Chronic respiratory diseases and respiratory symptoms after a mining dam rupture: Brumadinho Health Project

Attenuation of water contamination in the Paraopeba River after the collapse of B1 tailings dam: Natural wash-off and dredging contributions

Following the B1 dam collapse at Córrego do Feijão Mine, actions were taken to address environmental damage and enhance the quality of water in the Paraopeba River. Natural processes in the river involve gradual reduction of contamination through dispersion and downstream transportation of tailings-a slow, nature-driven process. Dredging, a human intervention, aimed to expedite recovery. Hence, this study aimed to explore dredging's role in reducing contamination in the impacted Paraopeba River zone. Analysis revealed a direct link between dredging and post-collapse turbidity, though recent trends suggest a lessening impact on pre-collapse conditions. Distinct seasonal variations were observed in iron and manganese concentrations, peaking during wet seasons and displaying notable upstream-downstream disparities. An analysis of ratios (downstream/upstream) was conducted to understand and even predict the return to pre-collapse conditions. Wet season averages for iron and manganese decreased by around 90 % over time, with standard deviations reducing by about 48 % and 58 %, respectively. In the dry season, the averages decreased by over 100 %, indicating water quality improvements surpassing pre-collapse levels. Standard deviations also decreased significantly, by approximately 67 % and 79 %, respectively. Employing an exponential decay model revealed that the contribution of dredging in the dry period is negligible, but in the wet period the contribution can be estimated at 28.6 % in the case of iron and 25 % in the case of manganese. While the models performed well based on extensive data, some limitations occur in estimating dredging contribution rates. The model's sensitivity might overlook influential factors, underscoring the importance of considering sediment nature and dredged area extent in understanding water quality dynamics. Despite these potential limitations, this investigation provides crucial insights into the intricate relationship between dredging and water quality in the Paraopeba River. These findings pave the way for future studies aimed at deeper exploration and more accurate assessments of this association.

[Respiratory changes in children exposed to dust from mining waste in Brumadinho, Minas Gerais State, Brazil: Bruminha Project]

This study aimed to investigate the occurrence of respiratory diseases in children exposed to dust from mining waste after the Brumadinho dam disaster, Minas Gerais State, Brazil. The study population included children aged 0-6 years, living in three communities exposed to mining waste dust (Córrego do Feijão, Parque da Cachoeira, and Tejuco) and one unexposed community (Aranha). Data were collected from July 19 to 30, 2021, using questionnaires that addressed sociodemographic information and a recall survey on signs, symptoms, and respiratory diseases. A total of 217 children were evaluated, 119 living in the exposed communities and 98 in the non-exposed community. The residents in the exposed communities reported an increase in the frequency of home cleaning (p = 0.04) and in vehicular traffic (p = 0.03). Among children aged four, a higher frequency of upper (p = 0.01) and lower (p = 0.01) airway disorders, as well as respiratory allergy (p = 0.05) was observed. The exposed group had 1.5 times more reports of respiratory allergy (75%; p = 0.02) compared to the non-exposed group (50.5%). Children living in communities exposed to waste dust were three times more likely (adjusted OR = 3.63; 95%CI: 1.37; 9.57) to have respiratory allergies than those not exposed. Two years and six months after the environmental disaster occurred, children living in the communities affected by waste from mining and remediation activities remained exposed to dust with harmful effects on respiratory health.

Genotoxic and mutagenic evaluation in Eisenia foetida annelids exposed to iron ore tailings from the region of Brumadinho, MG, Brazil

Soils that have a disproportion of metallic elements due to anthropic activities endanger the terrestrial fauna. This study evaluated whether earthworms (Eisenia foetida) exposed to ore tailings from Brumadinho region presented a higher frequency of genotoxic and mutagenic damages than annelids from a reference area (control). The animals were exposed to substrates containing 0%, 25%, 50%, 75%, and 100% iron mining waste. The results indicated increased DNA damage (p < 0.05), detected by the comet assay at 25% and 50%. There was a three-fold increase in micronuclei in animals on the substrates with the highest concentrations (75% and 100%) [F = 3.095; p = 0.02]. The earthworms lost weight as the percentage of mining waste increased. We concluded that E. foetida presented DNA damage in the contaminated soils of Brumadinho. However, more research is fundamental, once the environmental disaster in Brumadinho was one of the biggest mining catastrophe in Brazil.