Individual Differences in Cross-System Physiological Activity at Rest and in Response to Acute Social Stress.

OBJECTIVE: Individual differences in long-term cardiovascular disease risk are related to physiological responses to psychological stress. However, little is known about specific physiological response profiles in young adults that may set the stage for long-term increased cardiovascular disease risk. We investigated individual differences in profiles of resting cardiovascular physiology and stress reactivity, combining parasympathetic, sympathetic, and hemodynamic measures. METHODS: Participants (n = 744, 71% women, mean [standard deviation] age = 20.1 [2.4] years) underwent the Trier Social Stress Test, while blood pressure (systolic blood pressure, diastolic blood pressure), electrocardiograms (interbeat interval), and impedance cardiograms (preejection period, left ventricular ejection time) were recorded. Respiratory sinus arrhythmia was derived from the combination of the electrocardiogram and the impedance cardiogram. A three-step latent profile analysis (LPA) was performed on resting and reactivity values to derive clusters of individual physiological profiles. We also explored demographic and health behavioral correlates of the observed latent clusters. RESULTS: For resting physiology, LPA revealed five different resting physiology profiles, which were related to sex, usual physical activity levels, and body mass index. Five cardiovascular stress reactivity profiles were identified: a reciprocal/moderate stress response (Cr1; 29%), and clusters characterized by high blood pressure reactivity (Cr2: 22%), high vagal withdrawal (Cr3; 22%), autonomic coactivation (parasympathetic nervous system and sympathetic nervous system; Cr4; 13%), and overall high reactivity (Cr5; 12%). Men were more likely to belong to the high reactivity (Cr5) cluster, whereas women were more likely to have autonomic coactivation (Cr4). CONCLUSIONS: We identified five cardiovascular physiological reactivity profiles, with individuals displaying generalized hyperreactivity, predominant vagal withdrawal, autonomic coactivation, or blood pressure-specific hyperreactivity. Longitudinal studies are needed to determine whether these profiles are useful in early detection of individuals at high risk for cardiovascular disease.

Angular Momentum and Topological Dependence of Kepler's Third Law in the Broucke-Hadjidemetriou-Hénon Family of Periodic Three-Body Orbits.

We use 57 recently found topological satellites of Broucke-Hadjidemetriou-Hénon's periodic orbits with values of the topological exponent k ranging from k=3 to k=58 to plot the angular momentum L as a function of the period T, with both L and T rescaled to energy E=-0.5. Upon plotting L(T/k) we find that all our solutions fall on a curve that is virtually indiscernible by the naked eye from the L(T) curve for nonsatellite solutions. The standard deviation of the satellite data from the sixth-order polynomial fit to the progenitor data is σ=0.13. This regularity supports Hénon's 1976 conjecture that the linearly stable Broucke-Hadjidemetriou-Hénon orbits are also perpetually, or Kol'mogorov-Arnol'd-Moser, stable.

Natural radionuclides in waste water discharged from coal-fired power plants in Serbia.

Investigation of the natural radioactivity levels in water around power plants, as well as in plants, coal, ash, slag and soil, and to assess the associated radiation hazard is becoming an emerging and interesting topic. This paper is focused on the results of the radioactivity analysis in waste water samples from five coal-fired power plants in Serbia (Nikola Tesla A, Nikola Tesla B, Kolubara, Morava and Kostolac), which were analyzed in the period 2003-2015. River water samples taken upstream and downstream from the power plants, drain water and overflow water were analyzed. In the water samples gamma spectrometry analysis was performed as well as determination of gross alpha and beta activity. Natural radionuclide 40K was detected by gamma spectrometry, while the concentrations of other radionuclides, 226Ra, 235U and 238U, usually were below the minimum detection activity (MDA). 232Th and artificial radionuclide 137Cs were not detected in these samples. Gross alpha and beta activities were determined by the α/ß low level proportional counter Thermo Eberline FHT 770 T. In the analyzed samples, gross alpha activity ranged from MDA to 0.47 Bq L-1, while the gross beta activity ranged from MDA to 1.55 Bq L-1.

The Effect of Childhood Poly-Victimization on Adulthood Aggression: The Mediating Role of Different Impulsivity Traits.

