Mercury in the Environment
Most of the mercury in San Francisco Bay entered during the Gold Rush. It was used to extract gold from surrounding rocks and after use it was released to the air or washed downstream to the Bay.
While mercury levels in the bay have been declining since those times, more is being added each year from other sources. The major sources of new mercury are:
- Erosion of sediments already in the Bay
- Mercury in the rivers flowing from the Guadalupe and Central Valley Watersheds
- Urban stormwater runoff
- Direct atmospheric deposition
- Dental Amalgam
Microorganisms and bacteria in the environment can convert mercury from its elemental form to methyl mercury, which is readily absorbed into the bodies of fish and wildlife. The concentration of mercury increases as you move up the food web, resulting in larger fish having higher concentrations of mercury contamination. People whose diet consists primarily of large fish may be at higher risk of mercury exposure. Long-term exposure to low levels of mercury can negatively impact the nervous system, and mercury has been found to negatively impact the respiratory, cardiovascular, hematologic, immune, and reproductive systems.
Properly Dispose of Mercury
You can help keep mercury out of the environment by properly disposing of mercury-containing items.
If you are a Tri-City resident, USD will exchange your mercury thermometer for a digital one at no cost to you. Find our booth at a local community event or bring your mercury thermometer to our front desk during normal business hours (Monday-Friday 8:00a.m.-5:00p.m.) to be exchanged for a digital thermometer.
Alameda County residents can bring mercury-containing household items to the Household Hazardous Waste Facility in Fremont for proper disposal. A list of items accepted at the facility can be found on their website: HHW Facility (fremont-recycling.com)
Fremont Household Hazardous Waste Collection Facility |
41149 Boyce, Rd. |
Fremont, CA 94538 |
- General Public Drop-off |
Wednesday-Friday 8:30a.m.-2:30p.m. |
Saturday 8:30a.m.-4:30p.m. |
- Small Business only (CESQG) |
Tuesday by appointment only |
Call (510) 670-6460 to schedule an appointment |