Microwave radiation can heat body tissue the same way it heats food. Exposure to high levels of microwaves can cause a painful burn. Two areas of the body, the eyes and the testes, are particularly vulnerable to RF heating
Dielectric heating
Dielectric heating, also known as electronic heating, RF heating, high-frequency heating is the process in which a high-frequency alternating electric field, or radio wave or microwave electromagnetic radiation heats a dielectric material. At higher frequencies, this heating is ca…
Full Answer
Are microwaves harmful to your health?
Eleanor R. Adair conducted microwave health research by exposing herself, animals and humans to microwave levels that made them feel warm or even start to sweat and feel quite uncomfortable. She found no adverse health effects other than heat.
What are the health risks of micro-waved foods?
This has been a primary contributor to the rapidly increased rate of colon cancer in the United States The prolonged eating of micro-waved foods causes cancerous cells to increase in human blood Continual ingestion of micro-waved food causes immune system deficiencies through lymph gland and blood serum alterations
Do microwave ovens kill bacteria?
While microwave ovens can destroy bacteria as well as conventional ovens can, they cook rapidly and may not cook as evenly, similar to frying or grilling, leading to a risk that parts of the food will not reach recommended temperatures.
Is shortwave energy harmful to human health?
However, at a sufficiently high energy level, shortwave energy can be harmful to human health, potentially causing damage to biological tissues.
What does microwave oven mean?
Another misconception is that microwave ovens cook food "from the inside out", meaning from the center of the entire mass of food outwards. This idea arises from heating behavior seen if an absorbent layer of water lies beneath a less absorbent drier layer at the surface of a food; in this case, the deposition of heat energy inside a food can exceed that on its surface. This can also occur if the inner layer has a lower heat capacity than the outer layer causing it to reach a higher temperature, or even if the inner layer is more thermally conductive than the outer layer making it feel hotter despite having a lower temperature. In most cases, however, with uniformly structured or reasonably homogenous food item, microwaves are absorbed in the outer layers of the item at a similar level to that of the inner layers.
How many centimeters does a microwave penetrate?
Microwave ovens produce heat directly within the food, but despite the common misconception that microwaved food cooks from the inside out, 2.45 GHz microwaves can only penetrate approximately 1 centimeter (0.39 in) into most foods.
Why do microwaves heat food?
Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm (1–1.5 inches) of a homogeneous, high water content food item. The development of the cavity magnetron in the UK made possible the production of electromagnetic waves of a small enough wavelength ( microwaves ).
Why does a microwave have a small wavelength?
Heating from microwaves that have a wavelength that is small relative to the cavity (as in a modern microwave oven) is due to "far-field" effects that are due to classical electromagnetic radiation that describes freely propagating light and microwaves suitably far from their source.
How does a microwave work?
A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating.
What is a 1974 Radarange microwave called?
1974 Radarange RR-4. By the late 1970s, technological advances led to rapidly falling prices. Often called "electronic ovens" in the 1960s, the name "microwave oven" later gained currency, and they are now informally called "microwaves".
Why is microwave heating less efficient?
Microwave heating is less efficient on fats and sugars than on water because they have a smaller molecular dipole moment. Sugars and triglycerides (fats and oils) absorb microwaves due to the dipole moments of their hydroxyl groups or ester groups. However, due to the lower specific heat capacity of fats and oils and their higher vaporization temperature, they often attain much higher temperatures inside microwave ovens. This can induce temperatures in oil or fatty foods like bacon far above the boiling point of water, and high enough to induce some browning reactions, much in the manner of conventional broiling (UK: grilling), braising, or deep fat frying.
Why is a microwave oven so convenient?
Because microwave ovens are so convenient and energy efficient, as compared to conventional ovens, very few homes or restaurants are without them. In general, people believe that whatever a microwave oven does to foods cooked in it doesn’t have any negative effect on either the food or them.
What happens to the nutrients in microwaved food?
Minerals, vitamins, and nutrients of all micro-waved food is reduced or altered so that the human body gets little or no benefit, or the human body absorbs altered compounds that cannot be broken down. The minerals in vegetables are altered into cancerous free radicals when cooked in a microwave oven.
What changes did the microwave cause?
All foods that were processed through the microwave ovens caused changes in the blood of the volunteers. Hemoglobin levels decreased and over all white cell levels and cholesterol levels increased. Lymphocytes decreased. Luminescent (light-emitting) bacteria were employed to detect energetic changes in the blood.
