The link between the new energy-efficient CFL light bulbs and migraines is unproven, but still a subject of debate, writes Eoin Burke-Kennedy
THE DEPARTMENT of Environment has received a number of submissions from migraine sufferers who are concerned the impending switch from traditional incandescent light bulbs to low-energy alternatives may adversely affect their condition.
The submissions were made as part of a consultation process prior to the proposed phasing out of standard tungsten bulbs from September in favour of more energy-efficient compact fluorescent (CFL) bulbs.
In January, Minister for the Environment John Gormley shelved plans to proceed with domestic legislation for a gradual ban on the older bulbs from June.
He had wanted Ireland to take the lead in an EU-wide move to more efficient lighting but is now content to row in behind an accelerated EU plan due to commence in six months.
But some migraine sufferers believe the quality of light emitted by CFL bulbs may trigger headaches and want Gormley to avoid a complete ban, and leave some opportunity for conventional bulbs to be purchased.
While there is no proven link between migraine and CFL lighting, a slew of recent reports in the British media, citing anecdotal evidence from sufferers, have claimed the bulbs can cause migraine.
Concern surrounding the issue even prompted the British Migraine Action Association to advise its members to stock up on traditional bulbs ahead of a similar ban on their sale in Britain later this year.
The Department of the Environment here says it has sought expert medical opinion regarding a number of health concerns which have been raised over CFLs and found no evidence linking the bulbs to migraine.
A spokesman says Gormley has been aware of the health concerns raised in relation to new types of lighting from the outset of the process and the proposals are not designed to make CFLs mandatory.
He says the regulations will allow for a variety of lighting types, such as halogen lamps or LED (light-emitting-diode) lights, as long as they meet the minimum energy standards.
CFLs require only a fraction of the energy of the conventional tungsten bulbs and have the potential to dramatically reduce the electricity needed for lighting Ireland’s residential sector which generates nearly 900,000 tonnes of carbon dioxide emissions.
Traditional incandescent bulbs emit light when an electrical current is passed through a thin filament of tungsten until it glows white hot.
A CFL bulb consists of a gas-filled tube containing an electronic ballast. The gas in the tube glows when electricity from the ballast flows through it and light is emitted when the gas reacts with a white phosphor coating on the inside of the tube.
CFLs require on average three to four times less electricity and can last up to 10 times longer than conventional bulbs.
Since the light source emanates from a single point, incandescent bulbs project light further than CFLs which emit a more diffuse light.
One complaint traditionally levelled at CFLs is that they produce a dimmer light which can cause eye strain.
But advances in CFL technology have increased their illumination strength to such an extent that the difference between them and older lighting types is, at best, marginal.
Another problem with older CFL bulbs has been the flicker. The human brain can detect the 60 cycles per second which older bulbs, often found in office lighting, needed to refresh themselves to keep emitting light.
However, modern CFLs refresh themselves at between 10,000 and 40,000 cycles per second, rates too fast for the human eye or brain to detect.
Peter Thornes, a Dublin-based doctor with an interest in lighting technology, believes the area that might pose a risk to migraine sufferers is the quality of light produced by CFLs.
He says CFLs radiate a different light spectrum from that of conventional incandescent bulbs which contain significant variations in the frequencies of certain light.
“It’s conceivable that these imbalances may be triggering headaches in people with photosensitive migraine, although there is no data to back this up.”
The Migraine Association of Ireland says there are no scientific studies to suggest the new bulbs will have a detrimental effect on the frequency and severity of migraine.
Spokeswoman Donna Walsh says: “We do not want to unduly worry migrainers by giving advice based on anecdotal evidence.”
In its submission to the consultation process, the association asked the Department of the Environment to investigate the effect of CFL bulbs on migrainers and to forward any new information to it.
Migraine affects 12-15 per cent of Irish people and an average sufferer is estimated to lose 1.5-4.5 days from work annually.
Despite its prevalence, little is known about what causes migraine but its onset is often accompanied by visual disturbances known as the “aura stage”.
Dr Ronan Walsh, consultant neurologist at Beaumont Hospital, says a migraine is defined as a headache lasting from four to 72 hours with a one-sided pulsating quality.
“It is usually aggravated by routine physical activity and can be associated with nausea, vomiting, photophobia or phonophobia and has no other underlying cause.”
Walsh says there can be multiple triggers such as missing sleep, the day after alcohol, stress, certain foodstuffs, overuse of painkillers and light.
So the cause of migraines in individual patients is usually a combination of issues often relating to lifestyle and when treating migraine, doctors would rarely focus on just one issue such as light, he says.
“There is no evidence CFLs cause migraine but I would advise people concerned about the new bulbs to look at all the other potential issues in their lifestyle before ascribing migraine solely to this one issue.”