Publication

Back to overview

Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania)

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Author Bravo Andrea G., Loizeau Jean-Luc, Dranguet Perrine, Makri Stamatina, Björn Erik, Ungureanu Viorel Gh., Slaveykova Vera, Cosio Claudia,
Project Mercury threat in industrially impacted surface water bodies in Romania - integrated approach (MERCURO)
Show all

Original article (peer-reviewed)

Journal Environmental Science and Pollution Research
Volume (Issue) 23(11)
Page(s) 10529 - 10541
Title of proceedings Environmental Science and Pollution Research

Abstract

Chlor-alkali plants using mercury (Hg) cell technology are acute point sources of Hg pollution in the aquatic environment. While there have been recent efforts to reduce the use of Hg cells, some of the emitted Hg can be transformed to neurotoxic methylmercury (MeHg). Here, we aimed (i) to study the dispersion of Hg in four reservoirs located downstream of a chlor-alkali plant along the Olt River (Romania) and (ii) to track the activity of bacterial functional genes involved in Hg methylation. Total Hg (THg) concentrations in water and sediments decreased successively from the initial reservoir to downstream reservoirs. Suspended fine size particles and seston appeared to be responsible for the transport of THg into downstream reservoirs, while macrophytes reflected the local bioavailability of Hg. The concentration and proportion of MeHg were correlated with THg, but were not correlated with bacterial activity in sediments, while the abundance of hgcA transcript correlated with organic matter and Cl− concentration, indicating the importance of Hg bioavailability in sediments for Hg methylation. Our data clearly highlights the importance of considering Hg contamination as a legacy pollutant since there is a high risk of continued Hg accumulation in food webs long after Hg-cell phase out.
-