we noted inhibited plant growth and decreased photosynthetic pigments, monosaccharides, and proteins. In addition, Cd was found to be more toxic to plants than Pb. Heavy metals also induced oxidative damage as evidenced by increased lipid peroxidation and hydrogen peroxide levels. In contrast, the deleterious effects resulting from the cellular oxidative state can be alleviated by enzymatic (catalase, ascorbate peroxidase, nicotinamide dinucleotide [NADH] peroxidase) and nonenzymatic (ascorbate, glutathione) antioxidant mechanisms activated in W. arrhiza plants exposed to Cd and Pb, especially at 10 μM. These results suggest that W. arrhiza is a promising bioindicator of heavy-metal toxicity.
TL;DR: Correlations between log lipid-normalized concentrations of HCHs and DDTs and trophic levels (TLs) based on analysis of stable isotopes of nitrogen confirmed that persistent organic pollutants were magnified in the Baiyangdian Lake food web.
Abstract: Organochlorine pesticides (OCPs), such as hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), are ubiquitous anthropogenic environmental contaminants. They are persistent, broad-spectrum toxicants that accumulate in the food web with potential risks to the ecosystem and human health. HCHs were the predominant contaminants in Baiyangdian Lake, North China. Concentrations of HCHs and DDTs ranged from 58 to 563 ng/g lipid weight (lw) and 21 to 401 ng/g lw, respectively, for aquatic biota samples. The highest levels of HCHs and DDTs were observed in muscles of yellow catfish. The mean concentrations of OCPs were 4.6 ng/L for water, 95 ng/g dry weight (dw) for aquatic plants, and 14 ng/g dw for sediments. Among the isomers and metabolites, α-HCH and p,p′-1,1-di(p-chlorophenyl)-2,2-dichloroethylene (p,p′-DDE) were the predominant congeners in biota samples. Correlations between log lipid-normalized concentrations of HCHs and DDTs and trophic levels (TLs) based on analysis of stable isotopes of nitrogen confirmed that persistent organic pollutants were magnified in the Baiyangdian Lake food web. Significant positive relationships were found for α-HCH and p,p′-DDT and their trophic magnification factors, which were 1.6 and 1.7, respectively. These results provide evidence of biomagnification of persistent organic pollutants (POPs) in freshwater food webs.
TL;DR: The data suggest that the well-established protective effect of Zn and Se against Cd-induced toxicity passes through non-MT gene expression mechanisms, being more dependent on the oxidative stress status of the cell.
Abstract: Cadmium (Cd), one of the most widely distributed heavy metals, is highly toxic to humans and animals. It is well known that zinc (Zn) and selenium (Se) administration reduce the Cd-induced toxicity and that metallothioneins can have a protective effect to mitigate Cd toxicity in biological systems. In this study we report the expression analysis of the two metallothioneines gene classes MT-1 and MT-2 as well as the total metalloprotein content in the liver of rats exposed to Cd (200 ppm), Cd + Zn (200 ppm + 500 ppm), Cd + Se (200 ppm + 0.1 ppm) or Cd + Zn + Se (200 ppm + 500 ppm + 0.1 ppm) in their drinking water for 35 days. Metals accumulation was quantified in rat liver. Cd decreased significantly the hepatic concentrations of Se and increased those of Zn. The treatment of Cd-exposed rats with Se alone or combined with Zn reversed the Cd-induced depletion of Se concentrations in the liver. However, Zn or Zn + Se administration significantly increased the liver Cd uptake and had no effect on the Cd-induced increase in hepatic concentrations of Zn. The molecular assay showed a decreasing trend of MT-1 relative gene expression levels in animals supplemented with Zn (6.87-fold), Se (3.58-fold), and their combination (1.69-fold) when compared to Cd-treated animals (16.22-fold). Upregulation of the MT-2 expression were recorded in all conditions, although fold induction levels were less pronounced than MT-1 expressions. Our data suggest that the well-established protective effect of Zn and Se against Cd-induced toxicity passes through non-MT gene expression mechanisms, being more dependent on the oxidative stress status of the cell.
TL;DR: The toxic effects of the tested compounds on activity of ATPase indicated that spinosad caused the highest inhibitory effect in different organs compared with oxymatrine at the same concentrations, and high inhibition was found with ATPase isolated from the head.
