Health profile and metal exposure over three years in a child cohort study, Bruminha Project

To describe the health profile and patterns of exposure to mining waste over the period of three years in a cohort of children living in areas affected by the collapse of a mining tailings dam in Brumadinho, Minas Gerais State, Brazil, in 2019.

This prospective cohort study included all children aged 0 to six years residing in four selected locations: three in the disaster zone (Parque da Cachoeira, Córrego do Feijão, and Tejuco - exposed areas) and one located 10 km away (Aranha - non-exposed area). Assessments included anthropometric growth, neuromotor and cognitive development, and respiratory conditions. Urine samples were collected and analyzed for lead, arsenic, cadmium, mercury, and manganese using inductively coupled plasma mass spectrometry (ICP-MS).

The average percentage of children assessed in the period was 80% of the projected population. There was an increase in the percentage of children with urinary arsenic levels above the reference value over the three-year period (2021 = 42%; 2022 = 44%; 2023 = 57%), as well as in detection rates of lead (88.9%) and mercury (63.9%) in 2021, both reached 100% in 2023. The median urinary arsenic concentration increased from 2021 (9.35 μg/g; IQR = 5.45-13.9) to 2023 (10.8 μg/g; IQR = 7.0-15.3) in the total sample of children (p = 0.064), with a statistically significant increase among those living in exposed areas (p = 0.015; Parque da Cachoeira). Over the three-year period, there was a decrease in the percentage of neurodevelopmental alterations and overweight/obesity, and an increase in reports of respiratory alterations in the total population, although these changes were not related to metal exposure.

The findings indicate ongoing exposure of the metals analyzed in the study population; however, no associated health effects have been identified thus far. It is essential that the Brazilian Unified Health System be structured according to specificities of the productive processes in each territory.