Environmental contamination by fluoroquinolones

Over the past few decades, a high number of pharmaceuticals have been detected in surface, ground and drinking waters. This contamination comes from domestic sewage, livestock, hospitals and chemical-pharmaceutical industries. Typical examples of these pollutants are the fluoroquinolones - powerful antibiotics used in human and veterinary medicine. The presence of fluoroquinolones in the environment can pose a serious threat to the ecosystem and to human health due to their high consumption globally: in 1998, around 120 tons were produced. Even at low environmental concentrations, antibiotics stimulate bacterial resistance. The consequences of the presence of fluoroquinolones in the environment are not fully understood, but are known to be toxic to plants and aquatic organisms. Approximately 85% of the fluoroquinolones present in influents can be removed by conventional wastewater treatment plants, but the removed fraction is frequently accumulated in the sludge, which is sometimes used as fertilizer, representing an additional input route into the environment. The removal of fluoroquinolones by biological treatment is ineffective, and it is believed that only advanced oxidation technologies are able to destroy these emerging pollutants.

Nas últimas décadas, um grande número de fármacos tem sido identificado em águas superficiais, subterrâneas e potáveis. Tal contaminação advém do esgoto doméstico, hospitais, criação de animais e das indústrias químico-farmacêuticas. Exemplos típicos desses poluentes são as fluoroquinolonas – potentes antibióticos empregados na medicina humana e veterinária. A presença de fluoroquinolonas no meio ambiente pode representar uma séria ameaça para o ecossistema e para a saúde humana devido ao alto consumo mundial: em 1998 foram produzidas, aproximadamente, 120 toneladas. Mesmo em baixas concentrações, antibióticos podem estimular a resistência bacteriana. As consequências da presença de fluoroquinolonas no ambiente não são completamente compreendidas, mas sabe-se que são tóxicas para plantas e organismos aquáticos. Aproximadamente 85% das fluoroquinolonas presentes em efluentes podem ser removidos em estações de tratamento de efluentes convencionais, porém a fração removida é frequentemente acumulada no lodo, muitas vezes usado como fertilizante, o que representa uma rota adicional de entrada desses compostos no ambiente. A remoção de fluoroquinolonas por meio de tratamento biológico não é eficiente, e acredita-se que somente as tecnologias de oxidação avançada sejam capazes de degradar esses poluentes emergentes.

Cáncer por contaminación química del agua de consumo humano en menores de 19 años: una revisión sistemática / Cancer in the population under 19 years of age caused by chemical contamination in drinking water: a systematic review

OBJETIVO: Evaluar la asociación entre la exposición a los principales contaminantes químicos del agua de consumo humano (ACH) y el aumento de casos de cáncer en menores de 19 años. MÉTODOS: Se realizó una revisión sistemática de la literatura científica recogida en las bases de datos MEDLINE (via PubMed©), EMBASE©, Web of Knowledge, Cochrane Library Plus, Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS), SCOPUS y SCIRUS. Los descriptores utilizados fueron "neoplasms" y "water pollution, chemical", limitado a estudios que incluyeran a menores de 19 años. Se seleccionaron los artículos científicos de cualquier tipo y en cualquier idioma, desde el inicio de la indización de la fuente primaria hasta marzo de 2011. RESULTADOS: Se recuperaron 266 artículos, de los que se seleccionaron 20 tras aplicar los criterios de inclusión y exclusión. Los contaminantes del ACH analizados fueron: arsénico, subproductos de la desinfección, compuestos nitrogenados, derivados del petróleo, plaguicidas agrícolas, radionúclidos, así como otros de origen industrial. La mayoría de los estudios no hallaron una asociación significativa entre la exposición a los contaminantes encontrados en el ACH y el aumento de casos de cáncer en menores de 19 años. En algunas de las poblaciones estudiadas se observó una relación significativa dosis-respuesta en el período de exposición. CONCLUSIONES: Teniendo en cuenta el insuficiente nivel de actualidad de los artículos encontrados, se requieren más estudios dirigidos a conocer el efecto real de la contaminación del ACH en la incidencia de cáncer en la población, en particular en los niños y jóvenes por su mayor susceptibilidad.

