Micro-environmental personal radio-frequency electromagnetic field exposures in Melbourne: A longitudinal trend analysis

BACKGROUND

A knowledge gap exists regarding longitudinal assessment of personal radio-frequency electromagnetic field (RF-EMF) exposures globally. It is unclear how the change in telecommunication technology over the years translates to change in RF-EMF exposure. This study aims to evaluate longitudinal trends of micro-environmental personal RF-EMF exposures in Australia.

METHODS

The study utilised baseline (2015-16) and follow-up (2022) data on personal RF-EMF exposure (88 MHz-6 GHz) measured across 18 micro-environments in Melbourne. Simultaneous quantile regression analysis was conducted to compare exposure data distribution percentiles, particularly median (P50), upper extreme value (P99) and overall exposure trends. RF-EMF exposures were compared across six exposure source types: mobile downlink, mobile uplink, broadcast, 5G-New Radio, Others and Total (of the aforementioned sources). Frequency-specific exposures measured at baseline and follow-up were compared. Total exposure across different groups of micro-environment types were also compared.

RESULTS

For all micro-environmental data, total (median and P99) exposure levels did not significantly change at follow-up. Overall exposure trend of total exposure increased at follow-up. Mobile downlink contributed the highest exposure among all sources showing an increase in median exposure and overall exposure trend. Of seven micro-environment types, five of them showed total exposure levels (median and P99) and overall exposure trend increased at follow-up.

Mobile phone carrying locations and risk perception of men: A cross-sectional study

Little was known about the relationship between carrying mobile phone handsets by men and their risk perception of radiofrequency-electromagnetic field (RF-EMF) exposure due to carrying handsets close to the body. This study aimed to determine where men usually carried their handsets and to assess the relationship to risk perception of RF-EMF. Participants completed a self-administered questionnaire about mobile phone use, handset carrying locations, and levels of risk perception to RF-EMF. Data were analysed using linear regression models to examine if risk perception differed by mobile phone carrying location. The participants were 356 men, aged 18–72 years. They owned a mobile phone for 2–29 years, with over three quarters (78.7%) having a mobile phone for over 20 years. The most common locations that men kept their handsets when they were ‘indoors’ were: on a table/desk (54.0%) or in close contact with the body (34.7%). When outside, 54.0% of men kept the handset in the front trouser pocket. While making or receiving calls, 85.0% of men held their mobile phone handset against the head and 15.0% either used earphones or loudspeaker. Men who carried their handset in close contact with the body perceived higher risks from RF-EMF exposure compared to those who kept it away from the body (p<0.01). A substantial proportion of men carried their mobile phone handsets in close proximity to reproductive organs i.e. front pocket of trousers (46.5%). Men who kept their handset with the hand (p < .05), and those who placed it in the T-shirt pocket (p < .05), while the phone was not in use, were more likely to perceive health risks from their behaviour, compared to those who kept it away from the body. However, whether this indicates a causal relationship, remains open.

Less extensive surgery for low-risk papillary thyroid cancers post 2015 American Thyroid Association guidelines in an Australian tertiary centre

INTRODUCTION

The 2015 American Thyroid Association guidelines (ATA15) consider hemithyroidectomy (HT) a viable treatment option for low-risk papillary thyroid cancers (PTCs) between 1 and 4 cm. We aimed to examine the impact of ATA15 in a high-volume Australian endocrine surgery unit.

METHODS

A retrospective study of all patients undergoing thyroidectomy from January 2010 to December 2019.

INCLUSION CRITERIA

PTC histopathology, Bethesda V-VI, size 1-4 cm, and absence of clinical evidence of lymph node or distant metastases pre-operatively. Primary outcome was rate of HT before and after ATA15.