How much energy does a microwave use?
Every microwave oven contains a magnetron, a tube in which electrons are affected by magnetic and electric fields in such a way as to produce micro wavelength radiation at about 2450 Mega Hertz (MHz) or 2.45 Giga Hertz (GHz).
What changes were discovered in the blood samples from the intervals following the foods cooked in the microwave oven?
These changes included a decrease in all hemoglobin and cholesterol values, especially the ratio of HDL (good cholesterol) and LDL (bad cholesterol) values.
How does microwave energy change polarity?
All wave energy changes polarity from positive to negative with each cycle of the wave. In microwaves, these polarity changes happen millions of times every second. Food molecules – especially the molecules of water – have a positive and negative end in the same way a magnet has a north and a south polarity.
Does microwave blood kill?
Microwaved blood kills patient . In 1991, there was a lawsuit in Oklahoma concerning the hospital use of a microwave oven to warm blood needed in a transfusion. The case involved a hip surgery patient, Norma Levitt, who died from a simple blood transfusion. It seems the nurse had warmed the blood in a microwave oven.
What are the negative effects of ionizing radiation?
For the negative health effects of ionizing radiation, see radiation poisoning. Electromagnetic radiation can be classified into two types: ionizing radiation and non-ionizing radiation, based on the capability of a single photon with more than 10 eV energy to ionize atoms or break chemical bonds. Extreme ultraviolet and higher frequencies, such as ...
What is the wavelength of ultraviolet radiation?
Ultraviolet radiation of wavelengths shorter than 300 nm ( actinic rays) can damage the corneal epithelium. This is most commonly the result of exposure to the sun at high altitude, and in areas where shorter wavelengths are readily reflected from bright surfaces, such as snow, water, and sand.
What is the most common form of cancer?
Clear evidence establishes ultraviolet radiation, especially the non-ionizing medium wave UVB, as the cause of most non-melanoma skin cancers, which are the most common forms of cancer in the world. UV rays can also cause wrinkles, liver spots, moles, and freckles.
What is the damage to the macular area of the eye?
Photic retinopathy is damage to the macular area of the eye's retina that results from prolonged exposure to sunlight, particularly with dilated pupils. This can happen, for example, while observing a solar eclipse without suitable eye protection. The Sun's radiation creates a photochemical reaction that can result in visual dazzling and a scotoma. The initial lesions and edema will disappear after several weeks, but may leave behind a permanent reduction in visual acuity.
Is radio frequency electromagnetic radiation carcinogenic?
The World Health Organization began a research effort in 1996 to study the health effects from the ever-increasing exposure of people to a diverse range of EMR sources. In 2011, the WHO/International Agency for Research on Cancer (IARC) has classified radiofrequency electromagnetic fields as possibly carcinogenic to humans (Group 2B), based on an increased risk for glioma, a malignant type of brain cancer, associated with wireless phone use.
What are the effects of RF radiation?
Focused RF radiation can also cause burns on the skin or cataracts to form in the eyes.
What did the 1960s show about RF radiation?
Studies during the 1960s in Europe and Russia claimed to show effects on humans, especially the nervous system, from low energy RF radiation; the studies were disputed at the time. In 2019 reporters from the Chicago Tribune tested the level of radiation from smartphones and found it to exceed safe levels.
What to do if microwave door doesn't close properly?
Also, make sure that your microwave oven is in good condition. If it’s old or broken — or if the door doesn’t close properly — consider getting a new one. Microwaves are a form of electromagnetic radiation, similar to the radiation from cell phones.
Why do microwaves heat food?
For example, they may not be as effective as other cooking methods at killing bacteria and other pathogens that may lead to food poisoning. That’s because the heat tends to be lower and the cooking time much shorter.
Why is my food not boiled?
The main contributing factors are temperature, cooking time, and method. During boiling, water-soluble nutrients may leak out of the food. As far as microwaves go, cooking times are generally short and the temperature low. Plus, the food is usually not boiled.
What is microwave oven?
Microwave ovens are kitchen appliances that turn electricity into electromagnetic waves called microwaves. These waves can stimulate molecules in food, making them vibrate, spin around, and clash with each other — which turns the energy into heat. This is similar to how your hands heat up when you rub them together.
What is the best temperature to microwav?
Usually, the temperature doesn’t surpass 212°F (100°C) — the boiling point of water.
How far away should you keep your head from the microwave?
