RESUMO
A molecularly imprinted polymer was developed and evaluated for selective determination of metronidazole (MNZ) in wastewater. This was achieved by using sodium methacrylate as monomer, toluene as porogen, ethylene glycol dimethacrylate as crosslinker, azobisisobutyronitrile as initiator and metronidazole as template molecule to generate the selectivity of the polymer for the compound, as well as non-imprinted polymers were synthesized. Two different polymerization approaches were used, bulk and emulsion and the polymers obtained by emulsion presented higher retention percentages the MIP 2-M presented the higher retention (83%). The performed method, was validated in fortified water, showing linearity from 10 up to 1000 ng/mL; limit of detection and quantification for compound were between 3 and 10 ng/mL, respectively. Finally, the method was applied in samples of a wastewater treatment plant in the city of San Luis Potosí, México, and the concentrations of MNZ in these samples were 84.1-114 ng/mL.
Assuntos
Metronidazol/análise , Impressão Molecular/métodos , Ácidos Polimetacrílicos/síntese química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Adsorção , Limite de Detecção , Metacrilatos/química , México , Nitrilas/química , Ácidos Polimetacrílicos/química , Propriedades de Superfície , Tolueno/químicaRESUMO
A simple and rapid focused ultrasound extraction method was developed for the determination of Persistent Organic Pollutants (POPs) in liver tissue obtained of giant toad (Rhinella marina) using a gas chromatography coupled to a mass detector with electron impact ionization. The performed method for POPs, was validated in fortified matrix, showing linearity from the LOQ up to 100 ng/mL; LODs and LOQs for each compound were between 1.7 and 4.8 and 3.5-7.5 ng/mL, respectively. Recovery rates were among 79%-116% for POPs determined. Finally, the method was applied in liver samples of giant toads found in a malarial area in Mexico. The sensitivity of the proposed method was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.
Assuntos
Bufo marinus/metabolismo , Poluentes Ambientais/metabolismo , Animais , Poluição Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Fígado/metabolismo , MéxicoRESUMO
The aim of this study was to conduct a POP biomonitoring programme for children in high-risk areas. We evaluated 247 serum samples from children between the ages of 6 and 12years old from two zones in Mexico: (1) indigenous zones, which included Cuatlamayan (CUA), Tocoy (TOC), and Santa Maria Picula (SAM); and (2) industrial zones, which included Tercera Chica (TC), Industrial San Luis (IND) and Rincon de San Jose (SJR); Mundo Nuevo (MN); and Alpuyeca (ALP). Our results showed that α-endosulfan was similar to CUA, TOC, SAM, TC and MN (178.6-306.9ng/g lipid). ß-Endosulfan levels were higher in ALP (901.5ng/g lipid), followed by CUA (139.9ng/g lipid) and TOC, SAM, TC and MN, which had similar levels (55.4-64.5ng/g lipid). For endosulfan sulfate, the ALP community had the highest concentration levels (1096.4ng/g lipid), whereas CUA and TOC (212.3 and 289ng/g lipid, respectively) had concentrations similar to those found in SAM and TC (99.5 and 119.1ng/g lipid, respectively). DDE levels were found in malaria-endemic areas of SAM, CUA and TOC (1782.2, 1358.3 and 57.0ng/g lipid), followed by MN (35.1ng/g lipid). HCB concentration levels were found to be higher in MN and SJR (691.8 and 575.4ng/g lipid, respectively), followed by CUA and TC (363.9 and 269.1ng/g lipid, respectively), with levels similar to those found in TOC and SAM (191.8 and 181.9ng/g lipid, respectively). Finally, PCB 101 concentration levels were found to be the highest in ALP (1032.7ng/g lipid), followed by similar levels of SJR and IND (567.5 and 327.3ng/g lipid, respectively) and TC and MN, with 109.1 and 144.5ng/g lipid, respectively. The evidence provided by this exploratory study indicates that the evaluation of the health risks posed to children living in contaminated areas is a high priority health issue.
