WiFi, also known as wireless internet, has become an integral part of our daily lives. From homes to offices, schools to coffee shops, WiFi allows us to stay connected to the online world through our smartphones, laptops, tablets and other devices. However, some concerns have been raised about the potential health risks of WiFi, especially in relation to radiation exposure. In this article, we will examine the radiation emitted by WiFi and evaluate how much of a risk it poses to human health.
What is WiFi and how does it work?
WiFi refers to wireless networking technology that uses radio waves to provide high-speed internet access. WiFi enabled devices like routers and modems transmit and receive data wirelessly using radio signals instead of cables and wires.
For WiFi to work, a router connects to the internet via a wired Ethernet cable. The router then sends and receives radio signals at frequencies of 2.4GHz or 5GHz to communicate with WiFi enabled devices like laptops, smartphones, tablets etc.
The typical range of WiFi networks is about 20 meters indoors and up to 100 meters outdoors. The further a device is from the router, the weaker the radio signal will be.
Types of radiation emitted by WiFi
WiFi devices emit radiofrequency (RF) radiation which is a form of electromagnetic radiation. RF radiation has lower frequencies and longer wavelengths compared to other types like ultraviolet, x-rays and gamma rays.
There are two main types of RF radiation emitted by WiFi:
1. Non-ionizing radiation
This refers to radiation from WiFi routers and modems that does not have enough energy to remove electrons from atoms and molecules to cause ionization. Non-ionizing radiation does not damage DNA and is considered biologically harmless in low exposures. Other sources of non-ionizing radiation include radio waves, microwaves, infrared radiation and visible light.
2. Ionizing radiation
This refers to radiation with higher frequencies like x-rays and gamma rays that have enough energy to break molecular bonds and ionize atoms. Ionizing radiation has the potential to damage DNA and cause cancer. WiFi devices do NOT emit ionizing radiation.
How much radiation does a WiFi router emit?
WiFi routers emit non-ionizing radiation at power levels far below safety limits:
- Typical WiFi radiation: 0.1 to 1 mW/cm2
- Safety limits set by FCC: 1 to 10 W/cm2
So a WiFi router exposes you to about 100 to 1000 times lower RF radiation than the safe limit. The exposure decreases rapidly with distance from the router. Standing right next to a router you may get 0.2 to 5 mW/cm2 exposure. At 20 feet away, this drops to 0.0001 to 0.01 mW/cm2.
Radiation exposure from common WiFi devices
| WiFi Device | Distance from body | Typical radiation exposure(mW/cm2) |
|---|---|---|
| Laptop on lap | 0 cm | 0.1-2 |
| Tablet in hand | 0 cm | 0.5-4 |
| Smartphone in pocket | 1-5 cm | 0.01-0.1 |
| WiFi router at home | 1-5 m | 0.0002-0.01 |
As can be seen, radiation exposure depends on distance from the source. Laptops, tablets and smartphones used very close to the body deliver higher exposure than a router across the room. Still, even close range exposure is well below danger levels.
How does WiFi radiation compare to cell phones?
Since WiFi enabled devices need to transmit data over a limited range, the amount of energy required, and hence emitted radiation, is low.
Cell phones on the other hand require more power as they have to send signals over large distances to cell towers. As a result, radiation exposure from cell phones (0.5 to 2 W/Kg for head/body) is higher than WiFi devices like laptops and routers (0.003 to 0.04 W/Kg for head/body).
Potential health risks of WiFi radiation
Current scientific consensus is that WiFi radiation is unlikely to cause any adverse health effects in humans for these reasons:
- The radiation is non-ionizing and does not damage cell DNA
- Exposure levels are well below safety limits set by organizations like FCC
- Studies have found no link between WiFi and issues like brain activity, hormone levels, cancer etc
However, some concerns exist regarding long term exposure to low level WiFi radiation. Since the technology is relatively new (15-20 years), the long term effects are not fully known yet. Some studies have seen increased oxidative stress and DNA damage at WiFi frequencies. But this research is still in early stages.
More high quality long term studies are needed to conclusively determine if WiFi radiation has any effects on human health.
Tips to minimize WiFi radiation exposure
While there is no firm evidence of WiFi health risks, those concerned can take simple steps to reduce exposure:
- Keep router away from bedrooms and other high occupancy areas
- Turn off WiFi router when not in use
- Use ethernet cable instead of WiFi when feasible
- Download large files overnight when WiFi is not in active use
- Keep laptops and tablets off of your body when wireless is enabled
Following common sense measures allows peace of mind without sacrificing the productivity benefits of wireless technology.
Conclusion
In summary, WiFi routers emit non-ionizing radiation well below the levels considered harmful for humans. The maximum exposure from WiFi devices is about 100 to 1000 times lower than safety limits set for radiofrequency radiation. There is no definitive evidence currently that WiFi radiation causes health issues even with chronic exposure. However, moderating use and increasing distance from the source can minimize radiation received for those who prefer extra precaution. As more long term studies emerge, our understanding of WiFi safety will likely improve further. For now, WiFi remains a very low radiation technology that provides immense benefits for education, business and entertainment with minimal demonstrated risks.