We also spoke to experts and searched government reports to try to find any other high-quality evidence that may not have been published in an academic database. We included the National Toxicology Program’s animal studies, since they are considered some of the most important animal research that was funded by the government to help answer the question of whether cellphones cause cancer. We also included research on the fertility effects of cellphone radiation, since that was a concern many researchers in the field had.
But according to the FCC, comparing SAR values between phones can be misleading. The listed SAR value is based only on the phone operating at its highest power, not on what users would typically be exposed to with normal phone use. The actual SAR value during use varies based on a number of factors, so it’s possible that a phone with a lower listed SAR value might actually expose a person to more RF energy than one with a higher listed SAR value in some cases.

“If you're looking for ways to limit your exposure to the electromagnetic emissions from your cell phone, know that, according to the FTC, there is no scientific proof that so-called shields significantly reduced exposure from these electromagnetic emissions. In fact, products that block only the earpiece—or another small portion of the phone—are totally ineffective because the entire phone emits electromagnetic waves. What's more, these shields may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.”

The phone is placed in various positions on the head and body, including held to both ears, and all measurements are taken and reported to the FCC when the manufacturer is seeking approval. However, it should be noted that only the very highest SAR values for each type of radiation are included in final consideration for compliance with the FCC’s guidelines.
Wearable tech such as the Apple Watch might as well be called a wearable EMF device. These watches are even worse than mobile phones in that they remain in constant, direct contact with your skin. New York Times columnist Nick Bilton covered this issue in March 2015, noting that constant, low-level radiation from such devices can trigger the formation of cancerous tumors, blood abnormalities, and more.
Only 0.010 inch thick, PaperSHIELD is flexible and can be easily cut with a scissors and shaped by hand into simple or very complex shapes. High saturation and moderate permeability make this ideal for shielding weak magnets, or stronger magnets with many layers of shielding. This material is particularly suited for achieving precise levels of partial shielding as you can add exactly the right number of layers to achieve the desired result. White paper on one side can be imprinted (by you). Peel and stick adhesive on the other side permits easy and semi-permanent mounting almost anywhere. Magnets will stick to it nicely.
There’s a broad range of radiation types, and lots of harmless things emit radiation — like bananas, Brazil nuts, and granite countertops, according to Cincinnati Children’s Hospital. The type of radiation that comes out of our cellphones isn’t the same radiation that’s released by nuclear fallout or X-rays. Cellphone radiation, also known as radiofrequency radiation, is much weaker — so it can’t cause the same kind of cell damage that can lead to cancer.

These experimental findings raise new questions as to the potential for radiofrequency radiation to result in cellular changes and offer potential avenues for further laboratory studies. Cancers in the heart are extremely rare in humans, where the primary outcomes of potential concern with respect to radiofrequency radiation exposure from cell phones are tumors in the brain and central nervous system. Schwann cells of the heart in rodents are similar to the kind of cells in humans that give rise to acoustic neuromas (also known as vestibular schwannomas), which some studies have suggested are increased in people who reported the heaviest use of cell phones. The NTP has stated that they will continue to study this exposure in animal models to further advance our understanding of the biological underpinnings of the effects reported above.


"On the same [IARC] scale that said phone use was possibly carcinogenic, smoking is at the highest level. They are class 1 carcinogens; that's beyond doubt, they definitely do cause cancer ... There's an absolute difference between substances, where the evidence says that there is no doubt about the fact that they cause cancer, compared to mobile phones, where they say it is still possible because the data over ten years use still isn't in."

I have not gotten a cell phone, I was gifted a tablet, but it stays off most of the time, I use a desktop PC and my home phone is still landline but cordless. For me it’s been a bit of mixed bag in that I don’t want to rely so heavily on technology to do and remember things for me. When I hear about the new and latest tech that can now do X,Y, or Z for you, I think of the two little boys in the 80’s Cafe in BTTF.

“I think the overall evidence that wireless radiation might cause adverse health effects is now strong enough that it’s almost unjustifiable for government agencies and scientists not to be alerting the public to the potential hazards,” says David O. Carpenter, M.D., director of the Institute for Health and the Environment at the University at Albany in New York and one of the authors of the recent letter to the U.N. and WHO.
Another part of the INTERPHONE study compared more than 1,000 people with acoustic neuromas to more than 2,000 people without tumors, who served as matched controls. As with gliomas and meningiomas, there was no overall link between cell phone use and acoustic neuromas. There was again a suggestion of a possible increased risk in the 10% of people who used their cell phones the most, but this was hard to interpret because some people reported implausibly high cell phone use, as well as other issues.
Initially leaked in 2016, results from that $25-million study provided the most compelling evidence yet that RF energy may be linked to cancer in lab rodents. The strongest finding connected RF with heart schwannomas in male rats, but the researchers also reported elevated rates of lymphoma as well as cancers affecting the prostate, skin, lung, liver and brain in the exposed animals. Rates for those cancers increased as the doses got higher but the evidence linking them with cell phone radiation specifically was weak by comparison, and the researchers could not rule out that they might have increased for reasons other than RF exposure. Paradoxically, the radiation-treated animals also lived longer than the nonexposed controls. The study results were reviewed by a panel of outside experts during a three-day meeting that ended on March 28. They concluded there was "clear evidence" linking RF radiation with heart schwannomas and "some evidence" linking it to gliomas of the brain. It is now up to the NTP to either accept or reject the reviewer's conclusions. A final report is expected within several months.
In a February 2 statement, Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health, wrote that despite the NTP study’s results, the combined evidence on RF exposure and human cancer—which by now amounts to hundreds of studies—has “given us confidence that the current safety limits for cell phone radiation remain acceptable for protecting the public health.” Chonock says that for him, evidence from the Ramazzini study does not alter that conclusion. “We continue to agree with the FDA statement,” he says.
INTEGRITY: Many manufactures claim near 100% EMF protection, referring to the radiation blocking material, NOT the protection you receive on a call. If you covered your whole phone with EMF blocking material, then you'd have no signal. Our EMF blocking material is used on the front cover only, providing you real EMF protection with no sacrifice in reception.

This 2017 review, published in Neurological Sciences, looked at case-control studies on cellphone use, focusing on glioma, meningioma, and acoustic neuromas. This review was interesting because the researchers divided the studies by quality, and higher-quality studies — which tended to be funded by the government and not the cellphone industry — showed a trend toward an increased risk of brain tumors, while lower-quality studies did not. Overall, though, their meta-analysis found an increased risk of brain cancers (mostly gliomas) among people who were using cellphones for 10 or more years, and no increase in the risk of acoustic neuroma.
The main difference between our product and other radiation shields available on the internet is simple. OUR PRODUCT WORKS. We are the only cell phone radiation shield that provides full testing on our product by a leading SAR testing lab, IMST which tested the cell phones in the now famous ABC News 20/20 report, and publish these SAR Shield radiation tests on our website for everyone to scrutinize. In 2002 the US government tested various shields, and found that many did not work. The FTC then sued several makers of radiation blockers including, Wave Scrambler, Safety Cell and SafeTshield. This action was taken after Good Housekeeping Institute found that 5 shields did not reduce the radiation they claimed, these five shields were Wave Scrambler by Rhino International, Radiation Free Shield, Wave Shield by Interact Communications, Safe-T-Shield by SV1 Inc, and Safety Caps by Safety Cell. It is easy to say a product reduces radiation, but why don’t our “competitors” publish these results so we can actually see the claims they make are real?
Most cellphone shielding products are designed to reduce radiation to the user while still allowing the phone to function. This means that some radiation can still get to the phone… and some radiation can still get out of the phone! But sometimes you need to completely kill the signal. The RF Kill Box is a full-metal shielding jacket with very high shielding performance.
As a rule, modern medical equipment is well protected against exposure to radiowave radiation. Therefore, there is generally no need for concern regarding the effects of mobile phones on the normal function of the equipment. Nevertheless, the Ministry of Health recommends not to have a mobile phone in the immediate proximity (a distance of 30-50 cm from the portable medical equipment or from medical equipment implanted in the patient's body).

