Human risk assessment of benzene after a gasoline station fuel leak / Avaliacao de risco humano a benzeno apos vazamento de combustivel em posto de gasolina / Evaluacion de riesgo humano al benceno posterior al derrame de combustible en gasolinera

OBJECTIVE: To assess the health risk of exposure to benzene for a community affected by a fuel leak. METHODS: Data regarding the fuel leak accident with, which occurred in the Brasilia, Federal District, were obtained from the Fuel Distributor reports provided to the environmental authority. Information about the affected population (22 individuals) was obtained from focal groups of eight individuals. Length of exposure and water benzene concentration were estimated through a groundwater flow model associated with a benzene propagation model. The risk assessment was conducted according to the Agency for Toxic Substances and Disease Registry methodology. RESULTS: A high risk perception related to the health consequences of the accident was evident in the affected community (22 individuals), probably due to the lack of assistance and a poor risk communication from government authorities and the polluting agent. The community had been exposed to unsafe levels of benzene (> 5 µg/L) since December 2001, five months before they reported the leak. The mean benzene level in drinking water (72.2 µg/L) was higher than that obtained by the Fuel Distributer using the Risk Based Corrective Action methodology (17.2 µg/L).The estimated benzene intake from the consumption of water and food reached a maximum of 0.0091 µg/kg bw/day (5 x 10-7 cancer risk per 106 individuals). The level of benzene in water vapor while showering reached 7.5 µg/m3 for children (1 per 104 cancer risk). Total cancer risk ranged from 110 to 200 per 106 individuals. CONCLUSIONS: The population affected by the fuel leak was exposed to benzene levels that might have represented a health risk. Local government authorities need to develop better strategies to respond rapidly to these ...

OBJETIVO: Avaliar os riscos à saúde da exposição ao benzeno de comunidade afetada por acidente de vazamento de combustível. MÉTODOS: Dados de acidente de vazamento de combustível ocorrido em Brasília, DF, em 2002, foram obtidos dos relatórios produzidos pelo distribuidor de combustível e submetidos a autoridade ambiental. Informação sobre a população afetada foi obtida em grupos focais com oito participantes. Foram estimados o tempo de exposição e concentração de benzeno na água usando modelo de fluxo subterrâneo acoplado a outro de transporte. A avaliação de risco foi conduzida de acordo com a metodologia da Agência de Registro de Substâncias Tóxicas e Doenças ( Agency for Toxic Substances and Disease Registry ). RESULTADOS: Alta percepção de risco à saúde relacionada ao acidente foi observada na população afetada (22 indivíduos), provavelmente devido à falta de assistência e à comunicação de risco deficiente do governo e agente poluidor. A comunidade esteve exposta a níveis inseguros de benzeno na água (> 5 µg/L) a partir de dezembro de 2001, cinco meses antes de ser reportado o vazamento. A concentração média de benzeno na água consumida (72,2 µg/L) foi maior que aquela estimada pelo distribuidor usando a metodologia Ação Corretiva Baseada em Risco ( Risk Based Corrective Action ) (17,2 µg/L). A ingestão estimada de benzeno pelo consumo de água e frutas alcançou 0,0091 µg/kg pc/dia (risco de 5 x 10-7 câncer per 106 indivíduos). O nível de benzeno no vapor d´água durante o banho atingiu 7,5 µg/m3 para ...

