Quote: author=londonman link=1243257255/8#8 date=1243284511
4/ How long they take to reach full brightness after switch-on
5/ Whether or not they may cause migraines
6/ What heavy metals have been used in their manufacture
Perhaps. These are mostly CFL issues.
Perhaps surprisingly there is no scientific evidence they cause headaches. Modern CFLs actually switch faster than incandescent so they should flicker less. If there is a problem it's likely to be with older linear tubes.
http://www.thedailygreen.com/environmental-news/latest/compact-fluorescent-light... Quote:"We have not published a study linking CFLs and migraine," Karen Manning, head of membership support for the Migraine Action Association, told The Daily Green. "The recent media activity has been in response to anecdotal reports we have received from many migraine sufferers who have experienced adverse health effects following introducing low energy light bulbs into their homes. I am not aware of any scientific evidence on this subject, but as an Association we would welcome this to confirm there are real health issues affecting migraine sufferers."
http://www.migraine.ie/index.php?id=258 Quote:The Migraine Association of Ireland are not aware of any scientific evidence which states that CFL light-bulbs cause adverse health effects for migraine sufferers.
http://www.scientificamerican.com/article.cfm?id=flickering-fallacy-cfl-bulb-hea... Quote:Flickering Fallacy: The Myth of Compact Fluorescent Lightbulb Headaches
snip
Sometimes headaches are due to eyestrain from inadequate lighting. When replacing an incandescent bulb with a CFL, pay attention to the lumens, which indicate the amount of light a bulb gives out (watts measure the energy use of a bulb, not the light generated).