Josino Costa Moreira

Avaliação integrada do impacto do uso de agrotóxicos sobre a saúde humana em uma comunidade agrícola de Nova Friburgo, RJ

O impacto do uso de agrotoxicos sobre a saude humana e um problema que tem merecido atencao da comunidade cientifica em todo o mundo, sobretudo nos paises em desenvolvimento. O consumo de agrotoxicos na regiao sudeste do Brasil esta estimado em 12kg de agrotoxico/trabalhador/ano. Em algumas areas agricolas do Estado do Rio de Janeiro, como na regiao da Microbacia do Corrego de Sao Lourenco, Nova Friburgo, o consumo de agrotoxico foi estimado em 56kg de agrotoxico/trabalhador/ano. Elevados niveis de contaminacao humana e ambiental foram encontrados nesta regiao, como decorrencia do uso extensivo destes agentes quimicos. A avaliacao do impacto sobre a saude humana implica o conhecimento e a visualizacao da importância/magnitude relativa de cada uma das vias de contaminacao. Inumeros fatores, que, em geral, encontram-se inter-relacionados, contribuem para a situacao encontrada na Microbacia do Corrego de Sao Lourenco e a forma mais adequada de se avaliar toda a dimensao deste problema e o uso de uma abordagem integrada.

Influência de fatores socioeconômicos na contaminaçäo por agrotóxicos, Brasil

OBJETIVO: A elevada utilizacao de agrotoxicos, sem os cuidados necessarios, tem contribuido para a degradacao ambiental e o aumento das intoxicacoes ocupacionais, sendo um dos principais problemas de saude publica no meio rural brasileiro. O objetivo do trabalho e avaliar a exposicao de um grupo de trabalhadores da area rural do Estado do Rio de Janeiro a agrotoxicos anticolinesterasicos, atraves das atividades da acetilcolinesterase eritrocitaria (AChE) e da butirilcolinesterase plasmatica (BChE), e o impacto de alguns indicadores socioeconomicos e de utilizacao de agrotoxicos sobre a contaminacao humana. METODOS: Para a avaliacao da exposicao de 300 agricultores residentes em cinco comunidades do distrito de Mage, RJ, uma amostra aleatoria de 55 trabalhadores foi selecionada e determinadas as atividades individuais de acetilcolinesterase eritrocitartia (AChE) e butirilcolinesterase plasmatica (BChE). As atividades enzimaticas foram avaliadas segundo o metodo de Ellman modificado por Oliveira-Silva. Dados socioeconomicos e de utilizacao de agrotoxicos para cada trabalhador da amostra foram obtidos em entrevista estruturada. O possivel papel dos indicadores socioeconomicos e de uso de agrotoxicos sobre o nivel de contaminacao dos trabalhadores foi estimado por analise de regressao linear multipla, utilizando-se a atividade enzimatica como variavel dependente e os indicadores socioeconomicos e de uso de agrotoxicos como variaveis independentes. RESULTADOS E CONCLUSOES: Os dados obtidos mostraram resultados distintos em relacao a incidencia da exposicao excessiva, de acordo com o indicador enzimatico utilizado. No grupo de trabalhadores, 3,6% (2) foram identificados pelos resultados de BChE e 41,8% (23) pela AChE, sendo considerados intoxicados individuos com pelo menos um dos indicadores positivos. A avaliacao desses dados frente aos indicadores socioeconomicos e de utilizacao de agrotoxicos, destaca a importância do nivel de escolaridade sobre a prevalencia das intoxicacoes. Para os demais determinantes estudados, nenhuma correlacao significativa foi tao evidente.

Use of Titanium Dioxide Photocatalysis on the Remediation of Model Textile Wastewaters Containing Azo Dyes

The photocatalytic degradation of two commercial textile azo dyes, namely C.I Reactive Black 5 and C.I Reactive Red 239, has been studied. TiO2 P25 Degussa was used as catalyst and photodegradation was carried out in aqueous solution under artificial irradiation with a 125 W mercury vapor lamp. The effects of the amount of TiO2 used, UV-light irradiation time, pH of the solution under treatment, initial concentration of the azo dye and addition of different concentrations of hydrogen peroxide were investigated. The effect of the simultaneous photodegradation of the two azo dyes was also investigated and we observed that the degradation rates achieved in mono and bi-component systems were identical. The repeatability of photocatalytic activity of the photocatalyst was also tested. After five cycles of TiO2 reuse the rate of colour lost was still 77% of the initial rate. The degradation was followed monitoring the change of azo dye concentration by UV-Vis spectroscopy. Results show that the use of an efficient photocatalyst and the adequate selection of optimal operational parameters may easily lead to a complete decolorization of the aqueous solutions of both azo dyes.

