I watched Harry's Law on the teevee the other day and one of their cases involved information on this subject. I was so flabbergasted at some of the stats I thought I would share my flabbergast here.
http://en.wikipedia.org/wiki/Natural_burial#Environmental_issues_with_conventional_burialEach year, 22,500 cemeteries across the United States bury approximately:
30 million board feet (70,000 m³) of hardwoods (caskets)
90,272 tons of steel (caskets)
14,000 tons of steel (vaults)
2,700 tons of copper and bronze (caskets)
1,636,000 tons of reinforced concrete (vaults)
827,060 US gallons (3,130 m³) of embalming fluid, which most commonly includes formaldehyde.<2>
(Compiled from statistics by Casket and Funeral Association of America, Cremation Association of North America,
Doric Inc., The Rainforest Action Network, and Mary Woodsen, Pre-Posthumous Society)
The chemical properties of formaldehyde should be noted - once formaldehyde has been used for embalming purposes,
it is no longer (technically and chemically) formaldehyde. The formaldehyde has broken down and the chemicals released
into the ground after burial and ensuing decomposition are inert.
The problems associated with formaldehyde and its constituent components when used in a natural burial setting
are the unnecessary chemical exposure to mortuary workers <3> and the destruction of the decomposer microbes
necessary for breakdown of the body in the soil.<4>