RESUMO
This study identified and determined organochloride pesticide (OCs) concentrations in hair samples from children at two elementary schools: one exposed to fumigations in agricultural fields, the other unexposed. Three concentrations of OCs levels in the hair were compared (high, medium, low), and total nuclear abnormalities in buccal cells were determined: micronuclei (MNi), condensed chromatin, karyorrhexis, pyknosis, binucleate cells, karyolysis, lobed nuclei, and apoptosis. No significant differences were found for the presence of MNi between the schoolchildren from the exposed and unexposed schools, but the prevalence of OCs in both schools was over 50%, as well as the frequencies of MNi in the children were over 58%. Findings show a significant difference between the frequency of MNi in the total sample of schoolchildren (exposed school + unexposed school) in relation to the concentration of OCs detected in their hair. The children from exposed school that showed the higher concentrations of OCs in hair had higher levels of genotoxic damage in the buccal cells; compared against children with lower concentrations of OCs. The most frequent nuclear abnormalities in the exposed children were lobed nuclei (79.4%), binucleate cells (66.66%), apoptosis (65.07), and MNi (58.7%). We determined the prevalence ratio (PR) and prevalence odds ratio (POR) for the presence of MNi in buccal cells in relation to the OCs concentrations in the hair samples. Both ratios were high for MNi [PR 3.93, 95% confidence interval (CI) 1.97-7.84, p = 0.0003; and POR 7.97, 95% CI 2.62-24.28, p = 0.0003], indicating a 7.97 times greater risk that the exposed children will present > 0.2% of MNi when OCs concentrations exceed 0.447 µg/g. These indicators may be useful biomarkers of genotoxic damage in children exposed to persistent, highly-toxic compounds. Results suggest the potential risk to which those schoolchildren are exposed on a daily basis due to fumigations in nearby agricultural fields.
Assuntos
Hidrocarbonetos Clorados/toxicidade , Micronúcleos com Defeito Cromossômico/estatística & dados numéricos , Praguicidas/toxicidade , Morte Celular , Núcleo Celular , Criança , Cromatografia Gasosa/métodos , Dano ao DNA , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Feminino , Cabelo/química , Cabelo/metabolismo , Humanos , Hidrocarbonetos Clorados/efeitos adversos , Masculino , Testes para Micronúcleos/métodos , Mucosa Bucal/química , Mucosa Bucal/metabolismo , Praguicidas/efeitos adversosRESUMO
Although the anticonvulsant activity of 3-hydroxy-3-ethyl-3-phenylproionamide (HEPP) is well-known, its use is limited by the pharmacotoxicological profile. We herein tested its fluorinated and chlorinated derivatives (F-HEPP and Cl-HEPP) with two seizure models, maximal electroshock seizures (MES), and intraperitoneal pentylenetetrazole (PTZ) administration. Neurotoxicity was examined via the rotarod test. With in silico methods, binding was probed on possible protein targets-GABAA receptors and the sodium channel Nav1.2. The median effective doses (ED50) of HEPP, F-HEPP, and Cl-HEPP in the MES seizure model were 129.6, 87.1, and 62.0 mg/kg, respectively, and 66.4, 43.5, and in the PTZ seizure model 43.5 mg/kg. The HEPP-induced neurotoxic effect, which occurred at twice the ED50 against MES (p < 0.05), did not occur with F-HEPP or Cl-HEPP. Docking studies revealed that all tested ligands bound to GABAA receptors on a site near to the benzodiazepine binding site. However, on the sodium channel open pore Nav1.2, R-HEPP had interactions similar to those reported for phenytoin, while its enantiomer and the ligands F-HEPP and Cl-HEPP reached a site that could disrupt the passage of sodium. Our results show that, as anticonvulsant agents, parahalogen substituted compounds have an advantageous pharmacotoxicological profile compared to their precursor.
