[ggm]

Wouldn't that be the formaldehyde in embalming fluid? And mercury from amalgam fillings.

[kombookcha]

Embalming is very rare in places like continental Europe, and large swathes of the non-western world has religious bans on embalming, so formaldehyde in graveyards is almost purely a problem in the anglosphere.

[positr0n]

Also bioaccumulation of heavy metals.

[hulitu]

Some claim is the preservative in food.