Browsing by Author "Reste, Jeļena"
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Item The Aging Aspects of Humans Protractedly Exposed to Ionizing Radiation. Summary of the Doctoral Thesis(Rīga Stradiņš University, 2013) Reste, Jeļena; Eglīte, Maija; Kurjāne, NataļjaThe doctoral thesis “The Aging Aspects of Humans Protractedly Exposed to Ionizing Radiation” consists of 153 pages, 40 figures, 39 tables, 317 literature references and 11 annexes. The thesis is completed in Latvian. The current work is dedicated to the topical and still insufficiently investigated area of low-dose long-term radiation exposure effects on human aging processes. The use of ionizing radiation is progressively growing in various industries and technogenic accidents with release of huge amounts of radionuclides regularly happen worldwide. The most of the released radionuclides have long period of half-decay and increase the risk of protracted irradiation for inhabitants. It is important to realize the consequences of ionizing radiation exposure and understand in details the mechanisms of its effects on humans for timely resolving and prevention of radiation induced health problems. The aim of the study was to establish, if the persons, protractedly exposed to small doses of ionizing radiation, age faster and in a different way than chronically non-exposed humans. The work tasks included: the characterization of aging signs in humans protractedly exposed to small doses of ionizing radiation; the comparison of them with aging features of persons, who didn’t receive excessive exposure earlier in their life; and on the basis of study findings the development of practical recommendations for health care improvement. There were three study populations chosen: 1) Chernobyl nuclear power-plant (CNPP) accident clean-up workers from Latvia, whose organism accumulated certain amount of long-living radionuclides while working in Chernobyl, but after the return to Latvia these people were living in an area with relatively normal radioactivity level; 2) employees chronically exposed to ionizing radiation at work (radiologists, assistants of radiologists, X-ray laboratory assistants, etc.); 3) control group – Latvian inhabitants, who were not excessively exposed to ionizing radiation at work or in any other way previously in their life, except natural background and small medical X-ray examinations. Taking into account the complicated nature of aging, which cannot be characterized by one certain parameter, several aspects of irradiated humans’ senescence have been described in the doctoral thesis. Some different methods were used for realization of the current work: measurement of the relative telomere length in peripheral blood leukocytes by real-time quantitative polymerase chain reaction; detection of transforming growth factor β (TGFβ) level in blood serum by immune fermentative ELISA method; determination of the level of nitrogen oxide and iron in hair by electron paramagnetic resonance spectroscopy. Concurrently morbidity and mortality of CNPP clean-up workers were analysed in details, paying special attention to age-dependent diseases, including malignant neoplasms, and evaluating participation time and performed work tasks in Chernobyl. The results give evidence that aging processes in CNPP clean-up workers exceed the average rate of aging in general Latvian population. Moreover, the telomere shortening, normally seen in programmed replicative senescence, is not involved in the mechanism of aging of CNPP clean-up workers. The accelerated aging mechanism might be so called “stress induced premature senescence” due to ionizing radiation protracted exposure from incorporated radionuclides. It has been established that for formation of malignant neoplasm favourable conditions develop in the organism of humans chronically exposed to ionizing radiation. Slightly longer telomeres were found in CNPP clean-up workers comparing with other groups; in addition, significantly longer telomeres have been detected in persons with heavier radiation exposure. This probably indicates telomere lengthening ferment – telomerase – activation as the effect of permanent DNS damage from incorporated radionuclides, and may be an important factor for carcinogenesis. Significantly lower level of TGFβ was found in CNPP clean-up workers comparing with other groups, that reflects insufficient protection against malignancies in their organism. Similar tendencies, but much easier manifested, were observed in persons chronically irradiated at work, who have been working under radiation exposure for many years. Epidemiological study proved that CNPP clean-up workers, who were exposed to radiation during first year after