RESULTS

Of 5408 thyroidectomy patients, 339 (6.3%) met the inclusion criteria - 186 (54.9%) pre-ATA15 (2010-2015) and 153 (45.1%) post-ATA15 (2016-2019). The patient groups were similar; there were no significant differences between groups in age, sex, tumour size, proportion with Bethesda VI cytology, compressive symptoms, or thyrotoxicosis. Post-ATA15, there was a significant increase in HT rate from 5.4% to 19.6% (P = 0.0001). However, there was no corresponding increase in completion thyroidectomy (CT) rate (50.0% versus 27.6%, P = 0.2). The proportion managed with prophylactic central neck dissection (pCND) fell from 80.5% to 10.8% (P < 0.0001). Pre-ATA15, the only factor significantly associated with HT was Bethesda V. In contrast, post-ATA15, HT was more likely in patients with younger age, smaller tumours, and Bethesda V.

CONCLUSION

After the release of 2015 ATA guidelines, we observed a significant increase in HT rate and a significant decrease in pCND rate for low-risk PTCs in our specialised thyroid cancer unit. This reflects a growing clinician uptake of a more conservative approach as recommended by ATA15.

Quantifying the differences in surgical management of patients with definitive and indeterminate thyroid nodule cytology

INTRODUCTION

Thyroid nodules are increasingly common. Despite being an essential pre-operative diagnostic tool, up to 30% of fine needle aspirate cytology (FNAC) yields a non-definitive diagnosis. This study aimed to quantify differences in surgical management of patients with definitive and indeterminate thyroid nodule cytology, and determine if clinical factors can improve cytological diagnosis.

MATERIALS AND METHODS

Patients who underwent thyroidectomy for nodules from 2001 to 2015 were recruited. Those with benign and malignant preoperative cytology were included in the "definitive diagnosis" (DC) group; patients with all other preoperative cytology results were included in the "indeterminate diagnosis" (IC) group. We compared demographics and procedures between these groups. Clinical factors and demographics were also compared between patients with benign and malignant histology in the IC group.

RESULTS

A total of 3821 cases were included. A significantly larger proportion of the IC patients had a hemithyroidectomy (IC 69% vs. DC 39%, p < 0.001) initially, and also had a significantly higher rate of two-stage surgery compared to the DC group (IC 17% vs. DC 11%, p < 0.001). Patients in the DC group were twice as likely to undergo concurrent central lymph node dissection for papillary and medullary cancers than the IC group (p < 0.001). Overall, up to 60% of IC patients had been over- or under-treated at initial surgery. The clinical factors examined were not significantly associated with higher risk of malignancy in IC patients.

CONCLUSION

This study highlights the potential for improved preoperative diagnosis to streamline decision making for surgical management of patients with thyroid nodules.

Radiofrequency electromagnetic field exposure and risk perception: A pilot experimental study

BACKGROUND

Exposure to far-field radiofrequency electromagnetic fields (RF-EMF) has raised public concerns in recent decades. However, it is not known if individuals' perception towards the health risks of RF-EMF is dependent on their knowledge of the objectively measured personal RF-EMF exposure levels.

OBJECTIVES

This pilot study aimed to demonstrate the feasibility of objectively measuring personal RF-EMF exposure from mobile phone base stations (MPBS) and to determine if the risk perception of people to the potential health risk of exposure to RF-EMF from MPBS is dependent on their knowledge of personal RF-EMF exposure levels.

DESIGN

An experimental study was conducted in 383 adults, recruited in Melbourne, Australia. Participants were randomized to one of the three groups: 1) basic information group who were provided with basic information about RF-EMF to read prior to completing a risk perception assessment questionnaire; 2) precautionary group who were provided with an information pack which included precautionary messages; and 3) personal exposure measurement group who were provided with a summary of their quantitative RF-EMF exposure from MPBS. The same basic information about RF-EMF was also given to the precautionary and personal exposure measurement groups.

RESULTS

Participants had a mean (± SD) age of 36.9 ± 12.5 years; 66.7% were women. Overall, 44.1% had noticed an MPBS in their neighbourhood. The mean (SD) values (from 1 to 7) for risk perceptions to RF-EMF from MPBS were 4.02 (1.67) for basic information, 3.82 (1.62) for precautionary messages, and 3.97 (1.72) for the personal exposure measurement groups. These differences were not statistically significant. Nevertheless, the personal exposure measurement group were more confident that they could protect themselves from RF-EMF than the precautionary or basic information groups.

