RESUMO
This study investigated the contamination and health risk assessment of heavy metals and organophosphorus pesticides in single, double, and ratoon cropping of rice in Mazandaran province, north of Iran. A total of 17 sampling locations in rice farms were selected and soil and rice samples were collected from farms in 5 counties of Mazandaran. Soil and rice samples were then transferred to the lab for further analysis. The concentration of pesticides and heavy metals was then analyzed using gas chromatography-mass spectrometry (GC-MS) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Mercury was analyzed using a Leco mercury analyzer. Target hazard quotient (THQ), total target hazard quotient (TTHQ), carcinogenic risk (CR), and total carcinogenic risk (TCR) in children and adults were used. Potential ecological risk also was used to test the possible hazards of heavy metals to the environment. Heavy metals concentration in rice and soil samples in different farming steps revealed different levels. THQ showed no considerable risk in consuming contaminated rice to adults and children considered, while TTHQ revealed potential non-carcinogenic risks. Ni had the most carcinogenic risks to target human groups, and TCR showed carcinogenicity for carcinogenic heavy metals in all stations. Findings showed no ecological risks of metals to the environment. In conclusion, rice farmers in Mazandaran use the lands multiple times during the year to increase the performance, function, quality, and quantity of rice, but the possible toxic effects of heavy metals and pesticides on consumers and the environment should not be overlooked.
Assuntos
Mercúrio , Metais Pesados , Oryza , Praguicidas , Poluentes do Solo , Adulto , Criança , Humanos , Oryza/química , Compostos Organofosforados/análise , Monitoramento Ambiental , Praguicidas/análise , Irã (Geográfico) , Contaminação de Alimentos/análise , Metais Pesados/análise , Solo/química , Carcinógenos/análise , Mercúrio/análise , Medição de Risco , Receptores de Antígenos de Linfócitos T , Poluentes do Solo/análiseRESUMO
The objectives of this study were to understand the mercury daily intake and hair-to-blood mercury ratio in fishermen and non-fishermen families in the coast of the Persian Gulf in Iran. The mean mercury concentration in the hair of fishermen and non-fishermen families was 5.76 and 2.27 µg/g, respectively. The mean mercury concentrations of RBCs were obtained for fishermen families and non-fishermen families: 35.96 and 17.18 µg/L, respectively. Hair mercury concentrations in 17% of people were higher than 10 µg/g, the No Observed Adverse Effects Level set by the World Health Organization. 78% of people had a blood mercury value > 5.8 µg/L, the standard level set by the U.S. Environmental Protection Agency. A significant correlation (r = 0.94, p = 0.000) was seen between log hair and RBCs mercury concentrations. The mean mercury daily intake for fishermen and non-fishermen families was 0.42 and 0.20 µg/kg BW per day, respectively. The mean mercury daily intake of fishermen families was higher than the provisional tolerable daily intake (0.23 µg/kg BW per day) suggested by the Joint Expert Committee on Food Additives. Mercury daily intake significantly correlated with fish consumption (r = 0.50, p = 0.000) and log hair mercury (r = 0.88, p = 0.000). The total mean of hair-to-blood mercury concentration ratio was 306. We conclude that the use of mercury concentrations in the hair and RBCs could have been suitable biomarkers for predicting mercury exposure of people with a high rate of fish consumption.
