Radiophobic Society Government Sensationalist News Media TV & Film Public Misconceptions of Radiation Risk School GPs PUBLIC Nerdy Scientists Urban Myths Non-Ionising Radiation (NIR) Two contrasting examples involving NIR. Both socially emotive and in the media. Mobile Phone Base stations Approximately 20,000 in the UK! Sunbeds in high street tanning salons or solaria Introduced into UK in 70 s. Now widespread. Approximately 350 solaria in Merseyside. Mobile Phone Base Stations! Low power antennae - transmit up to a few 10 s s of Watts! Sector " phone handsets. Dish " other base stations.! Frequencies @ 0.9, 1.8 & 2.1 GHz. # Conical fan beam aimed horizontally with slight downward tilt. # Beam touches ground level at ~ 150m from tower. # Power density (W m -2 ) reduces with distance from tower. # Only within ~ 2m are power densities > human exposure limits. # Building materials attenuate to some extent. 1
The Media Mobile Phone Base Stations Plague of the Phone Masts The Sun 15 th July 2002 Mobile phones can trigger eye damage, fear scientists DailyTelegraph 7 th August 2005 Scientists study brain cancer link to mobiles The Scotsman 21 st January 2007 16 masts in Cancer Street The Sun 15 th July 2002 Men who use mobile phones face increased risk of infertility Daily Mail 23 rd October 2006 Scientific Reasoning Risk Assessment Case: Maintenance staff refusal to work on a rooftop where a base station was situated. Review the scientific literature. Assess the relevant information: Technical specifications of actual transmitters involved. International RF exposure guidelines. Layout of the installation e.g. position of tower, access etc. Identify the hazards and who could be harmed. Quantify the risks and compare to guidance. Conclude recommend control measures. Biological Effects Stochastic Effects (Athermal( Athermal) $ Cancer or Leukaemia $ Chemical bond! 10 6 x RF photon energy $ Cannot cause direct DNA damage At 1 to 2 GHz: RF penetration into tissue! 2cm Deterministic Effects $ Thermal - heating of tissue. $ Studied and understood. $ Basis for exposure guidelines. $ Exclusion zones. ICNIRP Guidelines International Commission on Non-Ionising onising Radiation Protection. Radio-Frequency (RF) Reference Levels. Public = 10 W m -2 Occupational = 50 W m -2 2
Mobile Phone Base Stations Mobile Phone Base Stations Lighthouse-like beams Safest place to be National Radiological Protection Board (NRPB) Report R321 Measurements of RF emissions from masts sited: % near schools or within school premises % on blocks of flats and other residential areas % on office blocks All cases RF power density < 0.2% guidelines (average = 0.002%) Independent Expert Group on Mobile Phone (IEGMP) The Stewart Report (May 2000) the balance of evidence indicates that there is no general risk to the health of people living near to base stations on the basis that exposures are expected to be small fractions of the guidelines. Base station on roof top of a student hall of residence. Urgent maintenance work required on roof. Workers refusing to go onto roof-top because of base station. Antenna Restricted Access Plant Room 4.5m # 2m 4. 2m 7 o Roof-top # = ICNIRP Occupational Reference Limit distance (50W/m 2 ). Recommended warning signs, no access to plant roof, written procedures. Communication with the maintenance workers. Mobile Phone Base Station O 2 tower in a primary school playground. Stakeholder meeting. Parents were somewhat aggressive! Power of an average light bulb! 100W I ll have NO additional risk to my child Single trans-atlantic flight» Equivalent to radiation dose of one chest x-ray.» 1 in 600,000 chance of fatal cancer. Money on educational resources - 6000 pa. Installation did NOT go ahead. 3
Mobile Phone Technology Scientifically reproducible link between RF exposure and a stochastic effect (e.g. cancer) remains unproven & unlikely. Deterministic effects (e.g. tissue heating) are understood and can be easily protected against (e.g.( exclusion zones). Socio-Economic benefits» possible health detriments. More base stations is better as less power transmitted per antenna. $ Phone handset transmits ~ 1-2 W $ Hair dryer ~ up to 1 W Other risks of death in daily life: & Being in the kitchen ~ 1 in 10,000 per annum & Smoking ~ 1 in 6000 & Travel by car ~ 1 in 100,000 per 300km travel Danger: May Contain Nuts In UK ~ 50 persons/year die from nut allergies Mobile Phone Technology January 2007 announcement of a new 5-year epidemiological study on long term mobile phone use and brain cancer, Parkinson s, s, and Alzheimer s. Professor Lawrie Challis Mobile Telecommunications Health Research programme. Study costing ~ 3,000,000 Swedish study (2003) suggesting a hint of a link between long term use and acoustic neuroma incidence. Challis reportedly of the opinion that the mobile phone could turn out to be the cigarette of the 21 st century. 