> Historically, 10-30% of mercury was lost in the mining process, resulting in widespread contamination of river and lake sediments
That is a LOT! That explains the frequency of red areas on the map. What a shame.
Here in BC it's a similar story with the ocean and dioxins from industrial effluents. You can't harvest shellfish around most of southern Vancouver Island. It seems like everyone has a story of poisoning their own food and water.
> That is a LOT! That explains the frequency of red areas on the map.
It seems like most the ones I clicked on weren't polluted by mercury (even if my local sources were). Looking closer, the north seems to be mostly mercury pollution (at least inland), and the south seems to be varying sources (chlordane, dieldrin, PCB, DDT).
Ah, okay then. Coincidentally I clicked around and mostly saw mercury and a couple seleniums, so it seemed like mercury was the biggest issue. I wonder what the others are caused by... I'm guessing industrial effluents.
I remember flying over the South Island of Japan. There are all these beautiful sandy beaches you can see from the air and nobody on them. I asked my host about that and he said, no one goes swimming because it's polluted.
Off topic, but holy crap, I thought the donation requests couldn’t get any more intrusive, yet somehow they did. Over two full screens’ worth of text to scroll past on my iPhone. [1] (Interestingly, after refreshing the page I get an entirely different donation request, a much smaller, red-colored bubble.)
They don't have to. Wikimedia has tons of money. They just want more. (As is human nature.) And the people in charge know they can get it by throwing up ads like this.
For what it's worth, not all of these areas are totally unsafe. I am familiar with some of the central valley lakes that are highlighted and I grabbed the current consumption flyer for one: https://oehha.ca.gov/media/downloads/advisories/millertonlak...
The situation is not great but it's not quite so bad as it might seem if you look at that map and think it indicates only areas where fish are completely unsafe to eat.
So the lake next to my house is NOT 'impaired' in that you can catch and eat fish from it but because of algae they have certain times that are impaired.
They actively stock it and encourage fishing. Not sure why it's listed here but makes me skeptical about the rest of the data as I've only looked at one data point and it was wrong.
I imagine it's considered safer to list anything that is impaired at times of the year as impaired, so people err on the side of being safer. That said, clicking on the specific item gives more details (sometimes with additional links), so perhaps that might explain why it's listed (or give you a clue of where to look to find out, if you're inclined)
"impaired" is the correct summary for a lake that is only impaired some of the time.
I can also see the reasoning behind having 2 categories and expecting people to check the specifics for a given body of water before fishing it. Less chance for confusion and so on.
I wouldn't eat any shellfish out of the bay or any waters that near a metro area or developed river system. Other fish like striped bass and halibut should be safe.
I'm not sure this map is trustworthy given CA's propensity to label everything under the sun as unsafe. I bought a turning signal to fix my grandpa's boat trailer and it had the famous CA cancer advisory. Crying wolf, man.
How about this: is the turning signal more likely to give you cancer than living with an indoor smoker? Unlikely. And yet living with secondhand smoke is associated with a ~20% increase in risk, i.e. from ~6% lifetime risk to ~7.2% lifetime risk
