Dominican University of California
 

Oral Presentations - Guzman 201

Presentation or Panel Title

Sources and Effects of Mercury: Global and in the San Francisco Bay Area

Location

Guzman 201

Start Date

4-23-2015 7:20 PM

End Date

4-23-2015 7:35 PM

Department

Natural Sciences and Mathematics

Student Type

Undergraduate

Faculty Mentor

Dr. Mietek Kolipinski, Dr. Mani Subramanian

Presentation Format

Oral Presentation

Abstract/Description

This report synthesizes and evaluates published scientific literature on the environmental occurrence and biomagnification of mercury with emphasis on the San Francisco Bay Area, California. Mercury is an element that forms various compounds, well-known for their toxicity in humans and environmental ecosystems. Elemental mercury and methylmercury are transported and distributed by air, water, and sediments. It has been well documented that mercury is converted into organic compounds, such as methylmercury, through metabolic processes of algae and bacteria. Methylmercury then bioaccumulates upward through trophic levels. In fish it is found primarily in skeletal muscle. In humans the primary target organs are the brain and kidneys. Health concerns exist about bioaccumulation of contaminants in humans. In evaluated species methylmercury reportedly reduces reproductive success, impairs growth and development, alters behavior, and decreases survival. Fish, particularly the apex species, are a known source of methylmercury for humans. The State of San Francisco Bay 2011 Report listed methylmercury as a contaminant of high concern. In July 2013 California issued a state health advisory stating children and women of childbearing age should not eat bass, carp and larger brown trout caught in California lakes and reservoirs due to their elevated levels of mercury.

In this study we summarize information on mercury in its various forms, with an emphasis on the reported levels of methylmercury found in the San Francisco Bay Area (SFBA). The amount present may vary from locality to locality. Known sources include atmospheric deposition, a long history of mercury mining, and dental amalgam. Some outstanding questions are: At what levels does mercury negatively impact human health? What levels of mercury negatively impact aquatic and terrestrial life?

We provide practical and realistic recommendations for reducing the level of mercury in the SFBA. Reported sources are aerial transport; dental offices that use amalgam separators and may not have wastewater discharge permits. Additional sources are sediments that are excavated and disposed of in different locations to form shipping channels in SFBA, which with movement, potentially re-introduce buried methylmercury in the surrounding food webs. Methods of decreasing mercury levels in the bay will likely improve the health of aquatic life, and by extension, the connected food webs leading to the top predators, including humans.

In summary, we provide specific data on methylmercury concentrations at different ecosystem levels, including data on humans, and recommendations for further research and potential remedial actions.

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Apr 23rd, 7:20 PM Apr 23rd, 7:35 PM

Sources and Effects of Mercury: Global and in the San Francisco Bay Area

Guzman 201

This report synthesizes and evaluates published scientific literature on the environmental occurrence and biomagnification of mercury with emphasis on the San Francisco Bay Area, California. Mercury is an element that forms various compounds, well-known for their toxicity in humans and environmental ecosystems. Elemental mercury and methylmercury are transported and distributed by air, water, and sediments. It has been well documented that mercury is converted into organic compounds, such as methylmercury, through metabolic processes of algae and bacteria. Methylmercury then bioaccumulates upward through trophic levels. In fish it is found primarily in skeletal muscle. In humans the primary target organs are the brain and kidneys. Health concerns exist about bioaccumulation of contaminants in humans. In evaluated species methylmercury reportedly reduces reproductive success, impairs growth and development, alters behavior, and decreases survival. Fish, particularly the apex species, are a known source of methylmercury for humans. The State of San Francisco Bay 2011 Report listed methylmercury as a contaminant of high concern. In July 2013 California issued a state health advisory stating children and women of childbearing age should not eat bass, carp and larger brown trout caught in California lakes and reservoirs due to their elevated levels of mercury.

In this study we summarize information on mercury in its various forms, with an emphasis on the reported levels of methylmercury found in the San Francisco Bay Area (SFBA). The amount present may vary from locality to locality. Known sources include atmospheric deposition, a long history of mercury mining, and dental amalgam. Some outstanding questions are: At what levels does mercury negatively impact human health? What levels of mercury negatively impact aquatic and terrestrial life?

We provide practical and realistic recommendations for reducing the level of mercury in the SFBA. Reported sources are aerial transport; dental offices that use amalgam separators and may not have wastewater discharge permits. Additional sources are sediments that are excavated and disposed of in different locations to form shipping channels in SFBA, which with movement, potentially re-introduce buried methylmercury in the surrounding food webs. Methods of decreasing mercury levels in the bay will likely improve the health of aquatic life, and by extension, the connected food webs leading to the top predators, including humans.

In summary, we provide specific data on methylmercury concentrations at different ecosystem levels, including data on humans, and recommendations for further research and potential remedial actions.