Radiation literature survey

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The SCHEER conducted an extensive literature review to assess the potential health risks from exposure to light emitting diodes (LEDs). Exposures included the use of LED display technology (smartphones, tablets and computer screens) and emissions from LED lights found in toys, car lighting and lamps for area illumination. Effects were assessed separately for the general population and in vulnerable and susceptible populations (e.g. children and the elderly).

The review concluded that, for normal use of LED displays and lamps, there was no evidence of any adverse health effects. However, there was some evidence to suggest that these types of exposures in the late evening may impact the circadian rhythm (sleep/wake cycle). This is thought to be due primarily to the blue light components of the emissions from the displays. At this time, it is unclear if this disturbance leads to any adverse health effects.

Although emissions from LEDs, including those found in children’s toys, may not be harmful, the committee concluded that blue LEDs may be dazzling to young children and may potentially induce photochemical retinopathy (light induced damage to the retina). This is due to the structure of children’s eyes making them more sensitive to blue light, especially under the age of three. Also, it was concluded that older people may experience discomfort from exposure to LEDs rich in light due to the effects of scattering. Due to flickering in some models of LEDs, there have been reports of stroboscopic effects which make moving objects appear stationary or as a series of stationary images when viewed under these types of lighting systems. The combination of these effects may lead to distraction or disorientation resulting in indirect safety concerns.

Finally, because LED technology is still evolving, the committee considered it important to monitor the risk of adverse health effects in the general population.

Final Opinion on Light Emitting Diodes (LEDs)

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Although there is research showing potential health effects from LED sources, these occurred at exposure levels that were greater than those likely to occur with the use of LEDs in practice.

The potential disruption of the circadian rhythm in humans supports reducing the use of LED displays in the late evening, or engaging functions such as “night-shift” for reducing the intensity of the blue light from the display.

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Summary:

This was a retrospective cross-sectional study that investigated the prevalence of specific cancers within flight attendants in the U.S. compared to the general population. Data on cancer prevalence was gathered by surveys returned from 5366 flight attendants and 2729 controls matched by similar socioeconomic status. The study reported a higher prevalence in flight attendants compared to the general population for breast cancer (risk estimate 1.51 with a 95% confidence interval (CI) of 1.02-2.24), melanoma (2.27, 95% CI 1.27-4.06) and non-melanoma cancer (4.09, 95% CI 2.70-6.20). There were no statistically significant associations with the other cancers examined (uterine, cervical, gastrointestinal and thyroid). The authors concluded that there was a higher prevalence of specific cancers within the flight attendant occupation than the general population.

Link to study

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Commentary by ARPANSA:

Although the authors reported an elevated risk of some cancers in the flight attendant cohort, these associations were based on prevalence of the disease compared to the general population. Prevalence of disease is limited in that it measures the occurrence of a disease at a point in time. Although this can serve as an indicator of the disease, the evidence supporting the associations is weakened by a limited understanding of how the disease rates changed over time. A better indication of the risk factors would have been achieved by measuring the incidence of the cancers examined where cases would have been recorded over the time period.

The study relied on tenure in the occupation as a surrogate for exposure. The authors identified a number of known and probable carcinogens that flight attendants would be exposed including ionising radiation, circadian rhythm disruptions from night shift work, irregular schedules and crossing time zones and, poor cabin air quality such as second hand tobacco smoke from before the implementation of smoking bans. The authors also identified but did not adjust for confounders such as recreational ultraviolet radiation exposure.

Overall, the results of the study were consistent with similar studies but given it’s limitations further studies with improved methods are required. In Australia, ARPANSA is involved in a study lead by QIMR Berhofer Medical Research Institute, investigating the incidence of melanoma in commercial pilots in Australia. The first results from this research are expected later in 2018.

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This was an in vivo study investigating the effect of sunscreen application in preventing human skin DNA damage that potentially is the basis for most skin cancers. A sunscreen with a very high level of UV protection (SPF 50+) was applied to 16 healthy young subjects with Fitzpatrick skin phototypes I and II.  Sunscreen was applied at thicknesses of 0.75, 1.3 and 2.0 milligrams per square centimetre of skin (mg/cm²). The volunteers were split into two exposure groups; a group that received a single UV radiation exposure (acute exposure group) and a group that received a daily UV radiation exposure for 5 consecutive days (repeated exposure group).  UV radiation exposure was provided artificially with characteristics closely matching sun exposure. The acute exposure group received 30 standard erythema doses (SED) per sunscreen application thickness. The repeated exposure group received 15 SEDs daily for all application thicknesses to simulate a typical holiday exposure at a tropical latitude. The repeated exposure group also received 30 SEDs daily at an additional site with a 2 mg/cm² sunscreen thickness. Unprotected skin was exposed to 4 SEDs in the acute exposure group and 1 SED daily in the repeated exposure group for experimental control.

