Metrology supporting the European regulation for radiation protection

The European Association of National Metrology Institutes (EURAMET) within its research programme European Metrology Programme for Innovation and Research (EMPIR) funded project EMPIR 19NET03 supportBSS that contributes to the establishment of a European Metrology Network (EMN) for Radiation Protection (RP). The EMN-RP was established in September 2021 with the intent to work as a meeting point for the metrology community and all stakeholders in the field of ionising radiation regulation, thus providing quality assurance for measurements in each of the exposure situations contemplated in the European Legislation. Within project EMPIR 19NET03, work package 3 aims at the preparation of a Strategic Research Agenda (SRA) by identifying the metrology needs to support the European legislation and regulation in Radiation Protection and of two Roadmaps for metrology services, one under the European Council Directive 2013/59/EURATOM and the other under the EURATOM Treaty. Following a Gaps Workshop held in September 2020 and a second internal workshop that took place in April 2022, a questionnaire was prepared for distribution to the stakeholders, e.g. RP platforms and authorities, academia, industry, among other, together with an accompanying paper. In this paper, the authors present the state of the art of European legislation in RP, address the importance of metrology, the practices and activities that need metrology to meet the requirements set in the regulations, emphasise the need for quality assured measurements in all fields, highlight the stakeholders contributions in their specific area and show their vision of the EMN-RP.

EURADOS ISO/IEC 17025 guidance for IMS: suggestions on how to interpret and implement the requirements including examples from accredited laboratories

Individual monitoring of external radiation is an activity usually regulated by national regulatory bodies in most countries. Regulations generally contain technical requirements to be met by the individual monitoring services (IMS), in order to ensure that the measurements are correct and therefore the dosimetry results are reliable. In some countries, the requirements include or even consist of the accreditation of the service according to the standard ISO/IEC 17025: 'General requirements for the competence of testing and calibration laboratories.' It is a fact that accreditation is a growing trend among European IMS as a way to guarantee confidence in their technical competence. The acceptance of the dosimetry results between countries and their indentation in the respective National Dose Registries is facilitated if laboratories conform to the ISO/IEC 17025 standard. In the framework of the activities of EURADOS (European Radiation Dosimetry Group) working group 2 'Harmonization of Individual Monitoring in Europe' and attending to the concern of many European IMS in the process of accreditation, a guide has been prepared. The purpose was to assist and encourage IMS to apply for accreditation and to share the authors' own experience with the process. The guide intends to be a practical reference for IMS on how to interpret and implement the ISO/IEC 17025 requirements to the specific activity of a personal dosimetry service for external radiation, emphasizing those aspects of special interest. It includes examples from dosimetry laboratories already accredited. The major novelties from a new edition of ISO/IEC 17025: 2017 are also identified in the guide. Finally, the guide aims to assist the auditing process, giving examples of auditor's questions and how to show evidence of compliance. The main findings are presented.

Protective Barriers and Radiant Exposure Delivered from Light-curing Units

OBJECTIVE

To evaluate the influence of different protective barriers as a function of the photoactivation distances on the radiant exposure of several light-curing units (LCU). The influence of the protective barriers on the degree of conversion of an adhesive resin was also evaluated.

METHODS

Five LCUs were evaluated: Valo Cordless- used in standard mode (Ultradent, South Jordan, USA); Radii-cal-used in continuous mode (SDI, Bayswater, AU); Emitter D-used in continuous mode (Schuster, Santa Maria, BR); Bluephase N- used in high-intensity mode (Ivoclar Vivadent, Schaan, LI); and Rainbow Curing Light-used in continuous mode (Axdent, Guangdong, CN). For each LCU, radiant exposure was measured with a spectrometer (MARC Resin Calibrator) using three different protective barriers (low-density polyethylene, polyvinyl chloride, or Radii-cal barrier sleeves) and five photoactivation distances (0, 2, 5, 10, and 20 mm). The degree of conversion of an adhesive resin (Adper Scotchbond Multi-Purpose, 3M ESPE, St. Paul, USA) was measured through Fourier-transform infrared spectroscopy. The translucency parameter of protective barriers was measured with a spectrophotometer. For all statistical tests, a significance level of α = 0.05 was set.

RESULTS

For all LCUs tested, radiant exposure was found to be significantly influenced by both protective barriers and curing distance (p≤0.001). In general terms, all the protective barriers significantly decreased the radiant exposure. Radii-cal barrier sleeves were the protective barrier that most decreased the radiant exposure. Irrespective of the protective barrier used, none of the LCU equipment reached the required minimum radiant exposure of 16 J/cm2 at 10 mm of curing distance. The degree of conversion was not effected by either LCU or a protective barrier (p≥0.211).

CONCLUSIONS

Protective barriers and photoactivation distance reduced the radiant exposure emitted by different LCUs.

