Francis' premise is that there is only one source of disease - damaged, dying cells. If you treat them, you treat the disease. Rather than looking for and treating symptoms you look at the causes at the root and treat them. So far, so good. Unfortunately, according to Francis, the toxins that attack us are in every aspect of our life. He even compares our showers to gas chambers because water is chlorinated. Everything from our dishwashers to our toothpaste are suspect. While I don't doubt there are some less than desirable elements in all these things, it is part of the modern world and largely unavoidable unless you wish to swaddle yourself in cotton (of course, making sure it's organic) and seal yourself off from society. Fear is its own toxin.
I believe strongly you can improve your well being by modifying your diet and getting a good walk in daily. I also believe if you look too closely at every element around you, you are bound to find "dangers". Make the changes you can a) afford, b) incorporate and c) sustain. My cell phone may be shooting death rays into my head every time I use it, but it is my most affordable, convenient and safe option. Be realistic and non-reactive to health updates and warnings. After all, a grain of salt doesn't have enough sodium to hurt you.