The sources of chemical stress include pollutants in the air, insecticides, medicine and certain food additives and preservatives. Harmful chemicals may be consumed, inhaled, or even absorbed when contacting the skin.
This could include paint stripper, varnish, bleach, air pollutants, cosmetic products, additives in food and drink. They maybe consumed, absorbed through the skin or inhaled. This may cause headaches, migraines dizziness, sickness, nausea, vision disturbances.