Effectiveness of chlorthalidone/amiloride versus losartan in patients with stage I hypertension and diabetes mellitus: results from the PREVER-treatment randomized controlled trial

AIMS

To compare the blood pressure (BP)-lowering efficacy of a chlorthalidone/amiloride combination pill with losartan, during initial management of JNC 7 Stage I hypertension in patients with type 2 diabetes mellitus.

METHODS

In an a priori subgroup analysis of a randomized, double-blind, controlled trial, volunteers aged 30-70 years, with stage I hypertension and diabetes mellitus, were randomized to 12.5/2.5 mg of chlorthalidone/amiloride (N = 47) or 50 mg of losartan (N = 50), and followed for 18 months in 21 clinical centers. If BP remained uncontrolled after three months, study medication dose was doubled, and if uncontrolled after six months, amlodipine (5 and 10 mg) and propranolol (40 and 80 mg BID) were added as open label drugs in a progressive fashion.

RESULTS

Systolic BP decreased to a greater extent in participants allocated to diuretics compared to losartan (P < 0.001). After 18 months of follow-up, systolic BP was 128.4 ± 10.3 mmHg in the diuretic group versus 133.5 ± 8.0 in the losartan group (P < 0.01). In the diuretic group, 36 out of 43 participants (83.7%) had a JNC 7 normal BP, compared to 31/47 (66%) in the losartan group (P = 0.089). Serum cholesterol was higher in the diuretic arm at the end of the trial. Other biochemical parameters and reports of adverse events did not differ by treatment.

CONCLUSIONS

Treatment of hypertension based on a combination of chlorthalidone and amiloride is more effective for BP lowering compared to losartan in patients with diabetes mellitus and hypertension.

TRIAL REGISTRATION

Clinical trials registration number: NCT00971165.

The impact of maternal touch of the abdomen on cardiotocography fetal patterns

INTRODUCTION

Some studies suggest that maternal touch of the abdomen produces an increase in the number of movements of the fetus. However, the influence of maternal touch of the abdomen on fetal cardiotocography patterns has not been studied.

METHODS

This nonrandomized, before-after clinical trial that assessed fetal cardiotocography patterns during maternal touch of the abdomen in 28 low-risk pregnant women.

RESULTS

Baseline fetal heart rate, accelerations, decelerations, and variability did not change with maternal touch of the abdomen, but fetal movements increased (p = 0.044).

CONCLUSION

Fetal movements increases during maternal touch of the abdomen.

Dose to the interventional radiologist in CTF-guided procedures

The aim of this work was to assess the occupational dose received by an interventional radiologist (IR) during computed tomography fluoroscopy (CTF)-guided procedures; to identify the most exposed areas of the body including the hands and fingers; to suggest recommendations for individual monitoring; and to improve radiation safety of the practice. A total of 53 CTF-guided procedures were studied. Twelve whole-body dosimeters were worn by the IR in each procedure for the assessment of the personal dose equivalent, H_p(10), on the chest, waist, and back, both over and under the lead apron, as well as the personal dose equivalent, H_p(0.07), on both arms, knees, and feet. Special gloves with casings to fit extremity dosimeters were prepared to assess H_p(0.07) to the fingers. The measured chest dose values were higher than those on the waist and back; the dominant hand or the left side was the most exposed. In general, the ring, middle, and index fingers of the dominant hand were the most exposed (maximum in the 36-39 mSv range), while wrist dose was negligible compared to finger doses. Based on the results obtained the following recommendations are suggested: protective devices (lead aprons, thyroid shield, and goggles) should be worn; H_p(10) should be assessed at the chest level both above and below the lead apron; finger doses can be measured on the basis of each middle finger; the arm closer to the beam should be monitored; and finally, a wrist dosimeter will not provide useful information.

TYPE TESTING OF LiF:Mg,Cu,P (TLD-100H) WHOLE-BODY DOSEMETERS FOR THE ASSESSMENT OF Hp(10) AND Hp(0.07)

In this work, the initial results of the type testing of the LiF:Mg,Cu,P (TLD-100H) whole-body personal dosemeters are presented. An assessment of reproducibility, linearity of the response, the residual signal as a function of the dose, energy and angular dependence of the response was performed. In general, the dosemeters show good reproducibility for different dose values and a linear behaviour for a range between 0.1 and 300 mSv. The detection limits obtained are lower than 50 μSv. The system presents a good energy and angular response for different radiation qualities.

EURADOS education and training activities

This paper provides a summary of the Education and Training (E&T) activities that have been developed and organised by the European Radiation Dosimetry Group (EURADOS) in recent years and in the case of Training Courses over the last decade. These E&T actions include short duration Training Courses on well-established topics organised within the activity of EURADOS Working Groups (WGs), or one-day events integrated in the EURADOS Annual Meeting (workshops, winter schools, the intercomparison participants' sessions and the learning network, among others). Moreover, EURADOS has recently established a Young Scientist Grant and a Young Scientist Award. The Grant supports young scientists by encouraging them to perform research projects at other laboratories of the EURADOS network. The Award is given in recognition of excellent work developed within the WGs' work programme. Additionally, EURADOS supports the dissemination of knowledge in radiation dosimetry by promoting and endorsing conferences such as the individual monitoring (IM) series, the neutron and ion dosimetry symposia (NEUDOS) and contributions to E&T sessions at specific events.

