What are environmental intolerances?

In recent years, there has been an increase in the number of illnesses that may be caused by a reaction to something in a person’s environment. These illnesses include:

• Multiple chemical sensitivity (MCS)
• Sick building syndrome
• Post 9/11 syndrome
• Silicone breast implant intolerance
• Gulf War syndrome
• Toxic mold syndrome
• Electromagnetic field intolerance.

This handout will focus mainly on multiple chemical sensitivity (MCS) because it is the best-studied of these environmental illnesses. But the causes, diagnosis, and treatment are similar for all of them. 

How does MCS affect people?

People vary a lot in their reactions. For some people, these illnesses can be quite disabling. They can affect a person’s ability to work, accomplish daily tasks, and enjoy leisure activities. They can also increase the cost of healthcare.

A study in 2003 of 1,582 individuals from the Atlanta area found that 12.6% reported being overly sensitive to common chemicals. Of that 12.6%, 13.5% of them (1.8% of the total group) had lost their jobs because of their sensitivities. Another 2003 study of 917 people with MCS, found that on average each spent $51,000 on health care, $7,000 in the past year.