You are correct. I did 4 grams. Apologies.There is a math error here going mg to kg. The correct estimate is 2560 kg, or 2.5 tonnes of Hg per year in the US.
For reasons like this ("only 250 deaths a year"), I have a box in my garage with used engine oil, CFLs (less and less), batteries, smoke detectors w/ radioactive elements, etc.A little googling suggests that coal combustion emissions was about 50 tonnes per year in 1998. Probably a third of that now due to less coal being used.
IIRC lighting was like 10% of electricity use back in the 1990's, so that suggests that the avoided coal emissions from switching incandescent to CFL would've been about 3 tons/yr assuming 40% efficiency. Comparable to their Hg content.
Conclusion: recycle your CFLs responsibly!
A regulatory webpage is here:
What EPA is Doing to Reduce Mercury Pollution, and Exposures to Mercury | US EPA
Learn about actions EPA, tribal and state agencies have taken to reduce mercury pollution and releases into the environmentwww.epa.gov
This suggests Hg exposure regulation would avoid 11,000 premature deaths. If we assume that coal plants are half of total emissions (WAG) that means that 50 tonnes = 5000 premature deaths. and 2.5 tonnes (from not recycling CFLs) would cause 250 premature deaths per year.
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For NOx, the US figure is 171,000 premature deaths per year:
Communities of color suffer disproportionately higher pollution-related deaths
In the United States, premature death associated with exposure to nitrogen dioxide (NO2) pollution — a toxic gas emitted primarily by burning fossil fuels in cars, trucks and power plants — is more likely to impact people of color compared to the white population, a new Northwestern University...news.northwestern.edu
Some more googling suggests that only one third of NOx emissions are from mobile sources, and 60% of those are light duty diesels. So that suggests that diesel light duty vehicles lead to about 25,000 premature deaths per year in the US. Versus ~35,000/year for crashes.
But hey, the towing capacity of gasoline trucks is just not all that.
My point was this: I understand that all we do has a footprint. That not all footprint can be avoided. (I need some heat to stay warm in winter; that does involve CO2 and some smoke, even if less smoke than folks that burn wet wood in a less efficient stove).
This particular thing about Hg in CFLs is something that can be avoided with zero cost (doing it when going to the right place anyway), and near zero effort (unless my kids place the freaking box in the middle of where we walk in the garage #&(*%(($ ;p ).
The return on investment of "footprint/investment" is therefore near infinite, even if the footprint is small.