But scientists disagree on how real—or how serious—these risks really are, and studies have not established any definitive links between health problems and radiofrequency (RF) energy, the type of radiation emitted by cell phones. “This document is intended to provide guidance for people who want to reduce their own and their families’ exposure to RF energy from cell phones,” the guidelines state, “despite this uncertainty.”
Prime free trial and invitee customers: We will automatically apply an Amazon.com Gift Card to your Gift Card Balance in the amount equal to the Prime exclusive discount after you become a paid Prime member. If you cancel your paid Prime membership or return the qualifying smartphone within the first 3 months of your paid Prime membership, we may void your Gift Card or charge you in the amount of the Gift Card. Terms and Conditions apply.
Though some findings were reassuring, others do raise concerns. Specifically, three of the studies—one from Sweden, another from France, and a third that combined data from 13 countries—suggest a connection between heavy cell-phone use and gliomas, tumors that are usually cancerous and often deadly. One of those studies also hinted at a link between cell phones and acoustic neuromas (noncancerous tumors), and two studies hinted at meningiomas, a relatively common but usually not deadly brain tumor.
As our video points out: Measurements will vary with signal strength and other factors and that includes ambient energy. I talk about ambient energy in a lot of my videos-it's the energy that's in whatever environment I happen to be measuring in that's coming from a source of wireless energy that isn't the subject of what I'm measuring.  My home is not a lab of course, but fortunately it's always measured very low for RF radiation. 
The BlocSock is a small, 3”x5½”, lightweight case that's only designed for cell phones, not tablets or laptops. One side is a normal fabric to ensure reception. The other side has a rectangular, metallic mesh to shield RF radiation. It's recommended that you keep the side with the shielding material between the phone and your body. When making or receiving calls, keep the shielding between your head and the phone. It can also be moved into a smaller “kangaroo style” pouch during calls. It's effective, and tests show that it reduces RF exposure 96%. For more information, check out the SAR research test or watch this video.
Protect your brain from RF (radio-frequency) pollution with this handsome baseball style hat. Specially designed to shield the head from frequencies from below AM through microwave, including cellular phone frequencies. Lined with sophisticated Staticot fabric woven from ployester/cotton with an ultrathin stainless steel fibers excellent radiation protection. This gives this unique fabric a truly comfortable, natural feel and the durability and washability of cotton, but with exceptional reflective characteristics.
The next day, telecommunications stocks took a big hit on Wall Street and the media had a field day. The industry trade association at the time, the Telecommunications Industry Association (TIA), went into crisis mode, claiming thousands of studies proved cell phones were safe and what Reynard and his attorney said was bunk. TIA reassured the public that the government had approved cell phones, so that meant they were safe. The media demanded to see the studies, but, says Dr. Carlo, “The industry had lied. The only studies in existence then were on microwave ovens. At that time, 15 million people were using cell phones, a product that had never been tested for safety.”

That’s because cell phones emit electromagnetic fields (EMFs) or electromagnetic radiation, which has the potential to damage the cells in the body. In fact, the International Agency for Research on Cancer classifies EMFs from cell phones as possible carcinogens. EMFs can interfere with the body’s natural electrical system and disrupt sleep, immune system function, hormone production, and the healing process. Kevin Byrne, president of EMF Solutions, also points out the simultaneous increase in conditions such as chronic pain, depression, anxiety, chronic fatigue syndrome, and Alzheimer’s disease and the significant rise in EMF exposure.
Finally, Brawley reminded me that cellphones kill humans in another way that we’re already certain about: because of inattention through distracted driving. In the US alone, there were 3,157 fatal crashes in 2016 that involved distracted driving, 14 percent of which included cellphone use, according to the latest data from the National Highway Traffic Safety Administration. That’s not the focus of this piece, but perhaps state and federal regulators could follow places like Washington state, California, New York, and Nevada and heavily crack down on distracted driving with bans or stricter laws.
Laptop computers are best placed on a table at as much of an arm’s length away as possible to minimize radioactive contact. If you must use your laptop on your lap, you can purchase a laptop cooling pad which will add a bit of extra space between the device and your body. Even better are laptop cases specifically designed to shield against radiation.
The FCC provides information about the specific absorption rate (SAR) of cell phones produced and marketed within the last 1 to 2 years. The SAR corresponds with the relative amount of radiofrequency radiation absorbed by the head of a cell phone user (47). Consumers can access this information using the phone’s FCC ID number, which is usually located on the case of the phone, and the FCC’s ID search form.
I also searched around to see if cell phone radiation was anything to worry about anyway. I turned up enough information from a lot of different credible sources to convince me it was worth protecting against the possible damaging effects of this radiation. IF there is no real health impact, then having a protective device would be overkill, but I figured better overkill than discover in time people started developing problems as a result of heavy cell phone use.
The dangers of driving and texting are old news; if someone were to be harmed by their cellphone’s radiation, though, that would make headlines because novelty grabs people’s attention. In psychological experiments where people have to choose images, they gravitate towards ones they haven’t seen before — a phenomenon known as the novelty bonus. So if I wanted to grab a reader’s attention, I’d bet on a hypothetical headline that said “For the first time, cellphone radiation causes brain cancer in humans” over “Another person has died today from driving and texting.”

