The Gold Rush Pollution

For the Muckraking Assignment, my group is researching water pollution in the Bay Area. One of the questions we asked our interviewees is if there were any particular times in California when water pollution was especially bad. An interesting point that we learned was that the real start of water pollution in this area--while it has always been here since the beginning of the city--was during the Gold Rush.

Mercury is a poisonous chemical that can infiltrate bodies of water, causing immense damage to all around it. It is one of the main polluters of the San Francisco Bay. The modern day source of mercury pollution is from people throwing out broken thermometers or other substances improperly, instead of disposing of them at a facility. But during the Gold Rush, the mining that took place left tons upon tons of contaminated sediments near rivers. According to Michael Singer, a geologist and hydrologist, "There is enough metal downriver and in the sediment to significantly add to levels of the heavy metal downriver and in the San Francisco Bay for the next 10,000 years."

Mercury can be converted to methlymercury by microbes, which is the organic form of the heavy metal. This can accumulate in animals, and when larger animals eat lots of smaller ones, mercury can become concentrated in living creatures. This causes a real danger to the wildlife around the Bay.

Gold Rush miners sought to expose gold metal by using high-pressure water cannons, then run it through "sluice boxes" which included adding mercury to bind to gold. This large quantities of metal found it's way downstream, and now in California's Central Valley, the area was tainted.

It is interesting how something that happened almost two centuries ago can affect our current condition so drastically. What is another historical incident that is now some kind of a problem for us today?