Radiation literature survey

Review date

September 2023

Article publication date

August 2023

Summary

Australia has one of the highest incidences of melanoma and non-melanoma skin cancers worldwide. A major cause of skin cancers is excessive and unprotected exposure to ultraviolet (UV) radiation, with effective sun protection behaviours making such cancers preventable. This cross-sectional study investigated changes in the sun protection behaviours of Western Australian adolescents and adults during the summers between 2015/16 and 2020/21. Over this six-year period, 1806 14-17 year olds and 1808 18-45 year olds were involved in a randomised phone survey that assessed their frequency of five sun protection behaviours – wearing protective clothing, applying sunscreen, wearing a hat, wearing sunglasses and seeking shade, as well as demographic factors such as their gender, skin type and area of residency. Sun avoidance by staying indoors was also assessed. Amongst the adolescent group, it was found that the use of hats and sunscreen remained relatively stable, seeking shade and sun avoidance increased, and wearing protective clothing and sunglasses decreased. All sun protection behaviours remained relatively stable over the six-year period in the adult group, except for wearing sunscreen, which increased. Overall, the sun protection behaviours of adults were found to be better than that of adolescents. It was noted that the findings of this study could assist in tailoring messages to shape future health promotions regarding sun exposure.

Link to

Patterns of Sun Protection Behaviours among Australian Adolescents and Adults over a Six-Year Period

Published in

Current Oncology

ARPANSA commentary

Australia experiences some of the highest levels of UV radiation in the world, with the UV index frequently reaching over 11 (extreme) in some parts of the country during the summer months. Consequently, more than two in three Australians will be diagnosed with skin cancer in their lifetime, many of which will be UV induced and preventable. Sun protection behaviours and actions are extremely important to reduce this exposure and decrease the incidence of UV induced skin cancers. Sun protection is strongly recommended when the UV index reaches 3 or higher. Real time UV index measurements that can be used to determine when sun protection is needed can be found on the ARPANSA Ultraviolet Radiation Index webpage.

Sun protection is particularly important for Australian children and adolescents. High sun exposure in the first decade of life more than doubles the risk of developing melanoma later in life. Similarly, intense, intermittent sun exposure (number of sunburns and sunbathing vacations) during each decade up to 29 years of age increases risk of melanoma by more than one-and-a-half times.

It is concerning that the study showed that the sun protection behaviours of adolescents decreased over the six-year period. Similar findings have been reported in studies completed by the Australian Cancer Council. Both studies also report that the percentages of adults and adolescents that engage in these behaviours are troublingly low. Ideally, 100% of Australians would partake in sun protection behaviours when outside and the UV index is 3 or above, but no single behaviour surpasses 61% in either study.

It is important that Australians, particularly children and adolescents, are aware of the dangers of UV exposure and are encouraged to partake in sun protection behaviours. The SunSmart Website provides advice on sun protection for families with teens. The results of this study indicate that more work needs to be done in increasing awareness and promoting sun protection behaviours. More information on UV protection can be found on the ARPANSA Sun Protection factsheet.

Review date

September 2023

Article publication date

August 2023

Summary

This multinational cohort study investigated the effect of long term low dose and low dose rate exposure to ionising radiation on cancer risk for workers included in an update to The International Nuclear Workers Study (INWORKS). INWORKS includes data from cohorts of nuclear workers with personal dosimeters in France, the UK, and the US. Overall, the study included 309 932 workers. The study found the excess relative risk  of mortality due to solid cancer with cumulative dose to be 0.52 (90% confidence interval 0.27 to 0.77) per gray (Gy). Smoking and asbestos exposure were investigated as confounders by excluding deaths from lung cancer and pleural cancer, and it was determined that they did not have a substantial effect. The results of this study show an increase in the relative rate of cancer mortality with increasing exposure to ionising radiation. The study notes that the estimated excess relative risk is even greater than estimates currently informing radiation protection.

Link to

Cancer mortality after low dose exposure to ionising radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study

Published in

BMJ

ARPANSA commentary

The study reports evidence of an increase in the excess relative risk of solid cancer mortality with increasing cumulative exposure to ionising radiation at low dose rates. This is consistent with the current approach to radiation protection where a linear association between cumulative low dose ionising radiation and solid cancer is assumed, primarily informed by studies of atomic bombing survivor cohorts (WHO). The reported findings are also consistent with the majority of epidemiological studies investigating low dose exposure and cancer mortality (Rühm et al., 2022 and Hauptmann et al., 2020).