Since 2001, the FCC has allowed manufacturers to test phones at a distance of up to one inch from the body to account for the use of a holster. In a 2012 report, however, the Government Accountability Office, the Congressional watchdog agency, noted that many cell phone owners actually keep and use their phones right next to the body, so these outdated testing policies could result in radiofrequency (RF) radiation exposure greater than the FCC’s legal limit (GAO 2012). The GAO report concluded:
Overall, the reviews of case-control studies seem to suggest there is perhaps no risk of cancer with cellphone use — unless you look at some subgroups (like people in blinded studies or people with long-term exposures). But these reviews are based on case-control studies — which are like the National Enquirer of the science world: cheap and often misleading.
Epidemiology studies investigating cell phone use patterns with human cancer risk have produced inconsistent results. Some studies enrolled people who already had tumors with suspected links to RF radiation, such as gliomas, acoustic neuromas and salivary gland tumors. Researchers compared the self-reported cell phone use habits of the cancer patients with those of other people who did not have the same diseases. Other studies enrolled people while they were still healthy, and then followed them over time to see if new cancer diagnoses tracked with how they used cell phones. All the epidemiology studies, however, have troubling limitations, including that enrolled subjects often do not report their cell phone use habits accurately on questionnaires.
However, there have been some studies that have shown that rats can develop a specific type of brain tumor, called a schwannoma, if they're subjected to prolonged radiofrequency radiation. These studies examined thousands of rats and mice, and exposed them to a variety of radiations — everything from "near-field" (which is what you get holding a phone to your ear) to "far-field" (which is what you get walking through everyone's Wi-Fi signals at Starbucks).
But there’s a huge public health crisis looming from one particular threat: EMR from cellular phones—both the radiation from the handsets and from the tower-based antennas carrying the signals—which studies have linked to development of brain tumors, genetic damage, and other exposure-related conditions.1-9 Yet the government and a well-funded cell phone industry media machine continue to mislead the unwary public about the dangers of a product used by billions of people. Most recently, a Danish epidemiological study announced to great fanfare the inaccurate conclusion that cell phone use is completely safe.10
The Specific Absorption Rate that the FCC, with input from many other government institutions, decided on, is defined using an average of a 30-minute phone call with the cell phone held directly to the ear. Since modern cell phones are used in all sorts of manners, ie speakerphone, scrolling through social media, browsing the web, etc, a base had to be set.

Well, Loyd really does seems like a guy with great intentions! However, he has put too much faith in Pong’s SAR testing, and SAR guidelines in general — to the point he no-longer believes his own eye’s when nothing is observed on his trusty RF meter.   Which proves (Using an RF Meter) there is absolutely no real reduction in actual radiation coming from the front of the phone when a pong cell phone case is used.
Safe Cell Technology is created out of unique material that is permanently encoded with specific signals or frequencies designed to interact with and change the quality of the electromagnetic field (EMF) emitting from cell phones. It converts the electromagnetic energy into low level infrared energy acting as a cell phone radiation protection shield drastically reducing the harmful effects of cell phone radiation.
Cell phone radiation refers to radiation in the form of electromagnetic waves that is emitted from mobile phones. This type of radiation takes the form of radio waves that are near the microwave range. The amount of radiation that a given cell phone will emit depends on the exact frequency of the radiation, as well as whether the device is using an analog signal or a digital one. There has been speculation that large amounts of cell phone radiation could be hazardous to the user's health, but there are no conclusive scientific findings on the subject.
If you're looking for ways to limit your exposure to the electromagnetic emissions from your cell phone, know that, according to the FTC, there is no scientific proof that so-called shields significantly reduce exposure from these electromagnetic emissions. In fact, products that block only the earpiece – or another small portion of the phone – are totally ineffective because the entire phone emits electromagnetic waves. What's more, these shields may interfere with the phone's signal, cause it to draw even more power to communicate with the base station, and possibly emit more radiation.

SAR LEVELS ARE very deceptive when it comes to health hazards!  The Pong case is taking advantage of the fact that current safety regulatory guidelines provide no non-thermal assurances of safety what so ever! Other-words Pong is using inadequate safety standards to prove the legitimacy of the Pong cell phone case – Citing official documents being reviewed by the FCC’s “Reassessment of Federal Communications Commission Radio-frequency Exposure Limits and Policies” (Proceeding Number 13-84), as it turns out, the level SAR rating of your phone is almost irrelevant, as it doesn’t consider health effects from non-thermal levels of radiation exposure at all.
What effects does it have on people wearing hearing aids? Streamer (like a remote, rope worn around the neck and streamer placed against the chest) connects your hearing instrument wirelessly to different audio sources and makes your hearing instrument work like wireless headphones Streamer transmits the sound directly into both hearing instruments and thereby improves the audio experience.

While an increased risk of brain tumours from the use of mobile phones is not established, the increasing use of mobile phones and the lack of data for mobile phone use over time periods longer than 15 years warrant further research of mobile phone use and brain cancer risk. In particular, with the recent popularity of mobile phone use among younger people, potentially longer lifetime of exposure, WHO has promoted further research on this group and is currently assessing the health impact of RF fields on all studied endpoints. A cohort study in Denmark linked billing information from more than 358,000 cell phone subscribers with brain tumour incidence data from the Danish Cancer Registry. The analyses found no association between cell phone use and the incidence of glioma, meningioma, or acoustic neuroma, even among people who had been cell phone subscribers for 13 or more years. (4)
Then there is non-ionizing radiation, which encompasses the vast majority of light we are exposed to: visible light from lightbulbs, infrared light from an oven and from people, gigahertz light from our wifi, megahertz light to/from our cell phones, and radio waves hitting our car radio. They are not harmful in small doses because one photon does not have enough energy to ionize atoms and/or break apart molecules. In very large doses, non-ionizing radiation can be harmful. For example, a visible light laser with sufficient power (at least several hundred times more than a legal laser pointer) which is concentrated in a small enough spot will burn your skin and do worse things to your eye if it gets in there. And those of us who are old enough, remember the gerbil-in-a-microwave flash animations which went viral 17 years ago [1] as a humorous (but not exactly factual) representation of what would happen if you microwaved a live rodent.
A study by the Corporate EME Research Laboratory and Motorola Florida Research Laboratories tested 9 different cell phone radiation shields, 5 of which claimed to block 99% of cell phone radiation. The other 4 shields tested claimed to emit a reverse radiation that would cancel out the harmful radiation from cell phones. The study found that all of the radiation shields had no effect on the amount of radiofrequency radiation a cell phone user is exposed to from their phone.[2]
The World Health Organization (WHO) says the intensity of radio frequency (RF) radiation from cell phones decreases exponentially the further the device is held away from the body. Therefore your safest bet it keep your cell phone as far away from your ear and body as possible at all times. Don’t carry it in your pocket, tucked into a bra strap, and definitely don’t sleep with it next to your head.
At high power levels, RF waves can heat up water molecules (which is how microwave ovens work). Scientists used to focus their concerns on the possibility that such heating of human tissue, which is mostly water, might damage cells. In fact, the FCC’s test of cell-phone emissions—which was set in 1996 and which all phones must pass before being allowed on the market—is based on that effect.
The government, however, does not require phone manufacturers to consider the effect of cases when they conduct compliance tests to meet the FCC’s allowable radiation exposure limits. The significance of this omission was underscored by tests commissioned by case-maker Pong Research and submitted to the FCC in May 2012. Those tests showed that three models of cases made by competing companies and used with an iPhone4 increased the phones’ Specific Absorption Rate, or SAR – the amount of radiation absorbed by the user’s body – by 20-to-70 percent (Table 1).
A large, long-term study has been comparing all of the people in Denmark who had a cell phone subscription between 1982 and 1995 (about 400,000 people) to those without a subscription to look for a possible increase in brain tumors. The most recent update of the study followed people through 2007. Cell phone use, even for more than 13 years, was not linked with an increased risk of brain tumors, salivary gland tumors, or cancer overall, nor was there a link with any brain tumor subtypes or with tumors in any location within the brain.