OBJETIVO: Evaluar los riesgos para la salud de la exposición al benceno en comunidad afectada por accidente de derrame de combustible. MÉTODOS: Datos del accidente ocurrido en el Distrito Federal (Brasil), fueron obtenidos de los informes realizados por el distribuidor de combustible y sometidos a la autoridad ambienta. Información sobre la población afectada fue obtenida en grupos focales con 8 participantes. Se hicieron estimaciones del tiempo de exposición y concentración de benceno en el agua usando modelo de flujo subterráneo acoplado a otro de transporte. La evaluación de riesgo fue conducida de acuerdo con la metodología de la "Agency for Toxic Substances and Disease Registry". RESULTADOS: Alta percepción de riesgo para la salud relacionada con el accidente fue observada en la población afectada (22 individuos), probablemente debido a la falta de asistencia y a la comunicación de riesgo deficiente del gobierno y agente contaminante. La comunidad estuvo expuesta a niveles inseguros de benceno en el agua (>5 µg/L) a partir de diciembre de 2001, cinco meses antes de ser reportado el derrame. La concentración promedio de benceno en el agua consumida (72,2 µg/L) fue mayor que la estimada por el distribuidor usando la metodología "Risk Based Corrective Action" (17,2 µg/L). La ingestión estimada de benceno por el consumo de agua y frutas alcanzó 0,0091 µg/kg pc/día (riesgo de 5 x 10-7 de cáncer per 106 individuos). El nivel de benceno en el vapor de agua durante el baño alcanzó 7,5 µg/m3 en niños (riesgo de cáncer de hasta 1 per 104). El Riesgo carcinogénico total fue de 110 a 200 per 106 individuos. CONCLUSIONES: La población afectada por el derrame de combustible estuvo expuesta ...

Distribution of volatile organic compounds around a polluted river

The objectives of this study were to investigate the species and the concentration distribution of volatile organic compounds around a heavily polluted river. Air samples were collected seasonally at different locations near the polluted river. Samples were then analyzed by gas chromatography [electron capture detector for chlorinated organic compounds and flame ionization detector for ordinary hydrocarbons]. The data was then analyzed by the statistical product and service solutions software. The results showed that total of 26 species of volatile organic compounds were identified. Each individual had its own concentration distribution pattern at different seasons and aliphatic volatile organic compounds displayed much higher concentrations than most benzenoic volatile organic compounds. In aliphatic volatile organic compounds, 1,2-dibromo-3-chloropropane, hexachlorobutadiene and 1,2-dibromoetane had much higher concentrations at the nearby environment of the river and they have been claimed to be carcinogenic to some experimental animals and possibly to human. Therefore, It is in doubt that for a long term, the volatile organic compounds evaporating out of the stream may threat the health of the residents living very close to the river. The concentrations of tetrachloroethene, 1,1,2,2-tetrachloroethane, hexachlorobutadiene, dibromoetane, dichlorobenzene and sec-butylbenzene appeared at the nearby environment of the river had significant correlations [P < 0.05] with those of each other or many other volatile organic compounds

Assessment of human health risk from organochlorine pesticide residues in Cidade dos Meninos, Duque de Caxias, Rio de Janeiro, Brazil

This article presents the results of a heath risk assessment in Cidade dos Meninos, an area contaminated with organochlorine pesticide residues located in the county (municipality) of Duque de Caxias, Rio de Janeiro State, Brazil. The Agency for Toxic Substances and Disease Registry (ATSDR) risk assessment methodology was applied. The following organochlorine compounds exceeded the established limits and were considered target pollutants: HCH and its isomers (in eggs, milk, and soil); DDT and its metabolites; trichlorobenzenes; trichlorophenols; dioxins and furans (eggs and soil). For all the substances studied (with the exception of trichlorophenols), the estimated doses exceeded the minimum risk levels for chronically exposed children and adults. According to the ATSDR classification, the area was considered an "urgent public health hazard" because of its high and serious exposure to substances that are dangerous to human health.