The authors reported that sunscreen significantly reduced DNA damage at application thicknesses of 1.3 and 2.0 mg/cm². Application thickness of 0.75 mg/cm², representative of typical application, was only significant in reduction of DNA damage in the repeated exposure group.

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The study showed that the use of a very high SPF factor sunscreen can inhibit DNA damage in human skin caused by exposure to UV radiation. Although typical sunscreen application showed some value in providing UV protection in people going out in the sun for consecutive days, the importance of better sunscreen application was supported by the reduction of DNA damage in going out in the sun on occasion.

Overall, the results reported by the authors support ARPANSA’s sun protection messaging. Further, the study emphasises the importance of communicating the most appropriate way to apply sunscreen to offer the best protection outcomes.

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Summary:

This was a double-blind provocation study investigating the association between providing precautionary information on electromagnetic fields (EMF) and the nocebo response. The study included 73 participants who received basic information on the use of Wi-Fi and 64 controls who received basic and precautionary information. All subjects were then sham exposed to EMF three times and asked if they could perceive the field or experience any health symptoms. There was no statistical significant difference between the risk perceived when given basic information or basic plus precautionary information. The authors concluded that precautionary information does not trigger the nocebo effect.

Link to study

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Commentary by ARPANSA:

The nocebo effect is the unspecified adverse effect caused by the expectation or belief that something is harmful to health, this can result in negative symptoms for individuals.  It has been suggested that in electromagnetic hypersensitivity the belief of exposure is enough to cause symptoms and the nocebo effect may play a role in their development (SCENIHR 2009). 

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Summary:

This was a case-control study that investigated the association between exposure to radiofrequency electromagnetic fields (RF-EME) from broadcast and mobile phone antennas and risk of lymphoma. The study included 322 cases and 444 controls. Exposure to RF was assessed via self-reported and quantified distance from the RF transmitters to the residential address and some residential measurements. There was an association between self-reported residential distances less than 50 meters (odds ratio 2.7, 95% confidence interval 1.5-4.6). However there was no statistically significant association with any type of lymphoma when exposure was assessed via quantifying distance to addresses or residential measurements. The authors concluded that there was no association between RF-EME exposure from mobile phone antennas and lymphoma development.

Link to study

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Commentary by ARPANSA:

The evidence on the effects of RF fields and human health has been reviewed recently by the European Scientific Committee on Emerging and Newly Identified Health Risks (SCENHIR, 2015). SCENHIR concluded that there is no substantiated evidence that exposure to RF from base stations and broadcast antennas increases cancer risk.

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The French Agency for Food, Environmental and Occupational Health & Safety (ANSES) at the end of March 2018 published the results of its expert appraisal on electromagnetic hypersensitivity (EHS). It was acknowledged that current scientific evidence shows no cause and effect link between the symptoms of EHS and electromagnetic fields and that it is only possible to identify EHS individuals by their self-reporting. Regardless of this ANSES stated that the suffering and pain of those who declare themselves EHS is real and has significant impact on their daily lives. ANSES recommended suitable training for health and social services professionals to ensure suitable care and counselling for people declaring themselves EHS and for better coordination between facilitators of their care. It was also highlighted that further research is needed and that it should be performed in consultation with the EHS community. ANSES said that long-term funding is required for research on the health effects of electromagnetic fields including long-term studies performed under controlled experimental conditions.

The findings of the expert appraisal by ANSES is in-line with the position of ARPANSA as found on our website and the full news release from ANSES can be found on their website.

ANSES website

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Summary:

In 2011, the International Commission on Radiological Protection (ICRP) made changes to their recommendations for the annual limit of ionising radiation exposure to the lens of the eye for occupational workers. The new limit was 20 mSv per annum, averaged over defined periods, with no year exceeding 50 mSv. This adjustment was due to epidemiological evidence relating to tissue reaction effects for doses to the lens of the eye and possible cataract formation.