Just to be on the safe side, don’t press your face against the window and keep your head at least 1 foot (30 cm) away from the oven.
What temperature does bacon get hot?
Usually, the temperature doesn’t surpass 212°F (100°C) — the boiling point of water. However, fatty foods like bacon can become hotter. Bacon is one food believed to form harmful compounds called nitrosamines when cooked. These compounds are created when nitrites in foods are heated excessively.
What is the FDA standard for microwaves?
A Federal standard (21 CFR 1030.10) limits the amount of microwaves that can leak from an oven ...
How does microwave radiation affect the body?
Microwave radiation can heat body tissue the same way it heats food. Exposure to high levels of microwaves can cause a painful burn. Two areas of the body, the eyes and the testes, are particularly vulnerable to RF heating because there is relatively little blood flow in them to carry away excess heat. Additionally, the lens of the eye is particularly sensitive to intense heat, and exposure to high levels of microwaves can cause cataracts. But these types of injuries – burns and cataracts – can only be caused by exposure to large amounts of microwave radiation.
How much radiation can a microwave leak?
A Federal standard (21 CFR 1030.10) limits the amount of microwaves that can leak from an oven throughout its lifetime to 5 milliwatts (mW) of microwave radiation per square centimeter at approximately 2 inches from the oven surface. This limit is far below the level known to harm people.
Why do microwaves leak radiation?
In general, microwave oven radiation injuries are caused by exposure to large amounts of microwave radiation leaking through openings such as gaps in the microwave oven seals. However, FDA regulations require that microwave ovens are designed to prevent these high level radiation leaks.
Why do microwaves work?
The microwaves are reflected within the metal interior of the oven where they are absorbed by food. Microwaves cause water molecules in food to vibrate, producing heat that cooks the food. That's why foods that are high in water content, like fresh vegetables, can be cooked more quickly than other foods.
How far is 20 inches from an oven?
A measurement made 20 inches from an oven would be approximately 1/100th of the value measured at 2 inches from the oven. The standard also requires all ovens to have two independent interlock systems that stop the production of microwaves the moment the latch is released or the door is opened.
What is the most common use of microwave energy?
But the most common consumer use of microwave energy is in microwave ovens.
How did microwave radio relays work?
In microwave radio relay, a microwave transmitter and directional antenna transmits a narrow beam of microwaves carrying many channels of information on a line of sight path to another relay station where it is received by a directional antenna and receiver, forming a fixed radio connection between the two points . The link was often bidirectional, using a transmitter and receiver at each end to transmit data in both directions. The requirement of a line of sight limits the separation between stations to the visual horizon, about 30 to 50 miles (48 to 80 km). For longer distances, the receiving station could function as a relay, retransmitting the received information to another station along its journey. Chains of microwave relay stations were used to transmit telecommunication signals over transcontinental distances. Microwave relay stations were often located on tall buildings and mountaintops, with their antennas on towers to get maximum range.
Why is microwave frequency important?
Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it.
Why are microwaves used in radio communications?
Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. This frequency reuse conserves scarce radio spectrum bandwidth. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it. A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can.
How does a microwave beam work?
The transmitter radiates a beam of microwaves into the sky, at a shallow angle above the horizon toward the receiver. As the beam passes through the troposphere a small fraction of the microwave energy is scattered back toward the ground by water vapor and dust in the air.
How far can a microwave relay be?
Terrestrial microwave relay links are limited in distance to the visual horizon, a few tens of miles or kilometers depending on tower height. Tropospheric scatter ("troposcatter" or "scatter") was a technology developed in the 1950s to allow microwave communication links beyond the horizon, to a range of several hundred kilometers. The transmitter radiates a beam of microwaves into the sky, at a shallow angle above the horizon toward the receiver. As the beam passes through the troposphere a small fraction of the microwave energy is scattered back toward the ground by water vapor and dust in the air. A sensitive receiver beyond the horizon picks up this reflected signal. Signal clarity obtained by this method depends on the weather and other factors, and as a result, a high level of technical difficulty is involved in the creation of a reliable over horizon radio relay link. Troposcatter links are therefore only used in special circumstances where satellites and other long-distance communication channels cannot be relied on, such as in military communications.
What is microwave transmission?
Microwave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave range (1 m - 1 mm) of the electromagnetic spectrum. Although an experimental 40-mile (64 km) microwave telecommunication link across the English Channel was demonstrated in 1931, the development of radar in World War II provided ...
