Acute and subchronic effects of petroleum on the freshwater fish Hoplias aff. malabaricus / Efeitos agudo e subcrônico do petróleo no peixe de água doce Hoplias aff. malabaricus

Abstract Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hoplias aff. malabaricus. The effects of WSF were evaluated at a molecular level using the comet assay and micronucleus test for genome damage; and at a morphological level through histological identification of liver pathologic lesions. In both acute and subchronic exposure we found low levels of DNA damage (< 10% of comet tail) and non-significant frequency of micronucleus in WSF exposed fish. The most significant liver lesions in WSF exposed fish were fatty vacuolization, hypertrophy and focal necrosis. Since these tissue injuries were progressive and persistent, their irreversibility may negatively affect fish recruitment, even in a such resistant top predator.

Resumo A fração solúvel de petróleo (WSF) prejudica os organismos, porém os danos podem variar entre os níveis celular e tecidual. O objetivo do presente estudo foi avaliar o efeito agudo (24 h, 48 h e 72 h) e subcrônico (36 dias) da WSF (0%, 25% e 100%) em juvenis do peixe neotropical predador topo Hoplias aff. malabaricus. Os efeitos da WSF foram avaliados no nível molecular utilizando o ensaio do cometa e o teste do micronúcleo para o dano genômico e no nível morfológico através da identificação histológica de lesões patológicas no fígado. Em ambas exposições (aguda e subcrônica) encontramos baixos níveis de dano no DNA (< 10% de DNA na cauda do cometa) e frequência de micronúcleos não significativa em peixes expostos a WSF. As lesões mais significativas no fígado dos peixes expostos a WSF foram a vacuolização lipídica, hipertrofia e focos de necroses. Como estas lesões foram progressivas e persistentes, sua irreversibilidade pode afetar negativamente o recrutamento dos peixes, mesmo sendo um predador topo resistente.

Tests of chronic and acute toxicity of crude oil on larvae of Chironomus kiiensis Tokunaga (Diptera: Chironomidae) / Teste de toxicidade aguda e crônica de óleo cru em larvas de Chironomus kiiensis Tokunaga (Diptera: Chironomidae)

The Amazon region, known for its mega-biodiversity, also holds large reserves of petroleum and natural gas. The increasing exploitation of natural gas and crude oil in the Amazon has not been accompanied by studies evaluating the impact of these pollutants on local biological communities, particularly aquatic organisms. The aim of the present study was to determine the values of acute and chronic toxicity of crude oil from Urucu to larvae of Chironomus kiiensis Tokunaga, 1936. The LD5048h of crude oil for second-instar larvae of C. kiiensis was 26.5 mg/L, and mortality for the majority of concentrations tested was greatest during the first 24 hours of the experiment. The survival of eggs of C. kiiensis exposed to concentrations of crude oil was also evaluated but did not differ significantly among the treatments. Despite the high tolerance observed for the species in the experiments, there is a possibility that in the natural environment the oil interacts with other factors, leading to synergistic effects, so further studies are needed to assess the effects of this pollutant on aquatic insect species.

A região Amazônica, conhecida por sua megabiodiversidade, também é detentora de grandes reservas de petróleo e gás natural. A crescente exploração de gás natural e óleo cru na Amazônia não é acompanhada de estudos avaliando o impacto destes poluentes nas comunidades biológicas locais, especialmente organismos aquáticos. Neste trabalho, o objetivo das autoras foi determinar os valores de toxicidade aguda e crônica de óleo cru proveniente de Urucu para larvas da espécie Chironomus kiiensis Tokunaga, 1936. A CL5048h de óleo cru para larvas de segundo instar de C. kiiensis foi de 26,5 mg/L e a mortalidade para a maioria das concentrações testadas foi maior durante as 24 primeiras horas do experimento. A sobrevivência dos ovos de C. kiiensis expostos a concentrações de óleo cru também foi avaliada, porém sem diferença significativa entre os tratamentos. Apesar da alta tolerância da espécie observada nos experimentos, em ambiente natural existe a possibilidade do óleo interagir com outros fatores, apresentando efeito sinérgico, e mais estudos avaliando o efeitos deste poluente sobre insetos aquáticos são necessários.

