Could chemical warfare in our minds not be what it sounds like, but still be here harming us?

I noticed that a lot of meats have been recalled, a lot of disease in schools, children diseases, and other chemical things, like Swine flu, could be work of silent cells placed years ago like they did for twin towers bombings.... I heard toys being recalled for more lead than normal, and other american stuff like apple pie and basball chemical warfare, not like in movies where they pour acid in the clouds, I'm talking years and years of silent cells infilltrating our sciene labs and and other such places, even abroad... Hmmmmm?