What are microwave links?
Uses of microwave links 1 In communications between satellites and base stations 2 As backbone carriers for cellular systems 3 In short-range indoor communications 4 Linking remote and regional telephone exchanges to larger (main) exchanges without the need for copper/optical fibre lines 5 Measuring the intensity of rain between two locations
Why do microwaves work so well?
[See: 7 Kitchen Items You Need to Replace to Protect Your Health .] “The latter is why microwaves work so well at cooking foods quickly. They cause water molecules in the food to vibrate – rapidly ,” Hunnes explains.
What makes a microwave so good?
A form of electromagnetic radiation, microwaves have three characteristics that make them so darn good at zapping your leftovers, explains Dana Hunnes, adjunct assistant professor of community health sciences at the UCLA Fielding School of Public Health. They are reflected by metal.
Is it better to heat food in the microwave or steam?
It depends exactly what you are comparing microwaved foods to, but in general, it’s actually better to heat food in the microwave versus steaming, boiling or baking it. “Much of this has to do with the fact that microwaves heat foods so quickly.
Does nuking food cause cancer?
Fortunately for time-starved schedules, research suggests that nuking food does not increase cancer risk. That’s largely because, no, you aren’t actually “nuking” anything. “The type of radiation typically associated with cancers and with ‘nuclear’ reactions are gamma, neutron and ionizing radiation. This type of radiation can change ...
Does microwaving retain vitamin C?
Vitamin C, a nutrient that is frequently lost in cooking, has been found to be well-preserved when microwaving,” Hunnes says. “In general, cooking methods that best retain nutrients are those that cook quickly – heating the food in the shortest amount of time and using as little liquid as possible.”.
Can radiation change DNA?
This type of radiation can change a cell’s DNA and predispose a person to cancer, ” Hunnes says. (FYI, we are constantly exposed to small doses of background ionizing radiation from natural sources, like soil, cosmic rays and even the foods we eat.
How does a cell phone antenna affect human health?
The antennas contained in mobile phones, including smartphones, emit radiofrequency (RF) radiation ( non-ionizing "radio waves" such as microwaves ); the parts of the head or body nearest to the antenna can absorb this energy and convert it to heat. Since at least the 1990s, scientists have researched whether the now-ubiquitous radiation associated with mobile phone antennas or cell phone towers is affecting human health. Mobile phone networks use various bands of RF frequency, some of which overlap with the microwave range. Other digital wireless systems, such as data communication networks, produce similar radiation.
What is the radiation from a wireless device?
Wireless device radiation and health. The antennas contained in mobile phones, including smartphones, emit radiofrequency (RF) radiation ( non-ionizing "radio waves" such as microwaves ); the parts of the head or body nearest to the antenna can absorb this energy and convert it to heat. Since at least the 1990s, ...
What is the Commission's restriction on exposure to the whole body?
The Commission added a restriction on acceptable levels of exposure to the whole body, added a restriction on acceptable levels for brief exposures to small regions of the body, and reduced the maximum amount of exposure permitted over a small region of the body.
How far should antenna towers be from living place?
Experts consulted by France considered it was mandatory that the main antenna axis should not to be directly in front of a living place at a distance shorter than 100 metres.
What is the frequency of 5G?
Next generation 5G cellular networks, which began deploying in 2019, use higher frequencies in or near the millimetre wave band, 24 to 52 GHz. Millimetre waves are absorbed by atmospheric gases so 5G networks will use smaller cells than previous cellular networks, about the size of a city block.
How does a cell phone work?
A mobile phone connects to the telephone network by radio waves exchanged with a local antenna and automated transceiver called a cellular base station ( cell site or cell tower ). The service area served by each provider is divided into small geographical areas called cells, and all the phones in a cell communicate with that cell's antenna. Both the phone and the tower have radio transmitters which communicate with each other. Since in a cellular network the same radio channels are reused every few cells, cellular networks use low power transmitters to avoid radio waves from one cell spilling over and interfering with a nearby cell using the same frequencies.
What frequency range is EMF?
In response to public concern, the World Health Organization established the International EMF Project in 1996 to assess the scientific evidence of possible health effects of EMF in the frequency range from 0 to 300 GHz.