Assuntos
Contaminação de Alimentos , Cabelo/química , Mercúrio/análise , Alimentos Marinhos , Adolescente , Adulto , Exposição Ambiental/análise , Feminino , Contaminação de Alimentos/análise , Humanos , Oceano Índico , Irã (Geográfico) , Masculino , Mercúrio/sangue , Pessoa de Meia-Idade , Adulto JovemRESUMO
The objectives of this study were to assess the biological water of the Iranian Tajan River using different metrics, i.e., a Multimetric Macroinvertebrate Index (MMI) and a traits-based method. Twenty-eight physico-chemical parameters, 10 habitat factors, and abundance of macroinvertebrates were obtained for 17 sites. The Shahid-Rajaie dam divides the Tajan River into an up- and downstream part, with different land uses. Eighteen metrics were used to represent four components of ecosystem quality, including tolerance (Hilsenhoff, SIGNAL), diversity (Margalef, Shannon-Wiener, Simpson, and Evenness), abundance (total number of taxa, individuals, Ephemeroptera, Plecoptera, Trichoptera, EPT, and Insects), and composition of assemblages (% Ephemeroptera, % Plecoptera, % Trichoptera, and % EPT Taxa). The integrated MMI was calculated by averaging the obtained scores of all indices. In the next step, we gathered information on 22 biological traits of macroinvertebrates to evaluate whether (group of) traits could be identified that are indicative for specific or general stress. Result showed a decrease in MMI from upstream (very good water quality) to downstream (bad) due to human activities. Industrial activities like pulping and papermaking operations or sand mining in the downstream part had more effects than agriculture and fish ponds in the upstream part. A redundancy analysis biplot showed the variation between the modalities of trait of macroinvertebrates and their correlation with physico-chemical parameters in Tajan River. The findings show that traits can be indicative for different kind of stress but that more effort has to be put in gathering data sets to disentangle the effect of habitat quality, pollution, and the physico-chemical properties of high- versus lowland rivers.
Assuntos
Ecossistema , Invertebrados , Rios , Agricultura , Animais , Monitoramento Ambiental/métodos , Indústrias , Invertebrados/classificação , Irã (Geográfico) , Mineração , Análise Multivariada , Densidade Demográfica , Rios/químicaRESUMO
Studying the concentration distribution of metals is necessary for soil pollution monitoring and maintaining environmental quality. To date, very little large-scale research has been performed to investigate metal contamination in developing countries. In this study, the content and spatial distributions of five metals (cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], and zinc [Zn]) were quantified based on 346 topsoil samples from 12 districts in the province of Golestan (northeast [NE] Iran). The concentration levels (mg/kg) of Cd, Cu, Pb, Ni and Zn varied from 0.02 to 0.36, 9.3 to 93.7, 6.8 to 44, 9.5 to 85.35, and 25 to 417.4, respectively. The average concentrations (mg/kg) obtained were as follows: Cd 0.12 ± 0.07, Cu 23.9 ± 9.07, Ni 34.88 ± 11.59, Pb 15.42 ± 5.81 and Zn 82.08 ± 30.87. Significant differences in the distribution of trace elements among districts were detected. The AzadShahr and BandarGaz districts displayed the highest metal concentrations. Greater metal values were obtained in the central, south, west, and NE areas, although Zn concentration was also high to the north of the province. Values of contamination factor and contamination degree indicated that the metal pollution level was on the order of Zn > Cd > Pb > Cu > Ni and that all of the metals belonged to a low or moderate pollution category. Ni and Cu levels derived from natural sources, whereas Cd, Pb, and Zn derived from anthropogenic activities with greater mean concentrations than reference concentrations.
Assuntos
Monitoramento Ambiental , Poluição Ambiental/estatística & dados numéricos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Irã (Geográfico)RESUMO
This study assessed the baseline concentrations and spatial distribution of total mercury (Hg) in urban soils of the city of Arak, Iran. Concentrations of Hg were determined in soil collected from urban areas, and the spatial distribution was analyzed using the semivariogram approach in geostatistical technology. Mercury in soil ranged from 66.3 to 581 µg/kg. The experimental variogram of soil mercury concentrations was best-fitted by a spherical model. A spatial distribution map revealed that Hg concentration showed decreasing trends from south to north, west to east and center to suburb. Overall, the results showed that Hg concentrations in urban soils of Arak may be considered medium or low.