[Assessment of Hematotoxic effects of occupational exposure to unleaded petrol]

Gasoline is a complex mixture of more than 500 hydrocarbons. The elimination of lead from petrol has been associated with the addition of significant amounts of hematotoxic monocyclic aromatic hydrocarbons such as benzene, toluene and xylene [BTX]. The main purpose of this study was to ascertain whether exposure to unleaded petrol, under normal working conditions, is associated with any hematotoxic response. This was a historical cohort study in which 200 subjects with current exposure to unleaded petrol from Shiraz petrol stations as well as 200 unexposed employees were investigated. Using standard methods, atmospheric concentrations of BTX were measured. Additionally, blood samples were taken from subjects for routine biochemical tests such as RBC, WBC and platelet count, Hemoglobin, hematocrit and RDW. The geometric means of airborne concentrations of BTX were found to be 0/24, 0/37 and 0/64 ppm, respectively. The results of blood chemistry tests showed that no significant differences exist between both groups as far as biochemical tests, but RDW and hematocrit, were concerned. The average exposure of petrol station workers to BTX did not exceed the current TLVs for these chemicals. Additionally, overt hematotoxicity is unlikely to be the outcome of exposure to unleaded petrol under the conditions described in our study.

Sibilância em crianças e adolescentes vizinhos a uma indústria petroquímica no Rio Grande do Norte, Brasil / Wheezing in children and adolescents living next to a petrochemical plant in Rio Grande do Norte, Brazil

OBJETIVO: Verificar a associação entre relato de sibilância em crianças e adolescentes e o local de residência em relação à dispersão dos poluentes atmosféricos emitidos pelo Pólo Petroquímico (PPQ) de Guamaré (RN). MÉTODOS: Estudo transversal de relato de sibilância em crianças e adolescentes de 0 a 14 anos de idade, residentes no entorno do PPQ de Guamaré, em 2006. Foi utilizado o questionário padronizado do International Study of Asthma and Allergies in Childhood, acrescido de questões relativas ao tabagismo, renda, moradia e escolaridade. Concentrações diárias de PM10, PM2,5, carbono grafítico, SO2, NO2, O3, benzeno, tolueno e xilenos foram medidas em uma estação de monitoramento fixa. As comunidades residentes na área de influência das emissões do PPQ foram classificadas, segundo a direção preferencial dos ventos, em expostas e de referência. RESULTADOS: Participaram do estudo 209 crianças e adolescentes. As concentrações médias diárias dos poluentes monitorados mantiveram-se abaixo dos limites estabelecidos nos padrões de qualidade do ar. A prevalência de sibilos nos últimos 12 meses foi de 27,3 por cento. Associações estatisticamente significantes com sibilos nos últimos 12 meses foram verificadas mesmo após ajustamentos para comunidades expostas [razão de chances (odds ratio, ORajust) = 2,01; intervalo de confiança de 95 por cento (IC95 por cento) 1,01-4,01], gênero masculino (ORajust = 2,50; IC95 por cento 1,21-5,18) e idade de 0 a 6 anos (ORajust = 5,00; IC95 por cento 2,41-10,39). CONCLUSÃO: Mesmo em baixas concentrações de poluentes atmosféricos, a ocorrência de sintomas respiratórios em crianças e adolescentes nas comunidades no entorno de um PPQ esteve associada a residência na direção preferencial dos ventos, mostrando-se mais vulnerável o grupo de pré-escolares do gênero masculino.

OBJECTIVE: To examine the association between wheezing in children and adolescents and living downwind of the dispersion plume of atmospheric pollutants emitted by the Guamaré Petrochemical Complex, in the state of Rio Grande do Norte, Brazil. METHODS: Cross-sectional study of wheezing in children and adolescents (aged 0 to 14 years) living in the vicinity of the Guamaré petrochemical complex in 2006. The standardized International Study of Asthma and Allergies in Childhood questionnaire was used, with additional questions concerning tobacco use, income, living conditions, and educational achievement. Daily concentrations of PM10, PM2.5, black carbon, SO2, NO2, O3, benzene, toluene, and xylenes were measured at a fixed monitoring station. According to their position relative to wind direction, communities present in the area affected by plant emissions were categorized into one of two groups, exposed communities and reference communities. RESULTS: Two hundred and nine children and adolescents took part in the study. Mean daily concentrations of the monitored pollutants were consistently below established acceptable upper limits. The prevalence of wheezing in the 12 months prior to study was 27.3 percent. After adjustment, statistically significant associations were found between wheezing and living in exposed communities (adjusted odds ratio [ORadj] 2.01; 95 percent confidence interval [95 percentCI] 1.01-4.01), male gender (ORadj 2.50; 95 percentCI 1.21-5.18), and age 0 to 6 years (ORadj 5.00; 95 percentCI 2.41-10.39). CONCLUSION: Even with low levels of atmospheric pollutants, respiratory symptoms in children and adolescents were associated with living downwind of a petrochemical plant. Male preschoolers were the most vulnerable group.