Overview
Hazards
Water and other homogeneous liquids can superheat when heated in a microwave oven in a container with a smooth surface. That is, the liquid reaches a temperature slightly above its normal boiling point without bubbles of vapour forming inside the liquid. The boiling process can start explosively when the liquid is disturbed, such as when the user takes hold of the container to remov…
History
The exploitation of high-frequency radio waves for heating substances was made possible by the development of vacuum tube radio transmitters around 1920. By 1930 the application of short waves to heat human tissue had developed into the medical therapy of diathermy. At the 1933 Chicago World's Fair, Westinghouse demonstrated the cooking of foods between two metal plates attached to a 1…
Principles
A microwave oven heats food by passing microwave radiation through it. Microwaves are a form of non-ionizing electromagnetic radiation with a frequency in the so-called microwave region (300 MHz to 300 GHz). Microwave ovens use frequencies in one of the ISM (industrial, scientific, medical) bands, which are otherwise used for communication amongst devices that do not need a licens…
Components
A microwave oven consists of:
• a high-voltage power source, commonly a simple transformer or an electronic power converter, which passes energy to the magnetron
• a high-voltage capacitor connected to the magnetron, transformer and via a diode to the chassis
Variants and accessories
A variant of the conventional microwave oven is the convection microwave oven. A convection microwave oven is a combination of a standard microwave oven and a convection oven. It allows food to be cooked quickly, yet come out browned or crisped, as from a convection oven. Convection microwave ovens are more expensive than conventional microwave ovens. Some convection microwave ovens—those with exposed heating elements—can produce smoke and b…
Heating characteristics
Microwave ovens produce heat directly within the food, but despite the common misconception that microwaved food cooks from the inside out, 2.45 GHz microwaves can only penetrate approximately 1 centimeter (0.39 in) into most foods. The inside portions of thicker foods are mainly heated by heat conducted from the outer 1 centimeter (0.39 in).
See also
• Countertop
• Electromagnetic reverberation chamber
• Induction cooker
• List of cooking appliances
• List of home appliances
How It All Started
- Officially, it is said that Percy Spenser (1894-1970), an American engineer who built magnetrons (vacuum time-of-flight tubes for generating electromagnetic waves) for radar systems at Raytheon, an armaments company and manufacturer of high-frequency technology, was the father of the microwave oven. He came up with the idea for a stove when he observed, rather by …
The Harmful Effects of Microwaves
- Fig. 2 Image source: From heb @Wikimedia Commons (mail) – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1860088 found at: https://de.wikipedia.org/wiki/Mikrowellenherd#/media/Datei:MW_on_fire.jpg We are now entering the area of the harmful effects of microwave ovens and the associated research and negative ef…
Leak Radiation and Electrosmog
- It is well known that microwave ovens are actually constantly emitting leakage radiation, and that we are therefore exposed to electrosmog. What is taken seriously or played down depends on the perspective, as we can read at the Federal Ministry for Radiation Protection (BfS). Quote:
Death from Microwave Leakage Radiation?
- An article by Benjamin Seiler and Siegfried Zwerenz in an older magazine editionfrom 1999 under the title “The great cell phone report / The Sword of Damocles over our heads” reports that microwave leakage radiation can even be fatal, which says:
David Versus Goliath
- Two researchers who publicly pointed out these negative effects and thus opposed a powerful industrial lobby were the agricultural engineer Dr. Hans Ulrich Hertl and Professor Bernand Blanc from the Swiss Federal Institute of Technology in Lausanne (Switzerland). Around 1989 they applied to the Swiss National Fund for funding of 150,000 francs, but this was rejected on the gr…
Old Research Not Recognized Today
- These old researches are now generally regarded as outdated or refuted and are accordingly disputed. Although the technology has basically not changed since it was invented and spread around the world. Conclusion: This leads to the conclusion that research and results on the harmful effects of microwaves have been around for a long time. At the same time, this scientifi…
Compact Assembly Oven as An Alternative
- Maintaining a comfortable and time-saving way of life and warming up food as quickly as possible would also be possible with a compact ready-made oven. It doesn’t cost much more and is available on the market as a multifunctional and energy-saving alternative without dangerous microwaves. Bon appetit after this mentally difficult food and hopefully also some thought-prov…
Waveguard – Certified Protection Products Against Electrosmog
- Take your EMF protection into your own hands. We develop exclusive products for you both for on the go and for at home or in the office. Our Qi technology is integrated in all Qi devices. Benefits of Qi technology: 1. modern technology such as Wifi, mobile network & Bluetooth can be used with ease 2. German technology & production 3. no electricity needed 4. easy use 5. free regeneratio…