A New Wavelength

We’ve been bringing you some pretty exciting examples of how LEDs can positively impact your everyday life. From business applications like more efficient commercial greenhouses and advances in the automotive industry to more personal levels like getting a better sleep, enhancing learning environments, and revolutionizing residential lighting, LEDs are changing our everyday lives. With all these new developments popping up around you, we thought we should highlight the potential of LEDs on a more global scale. It comes as no surprise that the prevention and treatment of disease is a major hurdle for developing countries, but did you know that a new study suggests that customized LEDs could be instrumental in diminishing the spread of these diseases?

Light bulbs in the developing world become instant meccas for insects. The lack of screens and windows in buildings make it difficult to prevent insects from getting to the light and, inevitably, people. A wide range of insects is attracted to the blue wavelengths of LED lights, which means people are at risk of a catching a variety of vector-borne diseases (infectious pathogens carried and transmitted into another living organism by a person, animal, or microorganism). Deadly diseases such as the Leishmaniasis parasite from sandfly bites, Chagas disease from a kissing bug, and, more vehemently, Malaria from certain mosquitos account for more than 1 million deaths annually around the world. In fact, the World Health Organization states, “half of the world’s population is at risk of Malaria.” Even a small reduction in the number of cases would add up to some pretty big numbers. That small reduction could come about if something could be done to rectify the dilemma presented by the growing popularity of indoor lighting in developing countries and the disease carrying insects they attract.

That’s exactly what USC Environmental Science Professor Travis Longcore and a team of former UCLA students set out to do. Knowing that the white light given off by bulbs attracts insects and that white isn’t an actual color, but a combination of light of all colors, the team set out to reduce the number of insects an LED bulb attracts by manipulating the color diodes to change the wavelengths of the bulb without impacting the white light required for indoor use. Since most insects are predominately attracted to blue, violet, and ultraviolet wavelengths, the researchers concentrated on reducing the blue and green diodes for their study. The customized LEDs were tested against off-the-shelf commercial LED bulbs, compact fluorescent bulbs, and a control with no bulb in several Las Angeles County sites. The team observed a 20% reduction in the number of insects attracted to the specialized bulbs.

This may sound like a small reduction, but it is very promising given the fact that this is only the first attempt to manipulate bulb wavelengths to repel, or become uninviting to, insects. The positive results the team observed means there are so many possibilities for further research. Longcore points out that the optimal wavelength configuration is still unknown, and future research could result in the development of bulbs that deter as many disease-transmitting insects as possible. Insect groups are not equally attracted to the same color temperature, so the goal is to identify a wavelength combination that is unattractive to the largest number of species.

The results from Longcore’s study bring about more than just indications of future success; they leave you with a little bit of hope for the future. Check back with Mission for more feel good stories on how LEDs can illuminate more than just your surroundings.