Sargazo: la irrupción atípica de un ecosistema milenario / Sargassum: the atypical irruption of an ancient ecosystem

Resumen El sargazo es un ecosistema marino milenario que circula en el sentido de las manecillas del reloj en el Océano Atlántico. A partir de 2011, el alga flotante que lo compone ha comenzado a recalar en playas de 19 países del Caribe, con consecuencias ambientales, sanitarias y económicas que deben atenderse con urgencia.

Abstract Sargassum constitutes an ancient marine ecosystem that circulates clockwise on the Atlantic Ocean. Upon 2011, the pelagic seaweed which is the main component of sargassum started to reach beaches on 19 Caribbean countries, with environmental, health and economic impacts that need to be addressed urgently.

Assessment of methyl methacrylate genotoxicity by the micronucleus test

The aim of this study was to evaluate the genotoxic potential of methyl methacrylate (MMA) vapor by simulating standard occupational exposure of 8 hours per day and using the micronucleus test. We used 32 adult male Wistar rats divided into three groups: A - 16 rats exposed to MMA for 8 hours a day, B - Eight rats receiving single subcutaneous doses of cyclophosphamide on the first day of the experiment (positive control), C - Eight rats receiving only water and food ad libitum (negative control). Eight rats from group A and all of the rats from groups B and C were sacrificed 24 hours after beginning the experiment (acute exposure in group A). The remaining animals in group A were sacrificed 5 days after the experiment began (repeated exposure assessment in group A, simulating occupational exposure 40 hours/week). Femoral bone marrow was collected from each rat at the time of sacrifice for use in the micronucleus test. Two slides were completed per animal and were stained with Giemsa staining. Two thousand polychromatic erythrocytes were counted per animal. The Kruskal-Wallis test followed by a multiple comparisons test (Dunn test) was used for statistical analysis. The median number of micronuclei was 7.00 in the group exposed to MMA for 1 day, 2.00 in the group exposed to MMA for 5 days, 9.00 in the group exposed to cyclophosphamide (positive control) and 0.756 in the negative control group (p < 0.0001). MMA was genotoxic when measured after 1 day of exposure but was not evidently genotoxic after 5 days.

Retrospective analysis of lung function abnormalities of Bhopal gas tragedy affected population.

Background & objectives: A large numbers of subjects were exposed to the aerosol of methyl isocyanate (MIC) during Bhopal gas disaster and lung was one of the most commonly affected organs. The aim of the present study was to analyze retrospectively the lung function abnormalities among the surviving MIC exposed population (gas victims) and to compare it with the non-MIC exposed (non gas exposed) population. Methods: The spirometry data of both gas victims and non gas exposed population who attended the Bhopal Memorial Hospital & Research Centre for evaluation of their respiratory complaints from August 2001 to December 2009, were retrospectively evaluated and compared. Results: A total 4782 gas victims and 1190 non gas exposed individuals performed spirometry during the study period. Among the gas victims, obstructive pattern was the commonest (50.8%) spirometric abnormality followed by restrictive pattern (13.3%). The increased relative risk of developing restrictive abnormality among gas victims was observed in 20-29 yr age group only (adjusted relative risk: 2.94, P<0.001). Male gas victims were more affected by severe airflow obstruction than females and the overall increased relative risk (1.33 to 1.45, P<0.001) of developing obstructive pattern among gas victims was observed. Interpretation & conclusions: The present study showed that the relative risk for pulmonary function abnormalities in gas victims was significantly more among those who were young at the time of disaster. Increased smoking habit among gas victims might have played an additive effect on predominance of obstructive pattern in spirometry.

Situación socio-sanitaria. síntomas respiratorios y función pulmonar medida por espirometría en ex trabajandores de la Industría del calzado, La Calera, Córdoba, Argentina / Socio-health. respiratory symptoms and lung function measured by spirometry in ex trabajandores of the footwear industry, La Calera, Córdoba, Argentina

Se evaluó la situación socio-sanitaria, los síntomas respiratorios y la función pulmonar en una muestra de 60 ex trabajadores (47 por ciento hombres y 53 por ciento mujeres, de una edad promedio de 47 años) que fueron empleados en una fábrica de la industria del calzado en la localidad de La Calera, Provincia de Córdoba, Argentina. Los mismos estuvieron expuestos a irritantes de la víaaérea (solventes, polvos de cuero y vapores) durante el tiempo en que trabajaron en la empresa, pero luego de ser despedidos su situación socio-sanitaria empeoró aún más debido a las consecuencias de la falta de cobertura médicas y al impacto físico y moral surgido del desempleo. Por este motivo, el objetivo principal de este trabajo fue realizar un estudio epidemiológico observacional analítico sobre la situación socio-sanitaria, síntomas respiratorios y función pulmonar medida por espirometría en extranbajadores de la industría del calzado, La Calera, Córdoba, Argentina.