Assuntos
Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/metabolismo , Compostos Orgânicos/metabolismo , Criança , Pré-Escolar , Diclorodifenil Dicloroetileno/metabolismo , Endossulfano/metabolismo , Exposição Ambiental/análise , Monitoramento Ambiental , Feminino , Locais de Resíduos Perigosos , Humanos , Masculino , México , Bifenilos Policlorados/metabolismoRESUMO
The aim of the present work was to complete an exposure assessment in three Mexican indigenous communities using the community-based health risk assessment, which is the first step in the CHILD framework. We used 1-hydroxypyrene (1-OHP) as an exposure biomarker to polycyclic aromatic hydrocarbons (PAHs) and trans, trans-muconic acid (t,t-MA) as an exposure biomarker to benzene, persistent organic pollutants (POPs), lead, manganese, arsenic, and fluoride. Anthropometric measurements were also taken. In these communities, high percentages of children with chronic malnutrition were found (28 to 49 %) based on their weight and age. All communities showed a high percentage of children with detectable levels of four or more compounds (70 to 82 %). Additionally, our results showed that in indigenous communities, children are exposed to elevated levels of certain environmental pollutants, including manganese with 17.6, 16.8, and 7.3 µg/L from SMP, TOC, and CUA, respectively. Lead and HCB levels were similar in the indigenous communities (2.5, 3.1, and 4.2 µg/dL and 2.5, 3.1, and 3.7 ng/mL, respectively). 1-OHP and t,t-MA levels were higher in TOC (0.8 µmol/mol of creatinine, 476 µg/g of creatinine, respectively) when compared with SMP (0.1 µmol/mol of creatinine, 215.5 µg/g of creatinine, respectively) and CUA (0.1 µmol/mol of creatinine, 185.2 µg/g of creatinine, respectively). DDE levels were 30.7, 26.9, and 9.6 ng/mL in CUA, SMP, and TOC, respectively. The strength of this study is that it assesses exposure to pollutants with indications for the resultant risk before an intervention is made by the CHILD program to manage this risk in the indigenous communities. Considering the large number of people, especially children, exposed to multiple pollutants, it is important to design effective intervention programs that reduce exposure and the resultant risk in the numerous indigenous communities in Mexico.
Assuntos
Exposição Ambiental/estatística & dados numéricos , Poluentes Ambientais/metabolismo , Pirenos/metabolismo , Arsênio/metabolismo , Benzeno/metabolismo , Biomarcadores/metabolismo , Criança , Pré-Escolar , Creatinina , Exposição Ambiental/análise , Poluentes Ambientais/análise , Feminino , Humanos , Masculino , México , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Medição de Risco , Ácido Sórbico/análogos & derivados , Ácido Sórbico/metabolismoRESUMO
A simple and rapid focused ultrasound extraction (FU) based method is presented for the determination of persistent organic pollutants (POPs) in soil using a gas chromatography coupled to a mass detector with electron impact ionization. The main experimental parameters affecting the FU step have been optimized by applying a PERMANOVA and PCO analysis allowing us to obtain a maximum amount of information with a minimum number of assays. The limits of detection for POPs fell within the 0.9-6.8 ng/g d.w. interval; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (25 ng/g d.w.) were 75.8%-110%, and at high concentrations (75 ng/g d.w.) 82.3%-109%; the evaluated precision as RSD% of repeatability and reproducibility were within a range of 0.5%-11% and 0.3%-18%, respectively.
Assuntos
Poluentes do Solo/análise , Cromatografia Gasosa/métodos , Reprodutibilidade dos Testes , UltrassomRESUMO
A simple and rapid headspace solid-phase microextraction (HS SPME) based method is presented for the determination of Persistent Organic Pollutants (POPs) in human serum by gas chromatography (GC) coupled to mass detector (MS) with electron impact ionization (EI). As an outcome of the assessment of several polymer phases; the one with the best result was the PDMS fiber (100 µm). A multivariate analysis of variance by permutations (PERMANOVA) was performed to establish the optimal extraction conditions as a function of temperature and time variables. The results were 1 mL serum+200 µL H2SO4 9M+1 mL of deionized water at 600 rpm with a temperature of 80°C for 50 min to expose the fiber. The limits of detection (LOD) for POPs pesticides fell within the 0.22-5.41 ng/mL interval, and within 0.07-1.79 ng/mL for PCBs; a linear method was used with correlation coefficients (r) higher than 0.99. Recovery percentages at low concentrations (15 ng/mL) were 67.8-120.2%, and at high concentrations (75 ng/mL) 80.2-119.2%. Evaluated precision as percentage Relative Standard Deviation (RSD%) of repeatability and reproducibility was within a range of 0.5-9% and 0.3-21%, respectively. This analytical method prevents some of the main problems for quantifying POPs in human serum, such as the elimination of the solvents, sample handling, integration of extraction steps, pre-concentration and introduction of samples; consequently, the time and cost of analyzing the sample can be significantly reduced. The method developed was applied to determine exposure to POPs in samples of children living in different polluted sites in Mexico. In children living in indigenous communities results show exposure to DDE (median 29.2 ng/mL range 17.4-52.2 ng/mL) and HCB (median 2.53 ng/mL range 2.50-2.64 ng/mL); whereas in the industrial scenario, exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (median Σ-PCBs 22.2 ng/ml range 8.2-74.6 ng/mL) and finally in petrochemical scenario was demonstrated exposure to HCB (median 2.81 ng/mL range 2.61-3.4 ng/mL) and PCBs (Σ-PCBs median 7.9 ng/mL range 5.4-114.5 ng/mL).
