- Healsoaz.org - - MCS WebGuide HEAL of Southern Arizona Are Chemicals Affecting Your Health Everyday chemical exposures can be harmful, especially for pregnant women, children, seniors, and people with asthma, allergies, and Multiple Chemical Sensitivities (MCS) Just a whiff of perfume or pesticide could make a person with MCS sick more Preventing MCS and other illness from chemical exposure ...www.healsoaz.org