INCANDESCENT REPLACEMENT LAMPS AND HEALTH

Incandescent replacement CFL and LED lamps have a larger blue component than red component. Contrary, incandescent lamps have a larger red component than blue component. Our eye has light sensitive cells that connect with the biological clock in the brain, which in turn connects with the pineal gland that controls for a part the rhythm of our hormone metabolism. One therefore wonders whether general domestic evening use of CFL and/or LED lamps can disturb our natural rhythm of hormone metabolism and therefore have negative consequences for our natural body rhythm and our health. The total non-visual biological effect of light ("biological dose") has been calculated for different light sources on the basis of the biological action spectrum. First, the relative spectral energy distributions are weighted according to the spectral photopic eye sensitivity V-lambda in order to arrive at equal lumen output. Our calculations show that CFL and LED lamps with a corrected colour temperature of around 4000 K and moderate colour rendering result in a ca. 34% higher biological dose than incandescent lamps. CFL and LED lamps in the range of 2700-3000 K and good colour rendering however result in a slightly lower biological dose than incandescent lamps (1-7% lower). Seen from a health point of view there is therefore no objection against a changeover in the domestic area from incandescent lamps to CFL and/or LED lamps with colour temperature 2700-3000 K and colour rendering 80 or more.