Forgive my indulgence in an old Jewish folk song in the title—it just seemed to fit the plot of last night's episode of Eleventh Hour so neatly. We open on a helicopter pilot who died in a fiery crash after mercury poisoning caused him to go blind mid-flight. Soon, other people in the town start showing symptoms of the same contamination, forcing Hood and Young and the newly introduced Felix Lee to trace the mercury down the food chain. Here's what they found by the end: Mercury in Lake Michigan -> maggots -> herring -> fish meal -> dairy cows ->milk -> people. Now, let's look at the steps one by one: Mercury barometers: Barometers were invented in 1640, by Evangelista Torricelli, but it was his friend, Galileo, who proposed that he use mercury. Because mercury is denser than water, less of it is required to register changes in atmospheric pressure. Barometers pretty much only used mercury until recently, so it probably wasn't hard for the evil park ranger to acquire enough of them to build up a pretty good supply of mercury. Flinging a bunch of them into Lake Michigan could increase the overall mercury levels in the water. Lake Michigan is huge–
so it would take a hell of a lot of mercury to matter to the fish population, but I'll just grant them dramatic license. Mercury-eating maggots: I couldn't help but notice that Hood tossed off this line and then we never heard from the maggots again. That's because maggots eat dead flesh, but not usually raw heavy metals (Not even Phish were heavy metal). But it turns out to be a red herring (see below). Herring eat maggots: That they do. Lots of sport fishing sites recommend maggot bait to catch herring. But, as Hood pointed out, herring are not typically repositories of mercury. The mercury in the water is consumed by bacteria who turn it into methylmercury, the compound that poses such a threat to the environment and too people. Plankton then eat the bacteria, small fish like herring eat the plankton, then other, larger fish eat them (or seagulls, as happened on the show), then yet larger fish eat them, until the amount of mercury in the biggest predators can be 10,000 times the amount in the surrounding environment. Since the evil park ranger in this episode was releasing huge amounts of mercury into the water, we can assume the traditional processes were in action, maggots or no maggots. Fish-eating cows: Thanks to an assortment of food scares in recent years, we all now know that cows can be fed all kinds of things besides grass: chicken meal, fish meal, even cow meal. Mad cow disease, for example, is spread when cows eating other cows. Farmers who use fish meal have to worry about the mercury in the fish. Cows that eat mercury-contaminated feed will absorb and store it much as predator fish do, and it can contaminate their meat and their milk. Mercury milk: If enough mercury got into the milk, and the people in this town drank local milk, and a lot of it, they would eventually suffer from mercury poisoning. Eleventh Hour made that point by having one victim inform Hood that he drank milk at every meal. Though we're told of dozens of other victims, they would all have had to be getting their dairy mostly from local sources that fed on this fish meal for it to be such an immediate problem. The fact that mercury poisoning presents with a variety of symptoms is also accurate, and doctors often mistake mercury poisoning for some other malady. Typically, though mercury poisoning is most dangerous to children and old folks. Since methylmercury can be passed on to mothers milk, women who are nursing who some day plan to nurse have to be so careful about eating products that contain it.