Cidade dos Meninos é uma área localizada no Município de Duque de Caxias, Rio de Janeiro, Brasil, onde ocorreu contaminação ambiental por deposição de pesticidas organoclorados. Este artigo apresenta os resultados de um estudo de avaliação de risco para a saúde da população residente, utilizando-se a metodologia de avaliação de risco à saúde da Agency for Toxic Substances and Disease Registry. Os seguintes compostos organoclorados superaram as normas estabelecidas e foram considerados contaminantes de interesse: hexaclorociclohexano (HCH) e seus isômeros (ovo, leite, solo); tricloro-bis-(clorofenil)-etano (DDT) e seus metabólitos (ovo, leite, solo); triclorobenzenos (solo); triclorofenóis (solo); dioxinas e furanos (ovo, solo). Para todos os compostos estudados, exceto triclorofenóis, na situação de exposição crônica, as doses estimadas estavam acima dos níveis mínimos de risco à saúde, para crianças e adultos. A área foi classificada como de perigo urgente para a saúde pública por exposição de alta intensidade e grave a substâncias nocivas à saúde humana. Os autores observam que a realização de estudos de avaliação de risco para a saúde humana é uma importante ferramenta para a tomada de decisões para ações de saúde pública.

Diurnal and monthly variation of indoor radon and thoron progeny concentrations at a hillside place of northern India.

The natural radioactivity levels all over the world can create health problems due to the inhalation of radioactive aerosols. Radon and thoron progeny content of indoor air have major contribution to natural radiation dose. In the present study, simultaneous indoor measurements of radon and thoron progeny concentrations have been carried out over a period of four months at a low activity hilly area of northern Punjab, India to see their diurnal and monthly variations. The method used for this purpose is based on the defined solid angle absolute beta counting of radioactive aerosols sampled on a filter. The average values of equilibrium equivalent radon and thoron concentrations were 5.20 Bq m(-3) and 0.235 Bq m(-3), respectively, over the period August to November 2003. Both, EECRn and EECTh show a negative correlation with temperature.

Polycyclic aromatic hydrocarbons in the ambient air of Jeedimetla Industrial Development Area-Hyderabad.

Polycyclic aromatic hydrocarbons (PAHs) have received increased attention in recent years in air pollution studies, as some of these compounds are highly carcinogenic or mutagenic. PAHs are mainly associated with respirable suspended particulate matter (RSPM) (diameter <10 m in size). Hence, it is important to determine the concentration of PAHs adsorbed on RSPM to know the extent of human exposure to these potentially carcinogenic substances. The study was carried out at 10 locations in and around the Jeedimetla industrial development area, Hyderabad during April 2000. Higher concentrations of B(a)A and B(b)F were observed at Nandanagar, Py and B(a)P at Kukatpally while, F1 concentrations at Allwyn Colony. These variations in the concentration can be attributed to their source and climatic conditions during sampling.

Appropriate models and an understanding of carcinogenic mechanisms--requirements for hazard risk assessment.

Given the immense variety of compounds developed for introduction into the human environment, appropriate carcinogen risk assessment is essential. One of the responsible international bodies recognized as providing a lead in this endeavour is the International Agency for Research on Cancer (IARC), primarily through the Monographs on the Evaluation of Carcinogenic Risks to Humans. However, serious allegations have recently been made that industry now has undue influence on the decisions of the IARC Workshops as to category assignment, especially concerning down-grading of risk. The contention is that too much stress is placed on mechanistic considerations which have not been sufficiently validated. Since avoidance of carcinogens in our environment is clearly of prime importance to cancer prevention, open discussion of how they should be identified is of essential significance to the APOCP. Clearly, decisions should be based solely on scientific evidence and there should be no place for politics or polemic. We have therefore looked, in what we hope is a dispassionate fashion, at the arguments offered in the recent literature, while admitting to a bias towards taking into account all the available knowledge on mechanisms of action of carcinogens and modulating agents. As scientists, generation of an understanding of this area is one of the main reasons why we receive our salaries. To blindly argue that carcinogenicity, for example at high dose in one strain of experimental animal, necessarily implies human risk at normal levels of exposure is obviously untenable. At the same time, precipitous conclusions regarding species-specific mechanisms must naturally be avoided. Both academic and industrial researchers need to apply a balanced judgement and to simply imply that any association with industrial concerns is likely to lead to irresponsible behaviour to the detriment of public health is not tenable. With regard to regulatory decision making, we should be concentrating more attention on mechanisms, rather than less, especially in light of recent findings pointing to hormesis at low doses of carcinogens, which will inevitably generate heated discussion and the charge of bias in favour of industry. The onus is on all members of the scientific community to impartially view all the epidemiological and experimental data which are available in decision-making.

