Mercury distribution and mobility at the abandoned Puhipuhi mercury mine, Northland, New Zealand

The United Nations 2013 Minamata Convention advocates for updated environmental assessments of potential point-source sites of mercury contamination, including historic closed or abandoned mines. The Puhipuhi mercury mine (Northland), a historic and abandoned mine site, is located near one of the headwaters of the Wairoa River. In this study, total mercury levels in soils and sediments (37.8-1748 mu gg(-1)), total and methylated mercury in waters (69.6-240ngL(-1) and 0.637-1.95ngL(-1), respectively), and elemental mercury in air (0.06-0.5ngm(-3)) were measured to assess the probability and form of mercury release from the site to the surrounding natural environment. Results showed that mercury concentrations at the site are elevated compared to regional backgrounds and further work is necessary to determine how mercury may be transported from the site.