Abstract: Under laboratory conditions, the comparative effects of two insect growth regulators, chlorfluazuron and oxymatrine, and spinosad as a biopesticide were examined on honey bee workers (Apis
mellifera L.). Separate groups of bees were left for 24 h to feed on 50% sucrose solution containing different concentrations of the tested insecticides, and the lethal concentration that caused 50% mortality (LC50) was estimated. The inhibitory effects on acetylcholinesterase (AChE) and adenosine triphosphatase (ATPase) activities as biochemical indicators were determined in vivo after 24 h in head, thorax, and abdomen of surviving bees obtained after treatments with a view to explore the possible mode of action of these compounds. Results indicated that exposure to spinosad showed toxicity to honey bees with LC50 value of 7.34 mg L−1, followed by oxymatrine (LC50 = 10.68 mg L−1), while chlorfluazuron was the least acutely toxic of the tested compounds (LC50 = 2,526 mg L−1). Oxymatrine and spinosad at the same tested concentrations (2.5, 5, 10, and 20 mg L−1) significantly inhibited AChE activity in different organs of honey bee workers, and high inhibition percentage was obtained with the enzyme isolated from the thorax. However, chlorfluazuron at 400, 1,000, 2,000, and 4,000 mg L−1 caused high inhibition of AChE activity isolated from the head (39.65% and 44.22% at 2,000 and 4,000 mg L−1, respectively). In addition, the toxic effects of the tested compounds on activity of ATPase indicated that spinosad caused the highest inhibitory effect in different organs compared with oxymatrine at the same concentrations, and high inhibition was found with ATPase isolated from the head. The results also indicated that oxymatrine was the least active compound for inhibition of AChE and ATPase.
TL;DR: Among the 8 age groups investigated, children age <2 years and 3 to 6 years had high intakes of PAHs compared with adult groups, and the estimated excess cancer risk values from seafood consumption for the general population, for men, and for women slightly exceeded the guideline value for potential cancer risk.
Abstract: Concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in 26 types of seafood commonly consumed by the general Korean population. The concentrations of total and carcinogenic PAHs ranged from 12.3 to 243 ng/g dry weight and from 0.21 to 18.4 ng/g dry weight, respectively, similar to those reported in other countries. The lower-molecular-weight aromatics, such as naphthalene, phenanthrene, and fluorine, predominated in the seafood samples. Estimated intakes of PAHs by seafood consumption for the general population, for men, and for women were 15.3, 16.7, and 13.8 ng/kg body weight/d, respectively. Squid, mackerel, and yellow croaker contributed to the highest intakes of PAHs. Among the 8 age groups investigated, children age <2 years and 3 to 6 years had high intakes of PAHs compared with adult groups. Dioxin toxic equivalents (TEQs) of PAHs were calculated using a TEQ proposed in the literature, and the intake was estimated to be 0.91 pg TEQ/kg body weight/d, which indicates that PAHs contributed the most (43%) to total TEQ intake. The estimated excess cancer risk values from seafood consumption for the general population (2.85 x 10(-6)), for men (2.93 x 10(-6)), and for women (2.68 x 10(-6)) slightly exceeded the guideline value (1.0 x 10(-6)) for potential cancer risk.
TL;DR: Levels of Hg in fish muscle and liver were the same and markedly higher than in gills, however, in muscle, the average concentrations of each metal were below their maximum limits, determined either by Slovenian legislation or by the Food and Agriculture Organization.
Abstract: The concentration of metals (Pb, Cd, Zn, Hg) in different ecosystem components (lake water, sediment, plankton, macrophytes, and fish tissues) has been determined in Velenjsko jezero, an artificial lake resulting from mining activity. The risk to humans from consuming fish has been evaluated from the heavy metal load of fish muscle tissue. Heavy metals are transferred through the food chain at different levels, and Hg is found to be the element of the highest ecotoxicological concern. Although both sediment and plankton contain relatively low concentrations of Hg, this element accumulates in high levels in fish, especially in the benthivorous species Abramis bramadanubii and predator species Perca fluviatilis. Moreover, Hg appears to be very mobile in the fish organism. Whereas the other metals remained mostly in liver (Cd) or gills (Zn, Pb), levels of Hg in fish muscle and liver were the same and markedly higher than in gills. However, in muscle, the average concentrations of each metal were below their maximum limits, determined either by Slovenian legislation or by the Food and Agriculture Organization.
