Background mercury concentrations in river water in Maine, U.S.A.

摘要: Mercury concentrations in 58 rivers Maine was measured to range from below detection up 7.01 ng L-1 and averaged 1.80±1.29 L-1. The concentration gradient for mercury across the state not uniform. strongly correlated with dissolved organic carbon (DOC) aluminum, less copper, lead, zinc. Mercuryexhibited significant differences correlations chemical variables local geology when partitioned by flow (high or low). were greatest flowingacross either wacke-type bedrock at low metamorphic grade, glacial-till deposits. Elevated of formed a locus northern under both high low-flow states while southwestern only during high-flowstates. These regional statistically significantwhen compared geographical location. We suggest that there is source northeastern dilutedduring periods runoff. elevated detected high-flow states, as noted Maine, may reflect released storage association withDOC indicates watershed processes can modulate rivers.