Application of ICP-Atomic Emission Spectroscopy to assessment of wetland sediments in the Montana counties of Lewis and Clark, Jefferson, Powell, and Broadwater: The influence of heavy metals on amphibian breeding activity.

Abstract

This study utilized ICP Atomic Emission Spectroscopy to assess heavy metal content in wetland sediments. Sixteen different sites, grouped into four categories, were sampled during the study. Sediment was filtered with a 63 pm nylon sieve, allowed to settle, and dried. The dried sediment was then microwave acid bomb digested with concentrated nitric acid and diluted for heavy metal analysis by ICP-AE spectroscopy. There was a strong correlation between elevated heavy metal levels and occurrence of past mining among the sites. No correlation was found between elevated heavy metal levels and amphibian’s absence of breeding activity. Large relative concentrations of arsenic, lead, cadmium, and zinc were found in the mining sites Upper and Middle Frohner Meadows and Dog Creek and in the non-mining site Spring Meadow Lake (SML). Spring Meadow also exhibited extremely high concentrations of manganese. Resampling and additional analysis was carried out on SML after preliminary results indicated elevated heavy metal levels. The second set of results also indicated elevated levels of arsenic, lead, and zinc and extremely high levels of manganese at Spring Meadow Lake.