disaster and performed more risky work with radioactive internal contamination, get ill with age-dependent disorders in younger age than others, but their mortality due to cardiovascular diseases in age group under 45 years exceeds age matched general Latvian male population mortality. Higher, comparing with general population, incidence of urogenital (prostate, kidney), thyroid and oral cavity malignant tumours was observed among young CNPP clean-up workers. On the other hand, oncologic mortality was lower in all age groups of CNPP clean-up workers comparing with non-exposed Latvian males, which indicates effective medical care of CNPP clean-up workers. Overall, it was established that protracted exposure to ionizing radiation is able to modify and accelerate aging processes in humans.Item Assessment of Indoor Radon Gas Concentration in Latvian Households(2024-05-18) Reste, Jeļena; Rīmere, Nadīna; Romans, Andris; Martinsone, Žanna; Mārtiņsone, Inese; Vanadziņš, Ivars; Pavlovska, Ilona; Department of Occupational and Environmental Medicine; Institute of Occupational Safety and Environmental HealthExposure to radon gas in households presents serious health risks, including an increased likelihood of lung cancer. Following the COVID-19 pandemic, the change in individual habits has led to more time spent in indoor environments with remote activities; thus, the need to raise the awareness of air quality in dwellings and to mitigate the exposure of inhabitants to radon has emerged. This study investigated radon gas concentrations in the air of Latvian dwellings. RadTrack2 passive detectors were deployed in a representative sample of households across 106 municipalities of Latvia (98% of the territory), yielding data from 487 households (973 detectors). The data revealed a median radon concentration of 52 Bq/m3 (Q1 and Q3 were 29 and 93 Bq/m3), with the majority of samples (95.6%) falling below the national reference limit of 200 Bq/m3. The building type and presence of a cellar significantly impacted radon levels, with structures lacking cellars and older buildings exhibiting higher concentrations. Mechanical ventilation proved to be more effective in reducing radon levels, compared to natural ventilation. These findings emphasize the necessity of proactive measures to mitigate indoor radon exposure and to ensure the well-being of occupants. Additionally, the dissemination of research data on radon exposure through open-access scientific publications is vital for raising awareness and implementing effective mitigation strategies.Item Biroja darbinieku mazkustīguma paradumu izmaiņas faktori atkarībā no darba dienas ilguma(Rīga Stradiņš University, 2024) Skujiņa, Vivita; Reste, Jeļena; Faculty of Residency; Rezidentūras studiju fakultāteBackground: Prolonged sedentary work is a contributor to sedentary behaviour in office workers who are constantly working with a computer. Working hours spent sitting and reduced movement throughout the working day can have adverse effects and consequences on employees' health. Prolonged sitting and sedentary time are occupational hazards for office workers and can lead to occupational musculoskeletal disorders, the most prevalent in Europe [25]. Workers' health conditions can have a negative impact on individuals, families, communities and a fulfilling long term health. Aim of the paper: To investigate the relationship between office worker sedentariness in relation to the length of the working day, the age of the employee, and employer factors motivating physical activity, and factors hindering the employee's ability to move. Materials and methods. This is a cross-sectional study. Data were collected in 2022 and 2023 from an anonymous online questionnaire distributed on social networks using a "snowball" method. The participants were 552 office workers aged 19-69 years, whose daily work involves a computer and prolonged sitting. Pearson Chi-square test and standardised residuals method were used to analyse the responses. Results. Office workers who work more than 9 hours find both meetings (AR=3.5; p=0.000) and intensive work (AR=4.4; p=0.000) disturb their mobility at work. In the 19-29 age group, those who work more than 9 hours consider that the nature of their work prevents them from moving (AR=2.2; p=0.027) and they do not see any reason to do so (AR=2.3; p=0.019). Office workers in the 40-49 age group who work up to 8 hours, the desire to look better is a motivation to engage in physical activity in their free time (AR=2.1; p=0.040). Employees are well aware of the need to exercise, would support motivational benefits, including space to exercise. A dynamic workplace is favoured by respondents aged 30-39 with a working day over 9 hours. Conclusions. Office workers who work more than 9 hours (61.0%) are reluctant to move unnecessarily during the working day because of too much work and intense work, work meetings, they try to save on working hours, less energy is left for other physical activities. 19-39 year olds are willing to accept change and reduce sedentariness, while over 50s are less responsive, especially if their working day is more than 9 hours.Item Darba un rehabilitācijas iespējas arodslimniekiem(Rīgas Stradiņa universitāte, 2023) Moisejevs, Deniss; Reste, Jeļena; Rezidentūras studiju fakultāte; Faculty of ResidencyIevads. 2021. gadā Latvijā reģistrēti 1807 pirmreizēji arodslimnieki. Diagnozes noskaidrošana un reģistrēšana ir sarežģīts process, kas prasa vairāku speciālistu slēdzienus un plašu diagnostiku. No 1993. gada līdz 2021. gadam Latvijā reģistrēti 23559 arodslimnieki, pārsvarā pacientiem ir muskuloskeletālas slimības. Pēc diagnozes noteikšanas pacientam nepieciešama atbilstoša ārstēšana, kas pārsvarā ir balstīta uz fizioterapiju un rehabilitāciju. Arodslimniekam ir iespēja saņemt finanšu līdzekļus rehabilitācijai no valsts. Lai novērstu veselības stāvokļa pasliktināšanos, arodslimniekam gandrīz vienmēr ir jāmaina darbs un apstākļi, jāiet pensijā vai jāmazina darba slodze. Darba mērķis. Noskaidrot, vai pacientiem tiek mainīti darba apstākļi pēc arodslimības diagnozes reģistrēšanas un cik bieži viņi izmanto rehabilitācijas iespējas Latvijā. Materiāli un metodes. Izmantojot anketēšanu, tika apjautāti 111 pacienti ar esošām arodslimībām vai tie, kuri pašlaik kārto arodslimību. Pacientiem tika uzdoti jautājumi par esošo arodslimību, darba apstākļu maiņu, kā arī par rehabilitāciju un pabalsta saņemšanu. Analizēti arī dati no internetā pieejamiem avotiem un Valsts sociālās apdrošināšanas aģentūras (VSAA). Rezultāti. 68% no visiem respondentiem aktīvi izmantoja rehabilitācijas programmu, kuras vidējais vērtējums starp respondentiem – 7,75 no 10 ballēm. 41,92% arodslimnieku pēc diagnozes noteikšanas mainījuši darbu vai darba apstākļus. Biežākais ieguvums no rehabilitācijas procesa ir sāpju mazināšana. Tikai 5% no aptaujātajiem apgalvoja, ka pēc procedūrām nav uzlabojumu. Biežākais iemesls, kāpēc pacienti neizmanto rehabilitāciju, ir neticība tam, ka procedūras palīdzēs (tā apgalvo 39% no šīs respondentu grupas). Pēc Valsts sociālās apdrošināšanas aģentūras datiem 2022. gadā pabalstu par arodslimību saņēma 5447 personas. 283 personas saņēma pabalstu sakarā ar nelaimes gadījumu darbā. Secinājumi. Pacienti aktīvi izmanto rehabilitācijas terapiju. Pašlaik mazāk nekā puse pēc diagnozes noteikšanas mainījuši darbu vai darba apstākļus, un tas varētu būt viens no iemesliem, kāpēc vēlāk šiem pacientiem pieaug arodslimību skaits un smagums.Item The effect of different workplace nanoparticles on the immune systems of employees(2017-09-01) Kurjane, Natalja; Zvagule, Tija; Reste, Jeļena; Martinsone, Zanna; Pavlovska, Ilona; Martinsone, Inese; Vanadzins, Ivars; Institute of Occupational Safety and Environmental HealthCurrently, nanoparticles are widely present in the environment and are being used in various industrial technologies. Nanoparticles affect immune functions, causing different immune responses. The aim of the current study was to evaluate several cytokines, interleukin (IL)-1b, IL-6, IL-8, tumour necrosis factor-a (TNF-α), interferon-γ, adhesive molecule sICAM-1, macrophage inhibitory protein 1a (MIP1a) and secretory immunoglobulin A, in nasal lavage fluid and in the peripheral blood of healthy subjects exposed to workplace nanoparticles. Thirty-six employees from three different environments were examined: 12 from a metalworking company, 12 from a woodworking company and 12 office workers. The nanoparticles in the different workplaces were detected in the air in the immediate vicinity of the employees. The particle number concentration and surface area values were significantly higher in the workplaces of the metal- and woodworking industries, but concentrations of mass were lower (the measurements were performed by an electrical low-pressure impactor ELPI+). Energy dispersive X-ray spectroscopy (EDS, an attachment to a high-resolution SEM) was used to provide elemental analysis or chemical characterization of the dust particles in a low-vacuum field-free mode operating at a potential of 15 kV spot 3.0. The technique used provided quantitative and spatial analyses of the distribution of elements through mapping (two to three parallel measurements) and point analysis (four to five parallel measurements). Samples from the metal industry contained more ultramicroscopic and nanometric particles, e.g. toxic metals such as Zn, Mn and Cr, and fewer microscopic dust particles. The