Higher urinary thallium concentration showed a nominal positive association with cardiovascular mortality in the original scale, but this association was not robust to natural-log transformation, and single-cell transcriptomic analyses identified candidate genes in vascular smooth muscle cells and macrophages that are hypothesis-generating only.
Urinary thallium concentration showed a nominal positive association with cardiovascular mortality in the fully adjusted original-scale analysis.
The association between urinary thallium and cardiovascular mortality was not statistically significant after natural-log transformation of urinary thallium.
Exploratory analyses of public disease-context single-cell transcriptomic datasets identified expression patterns of database-derived thallium-related candidate genes across vascular smooth muscle cells (VSMCs), macrophages, and other cell types.
The transcriptomic findings are hypothesis-generating and do not establish that thallium exposure directly caused the observed cellular changes or activated specific regulatory pathways.
The study was characterized as an exploratory cross-sectional analysis with multiple methodological limitations precluding causal inference.
This research examined whether higher levels of thallium — a toxic heavy metal found in the environment — in people's urine were linked to dying from cardiovascular (heart and blood vessel) disease. Using data from NHANES, a large U.S. health survey, the researchers found a statistically significant association when thallium was measured on its original scale, but this association disappeared when thallium levels were mathematically transformed in a standard way (using a natural logarithm). This inconsistency means the finding is not reliable, and the authors themselves described the results as preliminary and exploratory rather than as evidence of a real causal link. The study also analyzed publicly available single-cell genetic datasets from diseased blood vessels to look for genes that might connect thallium exposure to heart disease. They identified some candidate genes expressed in vascular smooth muscle cells and immune cells (macrophages) that overlapped with processes like lipid metabolism and changes in cell behavior. However, these datasets did not include any actual measurements of thallium in the donors, so the researchers were careful to say these observations only suggest ideas for future experiments — they do not prove that thallium causes these cellular changes. This research suggests that environmental thallium exposure warrants further investigation as a potential cardiovascular risk factor, but the current evidence is too weak and inconsistent to draw firm conclusions. The study's cross-sectional design (a snapshot in time), single urine measurement per person, and statistically fragile findings all point to the need for stronger studies with repeated exposure measurements, longer follow-up periods, and laboratory experiments before any conclusions about thallium and heart disease risk can be made.
Lei Y, Xia L, Xu M, Huang N, Jiang Q. (2026). Urinary Thallium Concentration and Cardiovascular Mortality: An Exploratory NHANES Analysis with Disease-Context Single-Cell Transcriptomic Hypothesis Generation.. Cardiovascular toxicology. https://doi.org/10.1007/s12012-026-10205-9