Acute Health Effects of the Hebei Oil Spill on the Residents of Taean, Korea / 예방의학회지

OBJECTIVES: On December 7, 2007, the Hebei Spirit oil tanker spilled out 12,547 kl of crude oil on the Yellow Sea 10 km away from the cost of Taean Province, Korea. As the coastline has been contaminated, local residents have been exposed to crude oil. Because the residents were showing many symptoms, we investigated the acute health effects of this oil spill on them. METHODS: We conducted a cross-sectional study consisting of the heavy and moderately oil soaked area in Taean and the lightly oil soaked area in Seocheon. Ten seashore villages were selected from each area, and 10 male and female adults were selected from each village. We interviewed the subjects using a structured questionnaire on the characteristics of residents, the cleanup activities, the perception of oil hazard, depression and anxiety, and the physical symptoms. The odds ratios and 95% confidence intervals were analyzed using logistic regression analysis. The logistic regression model was adjusted for age, gender, education, smoking, the perception of oil hazard and anxiousness. RESULTS: The more highly contaminated the area, the more likely it was for residents to be engaged in cleanup activities and have a greater chance of exposure to oil. The indexes of anxiety and depression were higher in the heavy and moderately oil soaked areas. The increased risks of headache, nausea, dizziness, fatigue, tingling of limb, hot flushing, sore throat, cough, runny nose, shortness of breath, itchy skin, rash, and sore eyes were significant. CONCLUSIONS: The results suggest that exposure to crude oil is associated with various acute physical symptoms. Long-term investigation is required to monitor the residents' health.

Effects of the pollution by petroleum on the tracheids along the stem of Podocarpus lambertii Klotzsch ex Endl., Podocarpaceae / Efeitos da poluição por petróleo nas traqueídes ao longo do caule de Podocarpus lambertii Klotzsch ex Endl., Podocarpaceae

Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) is native and a member of the Pinophyta (Gymnosperm) of southern Brazil, locally known as "pinheiro-bravo". The present work aims to investigate the effects of petroleum on the tracheids dimensions. Wood samples from twenty individuals were studied along the stem, ten being exposed to pollution and ten used as a control set. The wood samples were collected from incisions at three levels: at the ground level, and one and two metres above the ground level. From these samples, sub-samples were selected at the border of the growth layers in the vascular cambium-medulla direction. The methodology followed that traditionally recommended for plant anatomy studies, with analyses done by light microscopy (OLYMPUS - BX41) assisted by the software Image Pro-plus for measurements. Comparison of the individuals exposed to petroleum with the control set, showed that the length, diameter and cell wall width of the tracheids of the former were smaller, a trend which was statistically significant according to the Student's t-test. These traits were observed mainly on the tracheids of the last growth layer, corresponding to the year in which the individuals were exposed to petroleum.

Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae), popularmente conhecida por pinheiro-bravo, é uma espécie que pertence ao pequeno grupo de Pinophyta (Gimnospermas) nativas da região Sul do Brasil. O presente estudo teve como objetivo investigar os efeitos da poluição por petróleo nas dimensões das traqueídes que compõem o lenho dessa espécie. Para tanto, amostras do lenho de vinte indivíduos foram coletadas, dez deles expostos à poluição por petróleo e dez usados como controle (coletados em região livre de contaminação). As amostras foram obtidas por meio de incisões paralelas à superfície do solo em três alturas (nível do solo, 1 metro e 2 metros do nível do solo). As subamostras para o estudo da variação estrutural do lenho foram selecionadas no limite das camadas de crescimento no sentido câmbio-medula. A metodologia utilizada para desenvolver o trabalho foi aquela tradicionalmente recomendada para estudos em anatomia vegetal. As mensurações das traqueídes em material macerado, como comprimento, diâmetro e espessura da parede celular, foram feitas pelo software Image Pro-plus em Fotomicroscópio (OLYMPUS - BX41). Nos indivíduos expostos à poluição, o comprimento, diâmetro e espessura da parede das traqueídes foram menores quando comparados aos indivíduos controle e demonstraram diferenças estatisticamente significativas pelo teste t-student. Essas tendências foram observadas, principalmente, nas traqueídes da última camada de crescimento, correspondente ao ano em que os indivíduos permaneceram expostos ao petróleo.

