The Study
Selenium dietary intake, urinary excretion, and toxicity symptoms among children from a coal mining area in Brazil
This study looked at kids in two towns—one near a coal mine and one not—and found that kids near the mine had a bit more selenium in their urine. But it didn't prove the mine caused it; maybe they ate different food or drank different water. It just shows a connection, not a cause.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Kids living near coal mines in Brazil eat more selenium-rich food and pee out more selenium than kids in nearby towns, but they’re not sick from it.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 544 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even though selenium levels were higher near the mines, they didn’t reach levels known to cause sickness — so it’s not harmful at these levels.
- 2Kids near coal mines had higher selenium in their urine and diet than kids in other towns, but both groups were still within the safe, normal range.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Environmental Geochemistry and Health
Year
2020
Authors
M. D. dos Santos, J. Penteado, P. Baisch, B. M. Soares, A. L. Muccillo-Baisch, F. M. R. da Silva Júnior
Related Content
Claims (6)
Selenium stays in human tissues for weeks because it becomes part of selenoproteins instead of being quickly removed from the body.
Children in a coal mining area of Brazil consume more selenium in their diet and excrete more selenium in their urine than children in a nearby non-mining city, but both groups have selenium levels within the normal range and show few signs of selenium toxicity.
In children living in a coal mining region of Brazil, the main way they are exposed to selenium is through the food they eat, not through breathing polluted air or skin contact, because their urine shows higher selenium levels linked to diet than to environmental exposure.
Children living near coal mines in Brazil have higher levels of selenium in their urine than children living nearby without mining activity, but these levels are still within the normal range seen in healthy people.
Children in a coal mining region of Brazil consume more selenium and excrete more selenium in their urine, but they do not show common signs of selenium poisoning.
Children living near coal mines in Candiota, Brazil, have higher levels of selenium in their diet and urine than children living in a nearby city without coal mining.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.