HACREA (Hidroarsenicismo crónico regional endémico argentino): posible acción del vanadio como factor carcinogénico / Chronic regional endemic argentine hydroarsenicism: possible role of vanadium as a cocarcinogenic factor

Se estudia el vanadio en las aguas de pozos artesianos de la zona arsenical (Pampa Húmeda) de la provincia de Córdoba (Argentina), descubierto y bien estudiado en esas aguas por Bado en 1917. Se pone de relieve su coincidencia patológica con el arsénico en esas mismas aguas, arsénico que según Ayerza ocasiona lo que él llamó en publicación primigenia "Arsenicismo regional endémico (keratodermia y melanodermia combinadas)". La repetición constante durante muchos años de esos dos oligoelementos en los análisis bioquímicos de las aguas de bebida y la no referencia del vanadio en las manifestaciones clínicas del HACREA llaman la atención del autor. Se insiste en la diferencia que hay entre el HACREA y otros hidroarsenicismos del mundo; en el HACREA, a las características clínicas comunes se le agregan los muy frecuentes y múltiples carcinomas de todas las formas clínicas e histológicas, lo que haría suponer que el vanadio pudiera ser una condición de riesgo por una interacción química con el arsénico y en tal condición fuera un co-carcinógeno en el HACREA

Radiación ultravioleta en Chile: variaciones con la altura y la latitud / Ultraviolet radiation in Chile: variations with altitude and latitude

Chile tiene un territorio continental ubicado entre los 18º-56º de latitud sur y abarcan zonas entre el nivel del mar y los 5.000 metros de altura. Sus habitantes deben viajar a lo largo y ancho del territorio, ya sea por razones de negocios, oportunidades de trabajo, deportes o turismo, por lo cual están constantemente sometidos a variaciones del régimen de radiación ultravioleta. El objetivo de esta presentación es ofrecer una visión preliminar de las dosis diarias de eritema (DDE) a lo largo y ancho del país. Con un radiómetro portátil de cuatro canales en el UV se realizaron mediciones desde la salida hasta la puesta del sol en diferentes lugares entre los 18º y 53º S) en invierno y verano. A través del método de inversión se recuperó el espectro UV completo, minuto a minuto en pocos días de cada lugar de medición. Usando el espectro de acción (CIE) para eritema fueron estimadas las dosis diarias. Se comparan los valores de DDE de los lugares analizados para obtener un primer vistazo de los cambios debidos a latitud y altura. En general, los cambios por diferencias de altura o latitud son mayores en invierno que en verano. por otra parte, las personas que se desplazan 1.000 km de sur a norte en invierno se someten a un mayor estrés que si suben 1.000 metros en la cordillera

Aflatoxinas en maíz recién cosechado en Panamá / Aflatoxins in newly harvested corn in Panama

Mycotoxins are fungal metabolites that may contaminate foods and feeds, resulting at times in important disease in humans and animals. Thirty-six samples of nine varieties of newly harvested corn (4 samples each variety) were analyzed in search of aflatoxins by thin layer chromatography and high pressure liquid chromatography, and also cultured for the presence of Aspergillus flavus. Of the 36 samples studied, one was contaminated with 1290 ppb aflatoxin B1, which is 258x the concentration suggested by WHO, placed at 5 ppb in food for human consumption. Culture of the 36 samples of corn resulted in growth of 55 colonies of A. flavus from all but two (1 and 6) of the 9 varieties. Of the 55 colonies of A. flavus obtained, 15 (27.3%) were toxigenic. Comments are made on the public health implications of these findings.