Assuntos
Poluentes Ambientais/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Praguicidas/análise , Microextração em Fase Sólida/métodos , Criança , Monitoramento Ambiental/métodos , Poluentes Ambientais/sangue , Humanos , Análise Multivariada , Compostos Orgânicos/análise , Compostos Orgânicos/sangue , Praguicidas/sangue , Bifenilos Policlorados/análise , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
In this work, we describe the results of a preliminary soil assessment program for the detection of dioxins at different sites in Mexico performed by immunoassay. We studied five different sectors considered relevant sources of dioxins: Anaversa and Tekchem industrial areas where organochlorine pesticides were manufactured and released by accidental explosions, secondary smelters, brick kilns, and rural dwellings. In the context of the Agency for Toxic Substances and Disease Registry (ATSDR) guidelines, only the brick kilns sites can be considered as low-risk areas. The dioxin concentrations detected in the vicinity of the Anaversa and Tekchem chemical plants and secondary smelters exceed the screening level of 0.05 ppb set by the ATSDR, and therefore further site-specific studies are needed. The dioxin levels found in all soot samples from indigenous dwellings where wood is used for indoor cooking were above the evaluation level. Considering that the studied areas are representative examples of dioxin sources in less developed countries, our work demonstrates the useful application of dioxin immunoassays as a tool for dioxin screening for environmental assessment programs in developing countries.
Assuntos
Dioxinas/análise , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Solo , Monitoramento Ambiental/instrumentação , Ensaio de Imunoadsorção Enzimática , México , Padrões de Referência , Reprodutibilidade dos Testes , Solo/análise , Solo/normasRESUMO
The aim of this study was to assess the value of the children's version of the Rey-Osterrieth Complex Figure Test as a screening test in a population exposed to different mixtures of neurotoxicants. Copy and Immediate Recall scores were evaluated through the test. Children were recruited from three sites; an area with natural contamination by fluoride and arsenic (F-As), a mining-metallurgical area with lead and arsenic contamination (Pb-As) and a malaria zone with the evidence of fish contaminated with dichlorodiphenyltrichloroethane (DDT) and polychlorinated biphenyls (PCBs). Children aged 6-11 years old, living in one of the three polluted sites since birth were recruited (n=166). The exposure was evaluated as follows: fluoride and arsenic in urine, lead in blood and DDT, dichlorodiphenyldichloroethylene (DDE) and PCBs in serum. To evaluate the test performance, z-scores for Copy and Immediate Recall were calculated. The proportion of children by residence area with performance lower than expected by age (below -1 SD) for Copy and Immediate Recall was in the F-As area (88.7% and 59%) and in the DDT-PCBs area (73% and 43.8%), respectively. In the Pb-As area, the proportion was 62% for both tests. After adjustment, Copy correlated inversely with fluoride in urine (r=-0.29; p<0.001) and Immediate Recall correlated inversely with fluoride in urine (r=-0.27; p<0.05), lead in blood (r=-0.72; p<0.01), arsenic in urine (r=-0.63; p<0.05) and DDE (r=-0.25; p<0.05). This study provided evidence that children included in this research are living in high risk areas and were exposed to neurotoxicants. Poor performance in the test could be explained in some way by F, Pb, As or DDE exposure, however social factors or the low quality of school education prevalent in the areas could be playing an important role.
