Genome-wide association of iron content in rice grains grown in Southern Brazil

O objetivo deste trabalho foi mapear regiões cromossômicas responsáveis pelo acúmulo de ferro em grãos de arroz, na região Sul do Brasil. Oitenta e um acessos de arroz foram genotipados e fenotipados quanto ao acúmulo de Fe. Polimorfismos de nucleotídeos únicos foram mapeados no grão integral, nos cromossomos 1, 5, 6 e 10, dos quais 13 genes candidatos foram identificados. Alguns dos genes, como o Os10g0406800, parecem ter relação com a homeostase do Fe, enquanto outros têm relação com outros processos metabólicos ou função desconhecida.The objective of this work was to map the chromosomal regions responsible for iron accumulation in rice grains, in Southern Brazil. Eighty-one rice accessions were genotyped and phenotyped for Fe accumulation. Single nucleotide polymorphisms were mapped in the whole grain on chromosomes 1, 5, 6, and 10, from which 13 candidate genes were identified. Some of the genes, such as Os10g0406800, seem to have a relationship with Fe homeostasis, while others are related to other metabolic processes or have an unknown function

Potentially Toxic Elements in Costume Cosmetics Used by Children and Adults Are Associated with Cancer Risk

(1) Background: Costume cosmetics, such as face paints and pancakes, are used by adults and children during Halloween, Carnival, or children’s parties. However, the metallic-based pigments used as dyes in these products may contain toxic elements associated with different levels of exposure. Objectives: (a) to determine the Al, As, Ba, Cd, Co, Cr, Cu, Ni, Pb, Sb, Sn, and Sr concentrations in face paints and pancakes; and (b) to estimate cancer and non-cancer risks posed by the concentrations of each element in these products for dermal and ingestion exposure scenarios during children and adult use. (2) Methods: A total of 95 samples of face paints and pancakes (four brands in different textures and colors) were purchased at the largest high-street commercial center in São Paulo city, Brazil. An extraction procedure with nitric acid was carried out using a graphite-covered digester block. Toxic element determinations were performed using an ICP-MS. (3) Results: The non-cancer risks estimated were lower than 1, except for dermal exposure in adults for some target systems. High cancer risk values raise concerns in both groups. The risk for children ranged from 10−8 to 10−5 and proved higher in cases of accidental exposure by ingestion. For occupational exposure in adults, cancer risks were even higher, ranging from 10−3 to 10−5, with the highest values associated with dermal exposure. (4) Conclusions: The study results suggest the presence of potentially toxic elements (PTEs) in cosmetics should be regulated/monitored to protect human health, especially for occupational exposure and use by children

A high-throughput analytical tool for quantification of 15 metallic nanoparticles supported on carbon black

Metallic nanoparticles (NPs) have been widely used in different areas of science. Usually, they are immobilized on a low-cost support for catalysis purposes. However, there is a lack of studies for specific methods for analytical quantification since the extraction of these metallic NPs from the matrix is still a challenge. In this work, 15 metallic NPs were synthesized (Pt, Pd, Au, Ag, Rh, Ru, Nb, Mn, Co, Cu, Zr, Sn, Ce, Ni and W) supported on a commercial carbon black (Vulcan XC72). Then, six different methods were employed for sample preparation and further determination by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results can be divided in three groups concerning the extraction of metallic NPs: the first group could be extracted from the matrix with nitric acid, for the second one it was necessary to employ a digestion at 25 °C (room temperature), and finally a third group which was found to be independent of acid and temperature. These findings can contribute to future research in the field of catalysis to improve their characterization regarding the metallic NPs

Lead, Cadmium, and Arsenic Bioaccessibility of 24 h Duplicate Diet Ingested by Preschool Children Attending Day Care Centers in Brazil

Lead, known as a metal with high neurotoxicity to children, cadmium, which is a carcinogenic and bioaccumulative contaminant, and arsenic, a class 1 carcinogenic according to the International Agency for Research on Cancer, are toxic elements (TEs) whose relevant route of exposure may be diet. We determined the bio-accessible fraction of lead, cadmium, and arsenic from the diet of preschool children from two day care centers (DCC). A cross-sectional study was conducted with 64 one–four-year-old children from two DCCs where the 24-h duplicate diet samples were collected. The diet samples were analyzed by ICP-MS for lead, cadmium, and arsenic total concentrations (n = 64) and their bio-accessibility were analyzed for a subsample (n = 10). The dietary intake (DI) mean for lead, cadmium, and arsenic were 0.18 ± 0.11 µg kg−1 bw, 0.08 ± 0.04 µg kg−1 bw, and 0.61 ± 0.41 µg kg−1 bw, respectively. All DI calculated for TEs, considering total intake, were found lower than the tolerable limits (TL) (European Union, or World Health Organization, WHO, when applicable) except for one child’s Pb intake. Bio-accessibilities ranged between 0% to 93%, 0% to 103%, and 0% to 69%, for lead, cadmium, and arsenic, respectively. Although DI for TEs has been found lower than TL, these reference values have been recently decreased or withdrawn since it was for lead and arsenic whose TL were withdrawn by WHO