I think some or all of them were made using formaldehyde, too. God forbid a homeless family should have to breathe that for a few weeks/months! Better that they should live out in the open. /s
Every house and trailer made for the previous 50 years had that stuff in the particle board, plywood, etc.
Legend has it that a fresh tomato has more formaldehyde than MDF (medium density fiberboard) by weight!
http://www.cfs.gov.hk/english/whatsnew/whatsnew_fa/files/formaldehyde.pdf
Foods Known to Contain Naturally Occurring (more at link)Formaldehyde
Mg/Kg Fruits and Vegetables Apple 6.3-22.3 Banana 16.3 Cauliflower 26.9 Pear 38.7-60 Shiitake mushroom (dried / raw) 100-406 / 6-54.4 Meat and Meat Products Beef, pork, mutton and poultry meat 2.5-20 Seafood Cod 4.6-34 Fish ball 6.8 Crustacean 1-98 Bombay-duck (fresh) ≦140