Assuntos
Monitoramento Ambiental , Mercúrio/análise , Poluentes do Solo/análise , Cidades , Irã (Geográfico)RESUMO
The objective of this research was to examine and contrast the levels of cadmium (Cd), copper (Cu), zinc (Zn), and selenium (Se) in the muscle and hepatopancreas tissues of two species, namely pharaoh cuttlefish (Sepia pharaonis) and Indian squid (Uroteuthis duvauceli), from the Persian Gulf. A total of thirty individuals of each species were gathered in January 2009 from the northern waters of the Persian Gulf. The metal concentrations were significantly higher in muscle tissue (p < 0.05) than in other tissues. S. pharaonis had higher metal concentrations than U. duvauceli. In the muscle and hepatopancreas samples of S. pharaonis, the highest mean concentrations were found to be for Zn (58.45 ± 0.96 µg/g dw) and Cu (1541.47 ± 192.15 µg/g dw), respectively. In U. duvauceli, the highest concentration of measured elements was seen for Zn in both muscle (36.52 ± 0.56 µg/g dw) and hepatopancreas (60.94 ± 2.65 µg/g dw). Se had the lowest concentration among the elements measured in both species. There was a negative and significant correlation between Cu and biometrical factors (total body length and weight) in both muscle and hepatopancreas samples of S. pharaonic and only in the muscle samples of U. duvauceli (p < 0.01, R2 = - 052; p < 0.01, R2 = - 0.055). However, there was a strong correlation between Zn and biometrical factors in hepatopancreas samples of both species. The comparison of metal concentrations with standards revealed that only Cd levels in S. pharaonis exceeded the ESFA and WHO standards, whereas other metals were below the standards.
Assuntos
Metais Pesados , Selênio , Sepia , Poluentes Químicos da Água , Humanos , Animais , Zinco/análise , Cádmio/análise , Oceano Índico , Hepatopâncreas/química , Irã (Geográfico) , Poluentes Químicos da Água/análise , Metais , Decapodiformes , Músculos/química , Monitoramento Ambiental , Metais Pesados/análiseRESUMO
Organochlorine pesticides (OCPs) and PCBs were determined in water and sediment from the Anzali Wetland, north of Iran. The total concentrations of OCPs were 71.75-315.16 ng/l, 1.8-12.68 ng/g dry wt in water and sediments respectively, and those of polychlorinated biphenyls (PCBs) in the two phases were: nd-141.09 ng/l and 0.39-2.64 ng/g dw, respectively. Also, the results indicated that ß-HCH, DDE were the most common organochlorine pesticides contaminants. In this study, the ∑PCB/∑DDT reflect the relative importance of agricultural than industrial sources in this area. a significant difference was observed between the stations. Station number 3 showed the highest range of the pollutants studied.
Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/análise , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes Químicos da Água/análise , Áreas Alagadas , Internacionalidade , Irã (Geográfico) , Bifenilos Policlorados/análise , Extração em Fase SólidaRESUMO
Much of the variation in trace metal tissue concentrations in marine invertebrates has been attributed to the variety in individual organism size, age and sex. This study assessed the relationship between total mercury (Hg) concentrations in edible tissue, exoskeleton and viscera with length, weight and gender for 69 samples of crustaceans, Penaeus semisulcatus (n = 30), Thenus orientalis (n = 21) and Portunus pelagicus (n = 18) from the northern part of the Persian Gulf. Significant increase in the Hg level in muscle and viscera (r > 0.65, p < 0.01) with an increase in length and weight for all three species. No relationship was found between the Hg level in exoskeleton and length or weight. Significantly higher Hg levels (p < 0.01) were found in female P. semisulcatus than in males (muscle and viscera), but no gender differences were found for the other two species.
Assuntos
Crustáceos/metabolismo , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Braquiúros/crescimento & desenvolvimento , Braquiúros/metabolismo , Crustáceos/crescimento & desenvolvimento , Monitoramento Ambiental , Feminino , Oceano Índico , Irã (Geográfico) , Masculino , Palinuridae/crescimento & desenvolvimento , Palinuridae/metabolismo , Penaeidae/crescimento & desenvolvimento , Penaeidae/metabolismo , Poluição Química da Água/estatística & dados numéricosRESUMO
In this study, Arsenic (As) was measured in several varieties of imported and local cultivated rice. Soil samples collected from rice farms situated in south Caspian Sea (Iran) were also studied. The mean concentration of As in imported rice, local farmed rice and soil, were determined as 0.28, 0.39 and 3.80 µg g(-1) dry weight, respectively. Estimated daily intake of As through human consumption of imported and local produced rice was 0.77 and 1.074 µg day(-1) kg(-1) B.W., respectively. These values are much lower than the tolerable daily intakes estimated by JECFA. The As concentration in the soil (3.80 µg g(-1) dry) was below acceptable limit for agricultural soil of 20.0 mg kg(-1) as recommended by the European Community (EC). No correlation between the As concentrations in rice and soil samples was found (p > 0.05).
