Indoor UV exposure

Light bulbs emit UV exposure too

What is ultraviolet (UV) radiation?

Radiation from the sun has three main components: visible light, heat, and ultraviolet. Of these, it is the ultraviolet (UV) that poses the biggest threat to our healths. Although invisible, too much UV radiation causes adverse effects to our skin. It is a known trigger of symptoms in diseases such as Lupus. Because of this, the indoors have become somewhat of a safe haven because of the ability to control the heat (air conditioners), light (blinds and indoor lighting), and eliminate UV (no beaming sun).

At least, that’s what people are brought to believe.

Let’s measure UV from light bulbs with a Shade UV sensor

To test whether or not there is UV radiation around us inside, I used a Shade sensor in order to accurately view the realtime UV Index (UVI). The Shade sensor was developed by scientists at Cornell to help people with sun sensitivity manage their time outdoors and indoors. The sensor comes with a mobile app that automatically connects to the sensor to display its data in real-time. It is like a Fitness tracker for UV.

The UV Index is a medically accepted standard for measuring UV radiation in a way that is relevant to human health. The experiment itself was relatively simple: use the Shade sensor to measure the UVI from varying distances from each of the four sources.

Let’s find out, using the Shade UV sensor.

I started with the hallway fluorescent light. These lights have become a staple in schools, offices, and stores across the globe. As a result, it is almost certain that most will come into contact with these types of lights on a day-to-day basis.

In direct contact with these lamps, the UV index is comparable to the sun’s UV index in the morning in the Spring season. While it’s understood that these lights are generally not suspended within inches of our heads, it is important to note that most will be exposed to ultraviolet radiation from simply walking beneath these types of lights.

After recording these results, I went to three different types of desk lamps to see whether or not the trend continued. The first lamp had a fluorescent bulb (like the hallway light); the second had a halogen bulb (both with and without UV filter); the third had a LED bulb.

There are a couple different things we can conclude from these results.

First, the smaller fluorescent light bulb seems to emit UV as well, signaling that fluorescent lights emit UV regardless of the size or shape of the bulb. Because of this, people with Lupus may want to stay away from fluorescent-type of lights.

Second, Halogen bulbs emit a lot of UV without the use of a filter. Even so, a filter will not completely diminish the UV emitted from the light.

Finally, the Shade sensor did not detect any UV from the LED bulbs (the sensor has the capability to measure UVI to the nearest 0.01).

After having done these lamps, I went to the mecca of traffic in my household: the fridge. The results are shown below.

Finally, I went to the heart of all NYC transportation: the subway.

While the UVI detected is zero at two feet away, the lights suspended from the NYC subway platforms are very low to the ground (I was comfortably able to touch the light standing at 5'11"). Unfortunately, this means that all people are close enough to feeling the effects of these lights too.

How to manage indoor UV

There are a couple different solutions to the indoor UV we are continually exposed to:

A manufacturer’s manual will provide enough information in regards to UV radiation with a specific type of bulb.
Custom filters are available to put over existing lights in order to minimize the amount of UV radiation that is being emitted (see the Halogen bulb data above).
You can manage your UV exposure by using a device like the Shade sensor, which continuously monitors how much UV you receive and will allow you to track your exposure in real time. The Shade sensor is connected to an app that shows you in real-time your UV exposure and enables you to find a daily limit of UV exposure that is personal to you.