Neurodevelopment of 24 children born in Brazil with congenital Zika syndrome in 2015: a case series study

OBJECTIVE

To describe the neurodevelopment of children with congenital Zika syndrome during the second year of life.

DESIGN

Case series study.

SETTING

Instituto de Medicina Integral Professor Fernando Figueira (IMIP), Pernambuco, Brazil.

PARTICIPANTS

24 children with congenital Zika syndrome born with microcephaly during the Zika outbreak in Brazil in 2015 and followed up at the IMIP during their second year of life.

MAIN OUTCOME MEASURE

Denver Developmental Screening Test II, head circumference and clinical neurological examination.

RESULTS

All children presented neurodevelopmental delay: for an average chronological age of 19.9 months, language was equivalent to that of age 2.1 months, gross motor 2.7 months, fine motor/adaptive 3.1 months and personal/social 3.4 months. Head circumference remained below the third percentile for age and gender, and growth rate up to the second year of life was 10.3 cm (expected growth 13 cm). Muscle tone was increased in 23 (95.5%) of 24 children, musculotendinous reflexes were increased in the whole sample and clonus was present in 18 (77.3%) of 24 children. All children except one had epilepsy.

CONCLUSION

Children born with microcephaly associated with congenital Zika virus have a significant neurodevelopmental delay.

The use of needle holders in CTF guided biopsies as a dose reduction tool

PURPOSE

The purpose of this study was to evaluate the efficacy of needle holders in reducing staff hand exposure during biopsies guided by computed tomography fluoroscopy (CTF), through the analysis of data acquired during a detailed monitoring study, undertaken in parallel with an ongoing optimization process to reduce hand irradiation.

METHODS

Hand monitoring was performed with 11 extremity detectors, two per finger (base and tip) and one on the back of the wrist, for the left (dominant) hand, during two series of biopsies with comparable characteristics. The first series (47 biopsies) were performed with only quick-check method (QC) and occasional side-handle (SH) manipulation of the needle. The second series (63 biopsies) were performed after introducing needle holders (NH) in the course of an optimization process.

RESULTS

Choice of technique (QC, QC + NH, QC + SH) by the interventional radiologist (IR) was related to biopsy difficulty. Measured hand exposure was low (< 1 mSv) for all QC-only procedures, and for most of the QC + NH procedures. Occasional side-handle manipulation still occurred during challenging biopsies, so that 8% of biopsies in the second series accounted for ~70% of total fingertip dose (~90 mSv). The methodology used allowed a detailed insight into the dose reduction achievable with needle holders during real procedures, without the limitations of phantom measurements.

CONCLUSIONS

Needle holders proved effective in reducing mean hand exposure during clinical procedures where real-time manipulation was necessary. Occasional side-handle manipulation was found to contribute disproportionately to hand exposure. This highlights the importance of individual hand monitoring during CTF guided procedures.

CHARACTERIZATION OF AN ACTIVE DOSEMETER ACCORDING TO IEC 61526:2010

The active personal dosemeter, RaySafe i2, allows the measurement and record of Hp(10) in real time, every second, via wireless technology for real-time display on a portable computer and/or a local network. The system seems particularly attractive for individual monitoring at clinical facilities where high intensity and varying radiation fields may occur, as it enables the user to acknowledge and optimize the dose and dose rate values in real time for each procedure. Prior to its use, the system was characterized at the Metrology Laboratory of Ionizing Radiation of IST-LPSR aiming at the metrological characterization of the system in accordance with IEC 61526:2010 for metrological control purposes and to verify the technical specifications stated by the manufacturer.

ENVIRONMENTAL MONITORING WITH PASSIVE DETECTORS AT CTN IN PORTUGAL

The aim of this work is to present the methods in use for environmental dose assessment with passive detectors at Campus Tecnológico e Nuclear (CTN) of Instituto Superior Técnico, in Portugal. The methods are based on LiF:Mg,Ti (TLD-100) detectors inserted in Harshaw holders placed at four locations and exchanged on a quarterly basis. An initial group of measurements allowed the estimation of the time interval necessary to attain a stable value, the determination of a fading factor, as well as the calculation method for the assessment of the ambient dose equivalent rate.

