Crematoriums are NOT a major source of mercury pollution, they contribute less than 1% of total Hg pollution according to government statistics.
You're looking at pretty low volumes of emissions from crematoria as compared to your industrial sources, such as any coal-burning power plant. This is why the term "Mad as a hatter" has NOT been replaced by "Mad as a mortician".
Right or wrong, mercury has a stigma about it, primarily fostered by the EPA, way out of proportion to its environmental impact. We had a local junior high school here in Utah which had a spill of a couple tablespoons of liquid mercury in a science lab.
They shut down the school for a day, and cleanup costs were in the ten thousand dollar range. What a complete waste of time and money. This institutional paranoia, is pushed by the government boys (there's no problem so small that a bureauracracy cannot by justified to handle it) who depend on the "crisis du jour" for their livelihood, at our expense.
They have, in the process, just about killed any opportunity to get silver batteries refined at any kind of a reasonable charge, and made it next to impossible to make any money from scrap dental amalgam, unless you are duly certified and blessed by the government to handle mercury wastes. This, of course, is so expensive a proposition that hardly anyone is able or willing to jump through all the EPA, federal and state, hoops and paperwork.
Don't know about you, but I sleep a lot better at night knowing that dentists find it much easier and much more profitable to dump their mercury wastes down the drain than to pay a "mercury disposal company" to "handle" it (along with its 4 troy ounces of contained silver per pound), at a cost of many $$$ per container.
THAT is what I call a sweet business model, getting waste generators to pay me to haul their precious metals away for them, and charge THEM for the privelege! Unfortunately, it doesn't seem to make us any safer or healthier, does it?
Scott - recyclebiz.com