nasal lavage and peripheral blood were taken at the beginning and the end of the working week, when immune indices were measured. Our data showed a statistically significant increased level of the pro-inflammatory cytokine TNF-α in serum in both exposed groups compared with office workers as well as a higher level of TNF-α in workers from the woodworking company compared with the metalworking employees. We found an elevated level of IL-6 in the exposed groups as well as an elevated level of IL-8 in the nasal lavage in woodworking employees after work.Item Indoor Air Radon Concentration in Premises of Public Companies and Workplaces in Latvia(2022-02-10) Reste, Jeļena; Pavlovska, Ilona; Martinsone, Žanna; Romans, Andris; Mārtiņsone, Inese; Vanadziņš, Ivars; Institute of Occupational Safety and Environmental Health; Laboratory of Hygiene and Occupational Diseases; Department of Occupational and Environmental MedicineConsidering the multitudes of people who spend their time working indoors in public premises and workplaces, it is worth knowing what their level of exposure is to natural radioactive radon gas, the second most widespread and dangerous carcinogen for lung cancer development after cigarette smoking. This state‐level study covered most of the territory of Latvia and conducted 941 radon measurements with Radtrack2, placed for 4–6 months in the premises of public companies, educational institutions, medical care institutions, etc. The study found that 94.7% of samples did not exceed the national permissible limit (200 Bq/m 3), the level at which preventive measures should be initiated. The median value of average specific radioactivity of radon in these premises was 48 Bq/m 3 (Q1 and Q3 being 27 and 85 Bq/m 3), which is below the average of the European region. Slightly higher concentrations were observed in well‐insulated premises with plastic windows and poorer air exchange, mostly in schools (59 (36, 109) Bq/m 3) and kindergartens (48 (32, 79) Bq/m 3). Industrial workplaces had surprisingly low radon levels (28 (16, 55) Bq/m 3) due to strict requirements for air quality and proper ventilation. Public premises and workplaces in Latvia mostly have low radon concentrations in the air, but more attention should be paid to adequate ventilation and air exchange.Item Investigations on Health Conditions of Chernobyl Nuclear Power Plant Accident Recovery Workers from Latvia in Late Period after Disaster(2016-10-01) Reste, Jeļena; Zvagule, Tija; Kurjāne, Nataļja; Šķesters, Andrejs; Silova, Alise; Eglīte, Maija; Cīrule, Jolanta; Gabruševa, Natalija; Zīverts, Andris; Čurbakova, Elvira; Institute of Occupational Safety and Environmental Health; Bioķīmijas zinātniskā laboratorijaThe paper summarises the main findings on Chernobyl Nuclear Power Plant (CNPP) accident recovery workers from Latvia and their health disturbances, which have been studied by the authors during the last two decades. Approximately 6000 persons from Latvia participated in CNPP clean-up works in 1986-1991. During their work period in Chernobyl they were exposed to external as well as to internal irradiation, but since their return to Latvia they were living in a relatively uncontaminated area. Regular careful medical examinations and clinical studies of CNPP clean-up workers have been conducted during the 25 years after disaster, gathering knowledge on radiation late effects. The aim of the present review is to summarise the most important information about Latvian CNPP clean-up worker health revealed by thorough follow-up and research conducted in the period of 25 years after the accident. This paper reviews data of the Latvian State Register of Persons Exposed to Radiation due to CNPP Accident and gives insight in main health effects found by the researchers from the Centre of Occupational and Radiological Medicine (Pauls Stradiņš Clinical University Hospital) and Riga Stradiņš University in a number of epidemiological, clinical, biochemical, immunological, and physiological studies. Latvian research data on health condition of CNPP clean-up workers in the late period after disaster indicate that ionising radiation might cause premature ageing and severe polymorbidity in humans.Item Jonizējošās radiācijas ilgstošai iedarbībai pakļauto cilvēku novecošanas aspekti. Promocijas darba kopsavilkums(Rīgas Stradiņa universitāte, 2013) Reste, Jeļena; Eglīte, Maija; Kurjāne, NataļjaPromocijas darbā ir 153 lapaspuses, 40 attēli, 39 tabulas, 317 literatūras avoti, 11 pielikumi; darbs sarakstīts latviešu valodā. Promocijas darbs ir veltīts aktuālai, līdz šim nepietiekami izpētītai problēmai – nelielu jonizējošās radiācijas devu ilgstošas iedarbības ietekmei uz cilvēka novecošanas procesiem. Jonizējošo radiāciju