“Environmental Illness” or “EI” is an overarching term that is used to describe the illnesses and diseases that some people have whose symptoms and reactions occur or worsen when they are exposed to chemicals or substances in the environment (the external—both indoors and outside—environment, on other people, and on themselves.)

In an EI, something in the environment is toxic and/or an irritant or incitant and can cause individuals to have mild to severe and life-threatening reactions from their exposure to the chemical or substance.

Mastocytosis, mast cell activation syndrome (MCAS), chemical sensitivities, and mast cell activation-related disorders (such as iIrritable bowel xyndrome (IBS), chronic fatigue syndrome (CFS), and more) come under the heading of EI. Asthma, lung cancer from smoking, mesothelioma (a cancer often caused by exposure to asbestos) are EIs.

The National Institute of Environmental Health Sciences (NIEHS) includes in their publication, “Environmental Diseases from A to Z”—in addition to asthma and cancers—dermatitis, emphysema, goiters, fertility problems, lead poisoning, mercury poisoning, immune deficiency diseases, kidney disease, nervous system disorders (which includes the brain, spinal cord, and nerves), pneumoconiosis (or black lung disease), and vision problems as environmental illnesses.

Current research has shown that mast cells are involved in COVID and long COVID (also called Post COVID), in their mechanisms of action and in their symptoms (see here, here, and  here.)

EI information links:

Physical responses & health: