LEDs are they good for us?

This study would argue not.
http://www.israel21c.org/briefs/study-links-led-light-and-cancer
But then again what is good, except for sunlight (filtered of course to compensate for a thinned ozone layer.

Or are CFLs best?
So it's like this.
While Thomas Edison is rolling around in his grave because countries are making it law that incandescent cannot be sold, he did of course only try with 10,000 experiments to find the right filament to go in the lightbulb. Countries like Australia (first) and Israel (75 watts and above as of 2011) cannot be sold are getting on the eco-efficiency band wagon. But what's next LEDs?

Let's look at it from an electricity perspective.
100 watt incandescent = 15 watt CFL = 7 watt LED

OK now price
99 cents = ranges say $5 = $12
Breakeven assuming 15 cents per kwh?
when 0.99 + 0.15*0.1*x = $5 +0. 015*15*y = 12 + 0.015*7*z
or at least something like that.
answer
for an LED to pay back would take 6 months as compared to an incandescent and 25 as compared to a CFL
assuming 4 hours of use per day.
considering an LED has a life of 30,000 hours (20 years at 4 hours per day)
LED wins on the money side.
There are whole spectrum lighting, but they are much more expensive, like $30 a bulb.

CFLs are most cost effective today, LEDs will come down in price.
Health-wise - a cell phone is probably more lethal then an LED.
Shai