arvien vairāk pielieto dažādās nozarēs pieaug, pasaulē periodiski notiek tehnogēnas avārijas, kuru dēļ vidē noplūst liels radionuklīdu daudzums. To lielākai daļai ir garš pussabrukšanas periods, tādēļ iedzīvotāji tiek pakļauti ilgstošam apstarojumam. Lai varētu laikus rast risinājumus jonizējošā starojuma izraisīto veselības traucējumu novēršanai, svarīgi ir apzināties un detalizēti izprast starojuma iedarbības mehānismus, kā arī radīto bojājumu sekas. Darba mērķis ir noskaidrot, vai ilgstošai nelielu jonizējošās radiācijas devu iedarbībai pakļautie cilvēki noveco savādāk un ātrāk nekā personas, kuras netika hroniski eksponētas jonizējošai radiācijai. Darba uzdevumi iekļāva hroniskai nelielo jonizējošās radiācijas devu iedarbībai pakļauto cilvēku novecošanas izpausmju raksturošanu un to salīdzināšanu ar novecošanas izpausmēm personām, kuras netika hroniski eksponētas jonizējošajai radiācijai, lai, balstoties uz iegūtajiem rezultātiem, varētu izstrādāt praktiskas rekomendācijas hroniski apstaroto personu veselības aprūpes pilnveidošanai. Šim nolūkam izvēlētas trīs pētāmo cilvēku grupas: 1) Černobiļas atomelektrostacijas (ČAES) avārijas seku likvidētāji no Latvijas, kuru organismā darba laikā Černobiļā bija uzkrājušies ilgi dzīvojošie radionuklīdi, bet pēc atgriešanās Latvijā avārijas likvidētāji dzīvojuši vidē ar relatīvi normālu radioaktīvo fonu; 2) cilvēki, kuri darbā ir pakļauti jonizējošā starojuma hroniskai iedarbībai (radiologi diagnosti, radiologu asistenti, rentgenlaboranti u.c.); 3) kontroles grupā ietilpa Latvijas iedzīvotāji, kuri darbā un citur savā mūžā netika hroniski pakļauti jonizējošās radiācijas iedarbībai, izņemot dabisko radiācijas fonu un nelielus medicīniska rakstura rentgenizmeklējumus. Tā kā novecošanas process ir sarežģīts un to nevar raksturot ar vienu parametru, promocijas darbā aplūkoti vairāki apstaroto personu novecošanas aspekti. Darba realizācijai izmantotas vairākas metodes: tika noteikts telomēru relatīvais garums perifērisko asiņu leikocitārās rindas šūnās ar reālā laika kvantitatīvu polimerāzes ķēdes reakciju, transformējošā augšanas faktora β (TGFβ) līmenis serumā – ar imūnfermentatīvo ELISA metodi, kā arī slāpekļa monoksīda un dzelzs līmenis matos – ar elektronu paramagnētiskās rezonanses spektroskopijas metodi. Vienlaikus padziļināti vērtēta ČAES avārijas seku likvidētāju saslimstība ar vecumatkarīgām slimībām, t.sk. ar ļaundabīgiem audzējiem, un mirstība sakarā ar piedalīšanos ČAES avārijas likvidācijas laikā un veiktajiem darbiem Černobiļā. Darba rezultāti liecina, ka ČAES avārijas seku likvidētāju novecošanas procesi apsteidz Latvijas iedzīvotāju vidējos novecošanas tempus. Turklāt ČAES avārijas seku likvidētāju novecošanas mehānismā nav iesaistīta telomēru garuma saīsināšanās, kāda ir vērojama normālās ieprogrammētās replikatīvās novecošanas gadījumā. Iespējams, ka galvenais mehānisms ir inkorporēto radionuklīdu pastāvīgas jonizējošās radiācijas iedarbības izraisītā t.s. stresa inducētā priekšlaicīgā novecošana. Noskaidrots, ka jonizējošai radiācijai ilgstoši pakļauto cilvēku organismā veidojas labvēlīgi apstākļi ļaundabīgo audzēju attīstībai. ČAES avārijas seku likvidētājiem konstatēts nedaudz lielāks telomēru relatīvais garums, nekā pārējās grupās, turklāt garākās telomēras bija novērotas personām, kuras saņēma lielāku apstarojumu. Iespējams, ka tas netieši liecina par telomēru pagarinošā fermenta – telomerāzes – aktivāciju sakarā ar pastāvīgi notiekošu DNS bojājumu no inkorporētajiem radionuklīdiem, kas ir nozīmīgs faktors kanceroģenēzē. ČAES avārijas seku likvidētājiem konstatēts arī būtiski zemāks TGFβ līmenis nekā pārējo grupu cilvēkiem, kas atspoguļo nepietiekamu pretaudzēju aizsardzību viņu organismā. Daudz mazākā mērā līdzīgas tendences novērotas tikai tiem darbā regulāri apstarotajiem cilvēkiem, kuri radiācijas ietekmē nostrādājuši lielāko mūža daļu. Epidemioloģisko rādītāju analīze parādīja, ka ČAES avārijas seku likvidētāji, kuri bija pakļauti apstarojumam pirmajā gadā pēc avārijas un veica darbus ar lielāku iekšējā radioaktīvā piesārņojuma risku, saslimst ar vecumatkarīgajām slimībām jaunākā vecumā nekā citi. Turklāt avārijas seku likvidētāju mirstība ar sirds un asinsvadu slimībām vecumā līdz 45 gadiem pārsniedz attiecīga vecuma vispārējās Latvijas vīriešu populācijas rādītājus. Avārijas seku likvidētājiem novērota augstāka nekā vispārējā populācijā saslimstība ar uroģenitālajiem (prostatas, nieru), vairogdziedzera un mutes dobuma ļaundabīgajiem audzējiem, it īpaši vīriešiem jaunākā vecumā. Turpretī mirstība ar ļaundabīgajiem audzējiem ČAES avārijas seku likvidētājiem bija zemāka nekā populācijā visās vecuma grupās, kas liecina par efektīvu medicīnisku aprūpi. Kopumā noskaidrots, ka jonizējošās radiācijas