Wearing a mask for a long time can cause lung nodules to grow larger? Don't believe these rumors

The weather will become colder when the Earth reaches its aphelion, and wearing a mask for a long time can cause lung nodules to grow...

In the hot summer, don't let these rumors get hotter

【Rumors Refuted】

After the summer solstice, many parts of the country entered a high temperature mode, with the temperature in some areas even reaching 40 degrees Celsius. Along with the rolling heat wave, there are also rumors, including "the bigger the mosquito bite, the more toxic the mosquito", "food cooked in an air fryer is carcinogenic", "wearing a mask for a long time can cause lung nodules to grow", "the weather will become colder when the earth reaches the aphelion"...

Today, Science and Technology Daily reporters will review the new rumors that have emerged this month one by one to help you clear the fog and find the truth.

The bigger the mosquito blister, the more poisonous the mosquito?

The truth: It mainly depends on the mosquito species and personal sensitivity

In addition to the high temperature in summer, mosquitoes are also annoying. Some people may get a small red spot after being bitten by mosquitoes, while others will become horrible after being bitten - news reports of people becoming "protruding ears", "sausage mouth" and "pig trotter hands" due to mosquito bites have been seen frequently.

Why are the sizes of mosquito bites so different? It is said on the Internet that "the bigger the mosquito bite, the more toxic the mosquito is", and many people believe this statement. So what is the truth?

"After being bitten by a mosquito, symptoms such as wheals, papules, and itching will appear on the skin. What we often call mosquito bites are local allergic reactions of the skin." Liu Ruiling, deputy chief physician of the Department of Allergy at Tianjin Medical University General Hospital, said in an interview with Science and Technology Daily.

When mosquitoes bite people, they will pierce the human skin with their piercing-sucking mouthparts, causing damage. They will "poison" the human body while sucking blood, that is, they will secrete saliva to prevent blood from clotting and blocking their mouthparts. At the same time, these saliva can also play a paralyzing role, making it difficult for people to detect. After sensing the invasion of mosquito "saliva", the human immune system will be activated, and the secreted histamine and cytokines will cause blood vessels to dilate, increase vascular permeability, and cause local tissue edema, which will cause skin itching and local inflammatory reactions.

"The degree of inflammation after a person is bitten by a mosquito is mainly related to the type of mosquito and personal sensitivity." Liu Ruiling explained that when a person with an allergic constitution is bitten by a mosquito, a large amount of histamine and cytokines will be secreted in the body, which will trigger an allergic reaction. In mild cases, wheals, papules, and angioedema will occur, and in severe cases, systemic reactions will occur.

In addition, the size of the mosquito bite is also related to the part of the body that is bitten. Eyelids, lips, back of hands, children's foreskin and other loose connective tissue parts are prone to edema after being bitten, and the mosquito bite will also appear larger.

After being bitten by a mosquito, do not scratch it hard. Scratching will exert mechanical pressure on the local skin and also accelerate blood flow, which will aggravate the inflammatory response and cause the mosquito bite to become larger.

Do dishes cooked in air fryers cause cancer?

The truth: There is no clear experimental evidence of carcinogenicity

Some time ago, many people were brainwashed by a popular phrase "If I had an air fryer" on a short video platform. Many dishes cooked with air fryers appeared in the short video, which are not only easy to make but also use less oil. Some people therefore "planted grass" for air fryers and regarded them as a "magic tool" for fat-reducing cooking.

However, there have been recent reports online that food cooked in an air fryer can cause cancer because it produces acrylamide, which is a carcinogen.

"Whether carcinogens will be produced during the cooking process mainly depends on the ingredients, cooking temperature and cooking time." Wang Hao, a professor at the School of Food Science and Engineering of Tianjin University of Science and Technology, said in an interview with Science and Technology Daily that no matter what pot is used to cook, as long as the food is overheated, carcinogens may be produced.

"The air fryer is like a simple oven with a fan." Wang Hao introduced that it generates hot air through a built-in heat pipe, and then uses a fan to blow the high-temperature air to the surroundings, so that the hot air circulates in a closed space, thereby heating and dehydrating the food.

Acrylamide is produced by starch under high temperature and low water content conditions. Generally speaking, a small amount of acrylamide is produced when the temperature exceeds 120 degrees Celsius, and its output reaches a peak when the temperature is between 160 and 180 degrees Celsius. This temperature is exactly the right temperature for baking and frying foods. In addition, the more starch a food contains, the more acrylamide it produces at high temperatures.

"However, there is no need to worry too much." Wang Hao said that first of all, acrylamide is a Class 2A carcinogen. There is sufficient evidence that it is carcinogenic to animals, but there is still a lack of sufficient experimental evidence to prove whether it can cause cancer in humans. Secondly, when cooking carbohydrate-rich ingredients by frying or grilling, if the temperature exceeds 120 degrees Celsius, acrylamide may be produced, and the longer the cooking time and the less water content of the ingredients, the more acrylamide will be produced. Moreover, in terms of quantity, the air fryer has a higher heating efficiency, and the food is kept at high temperature for a shorter time, and it may even produce less acrylamide than other high-temperature cooking methods.

"We can't talk about toxicity without considering the dosage." Wang Hao said that for ordinary people, acrylamide will not be ingested in large quantities in a short period of time in their daily diet. As long as it is consumed normally, it will not reach a dangerous intake level. However, he suggested that when using an air fryer to cook starchy ingredients, it is best to do some pretreatment in advance, such as washing the starch on the surface of potatoes with clean water before frying French fries. At the same time, control the cooking time reasonably and don't cook at high temperatures for too long.

Can wearing a mask for a long time cause lung nodules to grow larger?

The truth: Normal use will not cause damage to the lungs

At present, as the COVID-19 epidemic has become normalized, masks are still a "must-wear item" for everyone every day. Not long ago, there was a rumor online that "wearing a mask for a long time can cause the lung nodules to grow larger", saying that the meltblown cloth in the middle layer of the mask is a petroleum product, and the fine particles in it can enter the human lungs through the respiratory tract, and long-term wearing can cause the lung nodules to grow larger.

In this regard, Qian Xiaoming, a professor at the School of Textile Science and Engineering of Tianjin Polytechnic University, said in an interview with Science and Technology Daily that wearing a mask within the normal use range will not produce tiny particles, let alone enter the lungs.

"In addition to textile materials such as cotton, wool, linen, silk, and regenerated cellulose fibers, many synthetic fibers, including meltblown fabrics, are made from petroleum-based materials." Qian Xiaoming introduced that polypropylene, as the main petroleum-based material, has a very wide range of applications. The meltblown fabric used to make masks is an ultra-fine fiber non-woven material made from polypropylene polymer materials.

"After being processed into meltblown cloth, this polymer material has a certain strength and very good filtering performance. It is impossible to produce small molecular substances within the normal use period." Qian Xiaoming said, however, polypropylene material is not resistant to ultraviolet rays. After long-term sunlight exposure, it will become brittle and weakened. Under the action of external forces, such as twisting or rubbing with hands, it may also turn into powder particles.

However, Qian Xiaoming emphasized that these powder particles exist in the form of large particles and are difficult to be inhaled into the lungs.

"As long as the meltblown cloth mask is not exposed to the sun and does not exceed the expiration date, it will not produce microscopic particles. Generally, there will be no problem if it is stored in a light-proof place for two years," Qian Xiaoming added.

Will the weather get colder when the Earth reaches aphelion?

The truth: The temperature of the weather is related to the angle of the sun

Recently, such a piece of news has been circulated on the Internet: Starting from May 22 this year, the sun will move away from the earth and gradually reach the aphelion. At this time, the weather will become colder, and this phenomenon will continue until August this year.

At present, the high temperatures in many parts of the country have dispelled the rumors, but some people are still worried that the current high temperatures are just a "flash in the pan" this summer and that the temperature will continue to drop in the future. Is this really the case?

"The orbit of the Earth around the sun is roughly elliptical, but its major and minor axes are not much different, so it can basically be seen as a circle." Yan Weiguo, executive vice president of the Tianjin Astronomical Society, said in an interview with Science and Technology Daily that when the Earth moves in its orbit, its distance from the sun is sometimes close and sometimes far. Its closest position to the sun is the perihelion, and its farthest position from the sun is the aphelion.

"Whether at perihelion or aphelion, the distance between the Earth and the Sun is almost the same." Yan Weiguo said that when the Earth is at perihelion, it is 147.1 million kilometers away from the Sun; when the Earth is at aphelion, it is about 152.1 million kilometers away from the Sun. The difference between the two is 50 million kilometers, accounting for only 3.3% of the average distance between the Earth and the Sun, which is almost negligible. Therefore, the difference in the amount of heat received by the Earth at perihelion and aphelion is very small.

The temperature changes people feel on Earth are mainly related to the angle of the sun. "There is an angle between the Earth's orbital plane and the equatorial plane. Around June 22 every year, the summer solstice in the northern hemisphere, the sun shines directly on the Tropic of Cancer. At this time, the northern hemisphere (most areas) are closest to the direct point and receive more heat, so the weather is hotter. On the contrary, around December 22, the winter solstice in the northern hemisphere, the sun shines directly on the Tropic of Capricorn, and the northern hemisphere receives less heat, so the weather is colder," Yan Weiguo explained.

"In fact, in early January every year, the earth is at its perihelion, which is winter in the northern hemisphere and the weather is relatively cold. But in early July, when the earth reaches its aphelion, it is summer in the northern hemisphere and the weather is relatively hot." Yan Weiguo said that it can be said that the coldness or heat of the weather has little to do with the perihelion and aphelion.

Reporter Chen Xi

Source: Science and Technology Daily