Assuntos
Arsênio/análise , Contaminação de Alimentos/análise , Oryza/química , Poluentes do Solo/análise , Dieta/estatística & dados numéricos , Monitoramento Ambiental , Contaminação de Alimentos/estatística & dados numéricos , Humanos , Irã (Geográfico) , Oceanos e Mares , Solo/químicaRESUMO
The aim of this study was to determine the concentrations and degree of metals contamination (Chromium, Cadmium, Nickel and Lead) and Arsenic in the soils of the three Industrial Estates in Arak city, Iran. The average concentrations of Arsenic, Chromium, Cadmium, Nickel and Lead were 5.06, 1.26, 37.13, 67.84 and 60.22 mg kg(-1), respectively. Pearson correlation indicated that Arsenic, Cadmium and Lead were mainly derived from anthropogenic inputs, and Chromium and Nickel were controlled by natural source, whereas Nickel appeared to be affected by both anthropogenic and natural sources. The geo-accumulation Index (Igeo) calculated in three industrial estates gave values indicating unpolluted to strongly polluted.
Assuntos
Resíduos Industriais/estatística & dados numéricos , Metais/análise , Poluentes do Solo/análise , Monitoramento Ambiental , Resíduos Industriais/análise , Irã (Geográfico) , Solo/químicaRESUMO
This study investigated the human biomonitoring of heavy metals in the water, sediments, and tissues of mostly consumed fish species using Turkmen pregnant women's biomarkers in winter 2019, at the Miankaleh Peninsula, north of Iran. Metal concentrations were measured in various fish organs as well as pregnant women's blood, hair, and nail as biological indicators. For this purpose, a total of 20 water and sediment, 14 fish, and 16 human samples were collected. Inductively coupled plasma mass spectrometry (ICP-MS) was used to evaluate the concentration of Cr, Co, Cu, As, Hg, and Pb. Results showed metals with the highest concentrations as Cu and Cr in water (93.35 and 80.91 µg/l, respectively), Hg and Pb in sediment (7.40 µg/g for both), Cu and Pb in the liver (27.00 and 18.9 µg/g for C. carpio; 1414 and 31.7 µg/g for L. auratus), muscle (10.00 and 18.80 for C. carpio; 37.20 and 8.27 µg/g for L. auratus), and skin (26.40 and 9.90 for C. carpio; 10.80 and 11.74 µg/g for L. auratus). In addition, Cu, in pregnant women samples, had the highest values at 2.53 mg/l, 8.87, 36.46, and 29.04 µg/g for blood, hair, fingernail, and toenail, respectively. However, Co showed the lowest concentration in all studied samples. Fish liver and fingernail of pregnant women did reveal the highest heavy metal accumulation, whereas fish muscle and blood of pregnant women had the lowest accumulated heavy metals. The concentration of Hg in water, sediment, fish muscle, and women's blood and hair exceeded the limits suggested by various organizations. Therefore, this study highlighted that heavy metal concentration, in particular Hg, in water, sediments, and fish is a serious risk to the health of local inhabitants who rely on fisheries products and recommended that necessary information should be provided to warn Turkmen pregnant women in consumption of Hg-contaminated fish in this area.
Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Animais , Monitoramento Biológico , Monitoramento Ambiental/métodos , Feminino , Peixes , Sedimentos Geológicos/química , Humanos , Irã (Geográfico) , Chumbo/análise , Mercúrio/análise , Metais Pesados/análise , Gravidez , Gestantes , Medição de Risco , Água/análise , Poluentes Químicos da Água/análiseRESUMO
Concentrations of polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and analogs, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB), were determined in 8 fish species collected during October and November 2007 from the largest Iranian wetland, the Shadegan Marshes. Fishes were selected on the basis of their importance in the local diet and feeding behavior. In all samples, OCPs were found in higher concentrations than PCBs. Common carp (Cyprinus carpio) had the highest OCs (1680 ng/g lipid wt.), with DDTs being most prevalent and p,p'-DDE contributing by 53-88% to the total DDTs. In all samples, OCs were found in order of DDTs>HCHs>PCBs>HCB. The highest concentration of HCHs was found in common carp (410±180 ng/g lipid wt.) and α-HCH was the predominant compound among HCH isomers (range 70-90%, mean 82%) in all species. All samples contained PCBs and CB 28 (37%) and CB 52 (26%) were the most frequently occurring congeners. common barbel (Barbus barbulus) (70±17 ng/g lipid wt.) exhibited the highest concentrations of HCB. OC levels in fish were relatively low, but the levels of several OCs in some of our specimens exceed the guidelines for food safety issued by the European Union (EU) and US Food and Drug Administration (FDA).
Assuntos
Peixes/metabolismo , Hidrocarbonetos Clorados/metabolismo , Praguicidas/metabolismo , Bifenilos Policlorados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , DDT/metabolismo , Monitoramento Ambiental , Hexaclorobenzeno/metabolismo , Hexaclorocicloexano/metabolismo , Oceano Índico , Irã (Geográfico) , Alimentos Marinhos/análise , Áreas AlagadasRESUMO
The objective of this research was to determine seasonal variation, distribution, potential health risk, and source identification of 16 polycyclic aromatic hydrocarbons (PAHs) in the surface dust of eight urban areas of Qom. The total levels of 16 PAHs ranged from 364.83 to 739.26 ng g-1, with an average of 478.27 ng g-1. Sites 1 and 8 showed the highest (491.33 ng g-1) and lowest (465.08 ng g-1) concentrations of PAHs, respectively. The PAHs demonstrated the highest and the lowest levels in autumn (553.41 ng g-1) and summer (402.30 ng g-1), respectively. Naphthalene (Nap) showed the highest amounts in all of the areas (75.57 ng g-1). Source apportionment indicated that vehicular emissions and combustion of fossil fuels (liquid fossil fuel, crude oil, and gas) are the main sources of the PAHs. Toxic equivalency quantities (TEQs) index exhibited a mean concentration of 47.41 ng g-1, and benzo[a]pyrene (BaP) and dibenzo[a,h]anthracene (DBA) together contributed more than 80% of TEQ, indicating high risk potential of these compounds. Total incremental lifetime cancer risk (ILCR) presented higher value (2.62 × 10-7) for children than for adults (2.53 × 10-7), one-fold lower than the threshold (10-6). The spatial ILCR for the study areas and seasons showed the highest cancer risk in site 2 and winter. Taken together, the carcinogenic risk of PAHs to children and adults, respectively, through direct ingestion and dermal contact pathways illustrated values close to the baseline, suggesting that more attention should be paid to the issue in the study area.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Adulto , Criança , China , Poeira/análise , Monitoramento Ambiental , Humanos , Irã (Geográfico) , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de RiscoRESUMO
An evaluation of suitability of applying hair as a noninvasive indicator for determination of the body burden mercury in mammals was carried out by determining the concentration of mercury in hair and liver tissue of the golden jackal, Canis aureus . Nineteen jackals killed on the roads along the Caspian Sea in the central region of Mazandaran Province, Iran were collected. The mercury measurements were carried out by AMA254 LECO and the standard method ASTM-D6722. SPSS and Excel were used for analytical statistics. There was a significant difference in Hg levels between the hair and liver tissue (P < 0.001). The average concentration of mercury was 187.3 + or - 22.7 and 53.3 + or - 7.3 ng/g, respectively. No significant differences were seen either between the sexes or in correlation between the tissues. But a significant and positive relation was seen between the mercury content in hair and body weight and length (P < 0.005). In general, the mercury concentration was less than the deleterious, effective limit on the species. It seems that this is the first study of Hg concentrations in jackals and demonstrates on easy and noninvasive sampling method.
Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/metabolismo , Cabelo/metabolismo , Chacais/metabolismo , Mercúrio/metabolismo , Animais , Tamanho Corporal , Feminino , Chacais/anatomia & histologia , Fígado/metabolismo , MasculinoRESUMO
Liver samples (n = 43) of 9 avian species representing the families Phalacrocoracidae, Podicipedidae, Laridae, and Anatidae, were collected from the Iranian coast of the Caspian Sea. Samples were analyzed for organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), and seven PCB congeners. p,p'-DDE was predominantly found in all species, at concentrations ranging from the limit of quantification (LOQ) to 340 ng/g ww. Most frequently encountered PCB congeners, in all samples, were 118, 153 and 138; and birds in Phalacrocoracidae had the highest liver PCB (mean 90 +/- 32; ranging from Assuntos
Aves/metabolismo
, Poluentes Ambientais/análise
, Hidrocarbonetos Clorados/análise
, Fígado/química
, Praguicidas/análise
, Bifenilos Policlorados/análise
, Migração Animal
, Animais
, Biotransformação
, Aves/classificação
, Peso Corporal
, Dieta/veterinária
, Poluentes Ambientais/química
, Poluentes Ambientais/metabolismo
, Hidrocarbonetos Clorados/química
, Hidrocarbonetos Clorados/metabolismo
, Irã (Geográfico)
, Fígado/metabolismo
, Oceanos e Mares
, Praguicidas/química
, Praguicidas/metabolismo
, Bifenilos Policlorados/química
, Bifenilos Policlorados/metabolismo
, Reprodução/efeitos dos fármacos
, Especificidade da Espécie
RESUMO
BACKGROUND: Carbaryl is widely used to control various insect pests on greenhouse cucumbers in Iran. Therefore the control of residual levels of this insecticide is highly necessary. The effects of the household processing such as washing, peeling and refrigeration storage, at 4 °C for 2 days on the reduction of residue levels in the plant tissues were investigated in the different groups. Samples were collected at 1 h to 14 days after application and analysed to determine the content and dissipation rate of carbaryl. Analysis was carried out by the QuEChERS method using HPLC-UV. RESULTS: Carbaryl residue in samples, which were collected post-application in different times showed a gradual and significant (P < 0.05) decrease. The half-life (t(1/2)) of carbaryl applied on cucumbers was 3.2 days. Carbaryl residues were detected in concentration ranges of 0.22-4.91 mg kg(-1). Also, the results indicated that the consumable safety time of carbaryl was found to be more than 14 days on cucumber. CONCLUSION: Household processing, such as washing and peeling and refrigeration storage, was effective in reducing the residue levels. Also, peeling was the most effective way to reduce the carbaryl residues of the cucumber samples. Washing and refrigerated storage also decreased carbaryl residues.
Assuntos
Carbaril/análise , Cucumis sativus/química , Contaminação de Alimentos/prevenção & controle , Manipulação de Alimentos/métodos , Controle de Insetos/métodos , Inseticidas/análise , Resíduos de Praguicidas/análise , Métodos Analíticos de Preparação de Amostras , Frutas/química , Meia-Vida , Irã (Geográfico) , CinéticaRESUMO
Two gonadotropin-releasing hormone (GnRH) isoforms were identified in the beluga (Huso huso) brain by cDNA sequencing: prepro-mammalian GnRH (mGnRH) and prepro-chicken GnRH-II (cGnRH-II). The nucleotide sequences of the beluga mGnRH and cGnRH-II precursors are 273 and 258 base pairs (bp) long, encoding peptides of 91 and 86 amino acids, respectively. To investigate the effect of methylmercury (MeHg) on GnRH gene expression, animals were fed with four diets containing increasing levels of MeHg (0 mg kg(-1) [control]; 0.76 mg kg(-1) [low]; 7.8 mg kg(-1) [medium]; 16.22 mg kg(-1) [high]) for 32 days. The effects of MeHg on brain GnRH mRNA levels were evaluated by real-time PCR. A significant decrease in brain mGnRH and cGnRH-II mRNA levels were detected in fish receiving high dietary MeHg dose compared to controls on day 11 (P < 0.05). On day 18 and 32, all treatment groups had significantly lower brain mGnRH and cGnRH-II mRNA levels compared to the control group (P < 0.05). These findings demonstrate a disruptive role of MeHg on the level of brain mGnRH and cGnRH-II mRNAs in immature beluga.