CONCLUSION

Our findings suggest that providing people with personal RF-EMF exposure measurements may not affect their perceived risk from MPBS, but increase their confidence in protecting themselves.

Personal Exposure to Radio Frequency Electromagnetic Fields among Australian Adults

The measurement of personal exposure to radiofrequency electromagnetic fields (RF-EMFs) is important for epidemiological studies. RF-EMF exposure can be measured using personal exposimeters that register RF-EMFs over a wide range of frequency bands. This study aimed to measure and describe personal RF-EMF exposure levels from a wide range of frequency bands. Measurements were recorded from 63 participants over an average of 27.4 (±4.5) hours. RF-EMF exposure levels were computed for each frequency band, as well as from downlink (RF from mobile phone base station), uplink (RF from mobile phone handsets), broadcast, and Wi-Fi. Participants had a mean (±SD) age of 36.9 ± 12.5 years; 66.7% were women; and almost all (98.2%) from urban areas. A Wi-Fi router at home was reported by 61 participants (96.8%), with 38 (61.2%) having a Wi-Fi enabled smart TV. Overall, 26 (41.3%) participants had noticed the existence of a mobile phone base station in their neighborhood. On average, participants estimated the distance between the base station and their usual residence to be about 500 m. The median personal RF-EMF exposure was 208 mV/m. Downlink contributed 40.4% of the total RF-EMF exposure, followed by broadcast (22.4%), uplink (17.3%), and Wi-Fi (15.9%). RF-EMF exposure levels on weekdays were higher than weekends (p < 0.05). Downlink and broadcast are the main contributors to total RF-EMF personal exposure. Personal RF-EMF exposure levels vary according to day of the week and time of day.

Representativeness and repeatability of microenvironmental personal and head exposures to radio-frequency electromagnetic fields

The aims of this study were to: i) investigate the repeatability and representativeness of personal radio frequency-electromagnetic fields (RF-EMFs) exposure measurements, across different microenvironments, ii) perform simultaneous evaluations of personal RF-EMF exposures for the whole body and the head, iii) validate the data obtained with a head-worn personal distributed exposimeter (PDE) against those obtained with an on-body worn personal exposimeter (PEM). Data on personal and head RF-EMF exposures were collected by performing measurements across 15 microenvironments in Melbourne, Australia. A body-worn PEM and a head-worn PDE were used for measuring body and head exposures, respectively. The summary statistics obtained for total RF-EMF exposure showed a high representativeness (r² > 0.66 for two paths in the same area) and a high repeatability over time (r² > 0.87 for repetitions of the same path). The median head exposure in the 900MHz downlink band ranged between 0.06V/m and 0.31V/m. The results obtained during simultaneous measurements using the two devices showed high correlations (0.42 < r² < 0.94). The highest mean total RF-EMF exposure was measured in Melbourne's central business district (0.89V/m), whereas the lowest mean total exposure was measured in a suburban residential area (0.05V/m). This study shows that personal RF-EMF microenvironmental measurements in multiple microenvironments have high representativeness and repeatability over time. The personal RF-EMF exposure levels (i.e. body and head exposures) demonstrated moderate to high correlations.

Radiofrequency-electromagnetic field exposures in kindergarten children

The aim of this study was to assess environmental and personal radiofrequency-electromagnetic field (RF-EMF) exposures in kindergarten children. Ten children and 20 kindergartens in Melbourne, Australia participated in personal and environmental exposure measurements, respectively. Order statistics of RF-EMF exposures were computed for 16 frequency bands between 88 MHz and 5.8 GHz. Of the 16 bands, the three highest sources of environmental RF-EMF exposures were: Global System for Mobile Communications (GSM) 900 MHz downlink (82 mV/m); Universal Mobile Telecommunications System (UMTS) 2100MHz downlink (51 mV/m); and GSM 900 MHz uplink (45 mV/m). Similarly, the three highest personal exposure sources were: GSM 900 MHz downlink (50 mV/m); UMTS 2100 MHz downlink, GSM 900 MHz uplink and GSM 1800 MHz downlink (20 mV/m); and Frequency Modulation radio, Wi-Fi 2.4 GHz and Digital Video Broadcasting-Terrestrial (10 mV/m). The median environmental exposures were: 179 mV/m (total all bands), 123 mV/m (total mobile phone base station downlinks), 46 mV/m (total mobile phone base station uplinks), and 16 mV/m (Wi-Fi 2.4 GHz). Similarly, the median personal exposures were: 81 mV/m (total all bands), 62 mV/m (total mobile phone base station downlinks), 21 mV/m (total mobile phone base station uplinks), and 9 mV/m (Wi-Fi 2.4 GHz). The measurements showed that environmental RF-EMF exposure levels exceeded the personal RF-EMF exposure levels at kindergartens.

Use of mobile and cordless phones and change in cognitive function: a prospective cohort analysis of Australian primary school children

BACKGROUND

Some previous studies have suggested an association between children's use of mobile phones (MPs)/cordless phones (CPs) and development of cognitive function. We evaluated possible longitudinal associations between the use of MPs and CPs in a cohort of primary school children and effects on their cognitive function.

METHODS

Data on children's socio-demographics, use of MPs and CPs, and cognitive function were collected at baseline (2010-2012) and follow-up (2012-2013). Cognitive outcomes were evaluated with the CogHealth™ test battery and Stroop Color-Word test. The change in the number of MP/CP voice calls weekly from baseline to follow-up was dichotomized: "an increase in calls" or a "decrease/no change in calls". Multiple linear regression analyses, adjusting for confounders and clustering by school, were performed to evaluate the associations between the change in cognitive outcomes and change in MP and CP exposures.

RESULTS

Of 412 children, a larger proportion of them used a CP (76% at baseline and follow-up), compared to a MP (31% at baseline and 43% at follow-up). Of 26 comparisons of changes in cognitive outcomes, four demonstrated significant associations. The increase in MP usage was associated with larger reduction in response time for response inhibition, smaller reduction in the number of total errors for spatial problem solving and larger increase in response time for a Stroop interference task. Except for the smaller reduction in detection task accuracy, the increase in CP usage had no effect on the changes in cognitive outcomes.

CONCLUSION

Our study shows that a larger proportion of children used CPs compared to MPs. We found limited evidence that change in the use of MPs or CPs in primary school children was associated with change in cognitive function.

Assessment of personal exposure from radiofrequency-electromagnetic fields in Australia and Belgium using on-body calibrated exposimeters

The purposes of this study were: i) to demonstrate the assessment of personal exposure from various RF-EMF sources across different microenvironments in Australia and Belgium, with two on-body calibrated exposimeters, in contrast to earlier studies which employed single, non-on-body calibrated exposimeters; ii) to systematically evaluate the performance of the exposimeters using (on-body) calibration and cross-talk measurements; and iii) to compare the exposure levels measured for one site in each of several selected microenvironments in the two countries. A human subject took part in an on-body calibration of the exposimeter in an anechoic chamber. The same subject collected data on personal exposures across 38 microenvironments (19 in each country) situated in urban, suburban and rural regions. Median personal RF-EMF exposures were estimated: i) of all microenvironments, and ii) across each microenvironment, in two countries. The exposures were then compared across similar microenvironments in two countries (17 in each country). The three highest median total exposure levels were: city center (4.33V/m), residential outdoor (urban) (0.75V/m), and a park (0.75V/m) [Australia]; and a tram station (1.95V/m), city center (0.95V/m), and a park (0.90V/m) [Belgium]. The exposures across nine microenvironments in Melbourne, Australia were lower than the exposures across corresponding microenvironments in Ghent, Belgium (p<0.05). The personal exposures across urban microenvironments were higher than those for rural or suburban microenvironments. Similarly, the exposure levels across outdoor microenvironments were higher than those for indoor microenvironments.