This study investigated the effect of the poly-victimization pattern of traumatic childhood experiences on aggression via the impulsivity traits positive urgency, negative urgency, lack of perseverance, lack of premeditation, and sensation-seeking in 102 poly-victims of childhood trauma (71.57% were females; Mage = 35.76; SDage = 15.91). Analyses with poly-victimization as an independent variable, impulsivity traits as parallel mediators, (1) reactive aggression or (2) proactive aggression as dependent variables, and gender as a covariate revealed that the poly-victimization did not have a direct or indirect effect on reactive or proactive aggression, nor did it have an effect on any of the impulsivity traits. Moreover, lack of premeditation had a positive direct effect on reactive aggression, while gender was a significant covariate in both models, with males reporting more aggression than females. Findings suggest that the poly-victimization does not influence impulsivity traits and aggression in adulthood. However, in males, the poly-victimization had a positive and moderate correlation with reactive aggression and negative urgency, while these correlations were absent in females. This finding implies that males are more vulnerable to the adverse effects of childhood poly-victimization than females.

"Goldmine" or "big mess"? An interview study on the challenges of designing, operating, and ensuring the durability of Clinical Data Warehouses in France and Belgium.

OBJECTIVES: Clinical Data Warehouses (CDW) are the designated infrastructures to enable access and analysis of large quantities of electronic health record data. Building and managing such systems implies extensive "data work" and coordination between multiple stakeholders. Our study focuses on the challenges these stakeholders face when designing, operating, and ensuring the durability of CDWs for research. MATERIALS AND METHODS: We conducted semistructured interviews with 21 professionals working with CDWs from France and Belgium. All interviews were recorded, transcribed verbatim, and coded inductively. RESULTS: Prompted by the AI boom, healthcare institutions launched initiatives to repurpose data they were generating for care without a clear vision of how to generate value. Difficulties in operating CDWs arose quickly, strengthened by the multiplicity and diversity of stakeholders involved and grand discourses on the possibilities of CDWs, disjointed from their actual capabilities. Without proper management of the information flows, stakeholders struggled to build a shared vision. This was evident in our interviewees' contrasting appreciations of what mattered most to ensure data quality. Participants explained they struggled to manage knowledge inside and across institutions, generating knowledge loss, repeated mistakes, and impeding progress locally and nationally. DISCUSSION AND CONCLUSION: Management issues strongly affect the deployment and operation of CDWs. This may stem from a simplistic linear vision of how this type of infrastructure operates. CDWs remain promising for research, and their design, implementation, and operation require careful management if they are to be successful. Building on innovation management, complex systems, and organizational learning knowledge will help.

Application and Experimental Substantiation of the Radioecological Model for Prediction in Behavior 90Sr in Cultivated Soil-Crop System: A Case Study of Two Experimental Agricultural Fields.

The radioactive fission product 90Sr has a sufficient half-life (28.8 years) to be detected long after its appearance in the environment. After its uptake into the soil-edible plant system, it enters the food chain and represents a potential source of contamination that threatens human health. Due to these facts, tracking the distribution of the artificial radionuclide 90Sr in the soil-edible plant system is a subject of intense research. The tracking of the 90Sr radionuclide distribution in the soil profile, as well as in the crops on the long-term experimental fields was carried out using beta radiation spectrometry. The radiochemical analytical method was used to analyze the 90Sr content in cultivated soil and crops. The conducted study focused on the experimental substantiation of the developed model for predicting the behavior of 90Sr in the cultivated soil-crop system. The results of using the applied radioecological model for the transfer of 90Sr from the soil to the above-ground part of crops showed a relatively good agreement with the experimentally determined values of the soil-crop transfer factor, which indicates that the used model can be successfully applied for the prediction of the behavior of 90Sr in the soil-soil solution-crop system.

Kinetic and thermodynamic analysis of Creosote degradation process under isothermal experimental conditions.

Isothermal degradation process of commercial Creosote was analyzed by the thermogravimetric (TG) technique in a nitrogen atmosphere, at four different operating temperatures (230, 250, 270 and 290°C). The kinetic triplet [Ea , A and f(α)] and the thermodynamic parameters (ΔH (≠), ΔS (≠)and ΔG (≠)) for investigated Creosote samples were calculated. It was found that two-parameter autocatalytic Sesták-Berggren (SB) kinetic model best describes the process, but in the form of accommodation function with phenomenological character. Applying the multiplicative factor, the true value of activation energy (E (true) a ) was calculated. The experimental density distribution function of the apparent activation energy values was evaluated from isoconversional kinetic analysis. Based of the characteristic shape of distribution curve, it was concluded that the isothermal degradation of Creosote represents a complex physico-chemical process, given the chemical structure of the studied system. It is assumed that the considered process probably includes primary and secondary (autocatalytic) pyrolysis reactions, together with various decomposition reactions and radicals recombination pathways. The objective of the presented work is the proof of principle of the pyrolysis-based thermo-chemical conversion technologies for the production of value-added chemicals from the complex organic compounds, which even include chemical contaminants (such as PAHs). Also, the present work allows us that by using a unified kinetic approach we can obtain a significant physico-chemical characteristics of the tested system, which can then be used in the procedure for the separation of organics from creosote-treated woods and creosote-contaminated soils. The significance of this research is to identify the global kinetic behavior of some target contaminant compounds for pyrolysis, which are primarily PAHs.

The impact of childhood maltreatment on aggression, criminal risk factors, and treatment trajectories in forensic psychiatric patients.

Introduction: Children's development into healthy well-functioning adults can be negatively affected by adversity. Adverse childhood experiences (ACEs) have been shown to lead to a variety of poor life outcomes, ranging from mental health problems (e.g., anxiety or suicidality) through problematic health behaviors to serious physical diseases and even early death. ACEs can also make people more prone to aggressive behavior, criminality, and recidivism. In this study, we investigated the association between ACEs, specifically childhood maltreatment (CM), and forensically relevant factors; aggression, criminal risk factors, and treatment trajectories, as little is known about these associations in forensic psychiatric patients. Methods: The study includes data derived from two studies in The Netherlands, of which the first study enrolled 128 patients residing in a Forensic Psychiatric Center (FPC) and the second study included 468 patients who were released unconditionally from FPCs between 2009 and 2013. We expected that more CM would be correlated with higher levels of aggression, higher clinical risk factor scores, and less decrease in clinical risk factor scores over time. To investigate this, we applied correlational analyses and linear growth curve modeling on risk assessment scores and self-report as well as staff report questionnaires on CM and aggression. Results: Consistent with our first hypothesis, patients with higher CM scores also had higher aggression and risk assessment scores. The effect sizes were small to medium (0.12 to 0.34). Unexpectedly, CM did not influence the course of these treatment trajectories, however, we found that patients with histories of CM had a significantly longer length of stay in a forensic facility than patients without CM (respectively, 10.8 years and 9.3 years on average). Discussion: This study underlines the importance of carefully examining the history of ACEs and CM in forensic psychiatric patients and considering this in forensic risk assessment and risk guided treatment. More research is needed to draw conclusions about whether and how histories of ACEs should be considered and targeted during treatment trajectories.

Does sports participation affect the mediating role of impulsivity in the association between adverse childhood experiences and aggression?

Introduction: Adverse childhood experiences (ACEs) and self-reported aggression have often been associated, however, the mediating and moderating mechanisms underlying this association are not fully understood. In addition, less is known about potential factors that could serve as protection against the development of aggressive behavior. In this study, we investigated a moderated mediation model of sports participation and five impulsivity traits including positive and negative urgency, sensation seeking, and lack of premeditation and perseverance, in the association between ACEs and two forms of aggression. Methods and results: The sample comprised 651 (68.5% females) individuals from a Dutch community ranging in age from 18 to 82 years (M = 34.08). Contrary to our expectations, sports participation did not affect the associations of ACEs, the five impulsivity traits, and reactive and proactive aggression, except the association between ACEs and lack of premeditation. Specifically, the detrimental effect of ACEs on the propensity to act without thinking, increases among individuals with lower levels of sports participation. In addition, it was also found that sports participation directly contributed to higher levels of sensation seeking. Finally, after controlling for sociodemographic variables, the positive association between ACEs and reactive aggression was significantly mediated by negative urgency, lack of perseverance, and lack of premeditation, while the positive association between ACEs and proactive aggression was significantly mediated by lack of premeditation and positive urgency. Conclusion: The findings of this study add to the body of knowledge about the role of sports participation and impulsivity traits in the development of both forms of aggression, however, replication studies among multiple populations are needed before firm conclusions can be drawn.

"In conferences, everyone goes 'health data is the future' ": an interview study on challenges in re-using EHR data for research in Clinical Data Warehouses.

More and more hospital Clinical Data Warehouses (CDWs) are developed to gain access to EHR data. The rapid growth of investments in CDWs suggest a real potential for innovation in healthcare. However, it is still not confirmed that CDWs will deliver on their promises as researchers working with CDWs face many challenges. To gain a better understanding of these challenges and how to overcome them, we conducted a series of semi-structured interviews with EHR data experts. In this article, we share some initial results from the ongoing interview study. Two main themes emerged from the analysis of the transcripts of the interviews: the importance of infrastructures in terms of data and how it is generated, and the difficulty to make care, clinical research, and data science work together. Finally, based on the experts' experience, several recommendations were identified when using a CDW.

Occurrence and localization of FOXP3 + cells in kidney biopsies in lupus nephritis and ANCA-associated vasculitis.

The study aims to increase the understanding regarding the role of regulatory T cells (Tregs) in lupus nephritis (LN) and ANCA-associated vasculitis (AAV) by comparing their localization in renal tissue and changes following immunosuppressive therapy. Kidney biopsies from 12 patients with LN and 7 patients with AAV were examined. Kidney biopsies had been performed both at active disease and following immunosuppressive treatment. Clinical data was collected at both biopsy occasions. Expression of Forkhead Box P 3 (Foxp3) in renal tissue was assessed by immunohistochemistry. An arbitrary scale was used to estimate the number of Foxp3+ cells. In LN, 8/12 (67%) had positive tissue staining for Foxp3 at baseline, most pronounced in inflammatory infiltrates, but also interstitially and in a peri-glomerular pattern. At second biopsies, after immunosuppressive treatment, 4/12 (33%) still had detectable Foxp3+ cells, found in persisting inflammatory infiltrates and some in the interstitium. Patients with a good clinical response to treatment had high grade of Foxp3+ cells in first biopsies. In AAV, only 2/7 (29%) had positive staining for Foxp3 at baseline, in inflammatory infiltrates and to a lesser extent in the interstitium, despite large areas of inflammatory infiltrates in all patients. At follow-up, 2/7 (29%) biopsies were positive for Foxp3. Our data show a higher presence of Foxp3+ cells in renal tissue from LN patients compared to AAV, suggesting that Tregs may be differently involved in the control of inflammatory mechanisms in these diseases. These findings could have further implication for therapeutic approaches aiming at restoring the immunological tolerance. Key Points • Foxp3+-cells are present in larger amount in renal tissue in lupus nephritis vs. ANCA-associated vasculitis. • Our data suggest that Foxp3+ regulatory T cells are involved in the control of inflammatory processes in lupus nephritis.

Why Are Data Missing in Clinical Data Warehouses? A Simulation Study of How Data Are Processed (and Can Be Lost).

In recent years, the development of clinical data warehouses (CDW) has put Electronic Health Records (EHR) data in the spotlight. More and more innovative technologies for healthcare are based on these EHR data. However, quality assessments on EHR data are fundamental to gain confidence in the performances of new technologies. The infrastructure developed to access EHR data - CDW - can affect EHR data quality but its impact is difficult to measure. We conducted a simulation on the Assistance Publique - Hôpitaux de Paris (AP-HP) infrastructure to assess how a study on breast cancer care pathways could be affected by the complexity of the data flows between the AP-HP Hospital Information System, the CDW, and the analysis platform. A model of the data flows was developed. We retraced the flows of specific data elements for a simulated cohort of 1,000 patients. We estimated that 756 [743;770] and 423 [367;483] patients had all the data elements necessary to reconstruct the care pathway in the analysis platform in the "best case" scenarios (losses affect the same patients) and in a random distribution scenario (losses affect patients at random), respectively.

Distribution of Natural Radionuclides and 137Cs in Urban Soil Samples from the City of Novi Sad, Serbia-Radiological Risk Assessment.

This work presents the natural radioactivity distribution of 21 surface soil samples taken in the city of Novi Sad, Serbia. The analysis for radioactivity was performed using a gas low-level proportional counter for gross alpha and gross beta activity, while the specific activities of radionuclides were determined using HPGe detectors. The gross alpha activity of 20 samples was below the minimum detectable concentration (MDC), while in 1 sample it was 243 Bq kg-1; the gross beta activity ranged from the MDC (11 samples) to 566 Bq kg-1. The gamma spectrometry measurements showed naturally occurring radionuclides 226Ra, 232Th, 40K, and 238U in all investigated samples, with average values (Bq kg-1) of 33.9, 36.7, 513.8, and 34.7, respectively. Natural radionuclide 235U was detected in 18 samples with activity concentrations in the range of 1.3-4.1 Bq kg-1, while in the other 3 samples, the values were below the MDC. The artificial 137Cs radionuclide was detected in 90 percent of the samples, with a maximum value of 21 Bq kg-1, while the other artificial radionuclides were not detected. Based on the obtained concentrations of natural radionuclides, hazard indexes were estimated, and radiological health risk was assessed. The results present the absorbed gamma dose rate in the air, annual effective dose, radium equivalent activity, external hazard index, and lifetime cancer risk.

Verification of the sampling procedure for radioactivity analysis of waste and industrial material.

In accordance with ISO/IEC 17025:2017, the testing laboratory needs to verify its ability to properly perform methods. For radiological testing, the sampling does not affect the results directly, but it has to ensure that sample adequately represents the tested material. To verify the procedure, a sampling of red mud and bauxite ore was conducted. All samples were measured in identical geometry by HPGe spectrometer. The counting rates per unit mass in the recorded spectra were compared. For each measurement series, the mean and standard deviations of respected peaks were calculated, as well as average and standard deviation of all series. The obtained results of each individual series were considered satisfactory, i.e. sampling procedure ensures the representativeness of the bulk material, if it is within ± two standard deviations of the average of the mean values.

Tritium concentration analysis in atmospheric precipitation in Serbia.

Tritium activity concentration were monitored in monthly precipitation at five locations in Serbia (Meteorological Station of Belgrade at Zeleno Brdo, Vinca Institute of Nuclear Sciences, Smederevska Palanka, Kraljevo and Nis) over 2005, using electrolytic enrichment and liquid scintillation counting. The obtained concentrations ranged from 3.36 to 127.02 TU. The activity values obtained in samples collected at Zeleno Brdo were lower or close to the minimum detectable activity (MDA), which has a value of 3.36 TU. Significantly higher tritium levels were obtained in samples collected in Vinca Institute of Nuclear Sciences compared with samples from the other investigated locations. Amount of precipitation were also recorded. A good linear correlation (r = 0.75) for Zeleno Brdo and VINS between their tritium activity was obtained. It was found that the value of the symmetrical index n (which indicates the magnitude of tritium content changes with time (months) through its second derivative) is the highest for Vinca Institute of Nuclear Sciences compared to other locations, which is in accordance with the fact that the highest concentrations of tritium were obtained in the samples from the cited place.

Radioactivity of mining sites of lead, zinc and phosphate ores in Serbia.

Natural resources such as ores contain radioactive nuclides at various concentrations. Therefore it is important to investigate the radioactivity in these resources as well as in the soil at the locations of ore deposits. For that reason we conducted preliminary measurements in the soil samples taken from the locations of lead and zinc ore deposits in Bosilegrad and Raska and from the locations of phosphate ore deposits in Bosilegrad to estimate the environmental conditions prior to the ore excavation. The activity concentrations of radionuclides in soil, water and plant samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23%). Results showed the presence of natural radionuclides (226)Ra, (232)Th, (40)K, (235)U, (238)U as well as the produced radionuclide (137)Cs (from the Chernobyl accident). Ambient gamma radiation dose rate in ground level air was also measured. In order to estimate the influence of subsequent mining on the working and living environment, radium equivalent (Ra(eq)), external hazard index (H(ex)), external gamma absorbed dose rate ([Formula: see text]) and annual effective dose (D(E)) were determined.

Violent Recidivism and Adverse Childhood Experiences in Forensic Psychiatric Patients With Impaired Intellectual Functioning.

Accurate risk assessment and insight into which factors are associated with recidivism are essential for forensic correctional practice. Therefore, we investigated whether the Historical, Clinical, and Future-Revised (HKT-R [Historisch Klinisch Toekomst-Revised]) risk assessment instrument could predict violent recidivism over a 2-year follow-up period in forensic psychiatric patients with intelligence quotient (IQ) < 80. We refer to these patients as intellectually disabled (ID) and patients with IQ ≥ 80 as non-ID. Additionally, the associations of the 14 clinical HKT-R factors with ID versus non-ID group membership were investigated, as well as a possible moderating role of adverse childhood experiences (ACE) in these associations. The final sample encompassed 748 forensic psychiatric patients (15.9% were patients with ID) who were unconditionally released from highly secured Dutch forensic psychiatric institutions between 2004 and 2014. The results showed that the HKT-R total score (AUC = 0.705, 95% confidence interval [CI] [0.527, 0.882]) and the clinical domain (AUC = 0.733, 95% CI [0.579, 0.886]) had a large effect size for predictive validity for 2-year violent recidivism, while the future domain (AUC = 0.653, 95% CI [0.524, 0.781]) and the historical domain (AUC = 0.585, 95% CI [0.397, 0.772]) had a medium effect size for predictive validity for 2-year violent recidivism in ID patients. It was also found that lower levels of self-reliance and social skills were associated with ID, indicating that treatment should prioritize these skills. However, ACE was not associated with ID, nor did it moderate the associations of the clinical HKT-R factors with ID. This study contributes to the understanding of both risk assessment and treatment of forensic psychiatric patients with ID.

The Moderating Roles of Resilience and Coping Strategy on Well-Being of Victimized Forensic Workers.

Previous research on workplace victimization has often disregarded forensic psychiatric populations and not yet been extended to the coronavirus pandemic. The present study expected the isolation of the government-issued lockdown to increase aggressive behavior in forensic patients, ultimately decreasing the general well-being of victimized forensic workers. Possible buffering protective factors (resilience and active coping) and enhancing risk factors (avoidant coping and passive coping) were investigated with the intention of optimizing the general well-being of at-risk forensic workers. The valid sample (N = 311) consisted of Dutch and Belgian forensic workers (74.6% females) with at least 9 hours of weekly patient contact, and with a mean age of 37.99 (SD = 12.20). Participants reported the number of violent incidents in the past 2 months, as well as completed a questionnaire battery including measures of well-being, resilience, and coping strategies. A significant increase of victimization during the lockdown compared to after it was lifted was found, however, the study did not find evidence to support that this negatively influenced the worker's general well-being. Active coping was found to be a significant moderator and protective factor for the general well-being of victimized forensic workers. In contrast, resilience, avoidant and passive coping were not significant moderators in this association. The present study has valuable clinical implications that could lead to preparatory and preventative measures for forensic workers at risk of being victimized. Future research may investigate constructs such as life satisfaction and post-traumatic growth, as well as be broadened into prison populations.

The Role of Dynamic Risk and Protective Factors in Predicting Violent Recidivism: Intellectual Ability as a Possible Moderator?

This study investigated which risk and protective factors, based on the 14 clinical indicators of the Historical-Clinical-Future Revised, significantly predicted violent recidivism in a sample of 315 male forensic psychiatric patients. Additionally, it was investigated whether these associations were moderated by intellectual ability. Regarding risk factors, a stronger influence of risky network members, and higher levels of hostility, impulsivity, and addiction significantly predicted violent recidivism. Likewise, regarding protective factors, poorer social and labor skills, and a lower degree of patient's acceptance of crime responsibility were significant predictors of violent recidivism. Contrary to our expectations, better coping skills and more insight into risky behaviors that can lead to relapse also contributed significantly to an increased likelihood of violent recidivism. Intellectual ability had no significant moderating effect on the associations between the factors and violent recidivism. The results offer an insight into which factors need to be prioritized during treatment.

Natural radioactivity of materials used in industry and construction in Serbia.

Four different kinds of materials (feldspar, gypsum, clay and kaolin) commonly used in building construction and industry in Serbia were analyzed for their natural radioactivity, using gamma spectrometry. The radium equivalent activity, Ra(eq), the absorbed dose rate, D, the annual effective dose, D(E), and the external hazard index, H(ex), were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The radium equivalent activities calculated in all samples are lower than the maximum admissible value 370 Bq kg(-1) set in the UNSCEAR report. The absorbed dose rate in air was found to vary from 0.02 to 0.19 µGy h(-1). Considering the fact that the average gamma dose rate indoors in Europe is 0.07 µGy h(-1), gamma dose rate calculated for feldspar, clay and kaolin samples exceed this limit. The obtained results for annual effective dose exceed limits of 0.41 mSv for feldspar, clay and kaolin samples. If the H(ex) exceeds unity, we might conclude that the potential external dose(s) to exposed individual(s) will exceed the acceptable level, and some action may be required. The obtained values of H(ex) are lower than unity for all investigated samples. All samples were measured immediately after preparation, except 10 samples of feldspar, because a comparative analysis were made between 215 samples which were measured immediately after preparation and 10 samples which were measured after radioactive equilibrium was reached in order to detect differences in the obtained concentrations.