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1.
Artigo em Inglês | MEDLINE | ID: mdl-33477475

RESUMO

Lead (Pb) is a metal toxicant of great public health concern. The present study investigated the applicability of the rat incisor in Pb exposure screening. The levels of lead in teeth (Pb-T) in the crown and root of incisors in laboratory Pb-exposed Sprague Dawley rats were quantified using inductively coupled plasma mass spectrometry (ICP-MS). The crown accumulated much Pb-T than the root of the Sprague Dawley rat incisor. The levels of lead in blood (Pb-B) were positively correlated with the Pb-T in the crown and root incisors of the Sprague Dawley rats. As an application of the Pb-T crown results in experimental rats, we subsequently analyzed the Pb-T in the crown incisors of Pb-exposed wild rats (Rattus rattus) sampled from residential sites within varying distances from an abandoned lead-zinc mine. The Pb-T accumulation in the crown of incisors of R. rattus rats decreased with increased distance away from the Pb-Zn mine. Furthermore, the Pb-T was strongly correlated (r = 0.85) with the Pb levels in the blood. Laser ablation ICP-MS Pb-T mappings revealed a homogenous distribution of Pb in the incisor with an increased intensity of Pb-T localized in the tip of the incisor crown bearing an enamel surface in both Sprague Dawley and R. rattus rats. These findings suggest that Pb-T in the crown incisor may be reflective of the rat's environmental habitat, thus a possible indicator of Pb exposure.

2.
Chemosphere ; 262: 127788, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182082

RESUMO

Lead (Pb) interferes with various bodily functions. Although high blood Pb (Pb-B) levels in residents from Kabwe, Zambia have been reported, the accumulation pattern of other metals remains unknown. The study was designed to determine the Pb-B, blood cadmium (Cd-B), and zinc (Zn-B) values of 504 representative samples from Kabwe, as well as the potential associated adverse health effects. The Pb-B level ranged from 0.79 to 154.75 µg/dL and generally increased in areas near the mine. A significant elevation of Cd-B was observed in two areas (0.37 ± 0.26 and 0.32 ± 0.30 µg/L) where the two highest mean Pb-B levels were recorded. By contrast, the Zn-B values did not differ greatly with respect to area. Some blood biochemical parameters relating to hepatic and renal functions were out of the normal range in approximately 20-50% of studied adult participants. The δ-aminolevulinic acid dehydratase (δ-ALAD) activity was significantly inhibited in the two areas contaminated by Pb and Cd. A significant negative relationship was observed between metal levels and clinical parameters, e.g., between Pb-B and δ-ALAD for all the age categories and between Cd-B and the estimated glomerular filtration rate for all the age categories except 0-4 years. The elevated Cd-B in areas near the mine relative to the other areas suggested the potential adverse health effects of Cd and/or the interaction of Pb and Cd. A significant association of metal levels with clinical parameters also indicated the effects of metal exposure on hematopoietic, hepatic, and renal systems.


Assuntos
Exposição Ambiental/análise , Poluentes Ambientais/análise , Metais/análise , Adulto , Cádmio/análise , Coleta de Dados , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental/métodos , Taxa de Filtração Glomerular , Humanos , Fígado/química , Registros , Valores de Referência , Adulto Jovem , Zâmbia , Zinco
3.
Sci Rep ; 10(1): 15092, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934309

RESUMO

This study quantitatively assessed the population-wide lead poisoning conditions in Kabwe, Zambia, a town with severe lead pollution. While existing data have reported concerning blood lead levels (BLLs) of residents in pollution hotspots, the data representing the entire population are lacking. Further, selection bias is a concern. Given the lack of compulsory testing schemes, BLLs have been observed from voluntary participants in blood sampling surveys, but such data can represent higher or lower BLLs than the population average because of factors simultaneously affecting participation and BLLs. To illustrate the lead poisoning conditions of the population, we expanded the focus of our surveys and then econometrically estimated the BLLs of individuals representing the population, including those not participating in blood sampling, using background geographic, demographic, and socioeconomic information. The estimated population mean BLL was 11.9 µg/dL (11.6-12.1, 95% CI), lower than existing data because of our wide focus and correction of selection bias. However, the scale of lead poisoning remained immense and 74.9% of residents had BLLs greater than 5 µg/dL, the standard reference level for lead poisoning. Our estimates provide a deeper understanding of the problem and a foundation for policy intervention designs.

