Sérgio Rabello Alves

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.

Comunicação relacionada ao uso de agrotóxicos em região agrícola do Estado do Rio de Janeiro

OBJECTIVE: To assess communications aspects related to pesticide use in a rural area of the Rio de Janeiro state, Brazil. METHODS: The study was carried out in the area of Sao Lourenco stream. It was based on methodological triangulation comprising: semi-structured interviews and observation of a local population sample (about 600 inhabitants); structured questionnaire to collect data on the local community; and records of lectures given by agronomic engineers, pesticides traders and other public service professionals. RESULTS AND DISCUSSION: This study pointed out to the historical misinformation on pesticides in rural areas; the emphasis on technical language in educational and training activities available which constitutes a barrier for rural workers knowledge acquisition and empowerment; and the industry/commerces pressure to legitimate pesticide trading, reinforcing the existing communication process, resulting in unfavorable inclusion of the rural worker into a broader market economy.OBJECTIVE To assess communications aspects related to pesticide use in a rural area of the Rio de Janeiro state, Brazil. METHODS The study was carried out in the area of São Lourenço stream. It was based on methodological triangulation comprising: semi-structured interviews and observation of a local population sample (about 600 inhabitants); structured questionnaire to collect data on the local community; and records of lectures given by argonomic engineers, pesticides traders and other public service professionals. RESULTS AND DISCUSSION This study pointed out to the historical misinformation on pesticides in rural areas; the emphasis on technical language in educational and training activities available which constitutes a barrier for rural workers knowledge acquisition and empowerment; and the industry/commerces pressure to legitimate pesticide trading, reinforcing the existing communication process, resulting in unfavorable inclusion of the rural worker into a broader market economy.

Cholinesterase activities determination in frozen blood samples: an improvement to the occupational monitoring in developing countries.

1 Studies were carried out on rural workers in Brazil to determine the decrease in the activity of plasma butyrylcholinesterase (BChE), erythrocyte cholinesterase (AChE) associated with exposure to organophosphorus pesticides (OP). The goal of this work is to help prevent injury to these workers. 2 In developing countries the distance between area of pesticide use and reference laboratories is a drawback for analytical techniques, since cholinesterase activity determinations require fresh blood samples. Field methodologies can be a useful alternative to laboratory tests, however they are not as sensitive as those found in laboratories. 3 The modification of Ellmans Method presented in this paper allows blood samples to be frozen and maintain enzymatic stability: 7 days for AChE and 3 days for BChE. The proposed method is also more sensitive than Ellmans Method Modified by Magnotti (EMMM). 4 The results suggest that the Ellman Method Modified by Oliveira-Silva (EMMOS) is valid for monitoring procedures. This method represents an important contribution to the process of monitoring OP exposures, since the evaluations no longer have to be conducted near the site of OP use.

The effect of neutral oximes on the reactivation of human acetylcholinesterase inhibited with paraoxon

Important defense agents against chemical warfare weapons, which are reactivators of human acetylcholinesterase (huAChE) inhibited by neurotoxic organophosphorus compounds (OP), need a reasonable permeation of the hematoencephalic barrier (HB). In this work, neutral oximes, which permeate HB better than the cationic oximes currently used as defense agents, were tested as reactivators of huAChE inhibited with paraoxon using the modified Ellman test with pralidoxime (2-PAM) as positive standard. The most active neutral oxime was (thiophen-2-yl)aldoxime, which reactivated 93% of the inhibited huAChE and was 12% more effective than 2-PAM. The results showed that simple neutral oximes have potential to function as antidotes for intoxication with neurotoxic OPs, suggesting further research on the development of neutral defense agents.

