To be fair, there are things that are toxic to the human body. The fixation on toxins however is overstated and obscures the real issue with our bodies today.
Our bodies do a good job of filtering out toxins, especially if we are nutrient juggling. One should be mindful of things like cooking with aluminum, arsenic in rice, and lead in drinking water. It is also wise to live somewhere without significant environmental pollution.
We must however not get distracted by things that do not actually have a large impact. When humanity is in crisis, why waste our time with such a minor issue?