Near ultraviolet light and ultraviolet A (UV-A), both have about the same wavelengths.
Radon-222 is a colorless, odorless, radioactive gas, and, when inhaled, it is the
source of about half of the background radiation that people in the U.S. are exposed
to. After cigarettes, radon is the second most common cause of lung cancer in
the U.S. Exposure to the combination of radon gas and cigarette smoke creates a
greater risk for lung cancer than either exposure alone and most radon-related lung
cancers occur among smokers. Radon is normally found at very low levels in
outdoor air and in drinking water from surface sources. Elevated radon levels have
been found in a wide variety of places and in every state in the U.S. Because fresh
air is usually not well circulated, radon can be found at higher levels in the air in
houses and other buildings. Most exposure to radon comes from being indoors and
from water from underground sources, such as well water.

The EPA estimates that nearly one out of every 15 homes in the United States may
have elevated radon levels. Radon levels in a home can be checked with a do-it yourself
kit or by hiring a professional. Radon levels are usually highest in places
closest to the soil or rock that is the source of the radon, such as the in the basement
or crawl space. The EPA recommends testing all homes below the 3rd floor, even
new homes. If the levels are high, various methods can be used to reduce radon
levels, such as sealing cracks in floors and walls or increasing ventilation. For more
information about radon testing, call the National Radon Hotline at 800–55–RADON
or go to

This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel