Lightning can produce from 2 – 16% of the amount of hydroxyl. The hydroxyl radical is important in the atmosphere because it triggers chemical reactions and breaks down air pollutant molecules like methane. Decomposition of atmospheric pollutants Lightning may play a bigger role than we thought in a fundamental process that helps clean our air of pollutants, according to the results of a new study. Lightning strikes during storms produce large amounts of molecules called oxidizing radicals, which can break down gases such as carbon monoxide and methane in the atmosphere. These are atmospheric pollutants that can contribute to global warming and damage to the ozone layer. Carbon monoxide and methane enter the atmosphere from both natural and industrial sources. Methane is produced by the decomposition of plants, but is also released by oil and gas development and agriculture. Carbon monoxide and other polluting hydrocarbons can be generated by industries and wildfires. However, natural processes in the atmosphere, driven mainly by sunlight, have produced molecules called radicals, the most important of which are hydroxyls. These molecules are very chemically active (meaning that they are more likely to react with other molecules) and can react with pollutants to form new compounds that are harmless or potentially harmful. can be easily attached to water and released into the air. New research led by Pennsylvania State University meteorology professor William Brune has found that lightning produces far more hydroxyl molecules than previously known. His work shows that more than 10% of the supply of these scavenging radicals in the atmosphere can be generated by lightning storms. Use an airplane to fly through the storm Lightning’s ability to clean the atmosphere. The work involved flying NASA’s DC-8 research plane through deep convection thunderstorms to collect data. According to Professor Brune, this is not as dangerous as one might think. “Very interesting indeed. The pilots are phenomenal. They know what they’re doing. They know how to keep planes safe. But it’s really interesting because you can see deep convection and this is very close and personal,” said Prof. Brune. “We did this study in 2012, flying over central China. America and try to see what’s going into the storm chemically, what’s going to come up above. And to our surprise, we saw a very large amount of OHs (hydroxyl molecules). At first, we did not believe the signals received. They are huge, a thousand times larger than the largest mass we have ever seen.” The data collected from the aircraft was compared with data collected from radio receivers on the ground that track lightning flashes in the clouds. Both data sets confirmed the production of high amounts of hydroxyl radicals due to lightning strikes. Hydroxyl radicals are produced when the energy of lightning strikes breaks down water vapor in the atmosphere. “You can think of it like water that has removed the hydrogen atom and then wants to get that hydrogen back. So it becomes very active as it goes and tries to get the hydrogen back,” he said. That means the hydroxyl radical is very reactive with methane or carbon monoxide molecules. Climate change models need to be updated According to the scientists, about 1,800 lightning storms circulate around the planet, which leads the researchers to estimate that this phenomenon produces between 2% and 16% of the amount of hydroxyl present in the atmosphere.

A single lightning bolt can release up to a billion volts, tens of thousands of amps, travel at more than 434,000 km/h and in just a few millionths of a second reach 30,000 degrees Celsius – hotter than the surface of the Sun. Professor Brune admits that it is difficult to gauge the effectiveness of this process on a global scale. The results of this study were based on a limited number of flights over a small portion of the United States. There is still a lot of information that needs to be gathered to create a global picture. However, Professor Brune believes that the hydroxyl generated by lightning has a significant worldwide impact. Previous models suggested that lightning was not a significant contributor to the clean-up of the atmosphere. “Our best estimate right now is from 2%, which is quite important, to more than 10%, which is very important, for the total cleanup of the atmosphere. These estimates may change as our planet warms. Some climate change models show an increase in thunderstorm activity, which means more hydroxyl production and more cleaning of the atmosphere in the future. Other climate models suggest that there may not be much lightning, but lightning strikes will be more intense and may also alter the numbers. In any case, future models of climate change and global pollution will have to take into account this new information about the cleaning of the atmosphere, according to Professor Brune. Existing models may need updating.

On the market today, there are many sunscreen products, from domestic to foreign: Japan, Korea, China … with different indicators. It is the diversity of origin, origin, composition (used for dry skin, normal skin, combination skin) … that makes it difficult for consumers to choose suitable sunscreen products.

Moreover, in addition to sunscreen products with clear origins, many small shops, markets, websites … sell low-quality sunscreen products but imitate the prestige “brand”, popular.

Import sunscreen products

In recent days, the weather in the North is more sunny, peaking more than 40 degrees Celsius, consumer demand for sun protection products such as sunscreen, gloves, glasses, masks, especially anti-sun sunshine increased. This is also the time for low-quality sunscreen products to hit the market.

Walking around the market for students in Cau Giay (Hanoi), it is not difficult to see the areas selling cosmetics of unknown origin and labels. Remarkably, most products sold on the market are not preserved under the necessary conditions, away from direct sunlight.