The INWORKS study does not have individual level data on some potentially important confounding factors, such as smoking and asbestos. The impact of these factors could only be indirectly assessed by excluding related cancers from the study. Lack of individual level data means the impact of these factors could not be measured empirically.

A cohort study (Sokolnikov et al., 2015) of workers employed at Mayak facilities for plutonium production, which has been influential in impacting estimates of excess relative risk in literature reviews due to its size and high magnitude doses, estimated an excess relative risk three to four times lower than the INWORKS study.

ARPANSA aims to ensure the highest standard of protection against the harmful effects of radiation to people and the environment, which is outlined in relevant Codes and Safety Guides. The requirements in Australia for the protection of both occupationally exposed people and members of the public for planned exposure situations are outlined in the Code for Radiation Protection in Planned Exposure Situations (2020), RPS C-1 (Rev.1). The annual exposure limits to ionising radiation, across all Australian jurisdictions, is 1 milliseiverts (mSv) for the public and 20 mSv for the occupationally exposed.

Review date

18 August 2023

Article publication date

July 2023

Summary

This ecological study evaluates the relationship between incidence and mortality trends of malignant brain tumours and  the number of mobile phone users in Taiwan. Data on brain tumour trends and mobile phone use (for the period of 2000–2019) were obtained from the Taiwan Cancer Registry and the National Communications Commission, respectively. The study showed a large increase in mobile phone use over the period whilst the brain tumour and mortality rates have remained stable. The study did not show any significant association between the number of mobile phone users and brain tumour incidences and mortalities over 20 years.

Link to

Incidence and Mortality of Malignant Brain Tumors after 20 Years of Mobile Use

Published In

Cancers

ARPANSA commentary

Consistent to previous studies (Deltour et al., 2022, Elwood et al., 2022) including that conducted in Australia (Karipidis et al., 2018), this study indicates no association between increased number of mobile phone users and brain tumour incidence and/or mortality. Ecological studies despite having their benefits (e.g., low cost and useful in hypothesis generation), offer a limited level of evidence and suffer from the ecological fallacy.

The findings of this study are in line with a recent review conducted by the US Food and Drug Administration on RF-EMF and Cancer. The World Health Organization is currently assessing state-of-the-art evidence on potential human health effects (including brain tumours) of exposure to radiofrequency (RF) electromagnetic fields (EMF) such as those associated with mobile phone use in human populations. Based on the current scientific evidence, and consistent with the findings of this study, it is the assessment of ARPANSA that there is no substantiated evidence that RF-EMF exposures at levels below the limits set in the ARPANSA Safety Standard cause any adverse health effects, including cancers in human populations.

Review date

9 August 2023

Article publication date

April 2023

Summary

This cross-sectional study assessed the relationship between self-reported skin cancer prevalence and the UV index in the United States (US). The study was based on the data from the Center for Disease Control and Prevention’s 2019 Behavioral Risk Factor Surveillance System. Self-reported data on lifetime skin cancer risk among 310,750 non-Hispanic white adults were collected from 47 continental states and the District of Columbia; while UV index data were gathered from the National Oceanic and Atmospheric Administration UV index database. The study examined the significance of living in a low (5 or less), medium (6–7), or high (8 or higher) UV index state. Among reported 29,925 skin cancer cases, the prevalence of skin cancer was significantly higher in high UV index (> / = 8) states than in medium UV (6–7) and lower UV (< / = 5) (p < 0.0001). Compared to the respondents from low UV index states, those from a medium or high UV index states had higher odds of reporting a skin cancer diagnosis; Odds radio (OR) = 1.21 [confidence interval (CI): 1.15–2.27], OR =1.55 [CI: 1.47–1.63], respectively. The study concluded that UV exposure index (i.e., geographical residence) is related to prevalence of skin cancers in the United States.

Link to

The epidemiology of skin cancer by UV index: cross-sectional analysis from the 2019 behavioral risk factor surveillance survey

Published in

Archives of Dermatological Research

ARPANSA commentary

This study indicated an association between UV exposure index and prevalence of skin cancers.

