Mercury exposure in riverine populations of Terra do Meio Extractive Reserves in the Xingu basin, Amazon, Brazil.

Amazon is a hotspot for mercury (Hg) contamination and Terra do Meio region, despite its protected status for sustainable use, has never been monitored for this element. Looking to address this gap, this study aimed to quantify capillary Hg concentration in riverine populations of Terra do Meio (Xingu Basin, Central Amazon, Brazil) and associated factors with high Hg levels (90 percentile). Hair samples from 182 individuals from Iriri, Riozinho do Anfrísio and Xingu Extractive Reserves (RESEX), aged between 18 and 70 years old, were collected to measure total mercury levels (HgT), and socioeconomic, demographic, and clinical-epidemiological data were annotated. Overall, high levels of Hg were observed (mean 4.985 µg/g, median 3.531 µg/g) with significant differences between localities. Among the factors related to high capillary Hg levels, male gender, smoking habit, work in agriculture, livestock or extractivism, and residence in Iriri and Riozinho do Anfrísio RESEX were highlighted. A high prevalence of symptoms related to Hg intoxication, including anxiety, memory deficit, and lower limb problems, was observed. Overall, the results reveal that communities in these RESEXs are exposed to Hg and appear to be suffering from chronic health effects. Considering the increased anthropogenic alterations observed recently in the Amazon region and the subsequent amplified environmental bioavailability of Hg, further studies and mitigating actions are critical. This includes better surveillance of illegal anthropic activities and provision of ongoing education on this matter and incentives for dietary adaptations.

Pointing out geographic and gender disparities related to productivity indicators among Brazilian ecotoxicologists.

Policies and actions related to diversity, equity, and inclusion have been discussed recently in Brazil, but there is still limited information available for most academic and knowledge fields, including ecotoxicology. This study aimed to describe the profile of Brazilian ecotoxicologists and assess gender and geographical disparities, especially regarding productivity indicators. An ecological study was conducted using data of the researchers registered in the open-access database of the Brazilian Society of Ecotoxicology, along with their respective curriculum data available on the Lattes Platform, which is the main registry portal for Brazilian researchers. The target population of our study was ecotoxicology researchers in academic educational institutions with a focus on human resource training. The data, collected in 2021, led to the inclusion of a total of 177 researchers in this study, with 62 men and 115 women, and 42.37% working in the southeastern region. Female researchers generally showed lower rates of scientific productivity when the analyzed metrics included research productivity scholarships, the number of articles published in scientific journals, and the number of articles published with international collaborations, compared to male researchers. Researchers from the southeastern and southern regions also had higher rates of productivity and human resource training compared to those from other regions of the country. The proportion of funding grants received was significantly higher among men, and this profile was also observed among researchers from the southern and southeastern regions, although with a smaller disparity. This means that there is an uneven distribution of funding grants from funding organizations, which favors men and urban centers. Our findings highlight gender and geographic disparities in the scientific production of ecotoxicologists working in Brazil and reinforce the existence of complex obstacles that need to be addressed and combated within scientific societies. Integr Environ Assess Manag 2024;00:1-8. © 2024 SETAC.

Genotoxicity and toxicity assessment in urban hydrographic basins.

The genotoxicity and cytotoxicity of water in small urban basins was evaluated by the Salmonella/microsome assay and micronucleus test in V79 cells. The results showed that the cytotoxic effect was the most significant response in areas with medium to heavy urban occupation for both assays evaluated. Water samples from these areas include different concentrations of chloroform, bromodichloromethane, toluene, ethylbenzene, m,p-xylene and 1,4-dichlorobenzene. As to genotoxic damage, the presence of mainly direct-acting frameshift mutagens was detected in areas with less urban concentration and showed genotoxic activity in V79 cells in more heavily urbanized areas. Water organic extracts, evaluated using a microsuspension procedure, showed frameshift mutagenic activity in the presence of hepatic metabolization that increased as the population density grow. Chronic toxicity studies of sediment samples with the microcrustacean Daphnia magna showed that, while survival was not highly affected, reproductive inhibition was found in 92% of the observations. A retrospective diagnosis of water quality using traditional physicochemical parameters that defined the differential contribution of urban wastes at the three sites was associated with the biological assays. It became clear that the biological assays were of significant benefit in the diagnosis of risks of contamination of hydrographic basins by pollutants from urban non-point sources.