TL;DR: A substantial increase in total urinary As metabolites for subjects consuming seafood from day 1, which recovered to control level at day 10, was attributed to the increase in DMA, which is a more harmful metabolite than organoarsenics.
Abstract: Arsenic (As) is a known human carcinogen and widely distributed in the environment. The main route of As exposure in the general population is through food and drinking water. Seafood harvested in Korea contains high-level organoarsenics such as arsenobetaine, arsenocholine, and arsenosugars, which are much less harmful than inorganic arsenics. However, for those who eat large amounts of seafood it is important to understand whether seafood consumption affects urinary levels of inorganic As metabolites such as arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). In this study we investigated urinary As metabolites (inorganic As, MMA[V], DMA[V]) and some biological indexes such as AST, GSH, GPX, lipid peroxidation, and uric acid in volunteer study subjects (seven males and nine females). Total urinary As metabolites were analyzed by the hydride generation method, followed by arsenic speciation using HPLC with ICP-mass spectrometry. Study subjects refrained from eating seafood for 3 days prior to the first urine collection and then ingested seafood daily for 6 consecutive days. The first voided urine of the morning was collected from each subject the first day of the consecutive 6 days of seafood ingestion but prior to the first seafood meal. The first voided urine of the morning was also collected on days 1, 2, 3, 4, 5, 6, 7, 10, and 14 after seafood ingestion. The daily mean intake of total As was 6.98 mg, comprised of 4.71 mg of seaweed (67%), 1.74 mg of flat fish (25%), and 0.53 mg of conch (8%). We observed a substantial increase in total urinary As metabolites for subjects consuming seafood from day 1, which recovered to control level at day 10. The increase in total urinary As metabolites was attributed to the increase in DMA, which is a more harmful metabolite than organoarsenics. However, no significant changes in response biological indexes were observed. These results suggest that it is necessary to evaluate As metabolism when assessing the exposure to inorganic As and potential chronic health effects of seafood consumption in Korea.
TL;DR: The higher elimination rate of PFOA through excretion indicated its lower accumulation in rats, thus inducing possible lower toxicities compared to PFOS, and the excretion rates of both PFCs increased with increasing exposure doses.
Abstract: Perfluorinated compounds (PFCs), a class of synthetic surfactants that are widely used, have become global environmental contaminants because of their high persistence and bioaccumulation. An increasing number of studies have described the pharmacokinetics of PFCs following in vivo exposure, however, few papers have focused on the excretion of these compounds during a period of consecutive exposure. In this study, the excretions of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in male Sprague-Dawley rats gavaged consecutively for 28 days were investigated and compared. The faster elimination rate in urine compared to feces indicated that urinary excretion is the primary clearance route in rats for either PFOA or PFOS. During the first 24 h after administration of PFOA (5 and 20 mg/kg body weight/day), about 24.7-29.6% of the oral dose was excreted through urine and feces, while for PFOS, the excretion amounts were only 2.6-2.8% of the total gavaged doses (5 and 20 mg/kg body weight/day). The excretion rates of both PFCs increased with increasing exposure doses. The higher elimination rate of PFOA through excretion indicated its lower accumulation in rats, thus inducing possible lower toxicities compared to PFOS.
TL;DR: The study suggests that the phytotoxicity of herbicides to legumes could be reduced by applying the growth-promoting herbicide-tolerant strain of Pseudomonas aeruginosa PS1.