This finding is consistent with a latest study from the US (Borad et al., 2023) that found an association between paediatric melanoma cases and UV index among white children. Similarly, a review (Xiang et al., 2014), that examined studies between 1978 and 2012, indicated higher ambient daily UV exposure to be associated with higher skin cancer incidence rates in white populations. Limitations of this study include self-reported skin cancer diagnosis by the respondents. Though comparable data from Australia are limited, a high proportion of skin cancers in Australia are attributable to high ambient levels of UV radiation exposure (Olsen et al., 2010). For example, 7,220 melanomas and essentially all keratinocyte cancers reported (in the year 2010) in Australia were attributable to high ambient UV exposure levels in Australia.

The Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) measures the UV index in various locations in Australia and makes this real-time data publicly available daily. In view of preventing skin cancer occurrences, Australia implements the world leading SunSmart program, which recommends people to adopt a combination of five sun protection measures, namely; Slip (on clothing), Slop (on SPF50 or higher), Slap (on a hat), Seek (a shade), Slide (on sunglasses), whenever the UV index is 3 or above. ARPANSA also provides evidence-based public health messages in relation to UV protection measures, including sun protection factsheets. A Free SunSmart Global UV app provides real time sun protection advice for Australian and major international cities to inform people about sun protection measures, whenever required.

Review date

July 2023

Article publication date

May 2023

Summary

This experimental and observational study examined bee exposure to extremely low frequency (ELF) electric and magnetic fields (EMF). The study observed bee visitation to flowers around active and inactive power transmission towers. The study also placed caged bees under active and around inactive power transmission towers and exposed bees to ELF EMF in the laboratory using a solenoid. ELF EMF exposure in the field around the active power transmission towers was approximately 9.47 μT compared to 1.5 μT around the inactive towers. The exposure in the laboratory was approximately 7.8 μT. The exposed bees were tested for changes in mRNA levels of stress response genes such as heat shock proteins (HSP) and genes that relate to behavioural changes in bees such as the caMKII that relates to long term memory.  The study also examined flower abundance around power transmission towers. The study reported that flower visits did not change based on ELF EMF exposure. However, flower abundance was reduced around active power transmission towers, and this reduced the number of bee visits to that area. The authors reported that bees exposed to ELF EMF both in the laboratory and in the field were showed increased expression of HSP70 and reduced expression in caMKII. The authors concluded that ELF EMF exposure impacts bee physiology and behaviour.

Link to

Electromagnetic fields disrupt the pollination service by honeybees

Published in

Science Advances

ARPANSA commentary

This paper reported an increase in the expression of HSP and genes related to behaviour in bees when exposed to ELF EMF. Very few studies have examined changes in expression related to ELF EMF exposures in bees or even in insects. A previous study exposed cockroaches  to ELF EMF at 1000 μT and found no changes in expression of HSP70, however, the study did find an increase in HSP expression at 10,000 μT, which is 50 times greater than  the international human safety limit of 200 μT (ILIJIN et al 2021). Another study exposed flies to ELF at 0.004 μT and reported increases, decreases and no changes in expression of HSP70 in different exposed fly groups when compared to controls (Tipping et al 1999).

The current study also reported changes in the expression of caMKII that may be associated with long term memory. However, despite this change in expression of this gene there were no behavioural changes observed in exposed bees. This may indicate that the level of expression change in caMMKII observed has no functional outcome in bees.

The study did not report on possible confounders, such as the presence of herbicides. They are commonly used to control vegetation around transmission lines and towers. The use of herbicide, specifically glyphosate also known as roundup, has been shown to change gene expression in bees (Battisti et al 2022). Glyphosate has been reported to increase the expression of HSP and effect learning and memory (Tan et al 2022). The use of herbicides would also explain the reduction in flower abundance around the power transmission towers.

Generally, most research has been at levels much higher than would normally be encountered by bees in the environment. The evidence on the effect of ELF EMF on insects remains weak with some conflicting results and further research is required (Vanbergen et al, 2019).