ilgstoša iedarbība var modificēt un paātrināt novecošanas procesus cilvēka organismā.Item Jonizējošās radiācijas ilgstošai iedarbībai pakļauto cilvēku novecošanas aspekti. Promocijas darbs(Rīgas Stradiņa universitāte, 2013) Reste, Jeļena; Eglīte, Maija; Kurjāne, NataļjaPromocijas darbā ir 153 lapaspuses, 40 attēli, 39 tabulas, 317 literatūras avoti, 11 pielikumi; darbs sarakstīts latviešu valodā. Promocijas darbs ir veltīts aktuālai, līdz šim nepietiekami izpētītai problēmai – nelielu jonizējošās radiācijas devu ilgstošas iedarbības ietekmei uz cilvēka novecošanas procesiem. Jonizējošo radiāciju arvien vairāk pielieto dažādās nozarēs pieaug, pasaulē periodiski notiek tehnogēnas avārijas, kuru dēļ vidē noplūst liels radionuklīdu daudzums. To lielākai daļai ir garš pussabrukšanas periods, tādēļ iedzīvotāji tiek pakļauti ilgstošam apstarojumam. Lai varētu laikus rast risinājumus jonizējošā starojuma izraisīto veselības traucējumu novēršanai, svarīgi ir apzināties un detalizēti izprast starojuma iedarbības mehānismus, kā arī radīto bojājumu sekas. Darba mērķis ir noskaidrot, vai ilgstošai nelielu jonizējošās radiācijas devu iedarbībai pakļautie cilvēki noveco savādāk un ātrāk nekā personas, kuras netika hroniski eksponētas jonizējošai radiācijai. Darba uzdevumi iekļāva hroniskai nelielo jonizējošās radiācijas devu iedarbībai pakļauto cilvēku novecošanas izpausmju raksturošanu un to salīdzināšanu ar novecošanas izpausmēm personām, kuras netika hroniski eksponētas jonizējošajai radiācijai, lai, balstoties uz iegūtajiem rezultātiem, varētu izstrādāt praktiskas rekomendācijas hroniski apstaroto personu veselības aprūpes pilnveidošanai. Šim nolūkam izvēlētas trīs pētāmo cilvēku grupas: 1) Černobiļas atomelektrostacijas (ČAES) avārijas seku likvidētāji no Latvijas, kuru organismā darba laikā Černobiļā bija uzkrājušies ilgi dzīvojošie radionuklīdi, bet pēc atgriešanās Latvijā avārijas likvidētāji dzīvojuši vidē ar relatīvi normālu radioaktīvo fonu; 2) cilvēki, kuri darbā ir pakļauti jonizējošā starojuma hroniskai iedarbībai (radiologi diagnosti, radiologu asistenti, rentgenlaboranti u.c.); 3) kontroles grupā ietilpa Latvijas iedzīvotāji, kuri darbā un citur savā mūžā netika hroniski pakļauti jonizējošās radiācijas iedarbībai, izņemot dabisko radiācijas fonu un nelielus medicīniska rakstura rentgenizmeklējumus. Tā kā novecošanas process ir sarežģīts un to nevar raksturot ar vienu parametru, promocijas darbā aplūkoti vairāki apstaroto personu novecošanas aspekti. Darba realizācijai izmantotas vairākas metodes: tika noteikts telomēru relatīvais garums perifērisko asiņu leikocitārās rindas šūnās ar reālā laika kvantitatīvu polimerāzes ķēdes reakciju, transformējošā augšanas faktora β (TGFβ) līmenis serumā – ar imūnfermentatīvo ELISA metodi, kā arī slāpekļa monoksīda un dzelzs līmenis matos – ar elektronu paramagnētiskās rezonanses spektroskopijas metodi. Vienlaikus padziļināti vērtēta ČAES avārijas seku likvidētāju saslimstība ar vecumatkarīgām slimībām, t.sk. ar ļaundabīgiem audzējiem, un mirstība sakarā ar piedalīšanos ČAES avārijas likvidācijas laikā un veiktajiem darbiem Černobiļā. Darba rezultāti liecina, ka ČAES avārijas seku likvidētāju novecošanas procesi apsteidz Latvijas iedzīvotāju vidējos novecošanas tempus. Turklāt ČAES avārijas seku likvidētāju novecošanas mehānismā nav iesaistīta telomēru garuma saīsināšanās, kāda ir vērojama normālās ieprogrammētās replikatīvās novecošanas gadījumā. Iespējams, ka galvenais mehānisms ir inkorporēto radionuklīdu pastāvīgas jonizējošās radiācijas iedarbības izraisītā t.s. stresa inducētā priekšlaicīgā novecošana. Noskaidrots, ka jonizējošai radiācijai ilgstoši pakļauto cilvēku organismā veidojas labvēlīgi apstākļi ļaundabīgo audzēju attīstībai. ČAES avārijas seku likvidētājiem konstatēts nedaudz lielāks telomēru relatīvais garums, nekā pārējās grupās, turklāt garākās telomēras bija novērotas personām, kuras saņēma lielāku apstarojumu. Iespējams, ka tas netieši liecina par telomēru pagarinošā fermenta – telomerāzes – aktivāciju sakarā ar pastāvīgi notiekošu DNS bojājumu no inkorporētajiem radionuklīdiem, kas ir nozīmīgs faktors kanceroģenēzē. ČAES avārijas seku likvidētājiem konstatēts arī būtiski zemāks TGFβ līmenis nekā pārējo grupu cilvēkiem, kas atspoguļo nepietiekamu pretaudzēju aizsardzību viņu organismā. Daudz mazākā mērā līdzīgas tendences novērotas tikai tiem darbā regulāri apstarotajiem cilvēkiem, kuri radiācijas ietekmē nostrādājuši lielāko mūža daļu. Epidemioloģisko rādītāju analīze parādīja, ka ČAES avārijas seku likvidētāji, kuri bija pakļauti apstarojumam pirmajā gadā pēc avārijas un veica darbus ar lielāku iekšējā radioaktīvā piesārņojuma risku, saslimst ar vecumatkarīgajām slimībām jaunākā vecumā nekā citi. Turklāt