Impact of soil types and petroleum effluents on the earthworm, Eudrilus eugeniae.

Earthworm, Eudrilus eugeniae, exposed to different concentrations of dump-site soil and petroleum effluents exhibited different morbidity and mortality responses. Lake sediments caused varied fluctuations in weight over a 20 day exposure period. Colour changes and mortality up to 15% were observed in earthworms cultured in 100% lake sediment, while weight loss, coiling and sluggish movement were observed in 50% lake water. The effects of 100% dump-site soils were more pronounced as 40% death, swelling, body lesions, stiffening, coiling and low reproduction were recorded. Earthworms were useful as an organism in testing the toxicity of dump-site soils and effluent from a petroleum industry. Dump-site soils and soils polluted with petroleum effluent reduced populations of earthworms and this could subsequently affect other components of the ecosystems associated with earthworm activities.

Testicular morphology and cauda epididymal sperm reserves of male rats exposed to Nigerian Qua Iboe Brent crude oil

Potential negative effects of exposure to Nigerian Qua Iboe Brent crude oil on the reproductive system of male rats was investigated. Forty Sprague-Dawley rats were used for the experiment. Exposure to Nigerian Qua Iboe Brent crude oil was achieved via oral administration of increasing doses (0.1, 0.2, and 0.4 ml/rat) every other day for 4 weeks. Cauda epididymal sperm reserves and relative weights of the testes as well as histological features of the testes of rats that received the crude oil treatment were compared to those of control rats. The results described here showed a significant (p < 0.01) dosedependent reduction in the cauda epididymal sperm reserves of rats that received crude oil treatment relative to the control group. The morphology of testes of the crude oil-exposed rats was characterized by the presence of interstitial exudates, degeneration, and necrosis of spermatogenic and interstitial (Leydig) cells. Findings indicate that exposure of male rats to Nigerian Qua Iboe Brent crude oil may have adversely affected their reproductive systems. This may imply possible reproductive health hazards for animals and humans that may be exposed to this environmental pollutant, especially in areas where oil spillage is a common feature.

Impact of diesel oil effluent in the mucosal surface of the alimentary canal of Oreochromis nilotica (Linnaeus): a scanning electron microscopic study.

Adverse effects of diesel oil on microanatomical structure of the alimentary canal of O. nilotica were studied using SEM observations. The study revealed irregular arrangement of the stratified epithelial cells along with fragmentation of the normal concentric pattem of microridges of the same cells in buccopharynx and oesophagus. The excessive secretion of mucus of buccopharynx and oesophagus were the salient changes caused by diesel oil pollution. The destruction and degeneration of the mucosal folds of stomach and intestine along with their epithelial cells exhibited a concrete hyperactivity resulting in abundant' secretion of mucus over the microridges of the epithelial cells. In the intestinal region the columnar epithelial cells showed tumefaction and microvilli of the plasma membrane of epithelial cells get heavily damaged. Disarray of the microridges of epithelial cells, excessive secretions of mucus formation of even cell sheet were the most conspicuous changes in rectum. It was concluded that chronic exposure of diesel oil may hamper the absorption of the nutrients through alimentary canal resulting into ill-growth and production of the fish.