Review date

19 July 2023

Article publication date

May 2023

Summary

This systematic review examined the physical agents flight crew are exposed to during their work. The review included 35 epidemiological studies (32 cohort, 2 case-control and 1 cross-sectional). The review reported that most of the included studies were of moderate quality, and often had short observation durations which reduce the level of evidence they provide. It found that cosmic radiation, air pressure, noise, and vibrations were the main risk factors for aircrew. The study also investigated hypobaric pressure as a potential risk factor but found knowledge gap in this area. The review reported conflicting results with some research linking cosmic radiation exposure in aircrew to increased cancer incidence and other research reporting no significant difference between cancer cases in aircrew and the general population. The systematic review concluded that long term studies are needed to improve the understanding of potential occupational health risks among aircrews.

Link to

Aircrew Health: A Systematic Review of Physical Agents as Occupational Risk Factors

Published in

International Journal of Environmental Research and Public Health

ARPANSA commentary

The findings of this review are consistent with a previous Australian study (Dusingize et al, 2019) conducted in conjunction with ARPANSA that examined how flying hours of pilots influence the incidence of cancer, particularly melanoma. The study identified cosmic radiation and ultraviolet (UV) radiation as possible risk factors. The Australian study found that the most exposed pilots are at no increased risk of melanoma when comparing pilots who fly the most and those that fly the least. Another review by Scheibler et al (2022) reported that the epidemiological literature provides little consistent evidence that directly links cosmic radiation with cancer in flight crew. This review does go on to say that there is some evidence of an association between cancer and occupational exposure to the flight environment, however, it is difficult to disentangle cosmic radiation exposure from other environmental influences such as circadian rhythm disruption.

The ARPANSA Guide for Radiation Protection in Existing Exposure Situations Radiation Protection Series G-2 provides a framework for managing existing exposure situations, including exposure of aircrew due to cosmic radiation. Similarly, ARPANSA’s Radiation Protection Standard for Occupational Exposure to Ultraviolet Radiation (2006) sets fundamental requirements for safety in relation to occupational UV radiation exposure. Although an elevated risk of skin melanoma among commercial pilots has been indicated by recent epidemiological studies (Olsen et al, 2019), generally, there is no increase in health risk from exposure to cosmic or UV radiation for casual flyers. However, some of the frequent flyers (critical population groups e.g., pregnant women and children) may exceed  exposure safety limits for cosmic radiation (Tate et al, 2021), and hence additional awareness or protection may be considered.

Review date

18 July 2023

Article publication date

June 2023

Summary

This cross-sectional study assessed sun protection behaviours and associated covariates (e.g.,  sex and job-related characteristics) among German outdoor workers. Data on their use of sun protection measures, job-related characteristics, socio-demographic, and skin type were collected (through interview) during October-December 2021 from 486 outdoor workers (aged 16-65 years). The study found that the main sun protection measures used were ‘taking a lunch break in the shade’ (~83%), ‘wearing a shirt that covers shoulders’ (~77%), and ‘long trousers’ (62%). About one third always or often wore headgear, sunglasses, and work gloves. Sunscreen was more often or always used on the face (38.4%) compared with the rest of the body (25.4%). Use of sunscreen (with Sun Protection Factor 50/50+) on the face or the body was only observed in less than one third of the workers. Compared with participants with low formal education, outdoor workers with high education were more likely to use sunscreen on their faces, and wear sunglasses. Further, females were more likely to use sunscreen, while males were more likely to wear sun protective clothes and headgear. The use of sun protection measures among female workers did not differ by participants’ individual and job-related characteristics; whilst it differed for male workers widely. Use of sun protection measures was not associated with skin type. Occupation type was associated with wearing a shoulder-covering shirt (e.g., police/security service/military, post, parcel, or delivery service workers) or wearing headgear (e.g., horticulture, agriculture/animal husbandry/forestry workers). The authors concluded that German outdoor workers had inadequate sun protection measures and this needs due attention by health authorities.  