Multibiomarker approach in fish to assess the impact of pollution in a large Brazilian river, Paraiba do Sul

This article examines the advantages of the use of biomarkers as environmental indicators by applying it to Paraiba do Sul watershed, one of the most important Brazilian water bodies, which is in a critical environmental situation. We use a multibiomarker approach in fish as an integrated strategy to assess the impact of pollution. It comprehends a general biomarker of fish health, the condition factor (CF), and specific biomarkers of contaminant exposure such as metallothionein (MT), acetylcholinesterase (AChE) activity and biliary polycyclic aromatic hydrocarbons (PAH) metabolites. Our results revealed different effects in the fish from diverse locations with varying degrees of pollution. Furthermore, fish located just upstream of the water-treatment plant of the metropolitan area of Rio de Janeiro has shown to be affected by metals. This study indicates the usefulness of integrating a set of biomarkers to define the effects of anthropogenic inputs in aquatic bodies under complex polluted situations.

Manganese exposure and the neuropsychological effect on children and adolescents: a review

OBJECTIVES Manganese (Mn) is an essential element, but overexposure can have neurotoxic effects. METHODS In this article, we review and summarize studies on exposure to Mn and nervous system impairments in children. RESULTS We identified 12 original articles published between 1977 and 2007. Overexposure to Mn was suspected to occur through diverse sources: infant milk formula, drinking water, industrial pollution, and mining wastes. The most common bioindicator of exposure to Mn was hair Mn content, but some studies measured Mn in blood, urine, or dentin; one study on prenatal exposure measured Mn content in cord blood. Most studies indicate that higher postnatal exposure to Mn is associated with poorer cognitive functions and hyperactive behavior. CONCLUSIONS The limitations of the existing studies are numerous: most were cross-sectional, had a modest sample size, and lacked adjustment for important confounders. Future investigations should be performed on a larger sample size and include a more detailed exposure assessment, addressing multiple sources of exposure such as food, water, and airborne particulates.

High levels of hair manganese in children living in the vicinity of a ferro-manganese alloy production plant

Manganese (Mn) is an essential element, but an effective toxic at high concentrations. While there is an extensive literature on occupational exposure, few studies have examined adults and children living near important sources of airborne Mn. The objective of this study was to analyze hair Mn of children living in the vicinity of a ferro-manganese alloy production plant in the Great Salvador region, State of Bahia, Brazil and examine factors that influence this bioindicator of exposure. We examined 109 children in the age range of 1-10 years, living near the plant. Four separate housing areas were identified a priori on the bases of proximity to the emission sources and downwind location. A non-exposed group (n=43) of similar socio-economic status was also evaluated. Mn hair (MnH) concentration was measured by graphite atomic absorption spectrometry (GFAAS). Possible confounding hematological parameters were also assessed. Mean MnH concentration was 15.20 microg/g (1.10-95.50 microg/g) for the exposed children and 1.37 microg/g (0.39-5.58 microg/g) for the non-exposed. For the former, MnH concentrations were 7.95+/-1.40 microg/g (farthest from the plant), 11.81+/-1.11 microg/g (mid-region), 34.43+/-8.66 microg/g (closest to the plant) and 34.22+/-9.15 microg/g (directly downwind). Multiple regression analysis on log transformed MnH concentrations for the exposed children derived a model that explained 36.8% of the variability. In order of importance, area of childrens residence, gender (girls>boys) and time of mothers residence in the area at the birth of the child, were significantly associated with MnH. Post hoc analyses indicated two groupings for exposure areas, with those living closest to and downwind of the plant displaying higher MnH concentrations compared to the others. The contribution of the time the mother lived in the community prior to the childs birth to the childrens current MnH suggests that in utero exposure may play a role. A study of neurobehavioral performance with respect to Mn exposure in these children is currently underway.

