Risk assessment of coffees of different qualities and degrees of roasting.

During the coffee beans roasting process, occurs the formation of polycyclic aromatic hydrocarbons, which are associated with the incidence of cancer in humans. This study aimed to evaluate the influence of coffee bean quality and roasting degree regarding mutagenicity, cytotoxicity and genotoxicity. Six samples of coffee drink made with roasted and ground Coffea arabica beans from different qualities and roast degrees were used after freeze-drying. Both commercial and special quality grains suffered light, medium and dark roasting. According to the Salmonella/microsome assay, the highest concentration of commercial grain sample (dark roast) significantly increased the number of revertants of the TA98 strain in the absence of metabolization. All the samples induced cytotoxicity to HepG2 cells. These effects can be ranked in the following order from most to least toxic: medium roast - special grain > light roast - special grain > dark roast - commercial grain > dark roast - special grain > light roast - commercial grain > medium roast - commercial grain. None of the samples induced genotoxicity in HepG2 cells. Our findings show that the harmful effects of coffee depend not only on the degree of roasting but also on the grain quality.

Toxicological evaluation of nail polish waste discarded in the environment.

Nail polish has been widely used around the world. However, the hazards of nail polishes discarded in the environment are still poorly investigated. Thus, the toxicogenetic effects of solubilized (SE) and leached (LE) extracts from nail polishes were investigated, simulating their disposal on water and landfill, respectively, and identifying their physicochemical properties and chemical constituents. Organic compounds and metals were detected in both extracts. SE and LE only induced mutagenic effects in TA98 Salmonella strain in the presence and absence of exogenous metabolic activation. Although both extracts did not significantly increase the frequency of micronucleated HepG2 cells, the cell viability was affected by 24-h exposure. No DNA damage was observed in gonad fish cells (RTG-2) exposed to both extracts; however, the highest SE and LE concentrations induced significant lethal and sublethal effects on zebrafish early-life stages during 96-h exposure. Based on our findings, it can be concluded that if nail polishes enter aquatic systems, it may cause negative impacts to the environment.

Removal of ammonia nitrogen from distilled old landfill leachate by adsorption on raw and modified aluminosilicate.

This study aimed to evaluate the ammonia-nitrogen removal by aluminosilicates, using both standard solutions as pretreated landfill leachate. Three types of commercial clays and one commercial zeolite were initially tested using standard solution; however, only one clay with the best removability and the zeolite were tested with pretreated leachate. The chosen clay sorption capacity with the standard solution reached 83%, while with the pretreated leachate solution has reached 95% and zeolites have reached, respectively, a removal of 73% and 81%. For this two adsorbents' studies of equilibrium and kinetic of the sorption were also performed. The Langmuir model was more adequate to describe the ion exchange equilibrium and the sorption mechanism fit the pseudo-second-order kinetic model. Moreover, the pretreatment used on leachate proved to be essential not only for ammonium detection in solution, but also to facilitate its sorption in aluminosilicates. This alternative of ammonia-nitrogen removal also generates a product derived from treatment that can be used as agricultural feedstock in the form of fertilizer.

Development of a solid-phase extraction system modified for preconcentration of emerging contaminants in large sample volumes from rivers of the lagoon system in the city of Rio de Janeiro, Brazil.

A single method modified for monitoring of emerging contaminants in river water was developed for large sample volumes. Water samples from rivers of the lagoon system in the city of Rio de Janeiro (Brazil) were analyzed by the SPE-HPLC-MS-TOF analytical method. Acetaminophen was detected in four rivers in the concentration range of 0.09µgL(-1) to 0.14µgL(-1). Salicylic acid was also found in the four rivers in the concentration range of 1.65µgL(-1) to 4.81µgL(-1). Bisphenol-A was detected in all rivers in the concentration range of 1.37µgL(-1) to 39.86µgL(-1). Diclofenac was found in only one river, with concentration of 0.22µgL(-1). The levels of emerging organic pollutants in the water samples of the Jacarepaguá hydrographical basin are significant. The compounds are not routinely monitored and present potential risks to environmental health.

Pyrene photochemical species in commercial clays.

The photochemistry of pyrene, a polycyclic aromatic hydrocarbon, adsorbed on kaolinite, sodium montmorillonite and acid bentonite K10® was investigated to determine how the concentration and structure of the clay minerals affect the formation of different species of pyrene. Fluorescence emission spectra were obtained using reflection geometry for pyrene at the concentrations ranging from 0.5 to 100.0 µmol g(-1) (pyrene:clay). Two pyrene photochemical species were observed, the monomer, which fluoresces at 396 nm, and its excimer which fluoresces at 470 nm. The formation of excimers occurred first on the kaolinite, due to the smaller surface area. In the acid montmorillonite, the fixed interlamellar space provided greater specific area, leading to lower formation of excimers. Emission from pyrene crystals was also detected for samples with high loadings.