American Journal of Public Health
Helen L. Walls, PhD, MPH, Kelvin L. Walls, PhD, and Geza Benke, PhD
Increased use of fluorescent lighting as a climate change mitigation strategy may increase eye disease. The safe range of light to avoid exposing the eye to potentially damaging ultraviolet (UV) radiation is 2000 to 3500K and greater than 500 nanometers. Some fluorescent lights fall outside this safe range.
Fluorescent lighting may increase UV-related eye diseases by up to 12% and, according to our calculations, may cause an additional 3000 cases of cataracts and 7500 cases of pterygia annually in Australia.
Greater control of UV exposure from fluorescent lights is required. This may be of particular concern for aging populations in developed countries and countries in northern latitudes where there is a greater dependence on artificial lighting.
The replacement of incandescent lamps with fluorescent lighting appears to be a global trend. However, this change in lighting sources may lead to an increase in eye diseases unless there is greater control of UV exposures from many of the fluorescent lights currently in use or technological advances enabling efficient lighting from other sources. For Australia alone, we estimate at least 10 000 additional cases of eye disease each year. Our estimates are conservative and crude in that they are limited by the poor information currently available with regard to the incidence and etiology of many eye diseases. We have not included in our estimates possible increases in AMD because there is not yet universal agreement in the literature regarding causality with UV radiation. But if a link between UV radiation and AMD is firmly established in the future, this would have significant public health implications.
Kitchel commented that “serious consideration as to how we light environments of persons with visual problems cannot come too soon” and suggested that such individuals should avoid environments where the predominant light waves are of a color temperature greater than 3500K or a wavelength less than approximately 500 nanometers.35 Clarkson supported this 500-nanometer threshold limit.10 Kitchel also suggested that UV light causes irreparable damage over time to the human retina, especially in young children,35 a public health issue that has not been investigated.
The evidence suggests that the least hazardous approach to lighting is to use warm-white tubes or incandescent bulbs of lower color temperature and longer wavelength light rather than fluorescent lamps. With incandescent bulbs and warm-white tubes, the eye is not subject to potentially damaging UV radiation from fluorescent lighting. The difficulty is that anything other than fluorescent lighting is considered inadequate for many workplaces and in the home. UV filters, available for some fluorescent lights that are manufactured with UV diffusers, should become a required standard. Furthermore, we support the suggestion of Hartman and Biggley that lamp manufacturers should not allow current levels of emission of UV light from fluorescent lighting to increase and should work toward reductions in emissions.7
The safe range of light, to avoid exposing the eye to potentially damaging UV radiation, appears to be between 2000 and 3500K and a wavelength of greater than 500 nm. Some fluorescent lights currently fall outside this safe range. This may increase UV-related eye diseases by up to 12% (estimate of 3.9%; 95% CI = 1.6%, 12.0%) and result in unforeseen adverse public health consequences. There is a conflict between climate change mitigation through elimination of incandescent lights and the unregulated use of primarily fluorescent lighting.
In our experience, lighting supply wholesalers and retailers are generally not adequately aware of the full characteristics of their products, such as color temperature and wavelengths of emitted light. Consumers and users of fluorescent lights are relatively unaware of the fact that these lights emit UV light and that this light could be harming their eyes.
In response, we advocate for the use of incandescent and warm-white lamps instead of cool-white fluorescent lamps, as well as for further research into improving lighting from such sources. This public health issue may be of particular concern for aging populations, such as those of many developed countries and countries in northern latitudes where there is a greater dependence on artificial lighting.
Click here for link to full text