Chemical compounds, which comprise the bulk of the environmental toxins, are currently spread all over the world, even if the chemical was not used in that area. This is due to spread by the ground water, surface rain and winds. And sometimes right in front of your face with the chemicals from the plastic bottle being leached out into your drinking water.
Bioaccumulation of these compounds cause disease in living beings, and in humans, the immune system, the endocrine system and neurological system is the most affected.
The effects of toxins are documented in a number of diseases, ranging from asthma, allergies, autoimmune diseases, cancers and cognitive deficit.