avārijas seku likvidētāju mirstība ar sirds un asinsvadu slimībām vecumā līdz 45 gadiem pārsniedz attiecīga vecuma vispārējās Latvijas vīriešu populācijas rādītājus. Avārijas seku likvidētājiem novērota augstāka nekā vispārējā populācijā saslimstība ar uroģenitālajiem (prostatas, nieru), vairogdziedzera un mutes dobuma ļaundabīgajiem audzējiem, it īpaši vīriešiem jaunākā vecumā. Turpretī mirstība ar ļaundabīgajiem audzējiem ČAES avārijas seku likvidētājiem bija zemāka nekā populācijā visās vecuma grupās, kas liecina par efektīvu medicīnisku aprūpi. Kopumā noskaidrots, ka jonizējošās radiācijas ilgstoša iedarbība var modificēt un paātrināt novecošanas procesus cilvēka organismā.Item Pain Among Latvian Workers : General Prevalence vs. Registered Occupational Diseases(2022-04-29) Kaluznaja, Darja; Reste, Jeļena; Vanadziņš, Ivars; Lakiša, Svetlana; Eglīte, Maija; Department of Occupational and Environmental Medicine; Institute of Occupational Safety and Environmental HealthThe problem of painful and disabling work-related musculoskeletal disorders (MSDs) is increasing in many employment sectors of Latvia. Official statistics may underestimate the proportion of affected employees, causing delays in preventive interventions, ineffective rehabilitation, and a reduction of the workforce. This study investigated the prevalence of painful health conditions among Latvian workers by analyzing survey data and comparing these to official statistics on registered occupational diseases (ODs). A total of 2,446 workers participated in the state-level “Work conditions and risks in Latvia, 2017–2018” survey that included questions about pain lasting longer than 3 days during the previous year. The frequency of subjective reports on the presence, severity, and location of pain and related behaviors was assessed in relation to sex, age, education, and job position. Descriptive statistics and cross tabulation with the chi-squared test as well as multinomial logistic regression were applied to the data. Overall, 27.7% of respondents (n = 678) reported experiencing pain, predominantly in the lower back (14.3%) and mostly moderate (47.1%) or severe (45.1%). Only one-fifth of respondents (20.5%) took sick leave from work and one-third (29.0%) did not take action to alleviate their pain. Participants aged 55–74 years had a significantly higher odds ratio (OR) for pain in at least one body region—including hands and legs—than those aged 18–24 years. Women had significantly higher odds of headache (OR = 2.55) and neck pain (OR = 1.85) than men. Respondents with a primary or elementary education level had higher odds of pain in at least one body region (OR = 1.60) and in the lower back (OR = 1.86), while those with secondary education had higher odds of pain in hands (OR = 1.51) than employees with higher education. Unskilled workers had significantly higher odds of pain in hands (OR = 2.42) and legs (OR = 2.12) than directors. Official data revealed a dramatic increase in the proportion of MSDs and related disabilities in the last decade, reaching 75.5% of all first registered ODs in 2019. These results demonstrate a high prevalence of painful conditions among Latvian employees; urgent attention to diagnostics, treatment, and prevention is needed to ensure the musculoskeletal health and productivity of this population.Item Reducing sedentary behaviour in office workers – motivational factors and barriers(EDP Sciences, 2024-03-29) Kauce, Rūta; Kiseļova, Viola Daniela; Jaudzeme, Māra; Hvostovoja, Anna; Reste, Jeļena; Vilka, L.; Krumina, J.; Sabiedrības veselības un sociālās labklājības fakultāte; Institute of Occupational Safety and Environmental HealthThe office workplace is considered a significant risk setting for long-term sedentary behaviour, which can lead to various adverse health consequences. Therefore, this article examines the obstacles and external factors that motivate office workers, who spend a significant part of their workday sitting, to engage in physical activity. This cross-sectional study analysed data from an anonymous survey of 232 Latvian office workers. Our results indicated that most respondents would be motivated to engage in physical activity during working hours, if employer provided motivational system (mean score 4.04 out of maximal 5 points), a specialist-led physical activity classes (4.01) or exercising together with colleagues (3.91) would be implemented at their workplace. Respondents in the following subgroups agreed more that employer provided motivational system would encourage them to be more physical activity at work: all age groups (between 3.93 and 4.18), both ‘time of sitting’ subgroups (between 4.00 and 4.07), men (3.93) and in-office workers (4.07). However, women (4.06) and remote workers (4.08) agreed more, that physical activity classes led by a specialist would be the most motivational. In contrast, highly intense work tasks were the main barrier for office workers not to be involved in physical activities at work, as it was the obstacle for 59% of the respondents. These findings can be helpful in implementing and organising health promotion interventions for office workers.Item Sapropel-enriched sodium carboxymethyl cellulose gel systems : formulation approaches, stability and bioactive potential(2025-03) Kļaviņa, Aneka; Reste, Jeļena; Mārtiņsone, Inese; Vanadziņš, Ivars; Juhņeviča, Inna; Pavlovska, Ilona; Institute of Occupational Safety and Environmental HealthSapropel, a sediment rich in organic matter and bioactive compounds, has significant potential for pharma- ceutical and cosmetic applications. This study aimed to develop a stable, water-soluble hydrogel containing sapropel extract as a delivery platform for these bioactive compounds. Sodium carboxymethylcellulose (Na-CMC) was used as a gelling agent in eight formulations, with or without sapropel extract, and buffer solutions (NaCl, MgSO4, MgCl2). The gels were evaluated for organoleptic properties, pH, viscosity, stability, and thermal resistance over a 2-year period under different storage conditions. All sapropel extract containing formulations exhibited a smooth, homogeneous and light-yellow appearance with good stability and spread ability. The pH levels ranged from 4.7 to 7.4, within the acceptable range for skin application, although formulations with MgCl2 showed greater pH fluctuations. Viscosity analyses revealed that sapropel extract decreased viscosity, particularly under fluctuating temperatures. MgSO4-buffered formulations exhibited the most stable viscosity over time. However, some formulations demonstrated decreased stability and viscosity after prolonged exposure to elevated temperatures and UV light. Centrifugal and thermal tests confirmed the physical stability of the gels, with no phase separation observed. Overall, the study confirms the feasibility of incorporating sapropel extract into stable, water-soluble hydro- gels, making them suitable for potential therapeutic and cosmetic uses.Item Unlocking the Therapeutic Potential of Freshwater Sapropel Extracts : In Vitro Analysis and Antioxidant Profiling for Skincare Applications(2024-03-27) Kļaviņa, Aneka; Reste, Jeļena; Mārtiņsone, Inese; Vanadziņš, Ivars; Lece, Anna; Pavlovska, Ilona; Department of Occupational and Environmental Medicine; Institute of Occupational Safety and Environmental Health; Bioķīmijas zinātniskā laboratorijaBackground and Objective: Sapropel, a biologically active sedimentary deposit, is high in organic matter and minerals and has been shown to offer health benefits. Its constituents, humic acid (HA) and fulvic acid (FA), have been found to have some therapeutic applications. The aim of this study was to determine the potential therapeutically significant properties of freshwater sapropel extracts: their polyacid content, antioxidative (AO) status, and biological activity in cell culture. Materials and Methods: Freshwater lakes from the southeast region of Latvia were investigated layer by layer. The total organic carbon (TOC) was determined through combustion using the catalytic oxidation method, HA and FA were measured via acid perspiration, and the total polyphenol content (TPC) and total antioxidant status (TAS) was analysed spectrophotometrically. Sapropel extracts’ regenerative abilities were tested in vitro using a Cell-IQ real-time monitoring system on mouse BALB/c 3T3 fibroblasts and human keratinocyte HaCaT cell lines. Cytotoxicity was measured through neutral red uptake assessment as a concentration-dependent reduction in the uptake of neutral red dye relative to a vehicle control or untreated cells. Results: The highest AO activity was observed in sapropel extracts with elevated concentrations of HA and TPC from Audzelu Lake (1.08 ± 0.03 mmol/L), and the lowest activity was found in extracts from Ivusku Lake (0.31 ± 0.01 mmol/L). Correspondingly, the concentrations of HA in Audzelu and Ivusku Lakes were recorded as 45.2 and 27.4 mg/g, respectively. High concentrations of HA promoted in vitro cell growth upon short-term exposure (up to 6 h). Conclusions: The results show that high TPC correlates with AO status and sapropel extracts with higher concentrations of HA exhibit greater AO activity and promote in vitro cell growth, suggesting a perspective use for short-term topical therapeutic skin applications. However, higher concentrations over longer durations showed cytotoxic effects, indicating the need for further investigation.