120,000 lives lost per year in UK as a result of smoking. How many people do you know that have died as a result of radiation from a mobile phone? Mechanism for such effects has yet to be postulated let alone found by reliable scientific methodology. How many lives could 3M save now without any doubt. Ultraviolet (UV) Sunbeds Typically 40 x 200W tubes (Total in lid + bed. 1.8m in length) Plus ~ 12 21 21 x 25W tubes (Boosters interleaved into the lid) Token operated One token = 3 minutes Not unusual for client to be allowed to buy 3 to 5 tokens for each session. $ A tanning regime of 9 minutes per week for 40 weeks a year is typical. $ Even more for tan-oholics. 4
Ultraviolet (UV) Sunbeds Private & Voluntary Healthcare Regulations 2001 Beauty salons using Intense Pulsed Lights (IPLs( IPLs) ) must be registered with Healthcare Commission. Treatments are aesthetic e.g. hair removal. BUT " Solaria offering aesthetic UV tanning treatments that arguably represent an equal (if not greater) optical radiation hazard NO SUCH CONTROL IPL Erythema UV Health Effects Erythema - skin inflammation that leads to reddening and mild burn. It is a surrogate for Skin Cancer particularly particularly squamous cell carcinoma Also basal cell carcinoma and malignant melanoma Relatively common Rarely fatal Uncommon Usually fatal Photo-ageing On average ~ 100 people die in UK per year as a direct result of sunbed usage. Standard Erythemal Dose (SED) Erythemal Reference Action Spectrum S(") Effective Radiant Exposure - H eff H eff = _ H(").S( ).S("). #" J/m 2 One SED = H eff = 100 J/m 2 Fitzpatrick Skin Type Score I (albino) up to VI (black) Most sunbed users are skin type II or III Minimum ED depends on skin type Type II MED! 2 x SED = 200 J/m 2 Type IV MED! 7 x SED = 700 J/m 2 Media Cancer risk from sunbeds doubles The Times 30 th January 2007 Dr. Harry Moseley Photobiology Unit, Ninewells Hospital, Dundee. 133 sunbeds in 50 different premises in Scotland. Compared to a similar survey in 1997. Over the past 10 years: Number of privately operated sunbeds increased by 30% Median cancer risk now comparable to Mediterranean sun (up by a factor of 2) Now 83% of all beds exceed British & European UVB limits. 5
Ultraviolet (UV) Sunbeds The Scientific Method Hypothesis Significant proportion of sunbeds within tanning salons in Merseyside routinely give UV exposures above those recommended in British & European standards. Project In collaboration with Liverpool City Council to take measurements from a range of sunbeds within a random sample of high street solaria. Measurement Method Solatell Sola-Scope 2000. Spectro-radiometer. Optics + photo-diode array. Spectral Irradiance (µw/cm 2 /nm). Range 230 400nm. Detector located at typical client skin positions e.g. 2cm from tubes. Results Typical UV Spectrum for 'clam-bed' Results SED in 1 minute Radiant Exposure Histogram - Clam-shell Bed 0.00025 7 Sample = 16 UVC Region UVB Region UVA Region 6 Spectral Intensity (W/cm 2 /nm) 0.0002 0.00015 0.0001 Integration Range Number of Beds 5 4 3 2 Mean = 1.32 SED / minute 0.00005 1 0 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 440 450 460 470 Wavelengthnm 0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25 2.5 2.75 3.0 Number of SED per minute 6
Mean Maximum Results Type: Clam-shell bed. Detector position: Mid-body. Bottom lid. 2cm from tubes. Sample of beds : 16 Effective Erythemal Irradiance (W / m 2 ) 2.2 ± 0.2 4.1 ± 0.1 SED s per minute 1.32 2.47 63% > 1 SED per minute Time to 1xMED for Skin Type II (seconds) 90.5 48.6 UV Conclusions Assume 3 minutes/week for 40 weeks/year. Gives 3 x 40 x 2.2 = 264 SED per year Recommended tanning schedule (BSEN 60335-2-27): 1 st radiant exposure (un-tanned skin) = 1 SED Waiting time between exposures = 48 hours Max. radiant exposure per session = 6 SED Max. radiant exposure per year = 150 SED Interpretation into increased cancer risk is very difficult. Relative risk factor for BCC at 70 years for a person who received 264 SED/year from ages 20 50 years! 3.4 1.0 for no sunbed use Summary Which technology represents the greater risk to human health? Significant % of populace believes it s s phones. Has anyone died from the radiation from a mobile phone or base station? Collective and individual risk? Psychological hazard? Our opinions may change over the next 100 to 200 years. 7