4.
Environ Sci Technol ; 54(22): 14474-14481, 2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-32490671

RESUMO

We investigated the potential effects of different land use and other environmental factors on animals living in a contaminated environment. The study site in Kabwe, Zambia, is currently undergoing urban expansion, while lead contamination from former mining activities is still prevalent. We focused on a habitat generalist lizards (Trachylepis wahlbergii). The livers, lungs, blood, and stomach contents of 224 lizards were analyzed for their lead, zinc, cadmium, copper, nickel, and arsenic concentrations. Habitat types were categorized based on vegetation data obtained from satellite images. Multiple regression analysis revealed that land use categories of habitats and three other factors significantly affected lead concentrations in the lizards. Further investigation suggested that the lead concentrations in lizards living in bare fields were higher than expected based on the distance from the contaminant source, while those in lizards living in green fields were lower than expected. In addition, the lead concentration of lungs was higher than that of the liver in 19% of the lizards, implying direct exposure to lead via dust inhalation besides digestive exposure. Since vegetation reduces the production of dust from surface soil, it is plausible that dust from the mine is one of the contamination sources and that vegetation can reduce exposure to this.

5.
Environ Res ; 188: 109759, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32554272

RESUMO

BACKGROUND: Lead (Pb) is a well-known toxic heavy metal which can have serious public health hazards. As of today, there is no safe threshold for Pb exposure, especially for children. Lead exposure has been associated with adverse health outcomes involving epigenetic mechanisms, such as aberrant DNA methylation. The objective of the present study was to elucidate the associations between blood lead levels (BLLs) and gene-specific promoter DNA methylation status in environmental Pb-exposed children from Kabwe, Zambia. METHODS: A cross-sectional study was conducted using 2 to 10-year-old children from high Pb exposed area (N = 102) and low Pb exposed area (N = 38). We measured BLLs using a LeadCare II analyzer and investigated the methylation status of the ALAD and p16 gene promoters by methylation-specific PCR. RESULTS: The mean BLLs were 23.7 µg/dL and 7.9 µg/dL in high Pb exposed and low Pb exposed children, respectively. Pb exposure was correlated with increased methylation of the ALAD and p16 genes. The promoter methylation rates of ALAD and p16 in high Pb exposed children were 84.3% and 67.7%, and 42.1% and 44.7% in low Pb exposed children, respectively. Significantly increased methylation was found in both genes in high Pb exposed children compared with low Pb exposed children (p < 0.05). Children with methylated ALAD and p16 genes showed an increased risk of Pb poisoning (odd ratio >1) compared to the unmethylated status. CONCLUSIONS: This study for the first time tries to correlate promoter methylation status of the ALAD and p16 genes in environmental Pb-exposed children from Kabwe, Zambia as a representative. The result suggests that Pb exposure increases aberrations in ALAD and p16 gene methylation, which may be involved in the mechanism of Pb toxicity.


Assuntos
Intoxicação por Chumbo , Chumbo , Criança , Pré-Escolar , Estudos Transversais , Metilação de DNA , Genes p16 , Humanos , Chumbo/toxicidade , Intoxicação por Chumbo/epidemiologia , Intoxicação por Chumbo/genética , Sintase do Porfobilinogênio/genética , Zâmbia
6.
Chemosphere ; 243: 125412, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995873