Assuntos
Anticonvulsivantes , Hidrocarbonetos Clorados , Hidrocarbonetos Fluorados , Fenilpropionatos , Convulsões/tratamento farmacológico , Animais , Anticonvulsivantes/efeitos adversos , Anticonvulsivantes/química , Anticonvulsivantes/farmacologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Eletrochoque , Hidrocarbonetos Clorados/efeitos adversos , Hidrocarbonetos Clorados/farmacologia , Hidrocarbonetos Fluorados/efeitos adversos , Hidrocarbonetos Fluorados/química , Hidrocarbonetos Fluorados/farmacologia , Masculino , Camundongos , Simulação de Acoplamento Molecular , Canal de Sódio Disparado por Voltagem NAV1.2/metabolismo , Fenilpropionatos/efeitos adversos , Fenilpropionatos/química , Fenilpropionatos/farmacologia , Receptores de GABA-A/química , Receptores de GABA-A/metabolismo , Convulsões/metabolismoRESUMO
This study describes the use of pesticides mixtures and their potential association with comet assay results in 223 rice field workers in Colombia. Thirty-one pesticides were quantified in blood, serum, and urine (15 organochlorines, 10 organophosphorus, 5 carbamates, and ethylenethiourea), and the comet assay was performed. Twenty-four (77.42%) pesticides were present in the workers. The use of the maximum-likelihood factor analysis identified 8 different mixtures. Afterwards, robust regressions were used to explore associations between the factors identified and the comet assay. Two groups of mixtures--α-benzene hexachloride (α-BHC), hexachlorobenzene (HCB), and ß-BHC (ß: 1.21, 95% confidence interval [CI]: 0.33-2.10) and pirimiphos-methyl, malathion, bromophos-methyl, and bromophos-ethyl (ß: 11.97, 95% CI: 2.34-21.60)--were associated with a higher percentage of DNA damage and comet tail length, respectively. The findings suggest that exposure to pesticides varies greatly among rice field workers.
Assuntos
Agricultura , Dano ao DNA/efeitos dos fármacos , Exposição Ocupacional/efeitos adversos , Oryza , Praguicidas/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carbamatos/efeitos adversos , Carbamatos/análise , Colômbia , Ensaio Cometa , Estudos Transversais , Etilenotioureia/efeitos adversos , Etilenotioureia/análise , Feminino , Humanos , Hidrocarbonetos Clorados/efeitos adversos , Hidrocarbonetos Clorados/análise , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/análise , Compostos Organofosforados/efeitos adversos , Compostos Organofosforados/análise , Praguicidas/sangue , Adulto JovemRESUMO
Phytoremediation is an attractive alternative to conventional treatments of soil due to advantages such as low cost, large application areas, and the possibility of in situ treatment. This study presents the assessment of phytoremediation processes conducted under controlled experimental conditions to evaluate the ability of Ricinus communis L., tropical plant species, to promote the degradation of 15 persistent organic pollutants (POPs), in a 66-day period. The contaminants tested were hexachlorocyclohexane (HCH), DDT, heptachlor, aldrin, and others. Measurements made in rhizosphere soil indicate that the roots of the studied species reduce the concentration of pesticides. Results obtained during this study indicated that the higher the hydrophobicity of the organic compound and its molecular interaction with soil or root matrix the greater its tendency to concentrate in root tissues and the research showed the following trend: HCHs < diclofop-methyl < chlorpyrifos < methoxychlor < heptachlor epoxide < endrin < o,p'-DDE < heptachlor < dieldrin < aldrin < o,p'-DDT < p,p'-DDT by increasing order of log K ow values. The experimental results confirm the importance of vegetation in removing pollutants, obtaining remediation from 25% to 70%, and demonstrated that Ricinus communis L. can be used for the phytoremediation of such compounds.
Assuntos
Biodegradação Ambiental , Poluição Ambiental/efeitos adversos , Hidrocarbonetos Clorados/efeitos adversos , Ricinus/crescimento & desenvolvimento , Monitoramento Ambiental , Hidrocarbonetos Clorados/química , Praguicidas/efeitos adversos , Praguicidas/química , Ricinus/químicaRESUMO
In October 2007, a light crude oil spill took place in the off shore Kab121 oil well, 32 km north of the mouth of the Grijalva River, Tabasco, Mexico. In order to estimate the possible effects of oil spill on the biota in the area surrounding the spilled well, the level of different fractions of petroleum hydrocarbons were measured in fish, as well as the concentration of some chlorinated hydrocarbons and PCBs. The organisms examined were cat fish (Ariopsis felis), in addition fluorescent aromatic compounds in bile, the contaminants above mentioned and their relationship with cyotochrome P-450 and Ethoxyresorufin-O-deethylase, Glutathion-S-Transferase and catalase activities in liver were determined. The concentration of most pollutants were low, except PAHs. Spatial distribution of these compounds, as well as most biomarkers, reflected the highest exposure of fish to pollutants in the area adjacent to well, as well as in the proximity of rivers. The profile of exposure to this environment was chronic in nature and not temporary.
