Mercury levels in residents of a geothermal area in the Central North Island.

: As a result of previous high trace metal findings in the soil, cattle, vegetation and water of the Broadlands area of New Zealand a study was made of the levels of mercury, selenium, arsenic and zinc in a group of children from this region. Arsenic and zinc levels were found to be normal but significantly raised urinary spot mercury concentrations were found in some of the children when studied in December 1975 and 24 hour urinary mercury concentrations recorded six months later were also raised, but to a lesser degree. Samples of household tap water showed increased mercury concentrations (median 0.001 micromol/L). In agreement with other New Zealand studies the blood selenium concentrations were low (76.7 mu/L) and they did not vary in relation to urinary mercury levels. The children were also examined for signs of peripheral neuropathy but only minor abnormalities were found. The source of the elevated mercury is uncertain but it may come from drinking water or possibly from locally produced meat or vegetables.