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Mushrooms as Bioindicators of Heavy Metals in Sites Affected by Industrial Activity in the Macatawa Watershed
Hope College
Introductions
Amber BoschMajor: BiologyMinor: Environmental Science
Brooke MattsonMajor: GeologyMinor: Environmental Science
Kathleen FastMajor: GeologyMinor: Environmental Science
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MotivationTo investigate if the Lake Macatawa watershed contains regions of soils with elevated heavy metals using a cost and time-efficient methodology
Questions
Can mushrooms be used as bioindicators to assess heavy metal concentrations in the soil of the Lake Macatawa Watershed?
To what extent is biomonitoring able to accurately represent heavy metal concentrations from the environment?
https://www.visittheusa.com/destination/holland
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Biomonitoring
● Relatively cost effective method that employs natural organisms as a way of quantifying environmental conditions
● Some organisms and organic materials that have been used as biomonitors include oysters, bee honey, and various non-vascular plants
Why Mushrooms?
● Over 2,500 mushroom species in Michigan
● Found in a wide range of habitats● Underground structures allow for
bioaccumulation and depositing of metals into fruiting bodies
http://www.mushbox.co/The-Mushroom-Life-Cycle_b_2.html
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Industrial Activity & Metal Concentrations in Mushrooms
● Studies associated with industrial activity result in high metal concentrations within mushrooms
● Uptake amounts can vary in different species
● Overall trends make mushrooms adequate bioindicators
Sample Site Selection
2 Clean Sites:
● Upper Macatawa Natural Area● Hope College Nature Preserve
3 Contaminated Sites:
● Howard B. Dunton Park● Riley Trails● Dredge Material Placement Site
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Sample Sites
Sample Digestion
Clean & Dry Samples
8hrs 2X with HNO3 on hotplate
8hrs with HNO3 + H2O2 on hotplate
Heated into solution for 1hr
Dilute for analysis via Atomic Absorption
Homogenize samples and mass out ~0.5 grams
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Flame Atomic Absorption Spectroscopy
● Analysis of Pb, Cd, Ni, and Fe● Standards were tested between
0.05 - 5.0 ppm for Pb, Cd, and Ni 0.5 - 25 ppm for Fe ○ to account for the relatively high
environmental abundance in soil
Results: Iron RT3: 8 ppmRT6: 9 ppm
Du1: 87 ppm*Du2: 10 ppm
DSWT: 6 ppmDSY: 7 ppm**
UP5: 9 ppm
HCNP3: 9 ppmHCNP4: 9 ppm
R² = 0.99829*R² = 0.92536**R² = 0.99885
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Cadmium RT3: 2 ppmRT6: 2 ppm
Du1: 2 ppmDu2: 2 ppm
DSWT: 1 ppmDSY: 2 ppm
UP5: 5 ppm
HCNP3: 5 ppmHCNP4: 5 ppm
R² = 0.37682
Nickel RT3: 4 ppmRT6: 5 ppm
Du1: 4 ppmDu2: 5 ppm
DSWT: 3 ppmDSY: 6 ppm
UP5: 2 ppm
HCNP3: 2 ppmHCNP4: 2 ppm
R² = 0.94166
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Lead RT3: 1 ppmRT6: 1 ppm
Du1: 1 ppmDu2: 1 ppm
DSWT: 1 ppmDSY: 1 ppm
UP5: 1 ppm
HCNP3: 1 ppmHCNP4: 1 ppm
R² = 0.99744
Discussion
● No trend found between predicted contaminated and clean sites
● Considerations for high iron concentration of Du1● Of the four metals, iron was best suited for analysis with
instrumentation of this sensitivity● Variation in R2 values
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Discussion
Metal R2 ValueIron (0-50 ppm) 0.92536
Iron 2 (0-10 ppm) 0.99885
Iron (0-10 ppm) 0.99829Cadmium 0.37682Nickel 0.94166Lead 0.99744
Discussion
Experimental Concentration Average (ppm)
Literature Concentration Average (ppm)
Michigan Soils Concentration Average (ppm)
EPA Soil Contaminant Direct Contact Criteria (ppm)
Iron 17 70-4,000 10520 160,000
Cadmium 2 0.3-25 0.9 550
Nickel 5 0.6-18 12 40,000
Lead 1 1.0-8 9.2 400
EPA (2013), A.M et al. (2016), Chen et al. (2009), Zhu et al. (2011), Zhang et al. (2008), Siric et al. (2016)
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Sources of Error and Limitations
● Metal contamination due to lack of metal free zone in lab
● Varying and limited detection levels between metals for
Flame Atomic Absorption Spectrometry
● Results weakened by lack of consistent species and
small sample size
Future Research and Implications
● Within our study○ Use ICP-OES to analyze metal content
of Cd, Ni, and Pb○ Analysis of heavy metals in soil samples○ Sampling throughout the year
● Further experimentation of this biomonitoring methodology in the Macatawa Watershed and Midwest to determine viability
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Questions?
References
A, K., M, S., & K, S. (2016). Determination of heavy metals in edible mushrooms consumed in shahrekord. Journal of Shahrekord University of Medical Sciences, 18(1), 54-62.
Chen, X., Zhou, H., & Qiu, G. (2009). Analysis of several heavy metals in wild edible mushrooms from regions of china. Bulletin of Environmental Contamination and Toxicology, 83(2), 280-285.
EPA. (2013). Risk-Based Cleanup Criteria. Cleanup Criteria for Contaminated Soil and Groundwater, 11-20García, M., Alonso, J., Fernández, M. et al. Arch. Environ. Contam. Toxicol. (1998)Jarvie, M. (2017, April 13). Identifying wild Michigan mushrooms that are safe to eat. In Michigan State University Agriculture and Natural
Resources. Retrieved September 19, 2017, from http://msue.anr.msu.edu/news/identifying_wild_michigan_mushrooms_that_are_safe_to_eat
Radulescu, C., Stihi, C., Busuioc, G., Gheboianu, A. I., & Popescu, I. V. (2010). Studies concerning heavy metals bioaccumulation of wild edible mushrooms from industrial area by using spectrometric techniques. Bulletin of environmental contamination and toxicology, 84(5), 641-646.
Širić, I., Humar, M., Kasap, A., Kos, I., Mioč, B., & Pohleven, F. (2016). Heavy metal bioaccumulation by wild edible saprophytic and ectomycorrhizal mushrooms. Environmental Science and Pollution Research, 23(18), 18239-18252.
ZHANG Dan GAO Tingyan MA Pei LUO Ying SU Pengcheng. (2008). Bioaccumulation of heavy metal in wild growing mushrooms from liangshan yi nationality autonomous prefecture, china.
Zhu, F., Qu, L., Fan, W., Qiao, M., Hao, H., & Wang, X. (2011). Assessment of heavy metals in some wild edible mushrooms collected from yunnan province, china. Environmental Monitoring and Assessment, 179(1), 191-199. doi:10.1007/s10661-010-1728-5