FADING EFFECT OF LiF:Mg,Ti AND LiF:Mg,Cu,P Ext-Rad AND WHOLE-BODY DETECTORS

Thermoluminescence dosemeters are widely used in individual and environmental monitoring. The aim of this work was to compare the thermal stability of dosemeters of the Ext-Rad and whole-body card types with LiF:Mg,Ti and LiF:Mg,Cu,P detectors stored at different temperatures and periods. The dosemeters were stored at 0°C, room temperature and 40°C for periods that lasted 8, 30, 45, 90 and 120 d. In general, TLD-100H detectors present higher TL signal stability than TLD-100 detectors. The intensity of the signal remained constant for both materials for storage periods at 0°C. At RT the same results was observed for TLD-100H. For TLD-100 detectors, a maximum variation of 22 % was registered for the longest period. At 40°C the TL signal decreased with storage time for both detectors. The TL signal of TLD-100H detectors presented maximum variations of 12 % whereas for TLD-100 detectors, larger variations of 25 % were observed.

Abdominal Fat Distribution Among Breastfed and Formula-Fed Infants

OBJECTIVES

To compare abdominal subcutaneous and preperitoneal fat thickness among breastfed, mixed-fed, and formula-fed infants during the first 6 months of life.

STUDY DESIGN

A cohort study started with 94 healthy newborns and 76 were followed during the whole first semester of life. Breastfeeding status was assessed by a personal interview. Abdominal subcutaneous and preperitoneal fat thickness was measured by ultrasound at the first, third, and sixth month of life.

RESULTS

Subcutaneous and preperitoneal fat thickness showed no differences from the first to the sixth month of life among breastfed, mixed-fed,s and formula-fed infants, respectively; subcutaneous: 26.1 ± 10.2 to 57.4 ± 10.3 cm, 27.7 ± 10.5 to 55.4 ± 1.4, and 28.1 ± 10.9 to 52.7 ± 10.6; p = 0.344; preperitoneal: 10.6 ± 2.0 to 15.2 ± 1.7, 10.3 ± 2.8 to 15.5 ± 1.7, and 9.7 ± 2.6 to 15.6 ± 1.6; p = 0.623). No differences were observed among male and female infants.

CONCLUSION

Abdominal fat distribution measured by ultrasound seems not to be different among breastfed and formula-fed infants during the first semester of life.

APOA5 polymorphisms associated with lipid metabolism in Brazilian children and adolescents

Single nucleotide polymorphisms in the APOA5 gene have been studied for their association with metabolic syndrome. Thus, elucidating the effect of the mechanism involved in APOA5 gene polymorphisms on lipid metabolism is of great importance. In this study we aimed to determine the allelic and genotypic frequencies of -1131T>C, Ser19Trp, and intergenic APOA4/A5 and to evaluate the association between these variants with plasma lipid levels in children and adolescents from Brazil. This study included 524 healthy children and adolescents from Mother and Child Hospital in Recife, Pernambuco, Brazil. Data were obtained on medical history, drug intake, lifestyle variables, and demography. DNA from collected samples was extracted and genotyped for the three polymorphisms. In this studied population, triglycerides and very low-density protein levels were significantly high in subjects carrying the 19WW genotype (P < 0.001), demonstrating the presence of this genetic risk factor in children and adolescents.

Gafchromic XR-QA2 film as a complementary dosimeter for hand-monitoring in CTF-guided biopsies

Computed tomography fluoroscopy (CTF) is a useful imaging technique to guide biopsies, particularly lung biopsies, but it also has the potential for very high hand exposures, despite use of quick-check method and needle holders whenever feasible. Therefore, reliable monitoring is crucial to ensure the safe use of CTF. This is a challenge, because ring dosimeters monitor exposure only at the base of one finger, while the fingertips may be exposed to the highly collimated CT beam. In this work we have explored the possibility of using Gafchromic XR-QA2 self-developing film as a complementary dosimeter to quantify hand exposure during CTF-guided biopsies. A glove used in a previous study and designed to contain 11 TLDs was adapted to include Gafchromic strips 7 mm wide, covering the fingers. A total of 22 biopsies were successfully performed wearing this GafTLD glove under sterile gloves, and the IR reported no difficulty or reduction of dexterity while wearing it. Comparison of dose distributions obtained from digitization of the Gafchromic film strips and absolute Hp(0.07) readings from TLDs showed good agreement, despite some positional uncertainty due to relative movement. Per procedure, doses at the base of the ring finger can be as low as 3%-8% of hand dose maximum. Accumulated dose at the base of the ring finger was four times lower than the dose maximum.

Visceral adiposity in the first half of pregnancy predicts newborn weight among adolescent mothers

OBJECTIVE

Maternal obesity is a strong risk factor for gestational diabetes mellitus and fetal macrosomia. We assessed the association between maternal visceral adiposity tissue (VAT) depth in the first half of pregnancy and both glucose tolerance in late pregnancy and newborn weight in pregnant adolescents.

METHODS

We completed a prospective cohort study of 73 pregnant adolescents aged 10 to 19 years, without pre-pregnancy diabetes. VAT depth was measured by ultrasound at 12 to 20 weeks' gestation, followed by a two-hour 75-g oral glucose tolerance test at 36 to 39 weeks' gestation, to determine the glucose area under the curve (AUC glucose0-120). The association between VAT depth and newborn weight was evaluated by multiple linear regression analysis, controlling for maternal age, parity, smoking, gestational age at delivery, infant sex, pre-pregnancy BMI, weight gain in pregnancy, and fasting serum glucose at 36 to 39 weeks' gestation. The relation between VAT depth and AUC glucose0-120 was assessed by linear regression analysis, adjusting for maternal age, parity, smoking, pre-pregnancy BMI, and weight gain in pregnancy.

RESULTS

A 1 cm increase in VAT depth was associated with a 206 g (95% CI 101 to 311) adjusted increase in mean birth weight. VAT depth and the other model covariates together explained more of the variance in birth weight (r(2) = 0.282; P < 0.001) than pre-pregnancy BMI with the other covariates in the same model (r(2) = 0.081; P = 0.076). All three glucose tolerance test measures were performed at 36 to 39 weeks' gestation in 51 of the 73 participants. The relationship between VAT depth and AUC glucose0-120 was not significant (P = 0.43).

CONCLUSION

VAT depth in the first half of pregnancy predicts newborn weight better than BMI, but is not associated with glucose tolerance in late pregnancy.

Smaller pelvic size in pregnant adolescents contributes to lower birth weight

Adolescent pregnancy is associated with low birth weight. This has been explained by socioeconomic or emotional factors. However, an adolescent's pelvis may not be completely developed and this can contribute to impairing fetal growth. Our aim was to compare the relationship between pelvic size and birth weight among adolescents and adult mothers. A cross-sectional study was carried out at Instituto de Medicina Infantil Professor Fernando Figueira (IMIP), Brazil. We studied 125 healthy adolescents and 207 healthy adult women, all of whom were primiparous with a singleton term and low-risk pregnancy. The conjugate, intercristal and interspinous diameters were assessed by the Collins pelvimeter. The effect of pelvic size on the birth weight was evaluated using principal component analysis and multiple linear regression model. The mean pelvic size was smaller in adolescent mothers compared to adult ones (35.1 cm vs. 37.5 cm; p<0.001; t-test). After adjusting for other confounding variables, the predicted birth weights corresponding to these mean values of pelvic size were: 3020±27 g for adolescent mothers and 3145±26 g for adult mothers and showed a significant difference (p<0.001). We concluded that a pelvis that is less than fully developed in adolescents, as assessed by pelvic size, may contribute to lower birth weight in adolescent mothers.

Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures

A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H(p)(10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H(p)(0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy.

The new EC technical recommendations for monitoring individuals occupationally exposed to external radiation

The purpose of the European Commission technical recommendations (TR) for monitoring individuals occupationally exposed to external radiation is to provide guidance on those aspects of the implementation of the European Union Parliament and Council Directives directly related to individual monitoring of external radiation, and to encourage harmonisation thereof. They are mainly aimed at the management and staff of IM services but also at manufacturers, laboratories supplying type-testing services, national authorities trying to harmonise approval procedures, and government bodies to harmonise regulations and guidance. The TR main topics are: objectives and aims of IM for external radiation; dosimetry concepts; accuracy requirements; calibration, type testing and performance testing; approval procedures; quality assurance and quality control; and dose record keeping. Attention is paid to particular aspects, such as wide energy ranges for the use of personal dosemeters, pulsed fields and non-charged particle equilibrium; and use of active personal dosemeters. The TR give proposals towards achieving harmonisation in IM and the eventual mutual recognition of services and of dose results.

Evaluation of the performance of two LiF:Mg,Ti and LiF:Mg,Cu,P dosemeters for extremity monitoring

In this paper, the results aimed at assessing the performance of two varieties of LiF detectors (LiF:Mg,Ti and LiF:Mg,Cu,P) in photon fields relatively to reproducibility, detection threshold and angular dependence as defined in the ISO 12794 standard are presented. The fading properties and the limit of detection were also investigated for both materials. The results suggest that both LiF varieties are well suited for extremity monitoring. However, better fading properties of LiF:Mg,Cu,P when compared with LiF:Mg,Ti, combined with previous results relatively to energy dependence suggests that LiF:Mg,Cu,P dosemeters are better suited for extremity monitoring.

A 6-month exercise intervention among inactive and overweight favela-residing women in Brazil: the Caranguejo Exercise Trial

OBJECTIVES

We examined the viability and efficacy of a known quantity of exercise in facilitating weight loss among previously sedentary or irregularly active overweight and obese adult women residing in a slum (favela) in Brazil.

METHODS

In this randomized controlled trial, 156 women were randomized to a control or intervention group (78 in each group). Exercise was supervised, consisting of three 50-minute aerobic sessions each week for 6 months.

RESULTS

Ninety-one percent (71) of the participants in the intervention group completed 6 months of the exercise program. At 6 months, women in the treatment group showed significant reduction in weight (mean=-1.69 kg; 95% confidence interval [CI]=-2.36,-1.03) and body mass index (mean=-0.63 kg/m2; 95% CI=-0.97, -0.30) compared with controls (P for both<.001).

CONCLUSIONS

A moderately intense, structured exercise program resulted in modest weight loss in women when sustained for 6 months.

Examining life-course influences on chronic disease: the importance of birth cohort studies from low- and middle- income countries. An overview

The objectives of this overview are to describe the past and potential contributions of birth cohorts to understanding chronic disease aetiology; advance a justification for the maintenance of birth cohorts from low- and middle-income countries (LMIC); provide an audit of birth cohorts from LMIC; and, finally, offer possible future directions for this sphere of research. While the contribution of birth cohorts from affluent societies to understanding disease aetiology has been considerable, we describe several reasons to anticipate why the results from such studies might not be directly applied to LMIC. More than any other developing country, Brazil has a tradition of establishing, maintaining and exploiting birth cohort studies. The clear need for a broader geographical representation may be precipitated by a greater collaboration worldwide in the sharing of ideas, fieldwork experience, and cross-country cohort data comparisons in order to carry out the best science in the most efficient manner. This requires the involvement of a central overseeing body--such as the World Health Organization--that has the respect of all countries and the capacity to develop strategic plans for 'global' life-course epidemiology while addressing such issues as data-sharing. For rapid progress to be made, however, there must be minimal bureaucratic entanglements.

In-flight dose estimates for aircraft crew and pregnant female crew members in military transport missions

Aircraft fighter pilots may experience risks other than the exposure to cosmic radiation due to the characteristics of a typical fighter flight. The combined risks for fighter pilots due to the G-forces, hypobaric hypoxia, cosmic radiation exposure, etc. have determined that pregnant female pilots should remain on ground. However, several military transport missions can be considered an ordinary civil aircraft flight and the question arises whether a pregnant female crew member could still be part of the aircraft crew. The cosmic radiation dose received was estimated for transport missions carried out on the Hercules C-130 type of aircraft by a single air squad in 1 month. The flights departed from Lisboa to areas such as: the Azores, several countries in central and southern Africa, the eastern coast of the USA and the Balkans, and an estimate of the cosmic radiation dose received on each flight was carried out. A monthly average cosmic radiation dose to the aircraft crew was determined and the dose values obtained were discussed in relation to the limits established by the European Union Council Directive 96/29/Euratom. The cosmic radiation dose estimates were performed using the EPCARD v3.2 and the CARI-6 computing codes. EPCARD v3.2 was kindly made available by GSF-National Research Centre for Environment and Health, Institute of Radiation Protection (Neuherberg, Germany). CARI-6 (version July 7, 2004) was downloaded from the web site of the Civil Aerospace Medical Institute, Federal Aviation Administration (USA). In this study an estimate of the cosmic radiation dose received by military aircraft crew on typical transport missions is made.

Occupational exposure in nuclear medicine in Portugal in the 1999-2003 period

The annual doses received by the staff of nuclear medicine departments from public hospitals and private clinics and evaluated by the Individual Monitoring Service of the Radiological Protection and Nuclear Safety Department (DPRSN) of the Nuclear and Technological Institute (ITN) in Portugal, in the 5 y period from 1999 to 2003, are analysed and presented in this paper. In the 1999-2003 period, ITN-DPRSN monitored on an average 462 workers from nuclear medicine departments, which represents 6% of the 8000 workers of the medical field (approximately). The medical sector represents 80-85% of all the monitored population in Portugal. The professions of the monitored workers at nuclear medicine departments were identified by the respective departments as administrative, auxiliary, medical doctor, nuclear medicine technician, nurse, pharmacist and physicist. This information was collected at the onset of the monitoring and was updated over the last 3 y. The annual whole-body doses evaluated in the period 1999-2003 were used to derive the distribution of workers by dose intervals for every profession. The respective annual average doses and annual collective doses, as well as, the total average and total collective doses for the nuclear medicine sector were also determined and are presented. Internal radiation hasn't been monitored.

Radioactivity in the environment around past radium and uranium mining sites of Portugal

Measurements of ambient radiation doses and determination of radionuclide concentrations in mining waste and soils were performed in 60 areas of former radium and uranium mining. In several places, mining waste and low-grade uranium ore left on the surface contain radioactivity above regional background. Most of the former mining sites present no enhanced radionuclide concentrations. However, in the mining facilities where the radioactive ore was chemically extracted, mill tailings contain materials with elevated levels of radioactivity, up to 200 times the levels in unaffected soils of the region. Mud from neutralization ponds used to treat acid mine waters contains also elevated radionuclide concentrations. Furthermore, depending on the type of waste, the radioelement composition varies. Environmental rehabilitation measures shall take these differences into account in order to prevent in the long term the radioactive contamination of agriculture soils and water resources, and to ensure adequate radiological protection to the public and to the environment.

Long-term stability of a TLD-based individual monitoring system

The thermoluminescence dosemeter (TLD) system at the Individual Monitoring Service (IMS) of the Nuclear Technology Institute (ITN) at the Radiological Protection and Nuclear Safety Department (DPRSN) comprises two 6600 Harshaw readers and the Harshaw 8814 TL card and the holder containing two LiF:Mg,Ti (TLD-100) dosemeters for the evaluation of H(p)(10) and H(p)(0.07). The readers are calibrated on a monthly basis and as part of the quality assurance programme implemented at the IMS a set of dosemeters is issued monthly to the DPRSN's Standard Dosimetry Laboratory for linearity measurements. The results obtained since November 2001 are presented. Fading and sensitivity change experiments are carried out every month covering 8 week periods so that enough time is given to simulate issuing, integrating and receiving times and respective delays. A set of 96 dosemeters organised in eight subsets of 12 are used. In each subset, four dosemeters are irradiated and stored at room temperature (RT), four are not irradiated at all and the last four are irradiated after storage. The 12 dosemeters of each subset are readout at the same time, one per week, covering the 8 week period. The results from the sets irradiated and stored at different periods allowed for the evaluation of fading and sensitivity changes experienced over the whole monitoring period and respective preparation time and readout delays. Time evolution charts of the reader calibration factors, of the linearity parameters and of the evolution of the integrated area in the region of dosimetric interest with storage at RT were obtained. This paper aims to quantify the long-term stability of the TLD system in use at the IMS.

Implications of the high voltage induced variation on TL readings

The high voltage (HV) induced variation on the thermoluminescence (TL) and on the reference light (RL) intensity was investigated in a previous work, which also allowed for the definition of warning levels for all the parameters of the readers' start up test. Based on the results obtained, a modification of the start up procedure was suggested: 'a 10 min warm up time was allowed prior to the beginning of the reader's start up tests. The actual and previous HV values should differ less than +/-5 V. In case it exceeds, a second test should be performed. If the difference exceeds +/-10 V, the voltage should be manually adjusted to the previous value and a calibration of the reader is needed. Should this occur for more than two successive days, maintenance should be called'. The results of the readers' start up tests obtained since the implementation of the start up procedure are analysed and the warning levels considered are discussed. Charts of the HV-induced variation on the TL and RL readings were obtained, compared with the preliminary results and the implications on the start up procedure are discussed.

Implementation of standards for individual monitoring in Europe

A large number of standards are available for radiation protection and individual monitoring purposes. They are published by various organisations, international and national. Moreover, the increasing policy of "Quality" applied to individual monitoring requires the implementation of standards on Quality Assurance (QA) both in technical and management aspects of a dosimetric service. Implementation of standards is not mandatory; therefore, varying degrees of implementation can be found in different European countries. However, for a number of good reasons, a degree of harmonisation within the European Union (EU) of the requirements and procedures for individual monitoring would be desirable. Harmonisation as applied to dosimetric services does not mean that they should all follow exactly the same procedures, but that they should aim to meet the same general requirements, and their results should be comparable. This article aims to compile information on the use of all standards applied within individual monitoring practices, be it on the calibration of dosemeters or on the QA procedures to be applied to the overall dose evaluation process. Both "technical standards" and "quality standards" will be discussed. A list of documents of relevance to subjects such as recommendations and requirements in the field of individual monitoring, whose application could help in the harmonisation of procedures, will also be given. As it is agreed that implementation of quality standards is a relevant framework within which harmonisation can be achieved, guidance on the implementation of quality standards in a dosimetric service is given. Accreditation and approval of dosimetric services will be of relevance in the process of harmonisation of individual monitoring within the EU. In this article, a discussion of various procedures and the meaning of both forms of recognition is also provided. Although most of the text applies to the monitoring of internal and external exposure to ionising radiation, the emphasis of this practical guidance is on monitoring for external radiation with passive dosemeters.

Databases in use at the individual monitoring service of ITN-DPRSN

In this work, the databases developed for routine use at the Individual Monitoring for External Radiation Service (IMS) of the Radiological Protection and Nuclear Safety Department (DPRSN) at the Nuclear and Technological Institute (ITN) in Portugal are presented. At the IMS there are two dosimetry systems running simultaneously, one based on film and the other one on thermoluminescent detectors (TLD). Two databases were initially and independently home-developed in order to meet each service's needs. A few modifications were introduced and while each service's requirements were maintained where needed, the databases were adapted in order to store the same type of information relative to the facilities and monitored workers, as well as to produce similar shaped reports and technical information. The necessary administrative features of the services were considered in the database development, made user-friendly and welcomed by the ordinary users. The improvements allowed a more direct analysis of the annual doses and an easy identification of professions and practices associated with higher dose values.

Study on quality control parameters of a TLD system for individual monitoring

This work intends to identify and follow up quality control parameters important for the general improvement of our thermoluminescence dosemeter (TLD) system for Individual Monitoring that is currently preparing its accreditation according to the EN ISO/IEC 17025 Standard. A retrospective analysis of the readers' start-up tests revealed an eventual variation of parameters, like the high voltage, which may affect the light collecting system, and hence the TL dose results. This was investigated and although the high voltage requires a careful look, the stability and reproducibility of the TLD system was ascertained by the results of quality control procedures. As a consequence of this work, the start-up procedure was modified and the warning levels used for the start-up daily tests of the readers were derived from a more realistic approach.

Occupational exposure in Portugal in 1999

This study reports the occupational radiation doses for external exposure received in 1999 by the radiation workers monitored by the Radiological Protection and Nuclear Safety Department (DPRSN) in Portugal. Occupational exposures arise from conventional industry, research laboratories, the health or medical sector, and mining. There are no nuclear power plants in the country. There are two dosimetry systems running simultaneously at DPRSN, one based on film dosimetry and the other on thermoluminescence dosimetry (TLD). In 1999, 8400 persons were monitored, 3100 with film and 5300 with TLD and the data presented in this report were obtained by using both technologies. The annual mean effective doses received from external radiation in the different fields of activity and the distribution of the annual effective dose by dose intervals are presented. The collective annual dose by field of activity is estimated and the contribution to the total annual collective dose is determined.

[Systolic and diastolic blood pressure levels of healthy newborn infants]

OBJECTIVE: To identify normative blood pressure (BP) levels for Brazilian newborn infants and to define a cut-off point for high systolic and diastolic BP in this population.METHODS: 634 healthy term neonates, aged 12 to 36 hours, who were born in the Instituto Materno Infantil de Pernambuco (IMIP) were included in this survey. An oscillometric method was used to acess the neonates BP. To identify high BP levels the Second Task Force definition was applied.RESULTS AND CONCLUSIONS: The normative BP values for the study sample was 82.0 -/+ 7.5 mmHg for systolic and 41.7 -/+ 5.8 mmHg for diastolic blood pressure. The cut-off points for high blood pressure were >/= 95 mmHg and >/= 52 mmHg for systolic and diastolic blood pressure respectively. These results are similar to those reported in other surveys done in other countries.

Partitioning of whey proteins, bovine serum albumin and porcine insulin in aqueous two-phase systems

Partitioning of the proteins from cheese whey, bovine serum albumin and porcine insulin were analysed using aqueous two-phase systems (ATPS) prepared with PEG-phosphate, PEG-citrate and PEG-maltodextrin (MD). Proteins were quantified through one of the following methods: FPLC, Bradford and spectrophotometry at 280 nm. Results showed that whey proteins partitioned unevenly on the phases of the systems used, with alpha-lactoalbumin (alpha-La) concentrated in the upper phase and beta-lactoglobulin (beta-Lg) in the lower. Albumin in PEG-MD systems concentrated in the MD-rich lower phase. Porcine insulin showed great affinity with the PEG-rich phase, its partition coefficient was always over 10 and increases with PEG molecular mass.

Fetal influences on neonatal blood pressure

OBJECTIVE

To identify if there is a relationship between some newborn variables (baby's sex, Apgar score, postnatal age, birth weight, birth length, and head circumference) and blood pressure (BP) in healthy term newborns.

STUDY DESIGN

A cross-sectional hospital-based study was carried out to determine BP levels and a cutoff point for hypertension in healthy term newborns. Afterward, a comparative study was conducted to identify fetal factors that could influence BP in this specific group.

RESULTS

According to the cutoff point (95th percentile), 34 infants were considered to be hypertensive. During the univariate analyses, infants with higher BP were heavier, longer, and had larger head circumference. After the multivariate analyses, birth weight was the only variable associated with higher BP in babies. Other newborn variables analyzed (baby's sex, Apgar score, and postnatal age) showed no influence on the babies' BP.

CONCLUSION

There is a positive relationship between birth weight and BP in healthy term newborns.

Transfontanelle ultrasonography in infants: comparative study with cranial computed tomography

The findings of transfontanelle ultrasonography, undertaken in 36 infants with clinical evidence of central nervous system (CNS) disorders, were compared with the findings of cranial computed tomography (CT). Considering the CT scan findings as gold standard, cranial ultrasonography had a sensitivity of 82 per cent and a specificity of 75 per cent in identifying cerebral pathology. The positive predictive value was 92 per cent and negative predictive value was 45 per cent.

[Determination of the arm circumference in newborn infants as a method of verifying low birth weight]

The authors studied 1,024 newborns in Recife, Brazil, to determine the association between arm circumference and birth weight. A strong correlation between these two parameters was found (R = +0.78). Specificity and sensitivity of this measurement in detecting low birth weight were also high. The authors concluded that arm circumference can be used as an alternative method of detecting at-risk neonates in areas where birth weight cannot be measured accurately.