Effets sur la santé de la lumière artificielle

6. How and where are people exposed to artificial light?

Exposure to UV from artificial light is equivalent to one week vacation in a sunny destination

There is very little information on personal exposures to different indoor lights but it is possible to make estimates by choosing exposure situations where there is some potential risk, either because the eye or the skin are exposed to UV from the general ambient light, or because of direct exposure of the eye to the blue component of light.

Office workers and school children are exposed to some UV and blue light from fluorescent lamps and task-lamps, for up to 8 hours a day. Those working in factories or large stores are exposed throughout the working day to more intense light sources but these are placed relatively far away in high ceilings. Customers visiting these shops are similarly exposed, but for much shorter periods of time. Performers and presenters on TV studios are under very bright lights so are exposed to UV, blue light and glare. Night drivers are also exposed to glare from headlights but only for a very short time so the main risk is that glare could cause them to have an accident rather than any eye or skin conditions. Finally, night reading for one or two hours using CFLs, LEDs or incandescent lights would expose people to some blue light.

People exposed to indoor lights receive some UV radiation which accumulates over a person’s lifetime and contributes to the risk of developing skin cancer. Exposure to fluorescent light in the home is generally negligible compared to that at school and the workplace. Therefore, worst-case scenarios consider lifetime exposure in school of 6 hours a day for 40 school weeks a year from 5 to 20 years of age, and 8 hours a week at work from 20 to 65 years of age and for 48 weeks a year.

Exposure and consequent risk depend very strongly on the lamp used. As a comparison, the added annual risk from a lamp at the very top limit of what is classed as safe is equivalent to 1 week of holiday in the Mediterranean and about 100 times smaller than living in Australia. At the other extreme, lamps emitting low levels of UV pose almost no added risk.

In practice, exposure to fluorescent lamps is much lower than the worst-case scenarios considered here and more data on personal exposures is needed to improve these estimates. More...

Table 6. Examples of exposure situations from artificial light for the general population

Table 7. Percent increase in SCC incidence and risk at 80 years of age due to certain added UV doses

Table 8. Estimates of SCC risk