Assuntos
Poluição por Petróleo/efeitos adversos , Hidrocarbonetos Policíclicos Aromáticos/efeitos adversos , Animais , Bile/química , Biomarcadores/análise , Peixes-Gato , Golfo do México , Hidrocarbonetos Clorados/efeitos adversos , Hidrocarbonetos Clorados/análise , Praguicidas/efeitos adversos , Praguicidas/análise , Poluição por Petróleo/análise , Bifenilos Policlorados/efeitos adversos , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análiseRESUMO
BACKGROUND: Several studies have investigated the effects of organochlorine (OC) pesticides on adverse reproductive outcomes. However, few previous studies explored their effects on sex hormones. OBJECTIVE: To examine the association between serum concentrations of OC pesticides and levels of sex hormones in adult population in a rural area in Brazil heavily contaminated with these pesticides. METHODS: A cross-sectional study with 304 men and 300 women was undertaken. Wet weight serum concentrations of 19 OC pesticides (dichloro-diphenyl-trichloroethane [DDT] and hexachlorocyclohexane [HCH], among others) were determined in all participants. Testosterone levels were obtained for men and estradiol, progesterone, prolactin, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) for women. Associations between OC pesticides and sex hormones were evaluated using linear regression models. RESULTS: Prevalence of women with non-physiological hyperprolactinemia was 4%. After adjusting for serum lipids and confounders, heptachlor and o,p'-DDT concentrations in men were associated with lower testosterone levels, while peri- and postmenopausal women (N=77) showed inverse associations between LH and hexachlorobenzene (HCB), p,p'-DDT, p,p'-DDD (dichloro-diphenyl-dichloroethane), endosulfan 1 and 2, aldrin and mirex, as well as between FSH and p,p'-DDD, endosulfan 1 and aldrin. Premenopausal women (N=210) did not show statistically significant associations between OC pesticides and sex hormones. CONCLUSIONS: Inverse associations between OC pesticide concentrations and testosterone in men and LH and FSH in peri-/postmenopausal women, together with the high proportion of women with elevated prolactin, suggest that these OC compounds may have triggered anti-androgenic effects in men and estrogenic effects in women in this population.
Assuntos
DDT/sangue , Exposição Ambiental/efeitos adversos , Poluentes Ambientais/efeitos adversos , Hormônios Esteroides Gonadais/sangue , Hexaclorobenzeno/sangue , Hidrocarbonetos Clorados/efeitos adversos , Praguicidas/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Estudos Transversais , DDT/efeitos adversos , Disruptores Endócrinos/efeitos adversos , Disruptores Endócrinos/sangue , Exposição Ambiental/análise , Poluentes Ambientais/sangue , Feminino , Hexaclorobenzeno/efeitos adversos , Humanos , Hidrocarbonetos Clorados/sangue , Hiperprolactinemia/epidemiologia , Hiperprolactinemia/etiologia , Masculino , Pessoa de Meia-Idade , Praguicidas/efeitos adversos , Prevalência , Adulto JovemRESUMO
Organochlorine pesticides have been used in Mexico in agriculture as a seed dresser, in sanitation, in malaria control programmes and in livestock to combat ectoparasites. The pesticides applied drift to areas where cattle graze and plants grow. Because of their chemical stability, they accumulate in the lipid-rich tissues of the body. In the body, they circulate throughout all compartments and accumulate in adipose fat. The aim was to monitor the organochlorine pesticide levels in bovine muscle fat and kidney fat from cows living in an endemic malaria zone, where the environmental contamination can be suspected as being higher. Two hundred samples (100 muscle fat, 100 kidney fat) were analysed by gas chromatography. From the pesticides, only hexachlorobenzene (HCB), beta-hexachlorocyclohexane (HCH), gamma-HCH, pp'-1.1.1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), op'-DDT and pp'-DDE, were detected frequently and at levels above the detection limits. The HCB mean level was low at 0.009 mg kg(-1) on a fat basis. From the HCH isomers, beta-HCH mean concentration was 0.039 mg kg(-1) and gamma-HCH was 0.025 mg kg(-1) on a fat basis. Among DDTs, pp'-DDT was the major constituent (0.032 mg kg(-1) on a fat basis) followed by pp'-DDE (0.025 mg kg(-1) on a fat basis) and op'-DDT (0.023 mg kg(-1) on a fat basis). The DDT total (sigma DDT) level was 0.067 mg kg(-1) on a fat basis. Comparing the previous study (1994) and the present one (2002-03), organochlorine pesticide levels were decreased. HCB decreased 3.7 times from 0.033 to 0.009 mg kg(-1) on a fat basis; beta-HCH decreased 3.8 times from 0.149 to 0.039 mg kg(-1) on a fat basis; pp'-DDE did not reveal a significant difference at 0.026 versus 0.025 mg kg(-1) on a fat basis. However, pp'-DDT decreased substantially, 6.7 times from 0.215 to 0.032 mg kg(-1) on a fat basis. The DDT total decreased 3.5 times from 0.236 to 0.067 mg kg(-1) on a fat basis. The tendency for reduced concentrations in organochlorine pesticide levels in Mexican cows is caused by their substitution with pyrethroids used in agriculture and by the Mexican Ministry of Health in sanitary programmes.