Abstract: The quizalafop-p-ethyl- and clodinafop-tolerant phosphate-solubilizing and plant-growth-promoting Pseudomonasaeruginosa PS1 isolated from the rhizospheric soils of mustard was used to determine its phosphate-solubilizing activity and other plant-growth-promoting traits both in the presence and absence of technical grade quizalafop-p-ethyl and clodinafop under in vitro conditions. Quizalafop-p-ethyl (at 40, 80, and 120 ppb) and clodinafop (at 400, 800, and 1200 ppb) reduced the P-solubilizing activity, synthesis of indole-3-acetic acid, and siderophores progressively with increasing concentrations of each herbicide. Hydrogen cyanide and ammonia synthesisized by this strain, however, did not change. Furthermore, the effects of three concentrations each of quizalafop-p-ethyl [40 (recommended dose), 80, and 120 ppb] and clodinafop [400 (recommended dose), 800, and 1200 ppb] were evaluated on plant-growth-promoting Pseudomonas aeruginosa strain PS1 inoculated greengram plants, grown in sandy clay loam soil. Generally, all of the concentrations of both quizalafop-p-ethyl and clodinafop showed phytotoxicity and severely affected the growth, symbiosis, grain yield, and nutrient uptake by greengram plants. The toxicity of quizalafop-p-ethyl and clodinafop enhanced gradually with the increase in the dose rate of herbicides. Quizalafop-p-ethyl was more toxic than clodinafop. In contrast, herbicide-tolerant P. aeruginosa strain PS1 when used with herbicides increased the measured parameters at all concentrations. Both quizalafop-p-ethyl at 120 ppb and clodinafop at 400 ppb increased total chlorophyll content, leghemoglobin, root N, shoot N, root P, shoot P, seed yield, and seed protein, relative to the uninoculated control. The study suggests that the phytotoxicity of herbicides to legumes could be reduced by applying the growth-promoting herbicide-tolerant strain of Pseudomonas aeruginosa PS1.
TL;DR: Analysis of SOD, CAT, and POD activities using nondenaturing polyacrylamide gel electrophoresis (PAGE) may help to understand how SA regulates plant response to organic contaminants and provide a basis to control herbicide/pesticide contamination in crop production.
Abstract: Napropamide is a widely used herbicide for controlling weeds in crop production. However, extensive use of the herbicide has led to its accumulation in ecosystems, thus causing toxicity to crops and reducing crop production and quality. Salicylic acid (SA) plays multiple roles in regulating plant adaptive responses to biotic and environmental stresses. However, whether SA regulates plant response to herbicides (or pesticides) was unknown. In this study, we investigated the effect of SA on herbicide napropamide accumulation and biological processes in rapeseed (Brassica napus). Plants exposed to 8 mg kg−1 napropamide showed growth stunt and oxidative damage. Treatment with 0.1 mM SA improved growth and reduced napropamide levels in plants. Treatment with SA also decreased the abundance of O2–. and H2O2 as well as activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX), and increased activities of guaiacol peroxidase (POD) and glutathione-S-transferase (GST) in napropamide-exposed plants. Analysis of SOD, CAT, and POD activities using nondenaturing polyacrylamide gel electrophoresis (PAGE) confirmed the results. These results may help to understand how SA regulates plant response to organic contaminants and provide a basis to control herbicide/pesticide contamination in crop production.
TL;DR: Fish and mollusk samples collected from markets located in Liaoning province, China, during August and September 2007, and 22 organochlorine pesticides (OCPs) were detected indicated, first, that freshwater fish are more easily influenced than seawater fish andmollusks by OCP residues in agricultural areas and, second, that there are different biota accumulation factors for OCPs between fish andMollusk.
Abstract: Fish and mollusk samples were collected from markets located in 12 cities in Liaoning province, China, during August and September 2007, and 22 organochlorine pesticides (OCPs) were detected. DDT, HCH, endosulfan, chlordane, and HCB were the dominating OCPs, with mean concentrations and ranges of, respectively, 15.41 and 0.57 to 177.56 ng/g, 0.84 and below detection limit (BDL) to 22.99 ng/g, 1.31 and BDL to 13.1 ng/g, 1.05 and BDL to 15.68 ng/g, and 0.63 and BDL to 9.21 ng/g in all fish and mollusk samples. The concentrations of other OCPs generally were low and were detectable in a minority of samples, reflecting the low levels of these OCPs in the study region. In general, OCP concentrations were obviously higher in fish than in mollusks, and higher in freshwater fish than in marine fish, which indicated, first, that freshwater fish are more easily influenced than seawater fish and mollusks by OCP residues in agricultural areas and, second, that there are different biota accumulation factors for OCPs between fish and mollusk. To learn the consumption of fish and mollusk, 256 questionnaires were sent to families in 12 cities of Liaoning province. Using the contamination data, average estimated daily intakes of OCPs via fish and mollusk consumption were calculated, which were used for exposure assessment. The public health risks caused by exposure to OCPs in the course of fish and mollusk consumption were compared to noncancer benchmarks and cancer benchmarks.
