Source: Water Resources Research
Lakes in urbanized areas accumulate arsenic in their bottom sediments as a result of human activities, such as mining, smelting, and the application of arsenic-containing pesticides. If this arsenic ends up in the water column close to the surface, it can endanger lake ecosystems and human health. Shallow lakes are more susceptible to high arsenic concentrations in their waters than deep lakes, but the cause of this was unknown.
Fung et al.  found the explanation by using a combination of dedicated observations of lake turbulence intensity, temperature, and concentrations of dissolved oxygen and arsenic. Understanding this mechanism will be highly beneficial in guiding measures to keep arsenic concentrations in shallow lakes at bay.
Citation: Fung, S. R., Hull, E. A., Burkart, K., Gawel, J. E., Horner-Devine, A. R., & Neumann, R. B. (2022). Seasonal patterns of mixing and arsenic distribution in a shallow urban lake. Water Resources Research, 58, e2022WR032564. https://doi.org/10.1029/2022WR032564
—Marc F. P. Bierkens, Editor, Water Resources Research