How many kilometers above ground level is ozone harmful?
How many kilometers above ground level is ozone harmful?
That may seem like a lot, but it is only 0.00006 percent of the atmosphere. The peak concentration of ozone occurs at an altitude of roughly 32 kilometers (20 miles) above the surface of the Earth. At that altitude, ozone concentration can be as high as 15 parts per million (0.0015 percent).
Which city has the highest UV index?
1. Laredo, Texas – 69.5
- El Paso, TX 67.9.
- Phoenix, AZ 66.7.
- Albuquerque, NM 63.8.
- Lubbock, TX 62.8.
- Reno, NV 62.6.
- San Antonio, TX 61.1.
- Henderson, NV 59.0.
- Colorado Springs, CO 58.6.
Should I wear sunscreen if UV index is 0?
0 to 2: Low A UV Index reading of 0 to 2 means low danger from the sun’s UV rays for the average person. Wear sunglasses on bright days. If you burn easily, cover up and use broad spectrum SPF 30+ sunscreen. Watch out for bright surfaces, like sand, water and snow, which reflect UV and increase exposure.
Why does UV Index go to 11?
UV rays can pass through the holes and spaces of loosely knit fabrics. A UV Index of 11+ (Extreme) means there is a very high risk of harm from unprotected sun exposure. Fair skin people may burn in less than 5 minutes.
What UV Index is safe?
Radiation: The ultraviolet (UV) index
| UV index | Action |
|---|---|
| 0 to 2 | You can safely enjoy being outside! |
| 3 to 7 | Seek shade during midday hours! Slip on a shirt, slop on sunscreen and slap on hat! |
| 8 | Avoid being outside during midday hours! Make sure you seek shade! Shirt, sunscreen and hat are a must! |
What UV is best for tanning?
Good UV Index for tanning
- UV Index 0 – 2. Low exposure level. Average time it takes to burn: 60 minutes.
- UV Index 3 – 5. Moderate exposure level. Average time it takes to burn: 45 minutes.
- UV Index 6 – 7. High exposure level.
- UV Index 8 – 10. Very high exposure level.
- 11+ UV Index. Extreme exposure level.
What makes UV index high?
Bright surfaces, such as sand, water, and snow, will increase UV exposure. A UV index reading of 8 to 10 means very high risk of harm from unprotected sun exposure. Take extra precautions because unprotected skin and eyes will be damaged and can burn quickly. Minimize sun exposure between 10 a.m. and 4 p.m.
Does the UV index have to be high to tan?
In order to get a suntan, the UV radiation needs to be high enough to affect the level of melanin in your skin, without burning.
Why is UV Index higher in summer?
UV sunshine is highest during summer because the sun is high in the sky. This means its rays arrive more directly and travel through much less ozone than during winter, when the sun is low in the sky. Clouds that block the sun greatly reduce direct UV. But diffuse UV from a cloudy sky can cause sunburn.
Are there more UV rays in summer?
During the summer months the sun is in a more direct angle, resulting in a greater amount of UV radiation.
What UV index makes you tan?
TABLE 1. MINUTES OF SUNLIGHT EXPOSURE FOR SUFFICIENT VITAMIN D
| SKIN REACTION TO SUNLIGHT | UV Index | |
|---|---|---|
| 3-5 | 6-7 | |
| Skin type III: Occasionally burn, slowly tan | 20-30 min. | 15-20 min. |
| Skin type IV: Rarely burn, rapidly tan | 30-40 min. | 20-30 min. |
| Skin type V & VI: Very rarely burn, always dark | 40-60 min. | 30-40 min. |