RESUMO

Childhood lead (Pb) poisoning has devastating effects on neurodevelopment and causes overt clinical signs including convulsions and coma. Health effects including hypertension and various reproductive problems have been reported in adults. Historical Pb mining in Zambia's Kabwe town left a legacy of environmental pollution and childhood Pb poisoning. The current study aimed at establishing the extent of Pb poisoning and exposure differences among family members in Kabwe as well as determining populations at risk and identify children eligible for chelation therapy. Blood samples were collected in July and August 2017 from 1190 household members and Pb was measured using a portable LeadCare-II analyser. Participants included 291 younger children (3-months to 3-years-old), 271 older children (4-9-years-old), 412 mothers and 216 fathers from 13 townships with diverse levels of Pb contamination. The Blood Lead Levels (BLL) ranged from 1.65 to 162  µg/dL, with residents from Kasanda (mean 45.7  µg/dL) recording the highest BLL while Hamududu residents recorded the lowest (mean 3.3  µg/dL). Of the total number of children sampled (n = 562), 23% exceeded the 45  µg/dL, the threshold required for chelation therapy. A few children (5) exceeded the 100  µg/dL whereas none of the parents exceeded the 100  µg/dL value. Children had higher BLL than parents, with peak BLL-recorded at the age of 2-years-old. Lead exposure differences in Kabwe were attributed to distance and direction from the mine, with younger children at highest risk. Exposure levels in parents were equally alarming. For prompt diagnosis and treatment, a portable point-of-care devise such as a LeadCare-II would be preferable in Kabwe.


Assuntos
Exposição Ambiental/análise , Intoxicação por Chumbo/epidemiologia , Chumbo/sangue , Chumbo/toxicidade , Adulto , Criança , Pré-Escolar , Poluição Ambiental/análise , Pai , Feminino , Humanos , Lactente , Masculino , Mineração , Mães , Registros , Reprodução , Manejo de Espécimes , Zâmbia/epidemiologia
7.
Chemosphere ; 247: 125884, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31978655

RESUMO

Lead (Pb)-poisoning is a serious public health concern and dogs have been useful as a sentinel-animal for Pb exposure of humans. In the present study, the blood Pb concentrations (BLC), isotope ratios (208 Pb/206 Pb and 207 Pb/206 Pb), and biochemistry of 120 domestically owned dogs living around a Pb mining area, in Kabwe, Zambia were analyzed to determine factors associated with Pb exposure. The overall mean value of Pb in dog blood in the present study was 271.6 µg/L. The BLC in the dogs from sites near the mine were significantly higher than those in the dogs from a site 4 km from the mine (352.9 ± 205.1 µg/L versus 28.0 ± 13.9 µg/L). BLC significantly decreased with both increasing age of the dogs and distance from the mine. The Pb isotope ratios in the dog that resided near the mine showed values similar to those reported at the galena mine in Kabwe, which is considered to be the source of Pb exposure. In contrast to the high metal exposure that was determined in these dogs, the mean values of most analyzed parameters in the blood biochemical analysis were surprisingly within or close to the standard reference values. Moreover, none of the dogs showed overt signs of Pb-poisoning or other clinical symptoms. The results of analysis of Pb exposure of the dogs obtained in the present study, which are similar to the previously reported results in human in this location, suggest that dogs could be useful as a sentinel animal for Pb exposure of humans in Kabwe.


Assuntos
Cães/fisiologia , Exposição Ambiental/análise , Chumbo/análise , Mineração , Poluentes do Solo/análise , Animais , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Humanos , Isótopos , Chumbo/metabolismo , Poluentes do Solo/metabolismo , Sulfetos , Zâmbia
8.
Environ Pollut ; 252(Pt B): 1267-1276, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252124

RESUMO

Metal pollution has been associated with anthropogenic activities, such as effluents and emissions from mines. Soil could be exposure route of wild rats to metals, especially in mining areas. The aim of this study was to verify whether soil exposure under environmentally relevant circumstances results in metal accumulation and epigenetic modifications. Wistar rats were divided to three groups: 1) control without soil exposure, 2) low-metal exposure group exposed to soil containing low metal levels (Pb: 75 mg/kg; Cd: 0.4), and 3) high-metal exposure group exposed to soil (Pb: 3750; Cd: 6). After 1 year of exposure, the metal levels, Pb isotopic values, and molecular indicators were measured. Rats in the high-group showed significantly greater concentrations of Pb and Cd in tissues. Higher accumulation factors (tissue/soil) of Cd than Pb were observed in the liver, kidney, brain, and lung, while the factor of Pb was higher in the tibia. The obtained results of metal accumulation ratios (lung/liver) and stable Pb isotope ratios in the tissues indicated that the respiratory exposure would account for an important share of metal absorption into the body. Genome-wide methylation status and DNA methyltransferase (Dnmt 3a/3b) mRNA expressions in testis were higher in the high-group, suggesting that exposure to soil caused metal accumulation and epigenetic alterations in rats.


