Kalliopi,
There may be one more way to be reasonably well-assured of toxin-free food...grow your own; or buy directly from a grower you trust.
Of course, one would have to be as certain as possible that the ground, water, and seeds were uncontaminated.
Last summer we grew flowers, some herbs, and Hubbard squash on a patch by our front door that had been covered in Junipers for thirty years. (Seniors pulling out twisted and rambling branches twenty and thirty feet long was a sight to behold, believe me.)
The soil was thickly covered with dead needles which had been soaking their nutrients back into the ground all the while.
Our plants fair leaped up and the huge squashes were delicious. We thin-sliced and dried many of the young ones with tender skin. We run the dry chips through the blender to make a powder, add some water, milk, a piece of butter, and boil lightly for a few minutes, to make a tasty soup.
And we saved mature seeds...enough to keep half this small city in toxin-free Hubbard squash all next winter.
Even if a person had only one square foot of growing space, they could plant a few peas, beans, or squash, and grow them up a trellis, with a couple of carrots and beets at their feet...or flavorful herbs.
Our town is surrounded by organic farmers, several of whom we know personally.
We also know a fellow who has trained himself to 'muscle test' with his fingers on one hand, while touching a person or thing with the other hand. He also works with percentages. We've watched him work long enough to believe the answers he gets.
We also know an accomplished kinesiologist.
In the sharing of information I suggested above, it wouldn't really matter what toxins participants were detecting, as long as they told us their methods of detection, what foods they found wholesome, and the improvements in health they experience.
Readers could then make their own judgements and choose their own paths, just as they do now, but with more testimonials to help them.
Experts, of course, could devise their own more 'scientific' studies.
I read a few weeks ago that Eliot Coleman's carrots are preferred by school children over store-bought. Maybe it's the flavor that pleases them...or maybe they have developed their own method of intuitive 'testing'. :) :) :)
My best,
fledgling