Link to

Sun Protection in German Outdoor Workers: Differences by Sex and Job-Related Characteristics

Published in

Annals of Work Exposures and Health

ARPANSA commentary

This study puts light on the inadequacy of sun protection measures among outdoor workers in Germany. The findings of this study are consistent with those of previous studies conducted in Germany (Schneider et al., 2018) and elsewhere (e.g., Grandahl et al., 2018; Modenese et al., 2020; Rydz et al., 2021). Limitations of this study include likely inaccuracies associated with the reporting of sun protection measures,  particularly related to social desirability bias and recall bias. Though comparable data from Australia are limited (Tabbakh et al., 2019; Haynes et al., 2020), use of sun protection measures for Australian outdoor workers has always been highly recommended during all months or seasons due to considerable UV exposure and potential health risk. Further, Australia’s world leading SunSmart program recommends outdoor workers to implement a combination of five measures, namely; Slip (on clothing), Slop (on SPF30 or higher), Slap (on a hat), Seek (a shade), Slide (on sunglasses). The Australian Radiation Protection and Nuclear Safety Agency provides evidence-based public health messages in relation to UV protection measures, including information on a real time UV index, estimation of UV dose and sun protection factsheets.

Review date

18 July 2023

Article publication date

February 2023

Summary

This retrospective cohort study evaluated the association between occupational radiofrequency-electromagnetic field (RF-EMF) exposure and incidence of cancer among military personnel. All military personnel serving in aerial defence units (with RADAR systems) exposed to RF-EMF exposures (n=11,049) and active-duty soldiers (with no occupational RF-EMF exposures, n=3,825) serving between 2009 and 2018 were included and were followed-up for on average of 4.6 (exposed group) and 4.8 (non-exposed group) years.  A total of 41 cases (13 in exposed group; 28 in non-exposed group) were diagnosed with cancer during the follow-up period. Information on RF-EMF exposure history (e.g., start year of exposure) and socio-demographics of the participants were collected from the Israel Defense Forces Medical Corps database, while cancer incidence data were collected from the Israeli National Cancer Registry. The results showed that there was no statistically significant association between occupational RF-EMF exposure and incidence of cancer (Odds ratio = 1.38 [95% Confidence Interval: 0.67-2.82]. The study concluded that RF-EMF exposure did not increase the risk for cancer in young adults.

Link to

Occupational Exposure to Nonionizing Radiation and Risk for Malignancy in Young Adults

Published in

Military Medicine

ARPANSA commentary

Overall, this study showed that occupational RF-EMF exposure in military personnel is not associated with short-term cancer incidence. This finding is largely consistent to a previous study conducted among veterans of the Korean War (Groves et al., 2002), but in contrast to other studies reporting increased risk of hematolymphatic cancers among Polish military personnel (Szmigielski, 1996)  and neurologic cancers (Grayson, 1996) among the US Air Force personnel. However, a meta-analysis (Variani et al., 2019) did not show any association between occupational RF-EMF exposure to radar and cancer incidence or mortality rate.  The study limitations include lack of objective data on personal RF-EMF exposure, small number of cancer cases and short follow-up time (e.g., a median of 4.4 years in the exposed group), and it did not adjust for potential confounders such as smoking status, alcohol consumption, dietary, lifestyle habits and other occupational exposures. It is the assessment of ARPANSA and international organisations such as the World Health Organisation (WHO) and the International Commission on Non-Ionising Radiation (ICNIRP) that there is no established scientific evidence to support that RF-EMF exposure increases the risk for cancer. In line with international guidelines from ICNIRP, the ARPANSA safety standard Radiation Protection Series S-1 (Rev. 1) | ARPANSA sets out the sets limits of exposure to RF-EMF for the public and workers. 

Review date

17 July 2023

Article published date

December 2022

Summary

This systematic scoping review analysed and summarised the available data (1980 - 2021) on the mortality burden of lung cancer due to radon. A total of 24 eligible studies from 14 different countries providing radon exposure and radon attributable mortality data were evaluated. Radon attributable mortality was estimated as population attributable fraction (PAF in %) and was given as a function of the radon geometric mean concentration in the area of study. Thirteen studies used risk models based on miners’ cohorts, eight used risks from residential radon case-control studies and three used both risk models. The reported radon concentration geometric mean was 11-83 Bq m^-3; whereas the PAF was 0.2-26%. Of the radon PAF for lung cancer mortality reported in the included high-quality studies, residential risk sources and miner risk sources had PAFs of 3-12% and 7-25%, respectively. Overall, the study found that PAF for lung cancer due to radon exposure varies widely between countries (0.2–26%), which is partly due to the different radon exposure levels and risk source types.