Assuntos
Cádmio/análise , Metilação de DNA/efeitos dos fármacos , Poluição Ambiental/análise , Chumbo/análise , Poluentes do Solo/análise , Animais , Cádmio/toxicidade , DNA (Citosina-5-)-Metiltransferases/metabolismo , Chumbo/toxicidade , Masculino , Mineração , Ratos , Ratos Wistar , Solo/química , Poluentes do Solo/toxicidade
9.
Chemosphere ; 202: 48-55, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29554507

RESUMO

Lead (Pb) and cadmium (Cd) are toxic metals that exist ubiquitously in the environment. Children in polluted areas are particularly vulnerable to metal exposure, where clinical signs and symptoms could be nonspecific. Absorbed metals are excreted primarily in urine and reflect exposure from all sources. We analyzed Pb and Cd concentrations in blood, feces and urine of children from polluted townships near a lead-zinc mine in Kabwe, Zambia, to determine concurrent childhood exposure to the metals. Moreover, the study determined the Pb and Cd relationships among urine, feces and blood as well as accessed the potential of urine and fecal analysis for biomonitoring of Pb and Cd exposure in children. Fecal Pb (up to 2252 mg/kg, dry weight) and urine Pb (up to 2914 µg/L) were extremely high. Concentrations of Cd in blood (Cd-B) of up to 7.7 µg/L, fecal (up to 4.49 mg/kg, dry weight) and urine (up to 18.1 µg/L) samples were elevated. metal levels were higher in younger children (0-3 years old) than older children (4-7). Positive correlations were recorded for Pb and Cd among blood, urine and fecal samples whereas negative correlations were recorded with age. These findings indicate children are exposed to both metals at their current home environment. Moreover, urine and feces could be useful for biomonitoring of metals due to their strong relationships with blood levels. There is need to conduct a clinical evaluation of the affected children to fully appreciate the health impact of these metal exposure.


Assuntos
Cádmio/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/análise , Fezes/química , Intoxicação por Metais Pesados/urina , Chumbo/análise , Urinálise/métodos , Peso Corporal , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Zâmbia
10.
Environ Res ; 165: 420-424, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29089102

RESUMO

Kabwe is a lead contaminated mining town in Zambia. Kabwe has extensive lead contaminated soil and children in Kabwe ingest and inhale high quantities of this toxic dust. The aim of this paper is to analyze the health impact of this exposure for children. Health data from three existing studies were re-analyzed. Over 95% of children living in the most affected townships had high blood lead levels (BLLs) > 10µg/dL. Approximately 50% of those children had BLLs ≥ 45µg/dL. The existing data clearly establishes the presence of a severe environmental health crisis in Kabwe which warrants immediate attention.


Assuntos
Exposição Ambiental , Intoxicação por Chumbo/epidemiologia , Chumbo/toxicidade , Mineração , Poluentes do Solo/toxicidade , Criança , Monitoramento Ambiental , Humanos , Zâmbia/epidemiologia
11.
Int J Mol Sci ; 18(7)2017 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-28718783

RESUMO

Anthropogenic pollution with heavy metals is an on-going concern throughout the world, and methods to monitor release and impact of heavy metals are of high importance. With a view to probe its suitability as molecular biomarker of metal pollution, this study has determined a coding sequence for metallothionein of the African sharptooth catfish Clarias gariepinus. The gene product was recombinantly expressed in Escherichia coli in presence of Zn(II), Cd(II), or Cu, and characterised by Electrospray Ionisation Mass Spectrometry and elemental analysis. C. gariepinus MT displays typical features of fish MTs, including 20 conserved cysteines, and seven bound divalent cations (Zn(II) or Cd(II)) when saturated. Livers from wild C. gariepinus fish collected in all three seasons from four different sites on the Kafue River of Zambia were analysed for their metal contents and for MT expression levels by quantitative PCR. Significant correlations were found between Zn and Cu levels and MT expression in livers, with MT expression clearly highest at the most polluted site, Chililabombwe, which is situated in the Copperbelt region. Based on our findings, hepatic expression of MT from C. gariepinus may be further developed as a major molecular biomarker of heavy metal pollution resulting from mining activities in this region.


Assuntos
Biomarcadores/metabolismo , Peixes-Gato/metabolismo , Metalotioneína/química , Metalotioneína/metabolismo , Metais Pesados/metabolismo , Transcrição Genética , Poluição da Água , Sequência de Aminoácidos , Animais , Sequência de Bases , Peixes-Gato/genética , DNA Complementar/genética , Monitoramento Ambiental , Regulação da Expressão Gênica , Geografia , Fígado/metabolismo , Metalotioneína/genética , Modelos Moleculares , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Zâmbia
12.
Bull Environ Contam Toxicol ; 99(1): 108-116, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28434067

RESUMO

Zambia's Kafue River receives wastes from various sources, resulting in metal pollution. This study determined the degree of contamination of 13 metals (Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Hg and Pb) in Kafue River sediment and the associated ecological risks at six sites in three different seasons. The level of contamination for most metals showed significant site and seasonal differences. The contamination factor and pollution load index indicated that concentrations of most metals particularly copper (Cu), cobalt (Co), manganese (Mn) and arsenic (As) were very high at sites within the Copperbelt mining area. The geoaccumulation index showed an absence of anthropogenic enrichment with Cd and Hg at all the study sites and extreme anthropogenic enrichment with Cu at sites in the Copperbelt mining area. Potential ecological risk showed that Cu and As were likely to cause adverse biological effects to aquatic organisms in the Copperbelt mining region of the Kafue River.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Rios/química , Poluentes Químicos da Água/análise , Arsênico , Ecologia , Sedimentos Geológicos/química , Mercúrio , Medição de Risco , Estações do Ano , Zâmbia
13.
Environ Pollut ; 208(Pt B): 395-403, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26549754

RESUMO

Stable Pb isotope ratios (Pb-IRs) have been recognized as an efficient tool for identifying sources. This study carried out at Kabwe mining area, Zambia, to elucidate the presence or absence of Pb isotope fractionation in goat and chicken, to evaluate the reliability of identifying Pb pollution sources via analysis of Pb-IRs, and to assess whether a threshold for blood Pb levels (Pb-B) for biological fractionation was present. The variation of Pb-IRs in goat decreased with an increase in Pb-B and were fixed at certain values close to those of the dominant source of Pb exposure at Pb-B > 5 µg/dL. However, chickens did not show a clear relationship for Pb-IRs against Pb-B, or a fractionation threshold. Given these, the biological fractionation of Pb isotopes should not occur in chickens but in goats, and the threshold for triggering biological fractionation is at around 5 µg/dL of Pb-B in goats.


Assuntos
Galinhas , Cabras , Isótopos/análise , Chumbo/análise , Animais , Galinhas/sangue , Monitoramento Ambiental , Poluição Ambiental/análise , Cabras/sangue , Isótopos/sangue , Chumbo/sangue , Mineração , Reprodutibilidade dos Testes , Zâmbia
14.
Chemosphere ; 119: 941-947, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25303652

RESUMO

Childhood lead poisoning is a serious public health concern worldwide. Blood lead levels exceeding 5 µg dL(-1) are considered elevated. In Kabwe, the capital of Zambia's Central Province, extensive Pb contamination of township soils in the vicinity of a Pb-Zn mine and posing serious health risk to children has been reported. We investigated BLLs in children under the age of 7 years in townships around the mine; where blood samples were collected and analyzed using an ICP-MS. All of the sampled children had BLLs exceeding 5 µg dL(-1). Children in these areas could be at serious risk of Pb toxicity as 18% of the sampled children in Chowa, 57% (Kasanda) and 25% (Makululu) had BLLs exceeding 65 µg dL(-1). Eight children had BLLs exceeding 150 µg dL(-1) with the maximum being 427.8 µg dL(-1). We recommend that medical intervention be commenced in the children with BLL exceeding 45 µg dL(-1).


Assuntos
Poluentes Ambientais/sangue , Intoxicação por Chumbo/sangue , Intoxicação por Chumbo/epidemiologia , Chumbo/sangue , Adolescente , Criança , Humanos , Mineração , Zâmbia/epidemiologia , Zinco
15.
Trop Anim Health Prod ; 47(2): 459-63, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25535151

RESUMO

African swine fever (ASF) is a highly contagious and fatal hemorrhagic viral disease of domestic pigs. The disease is widespread in sub-Saharan Africa and has repeatedly been introduced into other continents. The current study describes the diagnostic investigations of a hemorrhagic disease that was reported in pigs in Lusaka (October 2013), Zambia. Necropsy, histopathology, and molecular diagnosis using polymerase chain reaction and sequence analysis confirmed the disease to be ASF. The sequences obtained showed high similarity to previously isolated ASF viruses. Consistent surveillance and rapid diagnosis of the disease is recommended to prevent future outbreaks and economic losses as there is currently no vaccine against the disease.


Assuntos
Vírus da Febre Suína Africana/isolamento & purificação , Febre Suína Africana/epidemiologia , Surtos de Doenças/veterinária , Febre Suína Africana/diagnóstico , Febre Suína Africana/microbiologia , Vírus da Febre Suína Africana/genética , Animais , Feminino , Masculino , Filogenia , Reação em Cadeia da Polimerase/veterinária , Gravidez , Suínos , Zâmbia/epidemiologia
16.
Arch Virol ; 159(10): 2633-40, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24862188

RESUMO

Whilst remarkable progress in elucidating the mechanisms governing interspecies transmission and pathogenicity of highly pathogenic avian influenza viruses (AIVs) has been made, similar studies focusing on low-pathogenic AIVs isolated from the wild waterfowl reservoir are limited. We previously reported that two AIV strains (subtypes H6N2 and H3N8) isolated from wild waterfowl in Zambia harbored some amino acid residues preferentially associated with human influenza virus proteins (so-called human signatures) and replicated better in the lungs of infected mice and caused more morbidity than a strain lacking such residues. To further substantiate these observations, we infected chickens and mice intranasally with AIV strains of various subtypes (H3N6, H3N8, H4N6, H6N2, H9N1 and H11N9) isolated from wild waterfowl in Zambia. Although some strains induced seroconversion, all of the tested strains replicated poorly and were nonpathogenic for chickens. In contrast, most of the strains having human signatures replicated well in the lungs of mice, and one of these strains caused severe illness in mice and induced lung injury that was characterized by a severe accumulation of polymorphonuclear leukocytes. These results suggest that some strains tested in this study may have the potential to infect mammalian hosts directly without adaptation, which might possibly be associated with the possession of human signature residues. Close monitoring and evaluation of host-associated signatures may help to elucidate the prevalence and emergence of AIVs with potential for causing zoonotic infections.


Assuntos
Vírus da Influenza A Subtipo H3N8/patogenicidade , Pulmão/patologia , Animais , Animais Selvagens/virologia , Galinhas , Modelos Animais de Doenças , Feminino , Humanos , Vírus da Influenza A Subtipo H3N8/imunologia , Vírus da Influenza A Subtipo H3N8/isolamento & purificação , Influenza Aviária , Influenza Humana/virologia , Pulmão/imunologia , Pulmão/virologia , Camundongos , Camundongos Endogâmicos BALB C , Neutrófilos/imunologia , Zâmbia
17.
Jpn J Vet Res ; 61 Suppl: S79-81, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23631162

RESUMO

In order to assess the effects of metal contamination on wildlife, we collected wild black rats (Rattus sp.) from mining areas (Kabwe and Chingola) and a control area (Lusaka) in Zambia and compared metal and metallothionein (MT) levels in their tissues. Furthermore, we exposed metal-contaminated soil from Kabwe to laboratory Wistar rats (Rattus norvegicus) for one year in order to determine the accumulation factors and effects of metals caused by soil exposure. Results of both the field and laboratory studies suggested that metal-contaminated soil caused accumulation and biological responses such as elevation of MT-2 mRNA expression levels in rats.