Sunscreen is also sold on a variety of websites with different prices.

According to the survey, the prices of sun protection products in these markets are quite cheap, ranging from 70-100,000 VND / bottle, lower than in stores specializing in selling cosmetics from 50 – 100,000 VND / product. At first glance, the cosmetic products on the market have the same design, design, and design as genuine products, helping consumers’ eyes. Even for those with low incomes, this will be a popular product, suitable for money.

Sunscreen – the indomitable object on a hot summer day

As one of the indispensable products on a summer day, sunscreen helps people protect the skin, avoiding the effects of ultraviolet (UV) rays in the sun. Ultraviolet rays are divided into 3 types, UVA, UVB, and UVC rays. In which, UVA, UVB rays can pass through ozone layer and harm human health; UVC rays are blocked by the ozone layer, unable to penetrate the ground. Therefore, when going outdoors, our skin will be affected by UVA and UVB rays, which darken the skin, damage the skin, accelerate the aging process and increase the risk of skin cancer.

Sunscreen helps people protect the skin from the effects of ultraviolet (UV) rays in the sun.

To protect the skin from the effects of UV rays, consumers who choose sun protection products, including sunscreens, should pay attention to choosing a cream with a higher SPF number, which protects the skin from UV rays. higher. For example, SPF 2, skin protection ability is 50%; SPF 15, skin protection ability is 94%; SPF number is 100, the ability to protect the skin is 99%. However, consumers should not choose products with the SPF number too high, as it can cause skin irritation. Therefore, consumers only need to choose at 30, 50 for the best.

Besides, when buying a sunscreen, consumers also pay attention to the PA index (denoted PA ++, +++…) on the sunscreen. The more + sign, the better the resistance to UV rays.

However, consumers also note, it is possible that the sunscreen is suitable for one person, but irritates the skin for another. So, consider before choosing this skin protection product.

Experts warn against the harmful effects of sunscreen if used in the wrong way

Recently, the US Food and Drug Administration (FDA) recommends a sunscreen with a maximum SPF of 50-60 for the best skin protection. Two safe and effective ingredients in sunscreen are zinc oxide, titanium dioxide. Meanwhile, the ingredients aminobenzoic acid (PABA) and trolamine salicylate have been warned by the FDA to be unsafe.

FDA also requires manufacturers to demonstrate the safety of 12 sunscreen ingredients: cinoxate, dioxybenzone, oblulizole, homosalate, meradimate, octinoxate, octisalate, octocrylene, padimate O, sulisobenzone, oxybenzone, avobenzone. Therefore, consumers need to pay close attention to the ingredients on the product label when choosing sunscreen. Safe sunscreens approved by the FDA include sprays, oils, lotions, creams, gels, avocados, glues, ointments, and waxes. The agency says more information is needed before drawing a conclusion with its powdery sunscreen.

The US Food and Drug Administration (FDA) recommends a sunscreen with a maximum SPF of 50-60 for the best skin protection.

To prevent skin cancer, Associate Professor, Dr. William W. Huang, Wake Forest School of Medicine, recommends applying sunscreen about 30 minutes before going out in the sun and reapplying at least every two hours. Facial skin is a sensitive, vulnerable place to ultraviolet rays leading to skin cancer, so priority is given to applying cream on the face.

Ohio-based dermatologist Amy Kassouf also noted that sunscreen should be applied to small areas of skin like the eyelids, lips, and ears. Most lip cosmetics do not contain SPF. The skin on the edges of clothing is also often sunburned, so more sunscreen should be applied, according to dermatologist Jennifer Stein in New York. People with sensitive skin should use sunscreens containing zinc oxide and titanium dioxide in place of the chemical sunscreen ingredient.

According to chemist and founder of the beauty website The Beauty Brain – Perry Romanowski, expired sunscreens will no longer be able to protect your delicate skin. At this time, sunscreen, whether physical or chemical, has no longer reached the SPF level as advertised. Meanwhile, chemical sunscreens with ingredients containing oxybenzone, avobenzone and homosalate can oxidize and become less effective. Physical sunscreens contain zinc oxide or titanium dioxide, although there is no oxidation, they still lose the quality and effectiveness of sun protection. Simply put: while the sunscreen ingredients are active, they may not be able to function properly in skin protection.

Also sharing about the harmful effects of sunscreen, Dr. Erin Gilbert said that when you open the bottle of sunscreen with dirty hands, or open too many times can cause bacteria to enter the product. Decreases the quality of the cream and causes acne breakouts when used.

Dr. Gilbert recommends that if you leave sunscreen in a hot place such as in a car, swimming pool or in a bag, it will expire more quickly due to high temperature environments. In this case, you should replace it every few months to ensure that the sunscreen will always work effectively.