CURWOOD: Just ahead, more on the environmental impact of Colombia's drug wars. We'll hear about the controversy surrounding the U.S. funded program to eradicate coca by spraying with herbicide. First, this Environmental Health Note from Diane Toomey.

TOOMEY: Not much is known about the syndrome known as Multiple Chemical Sensitivity, or MCS. But it's generally described as a condition in which people have an acute hyper-sensitivity to low levels of chemicals such as cleaning products, pesticides, and even perfume. MCS can produce a wide range of symptoms including difficulty breathing, headaches, and nausea. Estimates of the number of people who suffer from this condition vary widely. But in one recent study, researchers tried to get a handle on the affected population through a random survey in Atlanta. About sixteen hundred people answered a questionnaire. And almost thirteen percent said they had Multiple Chemical Sensitivity.

Of those, almost fourteen percent said they lost a job because of their condition. And thirteen percent said they had to move from a home because living there aggravated their symptoms. Some speculate MCS is linked to other disorders, and this survey found that more than half of those who said they had MCS also said they suffered from other conditions, like allergies to natural substances.

Some also think MCS is linked to mental illness. But in this study, only about two percent of people with MCS reported suffering from depression or anxiety prior to onset of their symptoms. In a related study, researchers asked about nine hundred people in MCS support groups to rate the best treatments. Most highly rated were living in a chemical free house, avoiding chemicals altogether, and prayer.

That's this week's Environmental Health Note. I'm Diane Toomey.

CURWOOD: And you're listening to Living on Earth.