It is known that chemicals cause many human diseases. Some of the chemicals that have been shown to be dangerous to people include:

• Tobacco smoke. This is the major cause of lung cancer.
• Asbestos. This causes mesothelioma. This is an aggressive cancer that develops in the linings of the lungs, heart, or abdomen. This also causes lung cancer, asbestosis, and an increased risk for gastrointestinal cancer.
• Kepone. This is an insecticide that can cause infertility in people assigned male at birth. It also causes neurological disorders and kidney and liver damage.
• Dibromochloropropane. This is a pesticide that can cause infertility in people assigned male at birth. It may contribute to certain cancers.

Exposure to some chemicals may cause symptoms like an allergic reaction. This includes synthetic and natural substances found in:

• Carpeting
• Plastics
• Diesel exhaust
• Pesticides
• Perfumes
• Plants
• Paint
• Cigarette smoke

There are many other chemicals under review. The problem continues to grow because more types of chemicals are made over time.

While some chemicals are known to cause problems, some people are sensitive to a wide range of substances. This is known as multiple chemical sensitivity. It is also called idiopathic environmental intolerance (IEI).

Multiple chemical sensitivity, or IEI, is under debate in the medical field at this time. Some doctors question if the underlying illness is not medical but psychiatric. They suggest that the symptoms are caused by anxiety. Others say it is a medical disorder triggered by exposure to chemicals, electromagnetic forces, or other substances in the environment. Symptoms often begin with a short-term, severe chemical exposure, such as a chemical spill. Or they may happen after exposure over time.

After this, low levels of chemicals found in everyday materials can trigger physical symptoms in people with multiple chemical sensitivity. This includes chemicals in soaps, detergents, cosmetics, and newspaper inks.

Below are the most common symptoms. But each person's symptoms can vary. Symptoms may include:

• Headaches.
• Rashes.
• Asthma.
• Muscle and joint aches.
• Fatigue.
• Memory loss.
• Confusion.
• Hypersensitivity to the smell of chemicals.
• Nausea.
• Dizziness.

At this time, multiple chemical sensitivity, or IEI, is a diagnosis under debate. Some in the medical field lean toward the symptoms being physical signs of psychiatric illness. This means they think it's not a primary medical illness. Others in the medical field and some organizations agree these are physical reactions to substances. There is ongoing review about this condition as a clinical diagnosis. Multiple chemical sensitivity shares symptoms with other chronic conditions that are poorly understood, including fibromyalgia, Gulf War syndrome, sick building syndrome, and chronic fatigue syndrome. Talk with your doctor to learn more.