Assessment of methyl methacrylate vapor toxicity on the rat tracheal epithelium / Análise da toxicidade dos vapores de metil metacrilato sobre o epitélio traqueal de ratos

O metil metacrilato (MMA) é um monômero que se polimeriza em resina pela ação da luz e do calor, transformando-se em plástico claro, resistente e durável, relativamente inerte. Por apresentar tais características, o MMA tem sido muito usado na Medicina, como cimento ósseo, e na Odontologia, em aparelhos e próteses dentais, o que tem suscitado interesse na avaliação de sua toxicidade. Estudos experimentais e clínicos têm mostrado que os monômeros podem causar uma gama de efeitos adversos. A principal via de exposição ocupacional ao MMA é a inalatória. Este trabalho visa a avaliar a ação tóxica do MMA sobre o epitélio traqueal em relação ao tempo de exposição. Para isso, dois grupos experimentais de ratos foram expostos ao MMA por inalação, com restrição de ventilação: um grupo (n = 36) foi exposto continuamente, e outro (n = 36) foi exposto durante oito horas diárias, sem água e comida durante o período de exposição. Um grupo controle (n = 8) recebeu ar normal. Doze animais de cada grupo de estudo foram sacrificados com 5, 8 e 10 dias de exposição, junto com dois ou quatro animais do grupo controle. Vinte e nove (80,5%) dos ratos expostos continuamente ao MMA apresentaram inflamação do epitélio traqueal, assim como 58,33% (n = 21) daqueles expostos 8 horas/dia e 87,5% (n = 7) dos controles. Não se observou associação entre o processo inflamatório e a exposição ao MMA, nem alterações significativas na medida da espessura do epitélio traqueal. Novos estudos, com tempo mais prolongado de exposição e análise de outros parâmetros, devem ser realizados para que seja excluída, totalmente, a possibilidade de dano traqueal por vapores de MMA.

udefined lacrimating gas exposure in a chemical company: a case study

A chemical company which produces chlorine as a by-product was undertaking a new project for renewal of the plant. On application of paints, tile binders and coatings, the workers complained of unusual increased eye irritation and continuous lacrimation that hindered the progress of the work. Both the company and the project contractors denied their responsibility for the problem. To define the unknown irritant, gas samples of all raw materials used were collected and scanned by infra-red gas analyzer. Further on the spot direct sampling on point of application, as well as atmospheric air samples collected on active carbon were taken and analyzed by the same technique. In the mean time, chlorine gas samples were collected and analyzed at the same locations. Chlorine gas was found to be below the TLV, which could not be responsible for the irritating effect. Infra-red analysis revealed that styrene, methyl styrene, chloroform and methyl ethyl ketone are the most abundant vapours which are still below their TLVs. It has been concluded that lacrimation occurs by the interaction between styrene and low chlorine concentration in the atmosphere that is catalyzed by ultra-violet radiation to form a strong lacrimator

Frecuencia del intercambio de cromátides hermanas en un grupo de individuos expuestos ocupacionalmente a los vapores de derivados del petróleo / Sister chromatid exchange frequency in a group of individuals occupationally exposed to petroleum-vapour derivatives

La frecuencia de los intercambios de cromátides hermanas (XICH) fue establecida en 156 individuos expuestos ocupacionalmente a los vapores de derivados del petróleo y en 36 individuos ocupacionalmente no expuestos. el grupo expuesto se subdividió en 4 grupos de acuerdo con el área de trabajo. Se encontró una XICH altamente significativa (P<0,01) en los cuatro grupos de individuos expuestos de las áreas G1, PA, PB y LI (9,51, 9,66, 10,20 y 9,38, respectivamente), comparado con el grupo control (7,74). Se encontró que tanto la antiguedad laboral como el hábito de fumar y las condiciones intrínsecas de cada área de trabajo, tuvieron efecto sobre la inducción de ICH. La edad de los individuos no influyó significativamente sobre los ICH. Se encontró una reducción significativa (P<0,05) del índice de cinética celular (ICC) en un grupo de 73 individuos ocupacionalmente expuestos (ICC=2,08) con relación al grupo de individuos control (ICC=2.37). Los resultados sugieren que la exposición crónica y/o aguda a los vapores de productos de derivados del petróleo inducen la formación de ICH y podrían causar reducción del ciclo y proliferación celular in vitro en algunos de los individuos expuestos ocupacionalmente a los vapores de derivados del petróleo, dependiendo de la susceptibilidad de cada genoma expuesto

Intoxicaçäo pela fumaça / Intoxication due to smoke

Os autores destacam no presente trabalho a importância da intoxicaçäo pela fumaça ba gênese da mortalidade e morbidade do paciente queimado. Analisam sua composiçäo, descrevem a fisiopatologia da agressäo pulmonar, enumeram os principais sinais, sintomas e exames para a conclusäo diagnóstica e expöem as principais diretrizes para o tratamento