Researchers in the USA carried out a prospective study in the years 2003-2005 and 2012-2013 and published the findings. The purpose of the research was to estimate the risk of cataract incidents in a cohort of nuclear medicine (NM) technologists based on their work histories and radiation protection practices. Findings indicated an increased risk of cataracts observed among U.S. radiologic technologists who had performed an NM procedure at least once. The study recommended future studies incorporating estimated lens doses.

PUBMED

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Commentary by ARPANSA:

Previous work in the area of eye dosimetry internationally has been centred on image-guided x-ray interventional procedures (IGIP) that make use of high dose angiographic acquisitions and/or CT fluoroscopy guided interventions¹ with the emphasis for the need for optimisation of protection measures with respect to the lens of the eye. Recommendations that staff wear appropriate eye protection and use protective screens have been made. In Australia currently there is no requirement for medical staff to wear eye dosimeters to measure the radiation exposure to the lens of eye. Furthermore, no research has taken place to estimate the doses these people receive and in particular staff that use unsealed radiopharmaceuticals. Based on the published paper above, Australia may have an opportunity to contribute to international knowledge by carrying out clinical surveys and providing analysis of data from across the country.

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Summary:

Burgard et al conducted a meta-analysis of solarium use and the risk of malignant melanoma. The authors identified 2 cohort and 29 case-control studies that were deemed eligible for the meta-analysis. These studies included 11,706 malignant melanoma cases and 93,236 controls. The studies covered in the meta-analysis were primarily from Europe, North America and Australia.

The authors found that the data support an association between solarium use and malignant melanoma (Odds Ratio, OR=1.19; 95% Confidence Interval, CI=1.04-1.35). In addition, there was a higher association for high exposure to ultraviolet radiation from a solarium (>10 sessions in a lifetime) and melanoma risk (OR=1.43; 95% CI=1.17-1.74). This supports the existence of a dose-response relationship (i.e. the more UV exposure in a solarium, the higher the risk of melanoma). The authors also reported that they found an association between first exposure to ultraviolet radiation from a solarium before age 25 years and melanoma risk (OR=1.59; 95% CI=1.38-1.83).

Despite these findings, the authors concluded that the papers that were included in the analysis were of poor quality and had high risk of bias supporting these associations. Consequently, the meta-analysis concluded that there was no scientific evidence that moderate/responsible solarium use increases the risk of melanoma.

PUBMED

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Anticancer Research: International journal of Cancer Research and Treatment, February 2018; 38 (2) : 591 - 1219

Based on the reported associations between solarium use and malignant melanoma, the scientific evidence supports Australia’s nation-wide policy to ban all commercial solaria.

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This report produced by the Netherlands government compares the electromagnetic field (EMF) exposure policies for both the general public and occupational exposure between countries in the EU (European Union) and other countries including Australia. The report grouped countries by how they have responded to EU recommendations based on guidelines by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) for EMF frequencies and how this has influenced government policy. For group 1 EU recommendations were reflected in legislation and policy, for group 2 recommendations were not reflected in legislation and policy and for group 3 legislation and policy was stricter than recommendations. For power frequencies, Australia is within group 2 as there is no official regulations or guidelines for general public exposure. However Australian electricity grid operators do use the prudent avoidance principles and prescribe the ICNIRP guidelines. For radiofrequencies (RF), Australia is within group 1 as there are national standards regulating RF exposure from telecommunications sources.

Link to full report

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The opinion focussed on four main sources of risk associated with the use of Light Emitting Diodes (LEDs) lighting or displays. These included:

• Hazards to the eyes and skin from direct and diffuse light exposure and long-term health effects in the general population;
• Issues arising from direct viewing of some LED sources where the risk arises from impact on vision such as distraction, glare and after-images;
• Problems with temporal characteristics of the LED emission effecting visual perception of the light or the surrounding environment;
• The effect on the circadian rhythm (sleep wake cycle).

There was sufficient evidence to suggest that the blue light exposure caused disruptions in the circadian rhythm, especially if the exposure occurred in the evening hours before sleep times. This effect was more pronounced in children due to different light penetration properties of the young eye. It was not clear whether this disruption on the sleep wake cycle had any long-term health effects.

Link to opinion

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The main strengths of the review conducted by SCHEER were:

• SCHEER looked at age-dependent effects including exposure to children under 3, adults, the elderly and susceptible groups;
• The potential health effects were examined for exposure to LEDs under normal use or any reasonably foreseeable misuse;
• The review included comparisons to exposures from traditional lighting sources showing lower exposure from LEDs at wavelengths in the UV and Infrared regions.