bioindicators for mercury contamination

Rotary Kiln, New Almaden Quicksilver County Park DTMC Meeting – May 19, 2021 Peter Weiss-Penzias, Faculty Researcher Department of Microbiology and Environmental Toxicology UC Santa Cruz [email protected] Outline

• Utility of lichen as a bioindicator of atmospheric mercury deposition. • Need for monitoring with lichen to identify deposition hotspots. • Recent results in Hg-mine impacted areas. • Calibrating lichen Hg with direct measurements of Hg dry deposition. • Application of method to the Carson River Superfund site. farinaceae Flavopunctelia sp.

Ramalina menziesii

5 Principal Species of Lichen Usnea sp. in California Coast Range prunastri How lichen interacts with mercury in air

Dry deposition of Hg

Hg0 Bi-directional exchange of Hg0 HgII Algae

Wet deposition of MMHg

MMHg

Fun Facts about Lichen and Hg • Rapid uptake of Hg, especially HgII • Residence time of Hg of ~5 years (Nieboer and Richardson, 1981) • Time-integrated Hg accumulation rate reflects temporal variations in atmospheric Hg loads (Wittig, 1993) Previous Work: Methylmercury in along a coastal fog gradient

C&EN, 2016 Weiss-Penzias et al., 2019 Pros and Cons of Using as a Bioindicator of Atmospheric Deposition

Pros Cons • Less expensive than using instrumentation. • The metal uptake and bioaccumulation depend on its bioavailability, the amount of • Better measure of the net supply of the deposition, pH, species, metabolic growth metal to terrestrial ecosystems than data rate and surface area, which are all affected from wet deposition measurements or by climatic and environmental stress model calculation. factors. • Hg contamination around point sources or • Potential for poor distribution of lichen “hot spots” can be easily depicted. habitat across a broad landscape. • Allows for the tracing of large-scale maps • Current need for standardization and of Hg deposition and to locate “hot spots”. optimization of biomonitoring procedures • Validates the effectiveness of adopted and for a more in-depth knowledge of the environmental recovery procedures. mechanisms and factors affecting Hg uptake and bioaccumulation.

-From Bargagli, 2016 Monitoring Need

• There is developing interest in the regulating communities in the West to limit public exposure to high levels of toxic methylmercury ?? in fish. • The California Water Board and Washington State Department of Ecology are developing TMDLs to limit mercury inputs to and accumulation within reservoirs. • One of the principal, and unstudied, sources of mercury to reservoirs is atmospheric deposition (both to the reservoir and watershed). • The mercury amounts in lichen can help to constrain atmospheric deposition, helping managers manage mercury inputs in an informed manner. Mercury in Lichen at New Almaden and Lake Berryessa, 2020/2021

Unpublished data Total Hg in Lichen as a Function of Distance from Hg Mines

Knoxville to Lake Berryessa Tuscany, Italy 1400

1200

1000

800

600 Total Hg (ng/g) Total

400

200

0 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Distance from Mines (m) Unpublished data Elevated Lichen Hg at the Shore of Reservoir

• Fires? • Mines? • Free troposphere? Speciated Hg vs. Total Hg in Lichen MeHg vs. total Hg y = 0.0063x + 3.3137 R² = 0.2839 at Lake Berryessa 20 18 16 14 EPA Method 1630 12 10 quantifies 4 Hg 8 species 6 MeHg (ng/g) 4 2 0 0 200 400 600 800 1000 1200 1400 EtHg vs. total Hg y = 0.9531x - 87.327 R² = 0.9441 Total Hg (ng/g) 1400

y = 0.1503x + 6.2504 1200 Hg0 vs. total Hg R² = 0.6609 300

1000 250

200 800 150 600 100 Hg0 (ng/g) EtHg (ng/g)EtHg

400 50 0 200 0 200 400 600 800 1000 1200 1400 Total Hg (ng/g) 0 0 200 400 600 800 1000 1200 1400 Total Hg (ng/g) Total Hg as a Function of Species at Four Sites at Lake Berryessa

N. Smittle Creek Knoxville Rd 1 450 350 400 350 Ramalina menziesii 300 300 250 250 Ramalina menziesii 200 200 150 150 Usnea sp. 100 Ramalina menziesii 100 50 50 Usnea sp. 0 Ramalina menziesii 0 Ramalina menziesii (ppb) Hg Total Total Hg (ppb) Total Ramalina menziesii Ramalina menziesii Ramalina menziesii Flavopunctelia sp. Ramalina menziesii graph 2 Evernia Prunastri

Deer Turkey Knoxville Rd 3 - Total Hg across species 300 300 250 290 200 280 Evernia Prunastri 270 150 260 Ramalina menziesii 100 250 Evernia Prunastri 240 50 230 Ramalina menziesii 0 Evernia Prunastri Evernia Prunastri

Total (ppb) Hg Total Usnea sp. (ppb) Hg Total Evernia Prunastri Usnea sp. Usnea sp. Usnea sp. The Importance of Reactive Mercury in Atmospheric Deposition Reactive Mercury (RM) = gaseous Hg(II) + Hg(P)

RM is quickly deposited to the surface of the earth

Chen et al., 2014 Traditional Instrumental Analysis of Reactive Mercury (Tekran 1130/1135/2537)

• Artefacts and biases due to water vapor and ozone • Expensive system (~$100k) • Difficult to operate • One instrument per site Br/Cl New Instrumental Analysis: UNR-RMAS 2.0 Br/Cl/N

Br/Cl Br/Cl/N N Hg-Organics

Br/Cl N S

Luippold et al., 2020a

Br/Cl RM Concentration Br/Cl RM Speciation N Hg-Organics Nylon and cation-exchange membranes Different RM compounds are collected bi-weekly and analyzed for are desorbed at different total Hg in the lab. temperatures. Luippold et al., 2020b New Idea #1: Calibrate Hg in lichen concentration maps, with atmospheric RM measurements and dry deposition modeling

RM concentration measurements at Landscape scale Hg multiple locations deposition + + resistance estimates Spatial and temporal patterns of Hg modeling concentration in lichen across the landscape

New Idea #2: Compare speciated Hg in lichen with atmospheric RM speciation to determine potential sources of Hg deposition

Semi-quantitative assessment of sources of Hg + deposition UCSC/UNR/USBR Collaboration: Assessing the Susceptibility of Reservoirs and Watersheds to Pollution from Historical Mining Sites via the Atmosphere

1) Sample bioindicators in the watershed. 2) Make RM measurements and model dry deposition at two locations. 3) Combine RM and bioindicator Hg data to constrain atmospheric inputs to the reservoir. Acknowledgements

• Daniel Deeds, Branch Chief, Environmental Monitoring and Assessment, US Bureau of Reclamation • Mae Gustin, Professor, University of Nevada, Reno • Belle Zheng, Masters Student, UC Santa Cruz • Tarabryn Grismer, Undergraduate Student, UC Santa Cruz

Tarabryn with the lichen picker at Lake Berryessa