Micronucleus in exfoliated buccal cells of crack users: systematic review and meta-analysis / Micronúcleos en células bucales exfoliadas en consumidores de crack: una revisión sistemática y meta-análisis

Abstract This research aimed to conduct a systematic review and metanalysis to compare the frequency of cell damage in crack users and nonusers, through Micronucleous (MN) test in buccal mucosa cells. A comprehensive search was carried out on MEDLINE via PubMeb, Web of Science, LILACS and the grey literature without restrictions. It was included case-control studies that report the frequency of micronuclei in the oral mucosa of adult crack users and nonusers. A review protocol was registered with PROSPERO (CRD42018115672), and conducted in accordance with the PRISMA guidelines for the report of this systematic review. Furthermore, study quality was evaluated using an adapted Newcastle-Ottawa Scale for cross-sectional studies.The original search yielded 27 references, after eligibility criteriaonly five articles were included. The number of micronuclei was higher in crack users compared to nonusers. Also, secondary outcomes: binucleated cells, nuclear buds, pyknosis, karyorrhexis and karyolysis had higher prevalence in crack users.Crack use is associated with genotoxic and mutagenic effects because there is a higher frequency of micronuclei in exfoliated cells of crack users. In addition, MN test proved to be a goodbiomarker to assess the mutagenic impact of crack use in oral epithelium.

Resumen Esta investigación tuvo como objetivo realizar una revisión sistemática y un meta-análisis para comparar la frecuencia de daño celular en usuarios de crack y sin crack, a través de la prueba de micronúcleos (MN) en células de la mucosa bucal. Se realizó una búsqueda exhaustiva en MEDLINE a través de PubMeb, Web of Science, LILACS y la literatura gris sin restricciones. Se incluyeron estudios de casos y controles que informaron la frecuencia de micronúcleos en la mucosa oral de usuarios adultos de crack y sin crack. Se registró un protocolo de revisión con PROSPERO (CRD42018115672), y se realizó de acuerdo con las pautas de PRISMA para el informe de esta revisión sistemática. Además, la calidad del estudio se evaluó mediante una escala Newcastle-Ottawa adaptada para estudios transversales. La búsqueda original arrojó 27 referencias, después de los criterios de elegibilidad se incluyeron un total de cinco artículos. El número de micronúcleos fue mayor en los usuarios de crack en compa ración con los usuarios sin crack. Además, los resultados secundarios de células binucleadas, yemas nucleares, picnosis, cario- rrexis y cariólisis tuvieron una mayor prevalencia en los usuarios de crack. El uso de crack se asocia con efectos genotóxicos y mutagénicos porque hay una mayor frecuencia de micronúcleos en las células exfoliadas de los usuarios de crack. Además, la prueba de MN demostró ser un buen biomarcador para evaluar el impacto mutagénico del uso de crack en el epitelio oral.

Biomonitoring of trace elements in urine samples of children from a coal-mining region.

Biomonitoring through urine samples is important for evaluating environmental exposure, since urine is the main form of excretion for most chemical elements. Children are considered more vulnerable to adverse environmental conditions, especially children in developing countries. This study aimed to biomonitor trace elements in urine samples in children from a coal-mining region in the extreme south of Brazil. A cross-sectional study was conducted on 96 children between 6 and 11 years of age. Socioeconomic data and urine samples were collected to estimate the concentration of iron, zinc, selenium, lead, and cadmium. The prevalence of metals above the reference values was 52.0% for Se, followed by 15.6% for Zn. The data point toward a vulnerability to adverse environmental conditions in these children. Although the concentrations of the elements did not reveal intoxication cases, biomonitoring should be carried out continuously in order to assess exposure to metals and ensure the health of the population. This article provides data that help determine natural levels of metallic elements in children, specifically in South America, which have not yet been established.

Arsenic speciation in fish and shellfish from the North Sea (Southern bight) and Açu Port area (Brazil) and health risks related to seafood consumption.

In North Sea and Port Açu (Brazil) coastal areas, high arsenic (As) concentrations were observed in water, soil and sediments. Therefore, the impact of this contamination on fish and shellfish species bought from local fishermen was studied. Total As was assessed with ICP-OES (Brazil) and ICP-MS (North Sea) after microwave digestion. Toxic As was assessed with liquid chromatography-ICP-MS (Brazil) and hydride generation-atomic fluorescence spectrometry (North Sea). All analytical methods comply with Quality Assurance/Quality Control procedures. Several fish species have average Total As concentrations above 1 µg g-1 wet weight (ww), but the highest concentrations are found in less spotted dogfish, lemon sole and whelks from the North Sea, with respectively 50, 49 and 50 µg g-1 ww. High Total As concentrations correspond to high Toxic As concentrations, except for scallops having increased Toxic As concentrations. Toxic As fractions are highest in scallops (almost 10%) but rarely exceeds 2% in all other species. Liver samples were only analyzed in ray, dogfish and catfish and their Toxic As fractions are between 2 and 4 times higher than in muscle. For a consumption of 150 g of seafood, only 3 samples exceed the provisional total daily intake of 2 µg kg-1 bw, however, cancer risks are non-negligible. Using mean Toxic As concentrations for each of the different fish and shellfish species studied, Lifetime Cancer Risk values at the actual global seafood consumption rate of 54 g day-1 are above 10-4 for whelks, scallops, dogfish, ray and lemon sole.