Efeitos genotóxicos e alterações de enzimas hepáticas em trabalhadores do refino de petróleo / Genotoxic effects and hepatic enzymes alterations among petroleum refinery workers

Um estudo de casos e controles, aninhado num estudo de coorte, investigou a associação entre efeitos genotóxicos e alteração de enzimas hepáticas em trabalhadores de uma refinaria de petróleo do Nordeste. Foram examinados todos os dez novos casos de alterações de enzimas hepáticas - gama-glutamil transferase (GGT) e alanina aminotransferase (ALT) - ocorridos em 2002. Dez trabalhadores sem alterações de GGT ou ALT foram selecionados como controles. Os efeitos do fumo, sexo, idade e consumo de café foram controlados. O efeito genotóxico foi avaliado pela técnica de trocas entre cromátides irmãs (TCI) e alterações cromossômicas (AC) estruturais. As médias de TCI por célula (3,92 ± 1,04 versus 4,25 ± 1,47) e de ACE (8,85 ± 3,4 versus 9,1 ± 3,7) não diferiram de forma significante entre casos e controles respectivamente.

Impact of refined petroleum spills on water quality, macro-invertebrate and microbial communities of a tropical aquatic environment.

Water quality characteristics, benthic macro-invertebrates and microbial communities of three first order streams in South West Nigeria were investigated to assess the effects of refined petroleum five months after spillage. All physical and chemical conditions except temperature and pH were significantly different (P<0.01) at the upstream control stations and impacted stations reflecting the perturbational stress. The benthic macro-invertebrate fauna were dominated by arthropods, but the faunal spectrum was dissimilar at all the stations studied. Sampling stations at the epicentre of the spill showed considerable reduction in faunal compositions and relative abundance. Generally, the microbial density and diversity were highest in both soil and water samples from impacted sites than in control sites. There was a significantly higher proportion (P < 0.05) of hydrocarbon utilizers in soil than in water samples in all stations except in samples from stations (P<0.05).

Immunotoxicological effects of dermal application of scum of waste crankcase oil in mice.

The scum of waste crankcase oil (SWCO) forms due to weathering of waste crankcase oil, deposited on the surface of water bodies. It is known to attach to the feathers of aquatic birds and cause toxicity to the eggs of nestling birds. The water bodies contaminated with SWCO can also be a source of toxicity to the human beings and animals entering such bodies. Since SWCO used in the present study had an appreciable content of heavy metals like Zn, Pb, Cd, Mn, Cr and Ni, the present investigation was undertaken to study a probable effect on immune system of mice. Animals treated with SWCO at a dose of 0.5, 1.0, 2.0, or 4.0 g/kg body weight for 28 days, had no effect on the weight gain of vital organs. A depressing effect was observed on the cell population of spleen and thymus. The number of primary antibody (IgM) producing cells was significantly depressed in spleen. The IgM antibody titer of serum, reduction of NBT dye by peritoneal exudat cells and mounting of delayed hypersensitivity response were not affected. In view of above immunotoxic effects of SWCO, the waste crankcase oil should be carefully disposed of, away from water bodies.

molluscicidal efficacy of three products against Biomphalaria alexandrina and Lymnaea natalensis

The toxicity of three local formulated products [Sol EC [mineral oil], Sisi-6 [surfactant] and castor bean oil EC [plant oil]] was tested against Biomphalaria alexandrina and Lymnaea natalensis in two water sources. The results indicated that in dechlorinated water after 24-hour exposure, castor bean oil was the most toxic product against the snails, followed by Sisi-6 and Sol [EC] with LC90 of 250 ppm and 8 ppm against B. alexandrina and L. natalensis, respectively. When Nile water was used after 6-hour exposure, a high concentration of castor bean oil [4 LC90] did not cause 100% mortality of the snails; it was achieved by 2 LC90 of Sisi-6 with Nile water. On the other hand, castor bean oil was more fatal to eggs of the snails [LC90 = 660 ppm] than the other two products. In general, L. natalensis was more susceptible to the experimental products than B. alexandrina

La salud de mujeres que viven cerca de pozos y estaciones de petróleo en la Amazonía ecuatoriana / The health of women who live near oil wells and oil production stations in the Amazon region of Ecuador