TL;DR: Results suggest no toxicity of dietary selenomethionine up to 10 μg/g supplemented diet and that with total life-cycle exposure, cutthroat trout increase Se excretion to maintain whole-body concentrations below toxic levels.
Abstract: A 2.5-year feeding trial was conducted in which cutthroat trout (Oncorhynchus clarki bouvieri) were fed either a basal diet (1.2 microg Se/g diet) or the basal diet supplemented with 2, 4, 6, 8, or 10 microg Se/g diet as selenomethionine from 1 g weight to maturation [corrected]. After 44 weeks of feeding, a subsample of fish was removed from dietary treatment groups and fed the basal diet for an additional 32 weeks. Concentrations of Se in whole fish and eggs increased in proportion to dietary Se intake, but no differences in growth, feed intake, survival, or egg hatchability were observed among dietary groups. Cranial-facial deformities in second-generation offspring were less than 6% in all treatment groups except for fish fed the diet supplemented with 4 microg Se/g diet as selenomethionine [corrected], where a 9.2% incidence was observed. Fish switched from selenomethionine-supplemented diets to the basal diet lost Se, calculated as microg Se lost/g weight gain, at 1.01, 2.84, 4.42, and 4.42 for dietary treatment groups 3, 4, 5, and 6, respectively. Results suggest no toxicity of dietary selenomethionine up to 10 microg/g supplemented diet and that with total life-cycle exposure, cutthroat trout increase Se excretion to maintain whole-body concentrations below toxic levels.
TL;DR: The addition of P to the treatment with combined metals attenuated the decrease in plant growth and root length, and caused a significant increase in CSAs of total metaxylem vessels, suggesting that P increased the tolerance of P. stratiotes to metals.
Abstract: The effects of Cr, Ni, Zn, and P exposure on the root anatomic structure, growth, and chlorophyll a concentration of Pistia stratiotes L. were studied. Plastic aquaria containing 50 g of wet plants and 5 L of pond water added with the contaminant(s) were disposed. The treatments were: (1) Cr, (2) Ni, (3) Zn, (4) P, (5) Cr + Ni + Zn, (6) Cr + Ni + Zn + P, and (7) control. Contaminant additions were done seven times. In each addition, concentrations of 1 mg of metals or 5 mg of P per liter of water were added. Chlorophyll a was an indicator more sensitive to Zn and Cr toxicity than the relative growth rate. Ni and Cr + Ni + Zn treatments were the most toxic ones, in which biomass and the root anatomical parameters (root length, cross-sectional areas [CSAs] of root, stele, and metaxylem vessels) decreased significantly. The addition of P to the treatment with combined metals attenuated the decrease in plant growth and root length, and caused a significant increase in CSAs of total metaxylem vessels, suggesting that P increased the tolerance of P. stratiotes to metals. This fact has important implications for the use of this macrophyte in constructed wetlands for industrial wastewater treatment.
TL;DR: Alterations in AChE activity may be a good indicator of cadmium contamination in R. quelen, and metal accumulation in brain and muscle was altered during both exposure periods and these parameters did not return to control values after the recovery period.
Abstract: Cadmium is a metal with no biological function in superior organisms and it is very toxic even at very low concentrations. Thus the objective of this study was to verify some toxicological parameters in silver catfish (Rhamdia quelen) exposed to cadmium. In this study, silver catfish was exposed to 0 (control), 0.236, and 0.414 mg L−1 cadmium for 7 and 14 days, followed by the same periods of recovery. The effects of cadmium on acetylcholinesterase (AChE) activity and metal accumulation in brain and muscle were verified. Thiobarbituric acid-reactive substance (TBARS) formation was evaluated in brain. An increase in TBARS levels was verified after exposure and recovery periods and AChE activity in brain was reduced after 14 days of exposure. These parameters did not return to control values after the recovery period. In muscle AChE was altered during both exposure periods. Alterations in AChE activity may be a good indicator of cadmium contamination in R. quelen.