Measuring personal exposure from 900MHz mobile phone base stations in Australia and Belgium using a novel personal distributed exposimeter

The aims of this study were to: i) measure personal exposure in the Global System for Mobile communications (GSM) 900MHz downlink (DL) frequency band with two systems of exposimeters, a personal distributed exposimeter (PDE) and a pair of ExpoM-RFs, ii) compare the GSM 900MHz DL exposures across various microenvironments in Australia and Belgium, and iii) evaluate the correlation between the PDE and ExpoM-RFs measurements. Personal exposure data were collected using the PDE and two ExpoM-RFs simultaneously across 34 microenvironments (17 each in Australia and Belgium) located in urban, suburban and rural areas. Summary statistics of the electric field strengths (V/m) were computed and compared across similar microenvironments in Australia and Belgium. The personal exposures across urban microenvironments were higher than those in the rural or suburban microenvironments. Likewise, the exposure levels across the outdoor were higher than those for indoor microenvironments. The five highest median exposure levels were: city centre (0.248V/m), bus (0.124V/m), railway station (0.105V/m), mountain/forest (rural) (0.057V/m), and train (0.055V/m) [Australia]; and bicycle (urban) (0.238V/m), tram station (0.238V/m), city centre (0.156V/m), residential outdoor (urban) (0.139V/m) and park (0.124V/m) [Belgium]. Exposures in the GSM900 MHz frequency band across most of the microenvironments in Australia were significantly lower than the exposures across the microenvironments in Belgium. Overall correlations between the PDE and the ExpoM-RFs measurements were high. The measured exposure levels were far below the general public reference levels recommended in the guidelines of the ICNIRP and the ARPANSA.

Instruments to assess and measure personal and environmental radiofrequency-electromagnetic field exposures

Radiofrequency-electromagnetic field (RF-EMF) exposure of human populations is increasing due to the widespread use of mobile phones and other telecommunication and broadcasting technologies. There are ongoing concerns about potential short- and long-term public health consequences from RF-EMF exposures. To elucidate the RF-EMF exposure-effect relationships, an objective evaluation of the exposures with robust assessment tools is necessary. This review discusses and compares currently available RF-EMF exposure assessment instruments, which can be used in human epidemiological studies. Quantitative assessment instruments are either mobile phone-based (apps/software-modified and hardware-modified) or exposimeters. Each of these tool has its usefulness and limitations. Our review suggests that assessment of RF-EMF exposures can be improved by using these tools compared to the proxy measures of exposure (e.g. questionnaires and billing records). This in turn, could be used to help increase knowledge about RF-EMF exposure induced health effects in human populations.

Occupational Radiation Exposure in Health Care Facilities

Background  Radiation, which is used extensively to diagnose and treat human diseases, poses an occupational health risk for the concerned health workers. Personal dosimetry is an important tool to monitor occupational radiation exposures. Objective  This study was conducted to reveal and to describe the situation of occupational radiation exposure monitoring among staffs in different health care facilities in Nepal. Methods  A cross-sectional study was performed among the 35 Health Care Facilities. Information about types and number of X-ray procedures performed, types and number of personnel involved, workload and the availability of personal dosimetry service were collected. Results  Six Health Care Facilities had personal dosimetry service available for a total of 149 personnel. Of a total of nearly one million X-ray procedures performed in the 35 Health Care Facilities in 2007, 76 % was performed by non-monitored personnel. The majority of the facilities performing high dose procedures, like catheterisation, angiography and intestinal barium procedures did not offer personal dosimetry for the involved personnel. Conclusion  There are a limited number of personnel being monitored with personal dosimetry. There are no regulatory dose limits for occupationally exposed staff. Thus, there is an urgent need to establish a national radiation protection authority to regulate the use of radiation in Nepal. Kathmandu University Medical Journal | VOL.10 | NO. 3 | ISSUE 39 | JUL- SEP 2012 | Page 48-51 DOI: http://dx.doi.org/10.3126/kumj.v10i3.8019

Variation in the insertion of the latissimus dorsi & its clinical importance

The latissimus dorsi is the larger, flat, dorso-lateral muscle on the trunk, posterior to the arm, and partly covered by the trapezius on its median dorsal region. Origin of the latissimus dorsi is from spinous processes of thoracic T7-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribs, inferior angle of scapula and insertion on floor of intertubercular groove of the humerus. We have studied 50 cadavers in the different medical colleges in which we found 2% case of anterior and posterior slip of the muscle fibers with their extension up to the pectoralis major and teres major respectively. Usually, latissimus dorsi involve in extension, adduction, transverse extension also known as horizontal abduction, flexion from an extended position, and internal rotation of the shoulder joint. It also has a synergistic role in extension and lateral flexion of the lumbar spine. The latissimus dorsi may be used for the tendon graft surgeries. Tight latissimus dorsi has been shown to be one cause of chronic shoulder pain and chronic back pain. Because the latissimus dorsi connects the spine to the humerus, tightness in this muscle can manifest as either sub-optimal glenohumeral joint function (which leads to chronic shoulder pain) or tendinitis in the tendinous fasciae connecting the latissimus dorsi to the thoracic and lumbar spine. Latissimus dorsi used for pedicle transplant rotator cuff repair reconstruction of breast, face, scalp and cranium defect. The extra slip of the latissimus dorsi may puzzle any transplant operations. We as anatomist discuss the clinical implication of the extra slip of latissimus dorsi.

Prediction of cancer cases for a hospital in Nepal: a statistical modelling

OBJECTIVE

The aim of this study was to predict the number and trends of cancer cases for radiotherapy up to the year 2015 in Manipal Teaching Hospital, Pokhara, Nepal.

METHODS

A retrospective study was carried out on data retrieved from the radiotherapy treatment records of patients treated at Manipal Teaching Hospital between 28 September 2000 and 31 December 2008. Different statistical programmes were used for statistical modelling and prediction. Using curve-fitting methods, Linear, Logarithmic, Inverse, Quadratic, Cubic, Compound, Power, Exponential, and Growth models were tested.

RESULTS

Including constant term, none of the models were best fitted. However, excluding the constant term, the cubic model was best fitted; R2=0. 95, p=0.001 for total cancer cases, R2=0. 94, p=0.001 for female cancer cases and R2=0. 95, p=0.001 for male cancer cases. The cancer cases estimated using cubic model showed a steady increase in the total frequency of cancers (including male and female cancer cases) following the year 2010. The three most common cancers reported were head and neck 24.2% (CI 21.6 - 27.0), lung 20.9% (CI 18.4 -23.6), cervix 15.9% (CI 13.7-18.3) respectively.

CONCLUSION

The cancer cases in need of radiotherapy will increase in future years. The curve fitting method could be an effective exploratory modelling technique for predicting cancer frequency and trends over the years.

Cancer treatment by radiotherapy in Western Nepal: a hospital-based study

OBJECTIVE

The aim of this study was to describe utilization of radiotherapy and treatment compliance in the context of Nepal.

METHODS

A retrospective study was carried out on data collected from the radiotherapy treatment records of patients treated at Manipal Teaching Hospital (MTH), Pokhara, between 28 September 2000 and 30 May 2008.

RESULTS

In the 944 patients, the gender distribution showed a slight female preponderance (53.7 vs. 46.3%). Curative treatment was given to 62.8% (n= 593) and palliative to the remaining 37.2% (n= 351). Patients older than 50 years were more likely to receive palliative radiotherapy (p= 0.001). The commonest cancers treated were head and neck at 23.7% (n= 224), followed by lung at 21.3% (n= 201) and cervix at 16.1% (n= 152). The majority of patients were between 50-70 years of age (n= 564). Nineteen percent (n= 179) did not complete the prescribed dose of radiation. Unplanned treatment interruptions were found in 35.6% (n= 336) and this was not affected by age (p= 0.1) or gender (p= 0.1). The most frequent treatment interruption compromising optimal effectiveness of cancer treatment was observed for head and neck cancers, constituting 43% (n= 96) of patients in the group.

CONCLUSION

Head and neck in both sexes and cervix in females were the most common cancers treated with a curative intent. Lung cancer, the second most common in both genders, was treated with palliative intent in a large number of cases. This indicates the need for early diagnosis for a possible curative treatment.