Presence of artisanal gold mining predicts mercury bioaccumulation in five genera of bats (Chiroptera).

Mercury, a toxic trace metal, has been used extensively as an inexpensive and readily available method of extracting gold from fine-grained sediment. Worldwide, artisanal mining is responsible for one third of all mercury released into the environment. By testing bat hair from museum specimens and field collected samples from areas both impacted and unimpacted by artisanal gold mining in Perú, we show monomethylmercury (MMHg) has increased in the last 100 years. MMHg concentrations were also greatest in the highest bat trophic level (insectivores), and in areas experiencing extractive artisanal mining. Reproductive female bats had higher MMHg concentrations, and both juvenile and adult bats from mercury contaminated sites had more MMHg than those from uncontaminated sites. Bats have important ecological functions, providing vital ecosystem services such as pollination, seed dispersal, and insect control. Natural populations can act as environmental sentinels and offer the chance to expand our understanding of, and responses to, environmental and human health concerns.

Measurements of atmospheric mercury in the great lakes basin

To investigate the levels and atmospheric transport of mercury, and to investigate the emission and transfomiation of atmospheric mercury in source regions, the university of Michigan Air Quality Laboratory (UMAQL) has initiated several studies in the Great Lakes region. Reported here are results from sampling campaigns in two urban areas, Detroit, MI and Chicago, IL, several rural locations in Michigan, as well as over-water measurements on Lake Michigan aboard the research vessel Laurentian. Vapor- and particulate-phase Hg samples were collected, along with atmospheric acids and other trace elements, to investigate the urban/industrial sources of atmospheric mercury. We describe here our initial results fromm the ambient sampling and present our early results from precipitation Fig sampling across lhe state of Michigan. this paper will focus on the results of our multi-site amospspheric mercury measurements in rural and urban areas. We wiil highlight the finding that Hg levels in urban areas are significantly elevated over those measured concurrently in rural areas. Vapor phase Hg levels were on lhe average 4 times higher (8.7 ng/m3 vs. 2.0 ng/m3) in Chicago than in South Haven, MI Furthermore, a diurnal pattern was observed in the vapor-phase Hg levels measured at the Chicago site. The average concentration (ng/m3) for AM (8am to 2pm) sampies was 3.3 times greater ihan lhe NIGHT (8 pm to 8 am) samples and lhe average conceniration for PM (2 pm lo 8 pm) sampies was 3.3 times greater than lhe NiGHT (8am to 2pm) samples was 3.3 times greater than the nigth(8 am to 8am)samples and the average concentration for Pm(2pm to 8pm)samples was 2.1 greater than the NIGHT samples(average of NIGHT samples,3.7ng/m3)...

Particulate-phase mercury in the atmosphere: collectionl/analysis method development and applications

Particulate-phase mercury Hg(p) may constitute a small percentage of lhe total atmospheric mercury, but is thought to play na important role in deposition of mercury to terrestrial and aquatic ecosystems. This chapter presents techniques that have been utilized to collect and analyze Hg(p) in several recent projects including monitoring in Detroit and Ann Arbor, MI and during the Lake Michigan Urban Air Toxics Study. Fine (da <2.5 um) and total suspended particle (TSP) samples were collected and analyzed by two methods: (1) acid extraction followed by sparging and dual amalgamation cold vapor atomic fluorescence spectrometry, and (2) neutron activation analysis. The differences in Hg(p) detected ia the samples by these two analytical techniques, coupled with the size-segregated data collected, indicate that different foms of particulate mercury may be distinguished, and that differing physical/chemical properties may reflect potentially different sources.