Radiation from the damaged nuclear reactors in Fukushima Japan have caused many people to become very concerned about the safety of their water.
How To Understand Radiation
To understand the dangers of radioactivity in water, you must be able to distinguish between radiation and radioactivity.
Radiation is energy being emitted by some kind of particle. When particles that have mass emit radiation, they are said to be radioactive. For example, sunshine is a form of radiation. The sun, from which the sunshine is emitted, is a massive object that is radioactive.
The water molecule itself, is not and cannot be made to be radioactive (emit radiation.) When radiation hits water, it splits the water molecule into Hydrogen (H+) and a hydroxyl (OH-) radical, neither of which are radioactive. However, these ions can be dangerous because they can cause damage to cell structures including DNA.
The drawing to the right shows how radiation (top arrow) splits a water molecule to produce a hydrogen atom and a hydroxyl radical, and how that hydroxyl radical can affect DNA in a cell.
Because water is such an excellent solvent, water droplets tend to pick up gasses and particles carried by winds aloft which then fall to the ground as rain. Sooner or later this rain may become part of the water supply used for human consumption or watering crops. Water that comes from deep underground aquifers may also contain radionuclides (radioactive atoms or molecules) including radon gas, alpha and beta particles, radium and uranium.
Removing Radiation From Water
Because some radioactivity can be present in water as a dissolved gas (Iodine-131 and radon for example) processes like reverse osmosis are ineffective. For these substances, the best treatment method is proper contact time with a bed of activated carbon. Drinking water systems that have large amounts of carbon or catalytic activated carbon are best. Faucet mounted filters do not contain enough carbon to make a significant difference because the amount of water (usually at least 2 – 3 gallons per minute) flowing through such a small volume of carbon does not allow for enough contact time to assure adequate removal.
Other kinds of radioactivity like Cesium and Uranium exist as particles or ionic salts. For this kind of contamination water systems that employ reverse osmosis or capillary membranes are best. Systems that rely only on carbon, carbon blocks, or sediment filters (spun or pleated polyester or paper products) are ineffective.
Systems designed with certain ion-exchange media (including standard ion-exchange salt-based water softeners) are also effective for Cesium-137. KDF®55 is highly effective against radon.
LivingWaters™ Systems that utilize catalytic activated carbon, KDF®55, fluoride removal media and either capillary membrane or reverse-osmosis membranes are the among the most effective water treatment systems for radioactivity. That is because the majority of recent models use an abundant amount of two different types of carbon, an ion-exchange media (for fluoride) that is very effective on Cesium-137, and capillary membranes. If you are lucky enough to own one of these systems you have nothing to worry about.
For more information on Radioactivity in Water, click here.
For more information on Radon in Water, click here.
For more information on Radium in Water, click here.
For more information on Uranium in Water, click here.