Assuntos
Tecido Adiposo/química , Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Animais , Bovinos , DDT/efeitos adversos , DDT/análise , Diclorodifenil Dicloroetileno/efeitos adversos , Diclorodifenil Dicloroetileno/análise , Doenças Endêmicas/prevenção & controle , Exposição Ambiental/efeitos adversos , Contaminação de Alimentos/análise , Hexaclorobenzeno/efeitos adversos , Hexaclorobenzeno/análise , Hexaclorocicloexano/efeitos adversos , Hexaclorocicloexano/análise , Hidrocarbonetos Clorados/efeitos adversos , Isomerismo , Rim/química , Malária/prevenção & controle , México , Músculos/química , Resíduos de Praguicidas/efeitos adversosRESUMO
In this study, we determined the biologic activity of dichloromethane-extracted particulate matter < 10 micro m in aerodynamic diameter (PM10) obtained from filters at three sites in the Paso del Norte airshed, which includes El Paso, Texas, USA; Juarez, Chihuahua, Mexico, and Sunland Park, New Mexico, USA. The extracts were rich in polycyclic aromatic hydrocarbons (PAHs) and had significant biologic activity, measured using two in vitro assay systems: ethoxyresorufin-(O-deethylase (EROD) induction and the aryl hydrocarbon-receptor luciferase reporter system. In most cases, both EROD (5.25 pmol/min/mg protein) and luciferase activities (994 relative light units/mg) were highest in extracts from the Advance site located in an industrial neighborhood in Juarez. These values represented 58% and 55%, respectively, of induction associated with 1 micro M ss-naphthoflavone exposures. In contrast, little activity was observed at the Northeast Clinic site in El Paso, the reference site. In most cases, luciferase and EROD activity from extracts collected from the Tillman Health Center site, situated in downtown El Paso, fell between those observed at the other two sites. Overall, a statistically significant correlation existed between PM10 and EROD and luciferase activities. Chemical analysis of extracts collected from the Advance site demonstrated that concentrations of most PAHs were higher than those reported in most other metropolitan areas in the United States. Calculations made with these data suggest a cancer risk of 5-12 cases per 100,000 people. This risk estimate, as well as comparisons with the work of other investigators, raises concern regarding the potential for adverse health effects to the residents of this airshed. Further work is needed to understand the sources, exposure, and effects of PM10 and particulate organic material in the Paso del Norte airshed.
Assuntos
Poluentes Atmosféricos/análise , Exposição Ambiental/análise , Hidrocarbonetos Clorados/análise , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Emissões de Veículos/análise , Poluentes Atmosféricos/efeitos adversos , Animais , Biomarcadores , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/efeitos adversos , México , Camundongos , Mutagênese , Bifenilos Policlorados/efeitos adversos , Bifenilos Policlorados/análise , Risco , Células Tumorais Cultivadas , Estados Unidos , Emissões de Veículos/efeitos adversosRESUMO
Behavioral end points are being used with greater frequency in neurotoxicology to detect and characterize the adverse effects of chemicals on the nervous system. Behavioral measures are particularly important for neurotoxicity risk assessment since many known neurotoxicants do not result in neuropathology. The chlorinated hydrocarbon class consists of a wide variety of chemicals including polychlorinated biphenyls, clioquinol, trichloroethylene, hexachlorophene, organochlorine insecticides (DDT, dicofol, chlordecone,dieldrin, and lindane), and phenoxyherbicides. Each of these chemicals has effects on motor, sensory, or cognitive function that are detectable using functional measures such as behavior. Furthermore, there is evidence that if exposure occurs during critical periods of development, many of the chlorinated hydrocarbons are developmental neurotoxicants. Developmental neurotoxicity is frequently expressed as alterations in motor function or cognitive abilities or changes in the ontogeny of sensorimotor reflexes. Neurotoxicity risk assessment should include assessments of the full range of possible neurotoxicological effects, including both structural and functional indicators of neurotoxicity.