Electromagnetic fields, or EMF, are created by electricity and by wireless technology. This collection explains what EMF is, how the different types compare, where exposure comes from and how the technology developed.
Use the sections below to build a solid base before you move on to measuring or reducing exposure.
What EMF Is
Start with the plain language introductions: Understanding Electromagnetic Fields, The ABCs of EMFs, EMFs Uncovered and What Is EMF and How Does It Affect Us. For more depth, read EMF Basics and Beyond, Electromagnetic Field EMF, The Science Behind EMF and EMF Sources and Exposure. Decoding EMFs explains how fields are measured.
Types of EMF and the Spectrum
Not every field is the same. The Various Faces of EMFs, Differentiating the Spectrum and The EMF Spectrum From Radio Waves to Gamma Rays show where each type sits. The difference between ionizing and non-ionizing energy is covered in Ionizing vs Non-Ionizing Radiation and Classifying EMFs. For two common bands, see Extremely Low Frequency (ELF) and Radiofrequency (RF) Radiation, and read SAR, the Specific Absorption Rate to understand how phone emissions are rated.
Where EMF Comes From
Fields come from many everyday sources. The Devices and Technologies Behind EMF Emissions gives an overview, Everyday Sources From Microwaves to Power Lines covers common examples, and Identifying Common EMF Sources and Hidden Sources in Daily Life help you spot them.
The History of EMF Technology
Today’s wireless world has a long history. The EMF Usage Timeline lists key dates, EMF Technology Evolution and EMF History in Communication follow communication from the telegraph to 5G, and EMF Technological Milestones covers the main breakthroughs.
Find the Right Basics Guide
Match your question to a guide.
| If you want to know | Start here |
|---|---|
| What EMF is in plain language | Understanding Electromagnetic Fields |
| How the types of EMF differ | Differentiating the Spectrum |
| Ionizing and non-ionizing energy | Ionizing vs Non-Ionizing Radiation |
| How phone emissions are rated | SAR, the Specific Absorption Rate |
| Where fields come from at home | Identifying Common EMF Sources |
| How the technology developed | The EMF Usage Timeline |
A Good Order to Read
This order builds understanding step by step:
- Learn what EMF is and the main types
- Read about ionizing and non-ionizing energy
- Look at the common sources in daily life
- Move on to measuring and then reducing exposure if you choose to
Topics Covered
- What electromagnetic fields are
- Types of EMF and the spectrum
- Everyday sources of exposure
- How EMF technology developed
Frequently Asked Questions
What does EMF stand for?
EMF stands for electromagnetic fields. Understanding Electromagnetic Fields explains the term in plain language.
What is the difference between ionizing and non-ionizing radiation?
They differ in the amount of energy they carry. See Ionizing vs Non-Ionizing Radiation for details.
Where does EMF come from?
Fields come from power lines, wiring, appliances and wireless devices. Everyday Sources of EMFs lists common examples.
What is SAR?
SAR is a measure used to rate how much radiofrequency energy the body absorbs from a device. See SAR, the Specific Absorption Rate.