Spatial pattern of the environmental exposure to tin in the vicinity of an alloy industry in Volta Redonda, Rio de Janeiro State, Brazil

Occupational exposure to potentially toxic elements alters gene expression profiles in formal and informal Brazilian workers

Chemical elements, such as toxic metals, have previously demonstrated their ability to alter gene expression in humans and other species. In this study, microarray analysis was used to compare the gene expression profiles of different occupational exposure populations: a) informal workers who perform soldering of jewelry inside their houses (n = 22) in São Paulo (SP) State; and b) formal workers from a steel company (n = 10) in Rio de Janeiro (RJ) state, Brazil. Control participants were recruited from the same neighborhoods without occupational chemical exposure (n = 19 in SP and n = 8 in RJ). A total of 68 blood samples were collected and RNA was extracted and hybridized using an Agilent microarray platform. Data pre-processing, statistical and pathway analysis were performed using GeneSpring software. Different expression was detected by fold-change analysis resulting in 16 up- and 33 down-regulated genes in informal workers compared to the control group. Pathway analysis revealed genes enriched in MAPK, Toll-like receptor, and NF-kappa B signaling pathways, involved in inflammatory and immune responses. In formal workers, 20 up- and 50 down-regulated genes were found related to antimicrobial peptides, defensins, neutrophil degranulation, Fc-gamma receptor-dependent phagocytosis, and pathways associated with atherosclerosis development, which is one of the main factors involved in the progression of cardiovascular diseases. The gene IFI27 was the only one commonly differentially expressed between informal and formal workers and is known to be associated with various types of cancer. In conclusion, differences in gene expression related to occupational exposure are mainly associated with inflammation and immune response. Previous research has identified a link between inflammation and immune responses and the development of chronic diseases, suggesting that prolonged occupational exposures to potentially toxic elements in Brazilian metal workers could lead to negative health outcomes. Further analysis should be carried out to investigate its direct effects and to validate causal associations.

Tin speciation in the blood plasma of workers occupationally exposed in a cassiterite ore processing industry

ABSTRACT Mining is a high-risk activity due to its dangerous processes. Tin (Sn) is obtained from cassiterite ore and mining activities expose workers to the metal. Chronic exposure to Sn may cause pneumoconiosis, gastrointestinal and hematological effects, among others. This work aimed to assess the exposure of workers to tin in a cassiterite ore processing industry, using the speciation analysis in blood plasma. Twelve subjects donated the blood samples; six were occupationally exposed to Sn. Size exclusion chromatography separated proteins in blood plasma; a graphite furnace atomic absorption spectrometer determined total tin in the plasma and eluted fractions, while SDS-PAGE determined molecular masses of proteins. Tin levels in the workers’ plasma were four times higher than in the reference individuals. After fractionation, the metal only appeared in the total inclusion volume, not being possible to confirm the binding of tin to proteins, which certainly modifies their functions and impair workers’ health. Despite that, the work process needs to change since Sn levels in the workers’ plasma pointed to metal exposure. Further works are necessary to clarify whether the metal is free or bound to small proteins in blood plasma and understand the true impact of tin on workers’ health.

Unraveling Anthropocene Paleoenvironmental Conditions Combining Sediment and Foraminiferal Data: Proof-of-Concept in the Sepetiba Bay (SE, Brazil)

The Sepetiba Bay (SB), located in the state of Rio de Janeiro (SE Brazil), is a transitional ecosystem highly anthropized. Because of its great environmental, economic, and social importance, the SB has been the target of several studies to investigate the sources of pollution and their environmental impact. However, studies on the response of foraminifera to pollution are rare. This study applies for the first time in the SB the Ecological Quality Ratio (EQR) based on the biotic index exp(H’bc), related to foraminiferal diversity, coupled with granulometric, mineralogical, and geochemical data and a robust age model (based on 210Pb and 137Cs activity). This study aims to evaluate the paleo-ecological quality status (PaleoEcoQS) along core SP5, collected in the inner central region of the SB. In the sedimentary record of the first half of the 20th century, no foraminifera were found, and the moderate enrichment in lithogenic elements was probably related not only to weathering and erosion of rocks but also to mining activities in the region. From the second half of the 20th century, the study area was under higher marine influence. Progressive siltation took place because of anthropogenic interventions in river courses, eutrophication, and metal pollution. Weak hydrodynamic conditions favored the accumulation of fine-grained sediments and organic matters. In the same period, low diversified benthic foraminiferal assemblages, including mainly opportunist species, were developed. Paleo-ecological conditions inferred by the biotic index exp(H’bc) were poor around 1970 and worsened after the metal spill released by Companhia Ingá Mercantil (a zinc ore processing plant). After that, progressively recovery has led to good ecological conditions in 2015. This study shows how benthic foraminiferal methods could represent a very useful tool to track changes in the evaluation of PaleoEcoQS.