Lysine and arginine requirements of Salminus brasiliensis

The objective of this work was to determine the dietary lysine (DL) and dietary arginine (DA) requirements of dourado (Salminus brasiliensis), through dose-response trials using the amino acid profiles of whole carcasses as a reference. Two experiments were carried out in a completely randomized design (n=4). In the first experiment, groups of 12 feed-conditioned dourado juveniles (11.4±0.2 g) were stocked in 60 L cages placed in 300 L plastic indoor tanks in a closed circulation system. Fish were fed for 60 days on diets containing 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 % dietary lysine. In the second experiment, dourado juveniles (27.0±0.8 g) were fed for 60 days on semipurified diets containing arginine at 1.0, 1.5, 2.0, 2.5 or 3.0%, in similar conditions to those of the first experiment. Optimal DL requirements, as determined by broken-line analysis method for final weight, weight gain and specific growth rate, were 2.15% DL or 5% lysine in dietary protein, and 1.48% DA or 3.43% arginine in dietary protein. The best feed conversion ratio is attained with 2.5% DL or 5.8% lysine in dietary protein and 1.4% DA or 3.25% arginine in dietary protein.

A presença de mercúrio em casa constitui um risco de contaminação humana e / ou ambiental? Relato de um caso

Mercury kept in a garage of a residencial building in Rio de Janeiro was accidentally released and caused local (environmental and human) contamination. The concentration of mercury in indoor air of the most critical site reached 15.5 mg/m³. Outdoor air samples showed concentrations ranging from 0.37 to 6.6 mg/m³ . Seventy five per cent of the urine samples collected from 22 residents in the contaminated building showed levels of mercury higher than those observed in non exposed individuals (>6.9 mg/L); in 30% of these samples, the concentration was higher than 20 mg/L. These values show a high level of human contamination and the final consequences were not so serious owing to the quick action taken by one of the residents.

A qualidade do ar de interiores e a química

In Brazil, very little experimental work on measurements of indoor air pollutant levels has been done. Nowadays, increasing attention is being given to indoor air quality and the health problems associated with buildings and the indoor work environment. The scope of this paper is to review the major pollutants found in indoor environments and their sources. Subsequently, exposure to indoor air pollutants and health effects are considered. The review concludes by briefly addressing assessment of indoor air quality in Brazil and research needs.

Presença de compostos carbonílicos no ar em ambientes internos na cidade de São Paulo

The presence of low carbonyl compounds (C1-C4) and glutaraldehyde was observed in 14 work-locations in São Paulo city, Brazil, during January to July 1997 period. The quantification of other carbonyls was not possible due to a sampling artifact caused probably by undesirable reactions between the ambient ozone and the organic substract of C18 cartridge used to collect carbonyls. High indoor concentrations, compared to outdoor levels, were observed for all compounds. Formaldehyde was the most abundant species (29 ppb) followed by acetone and acetaldehyde (25 and 17 ppb) with a small contribution of propanal, crotonaldehyde and C4 isomers (0.7 to 1.5 ppb) when related to the total indoor carbonyls level. Glutaraldehyde was observed only in two different occupational locations in a hospital at high concentrations (121 ppb). In general, high individual carbonyl levels as well as total carbonyls levels found in several locations indicated an unpropitious air quality for the occupants of these non-industrial sites.

Gota suspensa para avaliação de aldeído total no ar interno e externo do ambiente

A sensitive and simple system was proposed for the in situ measurement of total aldehyde in outdoor or indoor ambient. The method is based on the use of a reagent drop as an useful interface to preconcentrate the sample prior to determination of total aldehyde as formaldehyde. The drop is formed at the tip of a cylindrical tube that contains two optical fibers placed on opposite sides and in contact with the reagent solution. One optical fiber carries the red light to the drop form a light emitting diode (LED). The transmitted light is measured by a second optical fiber/photodiode system. The analytical signal is read and converted into absorbance. The reagent solution of 3-methyl-2-benzothiazoline hydrazone (MBTH) forms a blue cation during reaction with formaldehyde that can be measured at 660 nm. Some aspects of kinetics reaction formation of dye were reevaluated. The formaldehyde reacts with MBTH and forms the azine in about 12 min. The oxidation of MBTH by Fe (III) and the formation of dye requires 3 min. The absorbance of the reagent drop is proportional to the sampling time and to the analyte concentration. The absorbance signal increases with increased sample gas flow until a maximum is reached then decreases until it forms a plateau. The proposed method was evaluated using both outdoor and indoor samples, and it was shown to viable provide an accurate measure of total aldehyde.

Exposição ocupacional a compostos orgânicos voláteis na indústria naval

The scope of this study involved the evaluation of the concentration of some volatile organic compounds in the internal environmental air of a naval shipyard in the State of Rio de Janeiro, during painting activities in enclosed, semi-enclosed and open areas. Xylene was the volatile compound found in greatest abundance (25.20 to 191.66 ppm) in the locations researched. Benzene in the air, which is a carcinogenic substance, attained levels of 3.34 ppm in semi-enclosed environments and the highest levels of toluene, xylene and n-butanol were found in the enclosed space of the ship. Results obtained highlight the need to establish air quality control programs in these internal areas, in order to safeguard the health of the workers.

Proposição de um reator fotocatalítico para destruição de microrganismos em ambientes interiores

The TiO2/UV photocatalytic reactor was investigated as an alternative system to inactivate airborne microorganisms. The experiments performed in the absence of the catalyst showed that direct photolysis was not efficient to destruct microorganisms, with only 30% of inactivation. Similar inactivation percentage was obtained using TiO2 in absence of UV radiation. The destruction of microorganisms present in a contaminated indoor atmosphere, using the combination of TiO2/UV was very efficient, reaching more than 98% of destruction.

Poluição química relacionada ao ar de interiores no Brasil

During the last two decades there has been increasing concern within the scientific community related to the effects of indoor air quality on health. Changes in building design devised to improve energy efficiency and new synthetic building materials have contributed to increase pollutant concentrations. These factors have generated poor air quality and caused the development of a lot of symptoms known as Sick Building Syndrome (SBS). In Brazil, there are few studies in this area, collected in this review to support researches and awareness of the need to adopt preventive measures to reach a better quality for the Indoor Environment.

Construção de amostrador passivo de baixo custo para determinação de dióxido de nitrogênio

A new passive sampling system for monitoring NO2 in air has been developed to measure gas concentrations in indoor and outdoor air. The sampler is inexpensive, and easy to construct and operate. Nitrogen dioxide forms a derivative after reaction with a filter coated with triethanolamine and ethyleneglycol. The nitrogen dioxide derivative is extracted from the filter, and the concentration is determined by colorimetry. To test the sampler for measuring ambient level nitrogen dioxide, measurements were carried out inside homes and in a range of workplace environments.

Principais carbonilas no ar de locais públicos no Rio de Janeiro

An air quality evaluation of indoor environments with focus on lower carbonyls was carried out in 50 public places using TO-11A methodology. Formaldehyde levels (ranging from 12.5 to 1034 mg m-3) were above the threshold limit in 49 of 50 analyzed samples while acetaldehyde (ranging from 5.2 to 840 mg m-3) and acetone (ranging from 5.5 to 4839 mg m-3) were respectively bellow the limits of OSHA and NIOSH in all samples. However all samples were bellow the threshold limits suggested by the Brazilian legislation - NR-15. A correlation study between the carbonyls and temperature and humidity was also done.

Avaliação de NO2 na atmosfera de ambientes externos e internos na cidade de Araraquara, São Paulo

The seasonal behavior of NO2 concentration shows a maximum occurring during sugarcane crop and this suggests that the biomass burning is significant source of emission at this time of the year. Along the day, the variation of the NO2 showed a decrease during the increased sunlight and an increase thereafter, caused by occurrence of photochemical reactions. Measurements of NO2 were done inside of residential and industrial kitchens and also inside of a parking garage located in the underground of a supermarket building. The indoor concentrations of NO2 were significantly higher than the concentrations of the external atmosphere and it shows the importance of the sources of internal emissions.

Impacto ambiental de kartódromos situados na cidade do Rio de Janeiro: monitoramento de BTEX no ar e do nível de ruído

In this work, noise and aromatic hydrocarbons levels of indoor and outdoor karting circuits located in Rio de Janeiro were assessed. The sampling was perfomed using active charcoal cartridges, followed by solvent desorption and analysis by gas chromatography with mass spectrometry detection. This study demonstrated that the karting circuits, venues for entertainment, were a major source of air pollution with the detection of considerable amounts of these compounds (2.0 to 19.7 µg m-3 of benzene; 4.1 to 41.1 µg m-3 of toluene; 2.8 to 36.2 µg m-3 of ethylbenzene; 0.7 to 36.2 µg m-3 of xylenes) and high noise levels.

Formaldeído em escolas: uma revisão

Formaldehyde has been classified as a probable human carcinogen. Indoor air quality measurements carried out worldwide in schools indicate that levels may be of concern. This paper provides an overview of emission sources, properties and methods for quantification of formaldehyde. Quantitative information from studies performed in school environments was compiled and a comprehensive picture of the causal relationships between pollutant exposures and children's health given. Mitigation actions to reduce formaldehyde levels and its adverse impacts in school buildings are recommended.

Comparative performance of two air samplers for monitoring airborne fungal propagules

Many studies have attempted to evaluate the importance of airborne fungi in the development of invasive fungal infection, especially for immunocompromised hosts. Several kinds of instruments are available to quantitate fungal propagule levels in air. We compared the performance of the most frequently used air sampler, the Andersen sampler with six stages, with a portable one, the Reuter centrifugal sampler (RCS). A total of 84 samples were analyzed, 42 with each sampler. Twenty-eight different fungal genera were identified in samples analyzed with the Andersen instrument. In samples obtained with the RCS only seven different fungal genera were identified. The three most frequently isolated genera in samples analyzed with both devices were Penicillium, Aspergillus and Cladophialophora. In areas supplied with a high efficiency particulate air filter, fungal spore levels were usually lower when compared to areas without these filters. There was a significant correlation between total fungal propagule measurements taken with both devices on each sampling occasion (Pearson coefficient = 0.50). However, the Andersen device recovered a broader spectrum of fungi. We conclude that the RCS can be used for quantitative estimates of airborne microbiological concentrations. For qualitative studies, however, this device cannot be recommended.