I have not heard a great deal about it, however, I am a therapist and most case would be detected by medical doctors through bloodwork. Toxins can affect behavior by affecting the functioning of the body, such as the thyroid and the liver. I have found that I have seen a number of people who have had their anxienty attacks linked to asthma attacks, and the increase in asthma can be linked to air pollution. The fact is that when people go to the hospital with an anxiety attack, the doctors have found that sometimes the attack is asthma, which can mimic anxiety or a panic attack. It can also be the case, I think, that anxiety can increase the frequency of asthma attacks and vice versa.