I have not gotten a cell phone, I was gifted a tablet, but it stays off most of the time, I use a desktop PC and my home phone is still landline but cordless. For me it’s been a bit of mixed bag in that I don’t want to rely so heavily on technology to do and remember things for me. When I hear about the new and latest tech that can now do X,Y, or Z for you, I think of the two little boys in the 80’s Cafe in BTTF.
As a good thing to keep in mind, there are hundreds of thousands of people suffering from EHS in the world. Some of them live in forests, tents, and anywhere they can get away from society and EMFs because their symptoms are so bad when exposed. I have not heard one single EHS person claim that any of these types of devices work. They sure don’t for me. Most EHS sufferers are so desperate that they have researched and tried just about everything. Getting away from EMFs, or blocking them with material that does actually block them, like as a Faraday cage, is what works. And this is clearly what the scientific evidence shows. If these devices worked, that would be fabulous. One could spend $100 and be well, instead of having their life turned upside down, and in the worst cases as with some, committing suicide due to complete hopelessness and helplessness.. However, that is not the case. To further prove whether they work or not, one could wear one, and measure with a meter designed to measure EMF absorption in the body (they exist now). Has the manufacturer had this done, and is their evidence of it? An EHS person can tell without a meter anyway, but to prove to others, this might be a good idea.
This site is for informational purposes only and is not intended as a substitute for advice from your physician. Foods and supplements discussed on this site are not intended to diagnose, treat, cure, or prevent any disease. You should consult with a physician before starting any diet, exercise or supplementation program, or if you have or suspect you might have a disease.
These stick on “blockers” don’t work. I am EHS and can tell you with certainty (because I feel the fields) that they are not blocking anything. You must use substantial materials like those used in faraday cages (silver and copper), which are now manufactured in materials and fabrics, or avoid EMF use period. Just look at military use for example. They are not using stick on blockers. Follow Ty’s advice for minimizing and avoiding EMF, and look up EMF blocking fabrics, building materials, etc… for the real blockers.
Bonus application! In addition to shielding magnetic fields, PaperSHIELD is also quite good at shielding radiowaves (cellphone, wifi, etc). And because of the adhesive backing, it can be adhered to almost any surface you need such as the inside or back of your cellphone case. (Use a near field meter to test RF shielding performance.) Note that it is not transparent, so it can't be used on the touch screen side. Cover the cut edges with sturdy tape as they can be sharp. 36 inches wide. Made in USA.
Universal Cell Phone EMF Radiation Shield – Wallet Case (Small: 3.3"x5.6" Cell Phones, Universal Cell Phone EMF Radiation Shield – Wallet Case (Large: Up to 3.2"x6.2" Cell Phones, iPhone X EMF Radiation Shield & RFID Blocker- Wallet Case, iPhone 8 / 7 EMF Radiation Shield – Wallet Case, iPhone 8 / 7+ (Plus) EMF Radiation Shield – Wallet Case, iPhone 8 / 7 EMF Radiation Shield – SlimFlip Case, iPhone 8 / 7+ (Plus) EMF Radiation Shield – SlimFlip Case, iPhone 6/6S EMF Radiation Shield – Wallet Case, iPhone 6 / 6S+ (Plus) EMF Radiation Shield – Wallet Case, iPhone 6/6S EMF Radiation Shield – SlimFlip Case, iPhone 6 / 6S+ (Plus) EMF Radiation Shield – SlimFlip Case, iPhone 5/5s/SE EMF Radiation Shield – SlimFlip Case, Galaxy S7 EMF Radiation Shield – Wallet Case, Galaxy S7 EMF Radiation Shield – SlimFlip Case, Galaxy S6/S6 Edge EMF Radiation Shield – SlimFlip Case, iPhone 5/5S/SE Case -Wallet
Lab studies: Lab studies usually expose animals to something like RF energy to see if it causes tumors or other health problems. Researchers might also expose normal cells in a lab dish to RF energy to see if it causes the types of changes that are seen in cancer cells. It’s not always clear if the results from these types of studies will apply to humans, but lab studies allow researchers to carefully control for other factors that might affect the results and to answer some basic science questions.
×