Data for mass concentration analysis and spectral analysis for the paper titled, "Comparison of primary laser spectroscopy and mass spectrometry methods for measuring mass concentration of gaseous elemental mercury"

Data for "Primary measurement of gaseous elemental mercury concentration with a dynamic range of six decades" article for submission

Data for "Primary measurement of gaseous elemental mercury concentration with a dynamic range of six decades" article for submission

Data for "Tate, M. T., Janssen, S. E., Lepak, R. F., Flucke, L., & Krabbenhoft, D. P. (2023). National-scale assessment of total gaseous mercury isotopes across the United States. Journal of Geophysical Research: Atmospheres, 128, e2022JD038276. https://doi.org/10.1029/2022JD038276". This dataset is associated with the following publication: Tate, M., S. Janssen, R. Lepak, L. Fluke, and D. Krabbenhoft. Assessment and Application of an Active Total Gaseous Mercury Collector to Survey Mercury Sources Across the United States. Environmental Science & Technology Letters. American Chemical Society, Washington, DC, USA, 128(8): N/A, (2023).

Location of sample points and analytical results for mercury concentrations from a soil survey.

This dataset includes water-quality and sediment data for 647 environmental samples collected at 53 surface-water sites in Cache Creek (Cache C) watershed, Yolo County, California, between December 2009 and April 2019, and data for 190 associated quality-control samples (replicates and blanks). About 90 percent of the samples were collected at the following six primary sites that were sampled most frequently, and the other 39 extra sites were sampled only 1-5 times each. In addition, continuous turbidity measurements were made at 8 sites to aid with the calibration of turbidity measurements. The sites Cache C at Rumsey (11451800), Cache C at Yolo (11452500), and CCSB Inlet at Rd 102 (11452600) are upstream of the Cache C Settling Basin (CCSB); all other sites are in the CCSB and are shown on the map included in this data release. NWIS_Site_Number: Field_ID: 11451800 Cache C at Rumsey 11452500 Cache C at Yolo 11452600 CCSB Inlet at Rd.102 11452900 CCSB Outlet 11452800 CCSB S. Abutment Spillway 384115121402501 CCSB N. Abutment Spillway Constituents analyzed include total mercury and methylmercury in dissolved and particulate forms, reactive divalent mercury in particulate form, suspended sediment, dissolved organic carbon, and absorption-fluorescence data for dissolved organic matter. The grain-size distribution of suspended sediment in selected samples is also reported. Six data tables and a Data Dictionary were prepared for this data release. All tables are provided as machine readable tab-delimited text (*.txt) files and as Excel formatted (*.xlsx) files. The data dictionary provides definitions and details presented in the data tables, including analytical methods citations. Two of the six data tables present and summarize quality control results collected for the study.

The Region 9 CRMS risk assessor specifically identified the need to obtain data for Tribal lands near Fallon, Nevada. Based on a 1994 study performed on OU1 samples, an estimated 12% of total mercury measurements is mercuric chloride (HgCl2). The Quality Assurance Project Plan (QAPP) summarized the OU1 historical analytical approaches for “speciation” with currently available methods summarized. Based on team scoping meeting with EPA Region 10 and the Region 9 Toxicologist, use of the Brooks Applied Lab (BRL) sequential extraction was selected primarily for reasons of comparability of approaches to simplify data assessment. (EPA Method 3200 was presented for comparative purposes.) There are significant sources of uncertainty in “speciation” using any approach, as each is technically a procedurally defined fractionation that may include other mercury species not specifically identified. As an example of this uncertainty, under the OU1 study of the EPA Las Vegas Lab data, it was unclear which fraction would have captured mercury oxide or whether the residual chlorides caused minor amounts of sulfide to combine with the nitric acid fraction. While the Oak Ridge approach may have reported mercuric chloride in the elemental mercury fraction. The primary factors driving the need for this speciation data were uncertainty about the quality of the historical OU1 data; applicability of the OU1 data at the locations below Lahontan Reservoir, and concerns expressed by the Region 9 CRMS risk assessor to better obtain direct measurement data near the Fallon Paiute-Shoshone Tribe. The data generated by this sampling were reviewed for laboratory quality control but decisions with the data were made by the EPA Region 9 CRMS risk assessor.

Total mercury in precipitation collected using ASPS automated wet-only instrument and analyzed by cold vapor atomic fluorescence spectroscopy. This dataset is associated with the following publication: Lynam, M., J.T. Dvonch, J. Barres, M. Landis , and A. Kamal. Investigating the impact of local urban sources on total atmospheric mercury wet deposition in Cleveland, Ohio, USA. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, USA, 127: 262-271, (2016).