OBJETIVOS: Investigar las condiciones ambientales y el estado de salud de las mujeres que viven en comunidades rurales rodeadas por pozos y estaciones de petróleo en la Amazonía del Ecuador. METODO: Se aplicó un diseño transversal comparativo, asignándose la exposición según la localización geográfica de las comunidades respecto a los pozos y estaciones de petróleo. Se analizaron muestras de agua de los ríos locales para determinar el contenido de hidrocarburos totales de petróleo y se proporcionó un cuestrionario estructurado a cada cabeza de familia. El estudio se localizó en comunidades campesinas del nordeste del Ecuador y duró desde noviembre de 1998 hasta abril de 1999. Se incluyenron en el estudio nueve comunidades en el área expuesta (368 participantes) y 14 en el área no expuesta (291 participantes). RESULTADOS: Los ríos de las comunidades expuestas presentaron niveles de contaminación muy superiores al límite aceptado para el uso humano. Se encontraron diferencias significativas en las razones de prevalencia de hongos en la piel (RP 1,37; IC951,01 a 1,86) en las dos semanas previas al estudio y de irritación de la nariz (RP 2,18; IC951,64 a 2,91) y garganta (RP 1,68; IC951,02 a 2,75) en los 12 meses aneriores. También se encontraron asociados con la exposición en las dos semanas previas el cansancio y "otros síntomas", y en los 12 meses anteriores, el dolor de cabeza, irritqación ocular, dolor de oídos, diarrea y gastritis. CONCLUSIONES: Los síntomas observados en las participantes de las comunidades expuestas concuerdan con los sítomas de toxicidad causados por el petróleo. Hay una necesidad urgente de establecer un adecuado programa de control y remediación ambiental que evite este innecesario e inaceptable reisgo para la salud de estas poblaciones

Impacts of crude oil on the germination and growth of cress seeds (Lepidium sp.) after bioremediation of agricultural soil polluted with crude petroleum using "adapted" Pseudomonas putida.

The impacts of crude oil on the germination, growth and morphology of cress seeds (Lepidium sp.) after bioremediation of agricultural soil polluted with crude petroleum using "adapted" Pseudomonas putida (PP) were examined for 15 days. At day 15 there was 100% germination in the untreated control samples, the mean height of the seedlings was 75.8 +/- 2.6 mm and all appeared to have grown morphologically normal. In the experimental samples treated with oil and PP inoculation, there was 98% germination and the seedlings reached a height of 63.8 +/- 6.9 mm; again, morphologically the seedlings appeared normal. However, in the control samples treated with oil but without PP inoculation, there was 31-38% germination and seedling heights of 34.2 +/- 11.4-42.3 +/- 8.5 mm with abnormal morphology. Treatment of oil-impacted agricultural soil with PP as a bioremediation agent does produce soil which is capable of growing larger and healthier plants than where bioremediation has not taken place.

[Evaluation of toxicity of crude oil on pearl oyster pinctada radiata and its effects of free omino acids in their hemolymph]

In this project, the toxicity of crude oil of the Siri Island on the Pearl Oyster, species Pinctada radiata have been investigated. The speciemens were collected from [Nakhilu port] one of the Persian Gulf fishing ports. In the beginning, a range finding test had been done to examine the sensitivity of pearl oyster to oil pullution, then another test bioassayed. The toxicity of the crude oil in 96 hrs. In this second test concentrations of 10, 50 and 100 percent of water soluble fractins [WSF] of crude oil have been used and the end of this test, there was no mortality in any of the treated groups, even in 100 percent concentration of WSF during the 96 hours. Therefore it became clear that these Oyster have perfect resistance against different concentration of water soluble fractions of crude oil. In the second part of this project, considering the work of Roeisijadi and Anderson [1979], the short term stress effect of the oil pollutin and amount of free amino acids in hemolymph, which usually is considered as a stree indicator was examined. Again, the above experimental groups were examined and the results indicated that after 96 hrs, there were no significant difference in concentration of free amino acid

Manual de toxicologia do refino de petróleo / Toxicology of petroleum refining handbook

A indústria do petróleo caracteriza-se pela multiplicidade de exposiçöes potenciais a agentes tóxicos e, por causa disso, encontra-se em desenvolvimento o Programa de Toxicologia Industrial, previsto na Política de Saúde Ocupacional da PETROBRAS. Deste manual, que muito contribuirá para o desenvolvimento de açöes de proteçäo da saúde contra os riscos químicos nas refinarias, constam os conceitos básicos de Toxicologia necessários à compreensäo do assunto e a aplicaçäo prática das informaçöes sobre extensa relaçäo de substâncias relacionadas ao refino de petroleo