Application of catalytic stripping voltammetry for the determination of organic sulfur compounds at a hanging mercury drop electrode: behaviour of cysteine, cystine and N-acetylcysteine in the presence of nickel ion

The differential-pulse cathodic stripping voltammetry of cysteine (CysH), cystine (Cys) and N-acetylcysteine (Ac-CysH) was studied at a hanging mercury drop electrode at pH 7 in the presence of nickel ion, 3-(N-Morpholino)propanesulfonic acid (MOPS) and phosphate–acetate buffer were used as supporting electrolytes. In the presence of CysH, after accumulation at potentials ranging between 0.0 and –0.4 V, the catalytic reduction of nickel ion gives a peak at –0.6 V versus the Ag—AgCl reference electrode. An additional effect of nickel ion is the suppression of the cathodic stripping peak due to mercury cysteinate reduction, thus permitting the simultaneous determination of another thiol with no catalytic activity (e. g., Ac-CysH), Consequently, CysH (or Cys) and Ac-CysH can be determined simultaneously or independently in the same sample. Cys is reduced at potentials preceding the catalytic peak, which is actually due to the CysH thus produced. Some differences between the behaviour of Cys and CysH are due to different accumulation mechanisms. The catalytic stripping voltammetry of CysH or Cys exhibits good sensitivity (detection limit about 1 nmol dm–3 for 3 min accumulation). The stripping voltammetric method described appears to be the first involving adsorptive accumulation of a metal complex in which the organic ligand is determined catalytically. Further, this particular method affords some selectivity in the determination of sulfur compounds, which are normally determined by cathodic stripping, voltammetry of their anodically accumulated mercury complexes.

Dietary intake and health effects of selected toxic elements

Anthropogenic activities have being contributing to the spread of toxic chemicals into the environment, including several toxic metals and metalloids, increasing the levels of human exposure to many of them. Contaminated food is an important route of human exposure and may represent a serious threat to human health. This mini review covers the health effects caused by toxic metals, especially Cd, Hg, Pb and As, the most relevant toxic elements from a human health point of view.

Dissolution of calcium-deficient hydroxyapatite synthesized at different conditions

Abstract The dissolution characteristics of several calcium-deficient hydroxyapatites (HA) have been investigated. Eleven samples were produced by varying synthesis parameters like temperature, pH, digestion time, reagent concentration and velocity of addition. Powder characterization was conducted using X-ray diffraction. Sample crystallinity was variable and samples examined by transmission electron microscopy showed acicular or plate-like morphology. After sample dissolution in Milli-Q water for 168 h, the calcium and phosphate contents in solution were measured by induced coupled plasma optical emission spectrometry (OES). The dissolution behavior of calcium-deficient HA was highly dependent on the sample calcium/phosphorus (Ca/P) molar ratio of the original HA. Dissolution in water was enhanced with decreasing HA sample molar ratio. However, the dissolution process equilibrium was not achieved at the end of 168 h (7 days).

Cancer mortality among agricultural workers from Serrana Region, state of Rio de Janeiro, Brazil

One of the proposed hypotheses to explain the higher incidence of specific-site cancers among agricultural workers is their higher exposure to pesticides. The role of pesticide exposure in morbidity and mortality profiles in Brazil is not well known. Therefore, in order to contribute to increase knowledge on this subject, an ecological analysis aiming to investigate cancer mortality among agricultural workers in an important agricultural area of the Rio de Janeiro State, Brazil, was performed. All causes of death for male workers 30-69 years old provided by the National Mortality Information System between 1979 and 1998 were evaluated. To estimate cancer mortality risks of selected sites, mortality odds ratio (MOR) was employed, and three reference populations were used. Higher mortality of esophagus, stomach, and larynx cancer in agricultural workers 50-69 years old was observed in the period from 1979 to 1988 and of esophagus and stomach cancer from 1989 to 1998. Agricultural workers 30-49 years old showed higher, but not statistically significant, mortality by stomach, esophagus, liver, testis, and prostate cancer, and soft-tissue sarcoma in the period of 1979-1988, and by testis and penis cancer, leukemia, and soft-tissue sarcoma in the period of 1989-1998. Despite the limitations of ecological approaches concerning causality ascertainment, we believe that this study raises questions of the possible role of pesticide exposure on the cancer mortality profile among Brazilian agricultural workers.