I wrote here on what Electromagnetic Fields (EMF) are, and why they can be a problem. In a nutshell, a flowing current produces a magnetic field perpendicular to the direction of the flow—this is the electromagnetic field (EMF). If we’re close enough to it, this magnetic field in turn can induce a current in our own bodies, disrupting the flow of the positively charged ions in our bodies (primarily calcium, so far as we know at the moment).
This is why those with EMF sensitivity tend to feel best when not only ‘off the grid,’ but also when grounding, or standing barefoot on the negatively charged earth (or at any rate without a barrier that prevents current from flowing, like rubber soled shoes). The exposure to negative charges at least appears to contribute to neutralizing the effects of EMF.
Where Negative Ions in Nature Come From
A negative ion is a molecule or atom that has an extra (negatively charged) electron attached to it, whereas a positive ion is an atom or molecule missing an electron.
One process by which negative ions are formed in nature is the Lenard effect in moving water, discovered by German physicist P. Lenard in 1892. The movement of the water itself creates a charge disparity: positive molecules stay with the larger, heavier droplets, while the mist generated around the moving body of water is primarily negatively charged. The movement and temperature of the air, contact with various surfaces, solutes dissolved in the water, and height from which the water falls will all contribute to the charge disparity. Waterfalls are therefore strong sources of negative ions— and the concentration of them gets higher the closer you get to it. (No wonder we feel so good around waterfalls!)
Any other source of moving water should produce the Lenard effect to some degree as well, with the aforementioned variables determining how strong the effect might be. Other sources would include waves on the beach, being outside in the rain, or even a fountain or shower.
Plants, by the very fact that they release negatively charged oxygen in the process of photosynthesis, are natural negative ion generators as well. This is part of why forest bathing may be so beneficial.
Effects of Negative and Positive Ions
Of course, when negative ions are produced, there must be a corresponding positive ion somewhere.
This particularly happens just prior to a storm. As pressure builds, water molecules and particulates in the air collide with one another, exchanging electrons and producing ions. Those that are negatively charged sink while those that are positively charged rise. Meanwhile, humidity (water) is a great conductor of electricity. When the charge disparity becomes great enough between the positively charged atmosphere and the negatively charged earth, lightning results.
High positive ion concentration has been associated with malaise, joint pain, and respiratory problems. This may be at least part of why many feel worse with thunderstorms, and better once the storm has passed, leaving a greater abundance of negative ions in is wake.
Negative ions tend to have a specifically antimicrobial effect, protecting us against various pathogenic organisms.
They have been shown in some subjects to decrease depressive symptoms.
So if positive ion buildup makes us feel worse, and negative ions make us feel better (particularly those sensitive to EMF), where (besides waterfalls or in the forest) might we find high concentrations of negative ions?
Other Sources of Negative Ions
In days gone by, doctors would recommend a “holiday by the sea” as a treatment for various ailments. Perhaps there was more to that than just rest and relaxation. In addition to the Lenard effect right next to the waves, the air also has a very high salt concentration from the briny sea.
Halotherapy, or salt therapy, is said to be another source of negative ions. The theory is that salt creates negative ions because it attracts water (water always follows salt). When water evaporates, it carries electrons from the salt off with the water molecules into the ambient air.
This may be the rational behind halotherapy for asthma. It has been shown to improve forced expiratory volume, forced vital capacity, and peak expiratory flow, as well as quality of life in asthmatics. It also has been shown to reduce “body sensitivity” in those with asthma as well. (Those who don’t have easy access to a salt cave might choose to try a Himalayan salt inhaler instead!)
Himalayan salt lamps may have a similar effect for the same reason, though considering the very small volume of water likely to collect on the surface and then evaporate, it would probably depend upon the surface area of the lamp, the humidity of the air, and the size of the room to have any appreciable effect on negative ion generation.
Plants are also natural negative ion generators, which is a great reason to keep indoor plants. (One caveat here, though: many of my patients are mold sensitive. If you’re one of those people, be aware that most soil does contain small amounts of mold, and even this might be sufficient to cause an inflammatory response.)
Some sources say that the minerals tourmaline and amethyst are natural negative ion generators as well, though I couldn’t find any studies to corroborate these claims. That doesn’t necessarily mean they don’t work; just that the studies haven’t been done.
We’re always finding more reasons why spending time out in nature is good for us; negative ions are yet another one. Since most urban life is indoors, and particularly if you tend to be EMF sensitive, it’s a good idea to be intentional about getting outside as much as possible. When you can’t, consider adding some negative ion-generating strategies such as fountains, house plants, or even Himalayan salt lamps to your environment.