Warm summer days mean more time spent outdoors, and with that comes more exposure to UV light. Although you may protect yourself from the sun on summer hikes and when going to the beach, these are not the only times you’re exposed to the sun’s ultraviolet rays — UV radiation can also reach you on cloudy days, and even when you’re at home!
Continue reading to learn about different types and sources of UV radiation, the health benefits and risks of sun exposure, and ways to protect yourself against UV rays and make the most of sunny summer days.
We need the sun. It gives us light and heat, without which we wouldn’t be able to survive. But it also sends three kinds of UV radiation our way:
So the UV light from the sun that reaches the Earth’s surface is mostly UVA and UVB rays. UV radiation is the strongest and most harmful from late morning to early afternoon, so it’s best to avoid spending a lot of time in direct sunlight during this time.
But what if the sun isn’t shining? Can its UV radiation affect you when it’s overcast? The answer is yes! UV rays can easily pass through the clouds, so it’s just as important to protect yourself on gray, gloomy days.
Do you notice that your mood improves when the sun is shining? Well, there’s a reason for that. When you’re exposed to sunlight, your brain releases the mood-boosting hormone serotonin, which helps you feel calm and focused during the day. Spending time in the sun can also help to regulate your circadian rhythms, contributing to more restful sleep, more energy during the day, and a better mood.
Sunlight also helps you get a healthy dose of vitamin D — it’s called a sunshine vitamin for a reason!
UV light boosts vitamin D production in your body; how much of it you can get from sun exposure depends on many factors, such as your skin color and how strong the sunlight is. People with darker skin produce more natural pigments called melanin which prevents their skin from absorbing as much UV radiation. Studies show that darker skin doesn’t produce as much vitamin D, so fair-skinned people may need to spend less time in the sun to get their daily dose of vitamin D.
Getting enough vitamin D has several health benefits. It helps to keep your bones and teeth healthy, supports your immune system, and — again — helps to regulate your mood and lower your risk of depression. So sunshine can really make you happier, you just need to be careful with it.
Going through a global pandemic, many people started wondering if UV radiation could kill viruses, particularly coronavirus. Well, it can… at least certain UV rays.
UVC radiation has been used as a disinfectant for air, water, and nonporous surfaces and has been known to effectively stop the spread of bacteria for decades. And far-UVC lamps have been found to successfully deactivate the airborne coronavirus.
Unfortunately for us though, UVC radiation doesn’t occur naturally, so we can’t benefit from its disinfecting properties every time the sun’s out. UVB and UVA rays that reach the Earth’s surface are less effective at killing viruses. Otherwise, we’d see a significant drop in Covid-19 cases in summer or in areas with a high UV index, which isn’t the case.
However, lamps with UVC radiation are commonly used in air ducts to disinfect the air.
But of course, there are certain limitations to how effective they can be: the virus needs to be directly exposed to UVC radiation to be affected by it. Also, many germicidal or UVC lamps for home use offer low-dose radiation, so it may take longer for them to effectively kill bacteria or viruses.
The sun is the main source of UV radiation, but there’re other sneaky ways you can get exposed to ultraviolet light from man-made sources:
Without a doubt, sunlight in moderation has its benefits, but spending too much time in the sun can cause certain health problems, such as:
How much damage UV rays can do depends on their intensity and how long you’ve been exposed to them without sun protection. Location is also an important factor — the UV index can tell you how strong UV radiation is where you are. If you live in an area with a high UV index year-round, your risk of sun-induced conditions is higher.
Everyone is susceptible to the effects of UV radiation, but you may be more sensitive to them if you:
Of course, protecting yourself from UV radiation is important for everyone, but it’s particularly crucial for children — most of our UV exposure to the sun happens before the age of 18. Too much sun exposure or frequent sunburns during your early years can increase your risk of skin cancer later in life.
The two most common types of skin cancer — basal cell and squamous cell cancers — form on the parts of the body that are most exposed to UV rays, such as the face, neck, hands, and arms. The risk of melanoma, a more serious type of skin cancer, is also linked to sun exposure and sun damage. Man-made sources of UV radiation like tanning beds also contribute to the risk of skin cancer.
Note: UVB rays that cause sunburn are mostly blocked by the glass, but UVA radiation that causes premature aging can still get to you. So if you often sit near a window when you’re at home, remember to apply sunscreen.
Even if you limit your sun exposure and take steps to protect your skin against UV radiation, it’s still important to have regular check-ups with a dermatologist to look for any skin abnormalities. You can conduct self-checks too — look for moles that have changed size, shape, or color, and bumps that don't seem to heal. Remember that most cases of skin cancer can be successfully treated when caught early.