All posts by Alejandro Perez

When does the brain stop developing?

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As early as 5 years of age, our brains have reached 90% of their potential volume. However, we all know that our brains continue to develop for many years; in fact, our brains continue evolving until death. So why then, do many people worry about cognitive decline with aging, and are their fears misplaced?

While it is evident and typical that specific cognitive functions decline with age, this is not necessarily associated with a cease in brain growth or weakened memory formation. General intelligence is complicated. It can be subdivided into two categories: crystallized and fluid intelligence.

Fluid intelligence allows you to solve problems without experience or knowledge—this type of intelligence peaks early in adulthood and declines later in life. Crystalized intelligence uses experience and prior knowledge to assess future relationships. This type of intelligence increases until approximately 60 years of age and then declines slightly. Therefore, skills like vocabulary, comprehension of new information, and arithmetic improve long after the brain ceases to grow in size and remain relatively stable throughout life. Other crystalized skills, such as conflict resolution and emotional regulation can continue to improve beyond 60 years of age.

The brain is an evolving organ as our lives go on. There might not be a moment in which our brains operate at maximum cognitive function in every specific area. So, next time you lose your keys, remember that just because your brain has stopped growing does not mean that your cognitive function is declining.

Do microwaves cause cancer?

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Microwave ovens are appliances that dominate almost every kitchen in the United States. Since their increasing household use in the 1980s there were rumors of risk from microwaves. The Think Twice Blog exists because the momentum of such “myths” can carry them for decades after they are proved false. To this day, as we reheat our leftovers in a microwave, we may stop to think twice about whether the convenience of a quickly heated meal is worth the potential risk of exposure to microwave radiation. Afterall, the sun can cause cancer due to ultraviolet (UV) radiation, and we have probably all heard not to stand too close to microwaves at some point in our lives. But do you actually have to worry about developing cancer from microwave radiation? 

Radiation is used to heat up our food. However, the radiation emitted by microwaves is low-energy. On the other hand, UV radiation is high-energy and can damage DNA in our cells. DNA damage can lead to cancer, which is why we protect ourselves using protective sunscreen. In contrast, microwave ovens only have enough energy to vibrate the water molecules in our food. This movement of water molecules creates the water vapor that heats and cooks our food, similar to how we generate heat when our hands rub together. The Minnesota Department of Health states irradiated energy passes through the food like”light through a window” which is also why food heated in a microwave is not radioactive after it is heated.

The potential harms of microwave radiation are minimal. Microwaves are very closely regulated to prevent high levels of radiation leakage through provisions such as safety locks to prevent the oven from operating when the door is open. The FDA allows 5 milliwatts per square centimeter of microwave radiation leakage two inches away from the microwave or farther, which is far below the level known to be harmful to humans. While we can decrease our exposure to microwaves by standing further from the device while it’s on, the waves emitted from this device are not dangerous to humans at any distance. 

Keep in mind that if your microwave is damaged in any way, it is best to not use it. However, in most cases, we can enjoy the convenience of microwaves without fear. No, the convenience of microwaves is not too good to be true. Enjoy those wonderful reheated seconds!

Do face masks cause harmful levels of carbon dioxide in the air we breathe?

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Alejandro Perez

Since the start of the pandemic, face masks have become a part of our everyday life. Even with masks mandates loosening up, the CDC recommends using a face mask while indoors regardless of vaccination status. On occasion, you might hear someone voice a concern about potential detrimental effects of wearing a mask. At one point there was a discussion about levels of carbon dioxide inhalation with masks.  

Carbon dioxide is toxic at levels of 10 percent in the breathed air. Carbon dioxide, oxygen, and other gases easily pass through masks. The molecules are so small only a solid barrier would prevent their passage. 

Respiratory droplets that carry the COVID-19 virus are much larger than carbon dioxide molecules and cannot pass through the masks. Even while undergoing intensive exercise, face masks have been found to be completely safe with only a slight reduction in physical performance due to slight restriction of airflow. 

Doctors, nurses, and surgical technicians have long worn masks for extended periods of time during surgery, up to 18 hours without impairment and with no increase of carbon dioxide levels in their blood. 

Low levels of carbon dioxide are not always harmful. For example, carbonated drinks, which are fizzy due to carbon dioxide being released from the liquid, are completely safe to consume. The carbon dioxide levels in carbonated beverages are way too low to have an effect on our bodies, and the same can be said about face masks and the normal carbon dioxide concentration in our environment of 0.04 percent that we inhale and exhale.

The concept of face masks causing harmful inhalation of carbon dioxide runs counter to knowledge, experience, and common sense. The idea is harmful and stressful at a time when we do not need any additional stressors and we need to take action to limit the pandemic.  Wearing a face mask is safe and allows us to control the spread of the COVID-19 virus. For more information about the COVID-19 virus, visit the CDC website. Stay safe!