Assuntos
Encéfalo/metabolismo , Peixes/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/genética , Compostos de Metilmercúrio/toxicidade , RNA Mensageiro/metabolismo , Sequência de Aminoácidos , Análise de Variância , Animais , Sequência de Bases , Galinhas , Clonagem Molecular , Primers do DNA/genética , DNA Complementar/genética , Relação Dose-Resposta a Droga , Peixes/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Compostos de Metilmercúrio/administração & dosagem , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
Mercury concentrations in feather, liver, kidney, and muscle tissue of Little egret (n = 8) and Cattle egret (n = 3) from Shadegan Wetlands in south-western Iran were examined. Liver of Little egret had significantly higher mercury compared to Cattle egret (p < 0.05). In addition, mercury values were consistently larger in Little egret when compared to Cattle egret, but mercury levels found in feather, kidney, and muscle did not differ statistically between the two bird species (p > 0.05). The small Cattle egret sample size, however, makes it difficult to conclude that the same trend would persist had we been able to include more Cattle egrets in this study. An interesting regional comparison between mercury concentrations in the feather of Little egret chicks, from China, Hong Kong, and Pakistan, and adult Little egrets, from Shadegan wetlands, revealed higher mercury in the adult of the species, as one would expect. Conversely, feathers of adult Cattle egrets form Shadegan had less mercury than values reported for young birds of the same species from Aswan in Egypt; but our Cattle egrets had higher or similar mercury concentrations to Cattle egrets from Pakistan, New York, Delaware, Puerto Rico, Hong Kong, and Cairo in Egypt.
Assuntos
Aves/metabolismo , Monitoramento Ambiental/métodos , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Animais , Plumas/metabolismo , Irã (Geográfico) , Rim/metabolismo , Músculos/metabolismo , Poluição Química da Água/estatística & dados numéricosRESUMO
Persian Gulf supports diverse ecosystems and biota in need of remediation and protection, and metal data from this region is needed. Mercury (Hg) in tissues of three waders (Black-winged Stilt Himantopus himantous, Red-wattled Plover Hoplopterus indicus, and White-tailed Plover Vanellus leucurus) from Shadegan Wetlands is reported. Black-winged Stilt had higher Hg in feather (6.6 +/- 0.6 microg/g dry weight), liver (3.5 +/- 1 microg/g dry weight), kidney (4.5 +/- 0.8 microg/g dry weight) and muscle (1.2 +/- 0.2 microg/g dry weight) (not statistically significant). Differences in Hg among waders could have resulted from diverse feeding habitats and dissimilar foraging sites.
Assuntos
Aves/metabolismo , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Animais , Oceano Índico , Mercúrio/farmacocinética , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinéticaRESUMO
Levels of organochlorine pesticides (OCPs) and PCB were determined in three duck species: Pintail (Anas acuta), Common Teal (Anas creaca), and Mallard (Anas platyhynchos). Both persistent organochlorines were more abundant in muscle than in the liver; Mallard had the highest levels of PCBs [84.0 +/- 39.0 ng/g wet weight (ww)], and Common Teal showed the highest levels of DDTs (561.0 +/- 220.0 ng/g ww). This exposure level is more than two orders of magnitude below provisional tolerable daily intake (PTDI) (0.01 mg/kg bw for DDT and its associated compounds) of The Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO).