Heavy metals and health risk assessment of Brazilian artisanal cheeses.

Dairy products stand out as a food matrix susceptible to the contamination of heavy metals via cattle feed and environmental or processing conditions. Specifically, in the case of cheese, the concentrations can be further increased depending on the production process. The artisanal cheese market has been standing out, especially in Brazil, due to cultural and gastronomic reasons. Eight types of Brazilian artisanal cheese were analyzed for metal concentrations (chromium, copper, cadmium, lead, arsenic, and mercury, n = 80, 10 samples of each cheese) using inductively coupled plasma mass spectrometry. Based on the results, a health risk assessment was carried out, based on the determination of estimated daily intake, target hazard quotient (THQ), and hazard index (HI). Variable concentrations were observed between the types of cheese, but in all cases the THQ and HI values were less than 1, indicating an absence of potential risk in the consumption of artisanal cheeses in relation to the intake of heavy metals.

Role of indigenous microorganisms and organics in the release of iron and trace elements from sediments impacted by iron mine tailings from failed Fundão dam.

After Fundão Dam failure in 2015, most of Gualaxo do Norte River in Doce River Basin in Brazil became silted by iron mining tailings consisting mainly of fine-grained quartz, hematite, and goethite. Previous work pointed to the possibility of reductive dissolution of iron and manganese from tailings, leading to mobilization of iron, manganese and trace elements. Several microorganisms were shown to reduce Fe(III) to Fe(II) and Mn(III, IV) to Mn(II) "in vitro", but their roles in mobilization of Fe and trace elements from freshwater sediments are poorly understood. In this work, bottom sediments and water collected in Gualaxo do Norte River were used to build anoxic microcosms amended with acetate, glucose or yeast extract, in order to access if heterotrophic microorganisms, either fermenters or dissimilatory Fe reducers, could reduce Fe(III) from minerals in the sediments to soluble Fe(II), releasing trace elements. The Fe(II) concentrations were measured over time, and trace elements concentrations were evaluated at the end of the experiment. In addition, minerals and biopolymers in bottom sediments were quantified. Results showed that organic substrates, notably glucose, fuelled microbial reduction of iron minerals and release of Fe(II), Mn, Ba, Al and/or Zn from sediments. In general, higher concentrations of organic substrates elicited mobilization of larger amounts of Fe(II) and trace elements from sediments. The results point to the possibility of mobilization of huge amounts of iron and trace elements from sediments to water if excess biodegradable organic matter is released in rivers affected by iron mine tailings.

Organic Black Beans (Phaseolus vulgaris L.) from Rio de Janeiro State, Brazil, Present More Phenolic Compounds and Better Nutritional Profile Than Nonorganic.

Brazil is the world's third largest common bean (Phaseolus vulgaris L.) producer, and 60% of its population consumes this legume. Although organic farming is a sustainable alternative to nonorganic agriculture, its effect on chemical composition is still controversial. Therefore, the aim of this study was to investigate differences in the nutritional and phenolic compounds profiles between organically and nonorganically produced Brazilian black beans. Samples were obtained from the same harvest periods and from near geographical locations at metropolitan and coastal regions of Rio de Janeiro state, Brazil. No residues of 294 evaluated pesticides were detected in the samples. In both regions, organic beans had 17% fewer lipids, 10% less phytate and 20% more proteins when compared to nonorganic ones. Sixteen different phenolic compounds were identified as soluble and insoluble forms in black beans, with anthocyanins being the most abundant (on average, 66%). In both regions, soluble and total phenolic compounds contents in organic beans were consistently higher (on average, 25% and 28%, respectively) than in nonorganic ones. Our results show that organic farming improves the nutritional profile and increases the phenolic compounds content of black beans.

Metal Bioaccumulation by the Neotropical Clam Anomalocardia flexuosa to Estimate the Quality of Estuarine Sediments.

This investigation evaluated the bioaccumulation potential of the tropical estuarine bivalve Anomalocardia flexuosa for trace metals. To this aim, chemical and sedimentological analyses and bioaccumulation tests were performed. The sediments were mainly composed by fine-sands and mud, with variable levels of organic matter and CaCO3. Muddy sediments from a depositional site (P2) presented the highest concentrations of metals, despite SEM/AVS not indicating bioavailability. Bioaccumulation factors showed high ratios for Cd, Ni, and Zn, while associations between the contents of mud, organic matter, CaCO3 and metals in sediments and tissues of A. flexuosa were indicated by a principal component analysis. The SEM/AVS was not effective to predict the bioavailability through dissolved metals. The results showed that contaminants were bioavailable, while the performed bioaccumulation test proved to be a reliable technique for assessing sediment contamination in estuarine regions. Moreover, A. flexuosa was considered an adequate test organism for bioaccumulation studies.

Metal accumulation in roadside soils of Rio de Janeiro, Brazil: impact of traffic volume, road age, and urbanization level.

Traffic-related metal emissions have become a global concern due to their deposition in roadside soils and potential hazardous effects. This study evaluates metal levels in soils adjoining four highways of Rio de Janeiro (Linha Vermelha, Via Dutra, BR-465, and Avenida Brasil), chosen for their diverse traffic volumes, age, and urban/rural settings. In addition to soil physicochemical properties, 11 elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, and Zn) were assessed on samples collected at different distances from the road (1, 3, 5, 10, 15 m) and soil depths (0-15 and 15-30 cm). Moreover, the geoaccumulation index was also computed to infer the soil contamination extent. The results indicate that soil metal levels at each highway are highly dependent on factors like traffic volume, distance to road, other anthropogenic sources of pollution, and their rural or urban location. The highways with greater traffic volume, Linha Vermelha and Avenida Brasil (154,000 and 126,000 vehicles day-1, respectively), clearly presented the highest soil metal concentrations. Still, as stressed by the principal component analysis, traffic volume alone fails to explain the distribution of metals in soils neighboring these highways. Thus, factors like their urban setting and larger exposure to anthropogenic activities may play a pivotal role. On the other hand, soils from Via Dutra and BR-465, both on a rural backdrop, were mostly influenced by traffic as their metal levels decreased with increasing distances from the road. Comparison with reference and preventive values for Brazilian soils and the assessment of the geoaccumulation index have shown that concentrations of Pb and V have reached concerning thresholds at Linha Vermelha and Avenida Brasil.