Effects of urbanization on mercury deposition and accumulation in New England

We compare total mercury (HgT) loading and methylmercury (MeHg) accumulation in streams and lakes
from an urbanized area (Boston, Massachusetts) to rural regions of southern New Hampshire and Maine.
The maximum HgT loading, as indicated by HgT atmospheric deposition, HgT emissions, and sediment
HgT concentrations, did not coincide with maximum MeHg concentrations in fish. Urbanized ecosystems
were areas of high HgT loading but had low MeHg concentrations in fish. Controls on MeHg production
and accumulation appeared to be related primarily to HgT loading in undeveloped areas, while
ecosystem sensitivity to MeHg formation appeared to be more important in regulating accumulation of
MeHg in the urban area.