Perfil epidemiológico de intoxicados por Aldicarb registrados no Instituto Médico Legal no Estado do Rio de Janeiro durante o período de 1998 a 2005

Aldicarb, commonly known as “chumbinho”, is sold illegally in the State of Rio de Janeiro and has been involved in poisonings, suicides and homicides resulting in a serious public health problem. This study presents the Aldicarb mortality profile in the State of Rio de Janeiro for the period of 1998–2005. A descriptive study was made through a secondary database containing the results of the Forensic Medical Institute’s (IMLAP/RJ) reports and toxicological characteristics of the patients We detected 746 positive cases of Aldicarb poisoning. The males (67.2%) prevailed over the females (32.8%). Regarding age, there is a predominance of poisoning in adults (56%). With regard to skin color, white prevailed (52.1%). The period with the highest numbers of cases was from 1998 to 1999 (43.5%). The municipality with the highest concentration of cases was Rio de Janeiro, with a total of 440 (59.8%). Of the 746 cases, 601 (80.6%) had information on the circumstances, and the higher prevalence of hospitalization was for unspecified condition with removal of the cadaver in the street (45.1%). Its commercialization and irregular use, especially in the metropolitan region of Rio de Janeiro, shows that enforcement actions to curb their use should be intensified.

Classificação clínico-laboratorial para manejo clínico de trabalhadores expostos ao benzeno em postos de revenda de combustíveis

Introduction: gas stations workers are exposed to volatile organic compounds, especially benzene. Clinical management of the broad spectrum of symptoms and signs observed in these workers is still a challenge for health care. Objective: to present a clinical-laboratory classification, based on hemogram analysis and clinical evaluation of workers exposed to benzene, as guidelines for health care professionals. Methods: the clinical-laboratory classification was defined based on priority-setting criteria for the results of clinical evaluations and health surveillance in order to allow the organization of health care flows and procedures. Results: the proposal defines the clinical management based on classification of workers exposed to benzene in four levels of clinical and laboratory alterations that determine procedures according to level of exposure and health effects: 1) without significant alterations; 2) unspecific or incomplete alterations; 3) clinical and/or laboratory alterations; and 4) alterations suggesting benzene poisoning. Conclusion: the proposal for classification of clinical and laboratory findings is potentially able to guide medical practice in the assessment of health conditions and risks of benzene exposure, and subsidize the systematic and continuous monitoring necessary for establishing health care practices offered to workers.

Estratégias analíticas com cromatografia e espectrometria de massas para biomonitorização da exposição ao benzeno pela determinação do ácido S-fenilmercaptúrico urinário

Introduction: benzene is a substance of recognized toxicity and its biomonitoring of exposure becomes critical for preventing health damages, especially in occupational exposure situations. Among all the biomarkers of exposure, S-phenylmercapturic acid is considered the only specific one, but due to its low concentrations in urine, acute analytical techniques capable of quantifying traces must be used. Objective: to review methodologies based on chromatography and mass spectrometry for determination of S-phenylmercapturic acid. Method: literature review on the determination of urinary S-phenylmercapturic acid by chromatographic techniques and mass spectrometry in the main scientific databases, considering the period between 1951 and 2015. Results: 120 documents served as theoretical basis for the construction of this review. The analytical technique that was most applied was the coupling of liquid chromatography with mass spectrometry. However, the methods differ according to the preparation of samples. Conclusion: the high cost of equipment acquisition and maintenance are limiting factors for the diffusion of chromatography systems and mass spectrometry. Nevertheless, its high sensitivity and selectivity enable these coupled techniques to elucidate situations of occupational and environmental exposure to pollutants, such as benzene.

Avaliação ambiental de BTEX (benzeno, tolueno, etilbenzeno, xilenos) e biomarcadores de genotoxicidade em trabalhadores de postos de combustíveis

Introduction: gas station workers are exposed to several chemicals in their workplace, highlighting benzene, due to its carcinogenic properties. Objective: to assess the genotoxic damage related to occupational exposure to BTEX (benzene, toluene, ethylbenzene, xylenes) in workers of five gas stations in Rio de Janeiro, RJ. Methods: analysis of BTEX concentrations in the air were carried out; as well as activities of catalase and glutathione S-transferase; and comet assay in whole blood samples of 97 workers. Results: BTEX levels were within the Brazilian threshold levels recommended by the NR 15, including Annex 13-A. However, an oscillation of the comet assay results was observed among workers of different gas stations, mainly in workers from gas stations with lower concentrations of benzene. Discussion: this result is in accordance with the current international scientific literature that indicates a supralinear exposure-response curve for benzene. In lower concentrations we could observe a high non-linear risk of leukemia, probably due to a greater benzene metabolism and a higher production of its toxic metabolites. Conclusion: the results of this study suggest that exposure to BTEX, even in low concentrations, contributes to genotoxic risk to human health.