Assuntos
Avaliação da Deficiência , Poluição Ambiental , Síndromes Neurotóxicas/diagnóstico , Índice de Gravidade de Doença , Amidas/urina , Antropometria/métodos , Arsênio/urina , Intoxicação por Arsênico/diagnóstico , Intoxicação por Arsênico/fisiopatologia , Criança , DDT/toxicidade , Monitoramento Ambiental , Monitoramento Epidemiológico , Feminino , Intoxicação por Flúor/diagnóstico , Intoxicação por Flúor/epidemiologia , Intoxicação por Flúor/fisiopatologia , Humanos , Hidrocarbonetos Fluorados/urina , Masculino , Síndromes Neurotóxicas/epidemiologia , Síndromes Neurotóxicas/etiologia , Neurotoxinas/classificação , Neurotoxinas/toxicidade , Bifenilos Policlorados/toxicidade , Reprodutibilidade dos TestesRESUMO
The aim of this work was to investigate the effect of cadmium, lead and arsenic on the apoptosis of human immune cells. Peripheral blood mononuclear cells (MNC) were incubated with increasing concentrations of these metals and then cellular apoptosis was determined by flow cytometry and by DNA electrophoresis. We found that arsenic induced a significant level of apoptosis at 15 microM after 48h of incubation. Cadmium had a similar effect, but at higher concentrations (65 microM). In addition, cadmium exerted a cytotoxic effect on MNC that seemed to be independent of the induction of apoptosis. In contrast, concentrations of lead as high as 500 microM were nontoxic and did not induce a significant degree of apoptosis. Additional experiments showed that arsenic at concentrations as low as 1.0 microM had a significant pro-apoptotic effect when cells were cultured in the presence of this pollutant for more than 72. Non-T cells were more susceptible than T lymphocytes to the effect of arsenic and cadmium. Interestingly, MNC from children chronically exposed to arsenic showed a high basal rate of apoptosis and a diminished in vitro sensibility to this metalloid. Our results indicate that both arsenic and cadmium are able to induce apoptosis of lymphoid cells, and suggest that this phenomenon may contribute to their immunotoxic effect in vivo.
Assuntos
Apoptose/efeitos dos fármacos , Arsênio/efeitos adversos , Cádmio/efeitos adversos , Poluentes Ambientais/efeitos adversos , Chumbo/efeitos adversos , Leucócitos Mononucleares/efeitos dos fármacos , Adulto , Arsênio/urina , Arsenitos/farmacologia , Arsenitos/toxicidade , Cloreto de Cádmio/farmacologia , Cloreto de Cádmio/toxicidade , Células Cultivadas/efeitos dos fármacos , Criança , Creatinina/urina , Relação Dose-Resposta a Droga , Exposição Ambiental , Humanos , Síndromes de Imunodeficiência/induzido quimicamente , Leucócitos Mononucleares/citologia , México , Mineração , Compostos Organometálicos/farmacologia , Compostos Organometálicos/toxicidade , Formação de Roseta , Compostos de Sódio/farmacologia , Compostos de Sódio/toxicidade , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacosRESUMO
This cross-sectional study examined the effects of chronic exposure to lead (Pb), arsenic (AS) and undernutrition on the neuropsychological development of children. Two populations chronically exposed to either high (41 children) or low (39 children) levels of As and Pb were analyzed using the Wechsler Intelligence Scale for Children, Revised Version, for México (WISC-RM). Geometric means of urinary arsenic (AsU) and lead in blood (PbB) were 62.9+/-0.03 (microgAs/g creatinine) and 8.9+/-0.03 (microg/dl) for the exposed group and 40.2+/-0.03 (microgAs/g creatinine) and 9.7+/-0.02 (microg/dl) for the reference group. The height for age index (HAI) was used as an indicator of chronic malnutrition and sociodemographic information was obtained with a questionnaire. Lead and arsenic were measured by atomic absorption spectrophotometry. Data on full, verbal, and performance intelligence quotients (IQ) scores, long-term memory, linguistic abstraction, attention span, and visuospatial organization were obtained through the WISC-RM. After controlling for significant potential confounders verbal IQ (P<0.01) decreased with increasing concentrations of AsU. The HAI correlated positively with full-scale and performance IQ (P<0.01). Higher levels of AsU were significantly related to poorer performance on WISC-RM factors examining long-term memory and linguistic abstraction, while lower scores in WISC-RM factors measuring attention were obtained at increasing values of PbB. Our results suggest that exposure to As and chronic malnutrition could have an influence on verbal abilities and long-term memory, while Pb exposure could affect the attention process even at low levels.