OBJECTIVE: To evaluate the association between exposure to the main chemical contaminants in drinking water and the rise in cancer cases among the population under age 19. METHODS: A systematic review was undertaken of the scientific literature compiled in the MEDLINE (via PubMed©), EMBASE©, Web of Knowledge, Cochrane Library Plus, Latin American and Caribbean Literature on Health Sciences (LILACS), SCOPUS, and SCIRUS databases. The descriptors used were "neoplasms" and "water pollution, chemical," limited to studies that included people under age 19. Articles selected were of any type in any language, from the inception of the indexing of the primary source until March of 2011. RESULTS: The search generated 266 articles, from which 20 were selected after applying the inclusion and exclusion criteria. Drinking water contaminants analyzed were arsenic, disinfection byproducts, nitrogen compounds, petroleum derivatives, agricultural pesticides, radionuclides, and others of industrial origin. The majority of the studies did not find a significant link between exposure to drinking water contaminants and the increase in cancer cases in the under-19 population segment. In some of the studied populations a significant dose-response relationship was observed. CONCLUSIONS: Taking into account that the articles located were insufficiently up-to-date, more studies are required in order to know the effect of drinking water contamination on cancer rates, in particular among children and youths, who are more susceptible.

Determinación de zonas de riesgo al agua arsenical y prevalencia de hacre en Villa Belgrano, Tucumán, Argentina / Determination of zones exposed to Arsenical Water and CERHA prevalence in Villa Belgrano, Tucumán, Argentina

INTRODUCCIÓN: En Tucumán la concentración de arsénico en agua fluctúa entre 0,1 y 0,01 ppm. El sistema de salud carece de registro de casos. OBJETIVOS: Elaborar un mapa de riesgo ambiental, estimar la prevalencia de hidroarsenicismo crónico regional endémico (HACRE) y explorar la relación entre la concentración de arsénico en agua y las manifestaciones clínicas en Villa Belgrano, Tucumán. MÉTODOS: estudio transversal. Se analizaron todas las fuentes de agua y se seleccionaron aleatoriamente 119 personas adultas. Para la definición de caso de HACRE se utilizó un criterio diferente al de la Organización Mundial de la Salud (OMS) en concentración de arsénico en agua, orina y cabello y tiempo de consumo, siendo éste más sensible en el valor de corte de arsénico en el agua. Se consideró caso definido a quien había consumido agua con un nivel de arsénico mayor a 0,01 partes por millón(ppm) por más de 5 años y presentado más de 3 ug/g en cabello y/o más de 40 ug/g en orina, con clínica compatible. RESULTADOS: El 75% de las fuentes de agua tenían valores mayores a 0,01 ppm de arsénico. Con los criterios de la OMS, se registraron 51 casos probables y no hubo casos definidos. Según los criterios del estudio, hubo 3 casos definidos y una prevalencia del 2,6%. No se halló una asociación entre lesiones no cutáneas o cutáneas graves y valores mayores a 0,01 ppm. CONCLUSIONES: La prevalencia estimada según los criterios del estudio tuvo valores similares a los establecidos en la bibliografía bajo las condiciones en cuestión, aunque con otros criterios no comparables.

INTRODUCTION: In Tucumán, the arsenic concentration in water fluctuates between 0,1 and 0,01 ppm.The provincial health system does not have any record of cases. OBJECTIVES: To identify and create a map of environmental risk, estimating also chronic endemic regional hydroarsenicism(CERHA) prevalence in Villa Belgrano and exploring the relation between arsenic concentration in water and clinical manifestations. METHODS: A cross-sectional study was performed. All water sources were analyzed and 119 adults were randomly selected. The definition of case considered the own criteria, which differed from the ones of World Health Organization (WHO) regarding arsenic concentration in water, urine and hair as well as time of consumption. The study criteria is most sensible in arsenic water concentration. Those who had consumed water with more than 0.01 parts per million (ppm) for over 5 years and presented more than 3 ug/g in hair and/or more than 40 ug/gin urine with compatible clinical signs were considered as cases. RESULTS: 75 % of water sources had arsenic levels higher than 0.01 ppm. According to the WHO criteria, there were 51 probable cases and there was not any defined case. According to the study criteria, there were 3 defined cases with a prevalence of 2.6%. The study did not find an association between withnon-cutaneous or serious cutaneous injuries and arsenic levelin water higher than 0.01 ppm. CONCLUSIONS: The prevalence estimated according to the study criteria was similar to the one established in the bibliography under the same conditions, though with other criteria which are not comparable.

Functional morphology of the hepatopancreas of Palaemonetes argentinus (Crustacea: Decapoda): influence of environmental pollution

We analyzed the morphological and functional state of hepatopancreas in Palaemonetes argentinusfrom two environments with different pesticide concentrations. Los Padres lagoon (Argentina) is an area subjectedto contamination due to the slow exchange of water, the shallow depth and the input of contaminatedwater. Prawns living in this lagoon accumulate high amounts of organochlorine pesticides in their tissues. Hepatopancreas of prawns from Canal 5, an adjacent shallow stream where the amount of pesticides is belowtoxic levels, and from Los Padres lagoon were processed by standard histological techniques with light microscopyand transmission electronic microscopy. At Los Padres lagoon, we found important tissular alterations,such as intertubular infiltration of haemocytes and connective tissue, epithelial retraction in some tubules, anda folded basal lamina. Important necrotic desquamation, with cariolysis, cariorrexis and lack of cellular detailswere also observed. Numerous tubules presented an enlarged and irregular lumen with the epithelium atrophiedor completely absent. In general, the lesions were particularly located in the medullar region of the organ. Atthe ultrastructural level, R and F cells were the most damaged. Both cell types had nuclear retraction, chromatincondensation and cytoplasmic lysis. Some R cells also had dilated mitochondria and numerous lysosomes, and the basal cytoplasm was nearly completely lysed. The hepatopancreas of prawns from Canal 5 did not evidenceany alterations. The histopathological study of the hepatopancreas is a highly sensitive tool to evaluate thephysiological condition of prawns and water quality. Other environmental conditions were similar, so it can beassumed that pollutants were the main cause of organ deterioration.

Analizamos el estado morfológico y funcional del hepatopáncreas de Palaemonetes argentinus de dosambientes con diferentes concentraciones de plaguicidas. La laguna Los Padres (Argentina) es un área sujeta a contaminación debido al lento intercambio del agua, la escasa profundidad y el influjo de agua contaminada. Las gambas acumulan aquí grandes cantidades de plaguicidasorganoclorados en sus tejidos. Los hepatopáncreas de gambas del Canal 5 y de la laguna Los Padres fueronprocesados mediante técnicas histológicas estándar para microscopía óptica y electrónica de transmisión. Loshepatopáncreas de los individuos recolectados en Los Padres tenían alteraciones tisulares importantes, comoinfiltración intertubular de hemocitos y tejido conectivo, retracción epitelial en algunos túbulos y láminas basalesplegadas. También se observó descamación necrótica importante, con cariolisis, cariorrexis y falta de detallescelulares. Vimos muchos túbulos con un lúmen irregular y agrandado, con el epitelio atrofiado o completamenteausente. En general las lesiones se localizaron en la región medular del órgano. Ambos tipos celulares mostraronretracción del núcleo, condensación de la cromatina y ruptura del citoplasma. Algunas células R también teníanmitocondrias y numerosos lisosomas dilatados, y el citoplasma basal casi completamente desintegrado. Nohallamos alteraciones en los hepatopáncreas de gambas deCanal 5. El estudio histopatológico del hepatopáncreas es una herramienta muy apropiada para evaluar la condiciónfisiológica de las gambas y la calidad del agua. Por la semejanza de otras condiciones ambientales, suponemosque los contaminantes fueron la causa principal del deterioro de los órganos.

Assessment of coastal pollution through bioassay and transplantation of intertidal clams.

In the present study, a survey of Mahim creek and Bay area was undertaken that indicated absence of fauna, particularly molluscs from the area, which was a repository in the past. During bioassay experiments of Mahim creek water, the clams G. divaricatum and C. antiquata could not open their valves in 100% creek water and died within 12 hrs of exposure. The 96 hrs LC50 values of Mahim creek water for G. divaricatum and C. antiquata were found to be 20% and 40% respectively during summer and 38% and 57% respectively during rainy season. When two sets of the clams were transplanted at Mahim creek, they died within 12 hrs. These experiments suggest the extreme level of pollution in the area. This level of pollution is responsible for transforming the area into barren locality in terms of fauna, specially the rich molluscan diversity. However, Gorai creek was found to be comparatively very less polluted and it still serves as breeding and nursery ground for various fishes and prawn species. Hence it must be protected and conserved.

Genotoxicity and mutagenicity of water contaminated with tannery effluents, as evaluated by the micronucleus test and comet assay using the fish Oreochromis niloticus and chromosome aberrations in onion root-tips

Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs) which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.

Effect of Cr in irrigation water on germination and growth of French beans (Dolichos lablab L.).

The waters containing chromium (Cr) mainly from industries enter into the sewers, municipal treatment plant, streams and lakes that are used for irrigation purposes. The effect of Cr in irrigation water on seed germination and growth of French bean (Dolichos lablab L.) was investigated. Germination studies were conducted in the lab and field conditions. Seeds were treated with different concentrations (0 to 25 mg/1) of Cr in irrigation water. The percentage germination of seeds and plant growth showed a gradual decrease with increase in Cr concentration. Stimulatory effect in growth of plant was observed at lower concentration (1 to 2 mg/l). Accumulation of Cr was in the order of Root > Leaf > Stem > Pod. There was an increase in the total concentration of Cr content of soil with increase in Cr concentration in irrigation water.

Effects of basic oxygen furnace slag and inorganic nutrients on the germination of resting cysts of two toxic dinoflagellates.

Effects of basic oxygen furnace (BOF) slag, inorganic nutrients and H2S on the germination of resting cysts of two toxic dinoflagellates Alexandrium catenella/tamarense and Gymnodinium catenatum were studied in batch cultures. The germination rate of the test species has increased by 23-25%, when the concentration of NO3--N or H2S in culture medium has increased to 2.0 ppm. At the treatment of enriched NH4+-N and PO43--p, the germination of resting cyst was increased. Nevertheless, the increased range in germination rates was less than those of NO3--N and H2S. When BOF slag in culture medium increased to 50 mg/ml (or 500 g/m2), the cyst germination rate fell to less than 5%. At higher level of concentrations germination was completely inhibited. Adding BOF slag to the culture medium reduced the concentration of inorganic salts and H2S in seawater and sediments, resulting in the inhibition of cyst germination. These findings demonstrate the potential use of BOF slag on the sediments seed bank of red tide organism because it has an ability to inhibit resting cysts germination.

Assessment of phytoplankton density in relation to environmental variables in Gopalaswamy pond at Chitradurga, Karnataka.

Surface water samples of the Gopalaswamy pond were studied at two different sites during September 1997 to January 1998 and phytoplanktons were studied in relation to ten environmental variables during this period. A total of 30 species of phytoplanktons were identified under four classes, Chlorophyceae, Cyanophyceae, Bacillariophyceae and Euglenophyceae. Among these, maximum density was recorded under Cyanophyceae, Chlorophyceae, Cyanophyceae and Bacillariophyceae showed considerable fluctuations with environmental variables.

Toxicological evaluation of bacterial decolourised anaerobically treated distillery effluent with common duckweed (Lemna minor).

Duckweed (Lemna minor) a small vascular plant, grows rapidly, is sensitive to a wide variety of toxicants and is easy to culture. A method is described that measures duckweed frond growth, chlorophyll, protein and biomass content as indicator of growth inhibition. The physico-chemical analysis of anaerobically treated distillery effluent revealed high BOD (28,000 mg/l), COD (52,400 mg/l) and dark brown colour (180,000 Co. Pt.). This effluent showed high toxicity to Lemna minor after 96 h of exposure in laboratory condition. EC50 of the fronds for chlorophyll, protein and biomass was found to be 25%, however, the bacterial decolourised effluent showed reduction of BOD (87.50%), COD (84.50%) and colour (76%). Further the toxicity evaluation with Lemna minor showed toxicity reduction up to 63% for all tested parameters. The EC50 noted for chlorophyll, protein and biomass was 100% concentration of decolourised effluent.

Lethal effects of elevated pH and ammonia on juveniles of neotropical fish Colosoma macropomum (Pisces, Caracidae).

Ammonia is the main nitrogenous waste material excreted by gills, then is oxided first to nitrite and then to nitrate. The proportion of ionized-un-ionized ammonia depends on pH and temperature, when this variables increase in a solution containing ammonia the equation goes to left, so the proportion of NH3 increases and the solution becomes more toxic. The purpose of this study was to investigate the acute lethal effects of elevated pH and ammonia on tambaqui juveniles. With a constant ammonia concentration of 5.0 mg/l NH3, there was no mortality a pH of 6.0 (control) and 7.0; but was of 10-20% a pH of 8.0 and 100% at 9.0. The lethal effects of elevated pH and un-ionized ammonia should be recognized as a potential factor contributing to the variable success of tambaqui production ponds, but this species is highly resistant in comparison with other freshwater fish.

The effect of lead bioaccumulation on haem biosynthetic enzymes in fish.

The bioaccumulations of lead in the liver and hepatic microsomes of fish after 1, 3, 7, 14, 28, and 45 days exposure were studied. In addition, the relationship between the bioaccumulated lead in both hepatic microsomes and the liver and their haem biosynthetic enzymes were studied. Lead toxicity was shown to result in a depression of the microsomal mixed function oxidase system, as assessed by a decrease in hepatic microsomal cytochrome P-450 and b5 content and by a decrease in the activity of the enzymes aniline hydroxylase and aminopyrine demethylase. Lead had a more marked effect on cytochrome P-450 than b5. The activity of the rate-limiting enzyme of haem biosynthesis, delta-aminolevulinic acid synthase, was inversely correlated with the microsomal cytochrome P-450 content. The activity of the heam biosynthetic enzymes delta-aminolevulinic acid dehydratase, coproporphyrinogen oxidase and ferrochelatase were decreased by increasing lead pretreatment. The activity of the haem catabolic enzyme, haem oxygenase, was increased by concentration and length of time to lead exposure.

Nickel induced changes on some aspects of protein metabolism in the tissues of Pila globosa.

Some aspects of protein metabolism were studied in foot, hepatopancreas and mantle tissues of snail, Pila globosa on exposure to lethal concentration for 2 days (336.7 mg/L) and sublethal concentration (67.34 mg/L) of nickel for 1, 5 and 10 days. Total, structural and soluble proteins decreased significantly and to continence, this the levels of amino acids and protease activity increased in all the tissues of snail at all time points examined. Activities of AAT (Aspartate aminotransferase) and AlAT (Alanine aminotransferase) showed contrasting trends of inhibition and elevation during lethal and sublethal concentrations of nickel treatment. GDH (Glutamate dehydrogenase) activity was increased in all the tissues with increase in exposure time. Level of ammonia decreased in snails at sublethal concentration, but increment was observed in lethal concentration along with increased urea content. Under lethal and sublethal exposures, the changes in all the parameters were more pronounced in hepatopancreas followed by foot and mantle. At most instances, snails in the lethal medium were affected more compared to sublethal concentration.

Cadmium toxicity induced changes in plant water relations and oxidative metabolism of Brassica juncea L. plants.

Excess of cadmium (Cd) induced changes in oxidative scenario and water status of plants viz.., total water content, specific water content, water saturation deficit (WSD) and transpiration of Brassica juncea plants grown in soil pot culture. Although lower and marginal levels of excess cadmium (100 and 250 ppm) improved growth but higher levels (500 ppm) caused significant suppression. Significant accumulation of proline, an indicator of water stress, occurred at higher level of Cd. Gradual increases in activities of certain antioxidant enzymes such as catalase and peroxidase along with increased lipid peroxidation are suggestive of disturbed oxidative metabolism. Taking together, the deleterious effects of Cd and its effects on oxidative metabolism clearly indicate enhanced generation of reactive oxygen species (ROS) to be instrumental in producing toxic effects of Cd. The excess levels of Cd also decreased the concentrations of soluble protein and chlorophylls and increased the ratio of chlorophyll a/b.

Acute toxicity evaluation of copper, arsenic and HCH to paddy field crab, Paratelphusa hydrodromus (Herb.).

Routine static tests were conducted for determining the median lethal tolerance limit of paddy field crab, Paratelphusa hydrodromus exposed to Copper, Arsenic and HCH at different time intervals of 24, 48, 72 and 96 hour. The LC50 values for Copper came to be 28.00, 22.00, 18.20 and 15.70 ppm; Arsenic 136.00, 128.00, 121.500 and 114.00 ppm and HCH 10.00, 8.80, 7.00 and 6.00 ppm, respectively. The safe concentration, application factor and safe application rate were also calculated. They were for, Copper: 5.56, 1.59 and 3.26 ppm, Arsenic: 38.53, 11.40 and 76.00 and HCH : 4.07, 0.06 and 1.28 ppm. Animals exposed to different concentrations of test chemicals (Copper, Arsenic and HCH) showed prominent behavioural/morphological alterations viz., coughing, redness on the ventral side, paralysis and disorientation in scaphognathite activity. Animals exposed to high concentrations showed an avoidance behaviour by keeping away from the direct contact with the toxic solution either by climbing on the wall of aquarium or by mounting over the weak individual and forming a type of pyramid.

Toxicity of a rice field herbicide in a nitrogen fixing alga, Cylindrospermum sp.

Supplementation of paraquat into the culture medium proved to be highly toxic for a blue-green alga Cylindrospermum sp. A concentration of 15 microg/ml proved algicidal for the test alga. Various concentrations (0.5 microg/ml - 15 microg/ml) of the herbicide affected the growth and reduced chlorophyll and phycocyanin contents of the alga. In addition, it inhibited differentiation of heterocysts and akinetes. The inhibition of algal growth was found to be partially relieved on addition of 500 microg/ml of glucose.

Effect of mercuric chloride on testicular activities in mice, Musculus albinus.

Impaired testicular function was observed after an exposure of Swiss albino mice (30 +/- 2 g) to mercuric chloride. A sublethal chronic exposure (0.5 ppm for 21 days) resulted in regressed histological and histochemical properties of the testis. The changes observed were degenerated tunica albuginea, abnormal configurations of seminiferous tubules, deformed primary and secondary spermatocytes, hypertrophy and vacuolization in interstitial cells and Sertoli cells. The 3 beta and 17 beta hydroxy steroid dehydrogenase enzyme and the level of testosterone hormone were significantly (p < 0.001) reduced. The diameter of different spermatogenic cells were significantly (p < 0.001) reduced.

Caracterizaçäo de toxicidade de efluentes de usina siderúrgica mediante bioensaios com microorganismos. / Characterization of effluent toxicity in steelworks against bioassay with microorganism

Faz levantamento bibliográfico nacional e internacional sobre poluiçäo hídrica de siderúrgicas notadamente coquerias e mostra pesquisa de campo realizada em 13 campanhas, com amostragens junto a saída de efluentes no porto da empresa no estuário santista. Os resultados das amostras no ponto responsável pelos efluentes das fábricas de coqueria, laminaçäo, aciaria e altos fornos, indicam toxicidade em 80 por cento das campanhas e mutagenicidade de moderada e alta em 75 por cento das amostras pesquisadas. Os resultados dos bioensaios utilizados, Microtox e Ames, respectivamente para toxicidade aguda e mutagenicidade, foram comparados aos dos últimos trabalhos realizados na COSIPA em 1986 e 1993, e aos relatórios do órgäo controlador CETESB de 1992 e 1994. Discute os resultados que apontam o particulado presente na amostra como tóxico e mutagênico e induzem à proposta de recirculaçäo e reaproveitamento total à jusante da empresa, de todas águas servidas descartadas no processo, a exemplo de países do 1§ Mundo que convivem com a produçäo do aço

Toxicidade e concentraçäo de agentes tóxicos em efluentes industriais / Toxicity and the concentration of toxicants in industrial effluents

Foram estabelecidas correlaçöes entre os resultados dos testes de toxicidade com Daphnia similis e os das análisis físico-químicas de efluentes líquidos provenientes de várias atividades industriais. De modo geral foram obtidas fracas correlaçöes entre a toxicidade e os valores das variáveis fisico-químicas consideradas isoladamente (r2 = 0,05 a 0,62). Através de análise de regressäo múltipla, foi obtido um excelente coeficiente de determinaçäo (r2 = 0,97, más a equaçäo estabelecida näo estimou a toxicidade de efluentes industriais com base nos resultados das análises físico-químicas. Considerando os resultados obtidos, recomenda-se que a toxicidade de efluentes líquidos seja sempre determinada através de testes de toxicidade com organismos aquáticos

Toxicidade de águas superficiais na regiäo da grande Säo Paulo / Toxicity of surface water in the great Säo Paulo area

Amostras de águas superficiais da regiäo da Grande Säo Paulo foram submetidas a testes de toxicidade aguda com Daphnia similis. Verificou-se que 50% das amostras apresentaram efeito tóxico, incluindo amostras de corpos receptores pertencentes as classes 2 e 3. Análises de regressäo entre os resultados dos testes de toxicidade e os das análises fisico-químicas indicaram a inexistência de correlaçäo entre essas variáveis. Através dos resultados obtidos, säo discutidas as limitaçöes do uso do monitoramento físico-químico e microbiológico para a avaliaçäo da qualidade das águas superficiais do Estado de Säo Paulo. É, ainda, recomendada a utilizaçäo de testes de toxicidade com organismos aquáticos para complementar a caracterizaçäo das águas destinadas a proteçäo da vida aquática