Assuntos
Metais/química , Ratos , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Animais , Animais Selvagens , Osso e Ossos/química , Encéfalo/metabolismo , Regulação Enzimológica da Expressão Gênica , Rim/química , Rim/metabolismo , Fígado/química , Fígado/metabolismo , Pulmão/química , Pulmão/metabolismo , Metaloproteinase 15 da Matriz/genética , Metaloproteinase 15 da Matriz/metabolismo , Tíbia
18.
Arch Environ Contam Toxicol ; 64(1): 119-29, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23052357

RESUMO

The Copperbelt region, upstream of the Kafue River, including Lake Itezhi-tezhi (ITT), in Zambia has extensive copper (Cu) mines. In our field study, geographic information system analysis in lake sediment indicated that the northern part of the lake, i.e., the Copperbelt region, could be the source of Cu pollution. Concentrations of Cu in stomach contents between fish species were not significantly different. However, Oreochromis spp. liver showed significantly greater Cu concentrations than those in other fish species. Log liver [Cu], standard length, and nitrogen stable isotope ratio were positively correlated only in Oreochromis spp. In the laboratory study, O. niloticus and O. latipes were exposed to Cu for 4 days, and recovery phases ≤ 28 days were examined. O. niloticus showed significantly greater concentrations of Cu compared with O. latipes at all sampling points. Significantly greater concentrations of Hg in Schilbe intermedius liver than for other fish species were observed, whereas O. macrochir showed significantly greater concentrations of cadmium. In conclusion, the northern part of the lake could be the source of Cu pollution in Lake ITT. Diet may not be the reason for high Cu accumulation in Oreochromis spp. Results from both field and laboratory studies imply that Oreochromis spp. contain high concentrations of Cu under normal physiological conditions.


Assuntos
Ciclídeos/metabolismo , Cobre/análise , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica , Lagos/química , Poluentes Químicos da Água/análise , Animais , Cobre/metabolismo , Poluentes Químicos da Água/metabolismo , Zâmbia
19.
Environ Toxicol Chem ; 32(1): 189-92, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23059509

RESUMO

Concentrations of Pb, Cd, and other metals in tissues of 17 free-range and 32 commercial broiler chickens from the Kabwe mining town in Zambia were determined. Mean concentrations of Pb and Cd exceeded maximum levels for human consumption in some organs including muscle (Pb only) in free-range chickens, in contrast to low levels in broiler chickens. Human consumers in Kabwe could be exposed to Pb and Cd in free-range chickens.


Assuntos
Galinhas/metabolismo , Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/metabolismo , Metais/metabolismo , Mineração , Animais , Exposição Ambiental/análise , Chumbo , Zâmbia , Zinco
20.
Environ Monit Assess ; 185(6): 4907-18, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23054276

RESUMO

The lead-zinc (Pb-Zn) mine in Kabwe City and the copper-cobalt (Cu-Co) mine in the Copperbelt Province are major mining areas in Zambia. To examine the effects of metal pollution on wildlife, wild black rats (Rattus rattus and Rattus tanezumi) were captured in Kabwe and Chingola (in the Copperbelt Province), and in Lusaka (a noncontaminated site). Wild black rats in Kabwe accumulated significantly higher concentrations of Pb and Cd in various organs than rats from Lusaka. In Chingola, significantly higher concentrations of Cu, Co, Pb, and Cd were accumulated in wild black rats than in rats from Lusaka. These results were in accordance with metal accumulation patterns in soil. From toxicological aspects, concentrations of Pb and Cd in rats were generally low. However, metallothionein-1 (MT-1) and metallothionein-2 (MT-2) mRNA expression levels in wild black rats from Kabwe were significantly higher than those in rats from Lusaka. A generalized linear model (GLM) showed that concentrations of Zn and Cu had positive effects on the MT-1 and MT-2 mRNA expression. These results suggest that wild black rats in Zambian mining sites were exposed to metals that accumulated in their organs, causing biological responses such as MT mRNA induction. GLM indicated that heme oxygenase-1 (HO-1) mRNA expression could be a marker for Cr exposure.


Assuntos
Monitoramento Ambiental , Poluentes Ambientais/metabolismo , Metais/toxicidade , Mineração , Animais , Poluentes Ambientais/toxicidade , Feminino , Masculino , Metais/metabolismo , Ratos , Zâmbia
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