All posts by Prachi Shah


Is There A Cell Phone Link To Cancer? A Definite Maybe

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Prachi Shah

In the 21st century, cell phones are considered a utility rather than a luxury. Sometimes one hears that waves emitted by these ubiquitous devices might promote tumor formation. That sounds frightening–let’s take a look at the evidence. 

Cell phones, like FM radio and microwave ovens, operate using electromagnetic (EM) waves. When the cell phone is held up to the body, the waves can be absorbed by the body in an amount known as the specific absorption rate (SAR). The SAR can vary dramatically by factors such as the phone model and the method/frequency/duration of use, meaning that each user may experience a different SAR based on their cell phone habits. Cell phones emit and receive RF waves, which are located in between FM radio waves and microwaves on the spectrum of EM wave frequency. 

The idea that absorbed radiation from a cell phone might be harmful came from research showing that ionizing radiation (such as the high-frequency waves released by an x-ray or CT scanner) could harm a human if they were exposed to it regularly over long periods of time. 

A number of studies on both humans and animals have not found a link between cell phone EM waves and cancer. RF waves are non-ionizing, meaning that they are not high-energy enough to directly damage the DNA within cells (unlike other known, dangerous types of waves known as ionizing radiation). In addition, cell phones emit this RF radiation in very small amounts such that the waves are not able to noticeably heat up the tissue that is in contact with the cell phone.

The idea that cell phones cause brain cancer can make us anxious and perhaps less able to function in the modern world. Given the potential for negative and frightening ideas to cause this type of harm, we feel they should not be promoted without solid experimental evidence. So far, all the studies performed have important limitations that prevent us from conclusively stating that cell phones do not have any harmful health effects. On the other hand, the scientific rationale for their safety is sound, there is no experimental evidence of potential harm, and the idea itself is harmful. So when it comes to cell phones and tumors, it’s probably best to think twice.

Medical Myths: Back to Backpacks

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After more than a year of almost entirely virtual school, most schools and universities are returning to in-person education this fall. This means that students will be spending more time walking to and from classes, studying on campus, and exploring the city, all while sporting any student’s quintessential accessory: the backpack.

While backpacks are practical and comfortable, the books, laptops, water, and other things inside can also be extremely heavy. For decades, concerns have been periodically raised regarding daily use of a heavy backpack. A heavy or awkward backpack might be uncomfortable, but the idea that it causes harm is likely an overstatement.  

There are also things you can do to improve comfort with a standard backpack. Backpacks with two, wide, cushioned straps allow weight to be distributed evenly, which may be more comfortable than a messenger bag or a backpack slung over one shoulder. A waist strap can also help distribute weight. Tighten all straps so the backpack hangs in the center of the back. 

In addition, packing one’s backpack with the heaviest items closest to the back and spreading items throughout all the pockets might also be more comfortable. Consider buying electronic copies of books or keeping duplicates of supplies at home so you don’t have to carry around as much weight. If you struggle to put on a backpack or lean forward while wearing one, you might want to try using a rolling bag.  

Backpacks are utilitarian, timeless parts of the student experience, and can and should be used in a way that makes you feel most comfortable and prepared for your day. While they may, at times, be uncomfortable, Think Twice thinks these references may overstate the potential for harm from backpacks. In our opinion, the imperatives (e.g. “should”) and statements that there is a “wrong” way to wear a backpack overstate what we see as options for getting around comfortably with school books. There is no evidence for harm associated with backpacks.

Toy Safety

Second-hand toys contain 'surprising' levels of toxic chemicals

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Prachi Shah

Believe it or not, summer is just around the corner. For many families, the end of the school year means that kids will be spending more time playing, often with toys made of various plastics. Plastics are safely used in countless household items, but recently, many people have begun to voice health concerns regarding their use. Let’s look at what the evidence says.  

One material that is a focus of concern is bisphenol A, commonly known as BPA. Concerns about BPA arose when a 1930’s researcher searching for an artificial estrogen found that BPA shared many of the properties of estrogen. In the late 1990’s, BPA was discovered to be leaching out of plastics when researchers in a lab at Stanford noticed cell cultures in plastic containers reacting as if they had been treated with estrogen. Some have suggested that BPA in low doses may be linked to a number of health effects, such as changes in thyroid function and fertility, birth defects, and others. However, the amount and quality of evidence supporting these theories is limited.   

Phthalates are another class of chemicals that have recently been considered. Since the 1920’s, phthalates have been added to plastics in order to increase flexibility, durability, and other desirable qualities. Some evidence suggests that these materials can come loose from the plastic that they were added to, leach into the surrounding area, and then be introduced into the body through diet. Other studies seem to show that high levels of phthalate exposure in utero could be associated with birth defects such as shorter gestation (pregnancy) period, motor deficits in females, disrupted male reproductive development, and other deficits. Regulatory agencies, such as the US Environmental Protection Agency (EPA) and the US Food and Drug Administration (FDA), now require warnings on products that contain phthalates. Furthermore, regulations and bans on the various uses of phthalates have been passed across North America and Europe.

Lastly, the summer season often comes with hours spent playing in the water, often with squeezable plastic toys such as a rubber duck (which may also be used in the bath). These toys, often stored in dark, damp areas such as a bathroom, are prime environments for the growth of microbes. This microbial growth can develop into what is known as a biofilm– an aggregation of microbes held together by a slimy, secreted matrix of polymers. When the child squeezes the toy to eject the water, the bacteria are expelled as well. Exposure to pathogens early in life can help strengthen a child’s immune system. However, pathogens (including some of those shown to grow in rubber duck biofilms) can potentially also infect children, especially through mucus membranes such as the eyes, ears, nose, or mouth. This infection can lead to diarrhea, meningitis, urinary tract infections, and other symptoms.  

These risks are small and are often mediated by other factors, meaning that overall, these toys should not be considered dangerous for use. For example, older toys tend to be higher risk for dangerous substances. In order to mitigate the risks of overexposure to these chemicals, some researchers have begun developing and advocating for a more clear labeling system and a standardization of materials used in children’s toys. In the meantime, however, cleaning toys regularly can be a great precaution to take.,infections%20%2C%20urinary%20tract%20infections%20etc.