Research
Energy efficient lighting
and migraine
Sensitivity to light is a feature of some people’s migraine.
New bulbs, available in shops across Europe, are being phased
in. What is the impact of these on people with migraine?
In March 2007, whilst still Chancellor of
the Exchequer, Gordon Brown
announced the intention to phase out the
basic ‘A’ shaped GLS (General Lighting
Service) or incandescent light bulbs for
domestic use by 2011. This was
re-iterated by Secretary of State for the
Environment, Hilary Benn, in September
2007 as part of the drive for the UK to
reduce its energy consumption and CO2
emissions. It is the result of a joint and
voluntary initiative between the UK
lighting industry, retailers and the
Government. The ‘A’ shaped GLS will be
replaced by Compact Fluorescent
Integrated light bulbs (CFLi bulbs). These
are designed to save 75% of the energy
that is burnt with the GLS bulbs.
What do CFLi bulbs mean for
people with migraine?
The flicker from some types of lighting,
particularly the older fluorescent lighting
can be a trigger for some people with
migraine. The original energy saving lights
operated at mains frequency which meant
that when they were first introduced they
caused problems for people particularly
sensitive to flickering light. With this now
resolved, the new type of lighting should
benefit people with migraine who are
affected by flicker although this initiative
by no means covers all forms of lighting.
Candle bulbs, golf ball and mini globe
bulbs, decorative and other specialist light
bulbs will not be included in this initiative.
6 Migraine News
ISSUE 95
The Lighting Association has produced
information which states that CFLi bulbs
emit a constant, flicker free, nonstroboscopic light. They operate at a high
frequency through their electronic
controller at between 30,000 – 50,000
hertz. They have evolved and are now
very similar in terms of function to the old
bulbs. A small number of cases have
been reported by people who react to
certain types of linear fluorescent lamps.
According to a statement from the
European Lamp Companies Federation,
the reactions are usually triggered by
older technology which used a
conventional ballast (electrical device
required to operate electric-discharge
lamp to obtain the necessary circuit
conditions (voltage, current, and wave
form) for starting and operating) with low
frequency (less than 50Hz mains
frequency).
This should not happen with the new
CFLi bulbs as they operate on high
frequency drivers. DEFRA (Department
for Environment, Food and Rural Affairs)
commented that “all [new] energy saving
bulbs operate at high frequency, reducing
flicker to less than would be experienced
by watching a computer monitor or TV”.
Equally the amount of ultraviolet (UV)
generated by CFLis is fractional compared
to natural daylight. Special covers such as
Plexiglas or special glass UV filters can be
fitted to filter most of the UV light. When
filters are not a practical option, switching
to halogen can be considered. Light
sources with a warm colour tone contain
the lowest amount of blue light which is
often the most problematic for people with
light sensitivity.
Good quality energy saving light bulbs
emit a light quality which is close to that
of the incandescent bulbs. The Colour
Rendering Index (CRI) expresses the level
to which colours are represented as if
they were lit by natural sunlight. A GLS
bulb has a CRI of 100 as compared to a
good quality CFLi which has a CRI value
of between 80 and 85. If a higher CRI is
needed then it is possible to use halogen
energy saving bulbs with a CRI of 100.
The new bulbs do not produce as
much heat as their GLS counterparts
CFLi bulbs have
evolved and are now
very similar in terms
of function to the
ordinary bulbs…
They have been
developed and
improved – some of
the earlier criticisms
no longer apply
and so they are thought to be safer,
particularly around children or in confined
spaces.
CFLi bulbs have been developed and
improved and some of the early criticisms
of these no longer apply. The earlier
models of the energy saving bulbs did
emit a greenish or blueish light but this
should no longer be the case with
products available now and they should
emit the same warm light as GLS bulbs
(between 2,600 and 2,800 degrees
Kelvin). Equally, CFLi bulbs are now
smaller and come in a variety of shapes,
their life is not shortened by switching
and new bulbs are available which can be
used on an ordinary household dimmer
switch. The availability of these newer
products will increase as 2011
approaches. Again the availability of
energy efficient light bulbs for use with
dimmer switches should benefit people
with migraine.
Anecdotal reports were received that a
small number of people with migraines
may have experienced problems with the
new bulbs. DEFRA stated that “This is a
concern to us and we will ensure that
there are no unintended consequences
of the voluntary phase out [of existing
light bulbs].”
“The Government is working to
consider how to avoid any unintended
consequences from the phase out of
inefficient light bulbs. The Government
would consider the full range of impacts
of any mandatory policy measure before it
is introduced and will continue to work
with stakeholders to avoid any unintended
adverse impacts.”
Buying CFLi bulbs
There are of course, a huge range of CFLi
products. The cheaper brands tend to
start more slowly and so take several
minutes to reach their full brightness.
The bulbs with the ‘Energy Saving
Recommended’ logo on the box, which
means the bulb has met the Energy
Savings Trust criteria and standards, are
recommended by the Lighting Association
and DEFRA as these should have a longer
life and emit a proper light. Those bulbs
with the logo should reach at least 60% of
their full brightness within 60 seconds.
They are expected to last between 6 and
15 years depending on the wattage and
product type. As time goes on they will
become less expensive, more efficient
and smaller.
Approaching 2011
DEFRA reminded the public earlier this
year that “Energy efficient light bulbs are
not a danger to the public. However, we
are aware of anecdotal evidence that
the use of these bulbs could have
adverse effects on some people’s health
and are working with the lighting industry
and the Department of Health to resolve
these issues.”
Sources
Department for Environment, Food and Rural Affairs
www.defra.gov.uk
Energy Saving Trust
www.energysavingtrust.org.uk
The Lighting Association
www.lightingassociation.com/
The European Lamp Companies Federation
http://www.elcfed.org
Lighting Industry Federation
www.lif.co.uk
ISSUE 95
Migraine News 7