Link to

Lung cancer mortality attributable to residential radon: a systematic scoping review

Published in

Journal of Exposure Science & Environmental Epidemiology

ARPANSA commentary

The study provides a pooled estimation of the burden of lung cancer mortality associated with radon exposure and indicates that PAF for lung cancer varies widely. The reported higher PAF for lung cancer among radon-exposed miners is consistent with existing literature reporting an increased lung cancer incidence among miners (e.g., Lane et al., 2019; Zablotska et al., 2022).Though comparable data (including that on radon exposure related PAF for lung cancer) from Australia are limited, an Australian study (Peters et al., 2013) has shown an elevated risk of lung cancer among underground mining workers.

According to the Australian Radiation Protection and Nuclear Safety Agency led nationwide survey of more than 3300 Australian homes, the average radon exposure level in Australian homes is much lower (~10 Bq m⁻³) compared to the global average (40 Bq m⁻³). Similarly, radon exposure among Australian miners (e.g., uranium mining and milling industry) also remains low and is regulated to minimise cancer risk. The Code for Radiation Protection in Planned Exposure Situations sets out the requirements for the protection of occupationally exposed persons in uranium mines. Though an additional risk of lung cancer incidence related to radon exposure has been established, the risk is much smaller compared to that from tobacco smoking (ICRP, 2010). Therefore, avoiding tobacco smoking ultimately reduces the total lung cancer risk, including that from radon exposure. This would translate to the reduction in PAF for radon exposure related lung cancer.

Review date

June 2023

Article published date

May 2023

Summary

This systematic review and meta-analysis examined the association between ionising and different types of non-ionising radiation exposure and childhood health conditions. The meta-analysis included 14 epidemiological studies (4 cohort, 8 case-control, 2 cross-sectional). The meta-analysis found an increase in the risk of birth defects (odd ratios (OR) 1.34; 95% confidence intervals (CI) 1.17–1.52), cancer (OR 1.14; 95% CI 1.05–1.23) and developmental disorders (OR 2.10; 95% CI 1.00–3.21) in children of parents exposed to ionising and non-ionising radiations compared to those who were not. The authors concluded that there is evidence of negative health outcomes in children from parental exposure to radiation, however, they suggested that due to the poor exposure assessment of the included studies and the inherent bias of case-control/cross-sectional studies their results should be interpreted with caution.

Link to

Electromagnetic fields exposure on fetal and childhood abnormalities: Systematic review and meta-analysis

Published in

Open medicine

ARPANSA commentary

This meta-analysis conflated radiofrequency electromagnetic fields (RF EMF) , ultrasound, X-rays and extremely low frequency electric and magnetic (ELF EMF) fields together when it assessed childhood health effects. This goes against the expected formulation of how to conduct a meta-analysis and is not good science. This is because all these types of radiation can affect the body in different ways and should be assessed separately.

The authors did not include many studies that would have fit their inclusion criteria. Some key articles they missed are: Malagoli et al (2012) that found no risk of birth defects from maternal exposure to ELF EMF, two studies by Auger et al (2019a, 2019b) that found no evidence that proximity to powerlines increases the risk of birth defects or cancer, and Reid et al (2011) that found parental exposure to ELF EMF had no impact on childhood acute lymphoblastic leukaemia. The authors have missed many more studies than those outlined here. However, because of the wide range of radiation types and health effects they examined it is difficult to identify them all without completely redoing their study. The large number of studies they missed is a failure in study design to effectively narrow down on a topic.

Overall, this meta-analysis adds no value to the research on the association between ionising and non-ionising radiation exposure and childhood health conditions.

It is the assessment of ARPANSA and other health authorities, including the World Health Organization (WHO) and International Commission on Non-Ionizing Radiation Protection (ICNIRP), that there is no substantiated scientific evidence that RF EMF or ELF EMF exposure at levels below the Australian Electromagnetic Fields Standard cause any adverse health effect, including in children.

The WHO has published the protocol for two upcoming systematic reviews on birth outcomes resulting from RF exposure that will be completed in 2023 (Pacchierotti et al (2022) and Kenny et al (2022)). These reviews should provide a high quality assessment of the evidence on this topic.