Revisiting methods for the assessment of naturally-occurring radioactivity in drinking water.

A comprehensive radioactivity characterisation of Castilla y León (Spain) groundwater intakes intended for human consumption is addressed between 2017 and 2021. This study responds to the radiological requirements stated in the European Council Directive 51/2013/EURATOM concerning drinking water for public health. Given that the gross α- and gross ß-activity determination is used as a screening strategy for water radioactivity monitoring, the reliability of the thin-source deposit method (ISO 10704, 2019) has been improved to achieve representative values of the total activity coming from α- and ß-particle emitters in the samples. More than 400 groundwater samples have been considered for this purpose, analysing their 238,235,234U, 228,226Ra, 210Pb, and 210Po activity concentrations, which are needed for the indicative dose assessment. These results, considered reference activity values, are compared with the gross α- and gross ß-activities determined by the different procedure approaches. Ultimately, the results of the liquid scintillation counting method (ISO 11704, 2018) are also used to validate the optimised method.

Manejo del «dolor de piedra» entre los siglos xviii y xix: breve historia de una receta médica del Virreinato en la Nueva Granada / Management of “stone pain” between the 18th and 19th centuries: A brief history of a medical prescription in the Viceroyalty of New Granada

Introducción: La presencia de cálculos en el tracto urinario es una afección que acompaña al ser humano desde la antigüedad. En la época colonial, esta se denominaba «dolor de piedra» y su manejo no quirúrgico se basaba en el uso de medicinas de origen vegetal, animal o mineral.ObjetivoContextualizar una receta médica que data del siglo xviii en el Nuevo Reino de Granada, utilizada para modular el dolor de piedra. Adicionalmente, analizar sus componentes para evaluar el fundamento de sus posibles efectos fitoterapéuticos sobre la enfermedad y el dolor.Material y métodoBúsqueda documental en el Archivo Histórico Cipriano Rodríguez Santamaría de la Biblioteca Octavio Arizmendi Posada de la Universidad de La Sabana. Se analizó el documento denominado «Receta para el dolor de piedra de la vejiga o riñones». Posteriormente, se realizó una revisión de la literatura científica actual y textos originales, sin límite de tiempo.ResultadosLa transcripción del documento fuente reveló diversos agentes fitoterapéuticos como la Manzanilla (Matricaria recutita), la azucena (Lilium lancifolium), el trébol (Trifolium pratense) y raíces de malva (Malva sylvestris), acompañados para su consumo de gran cantidad de agua. (AU)

Introduction: The presence of stones in the urinary tract is a condition that has accompanied humans since ancient times. In colonial times, this condition was known as “stone pain” and its non-surgical management was based on the use of medicines derived from plants, animals and minerals.ObjectiveTo contextualize a medical prescription used to modulate stone pain in the 18th century in the New Kingdom of Granada. Additionally, to analyze its components and evaluate the basis of its possible phytotherapeutic effects on the disease and pain.Material and methodDocument search in the Cipriano Rodríguez Santamaría Historical Archive of the Octavio Arizmendi Posada Library at Universidad de La Sabana. The document entitled “Prescription for bladder or kidney stone pain” was analyzed, and a complementary review of current scientific literature and original texts was performed with no time limits, in order to compare this prescription to related findings in the history of medicine.ResultsThe transcription of the source document revealed several phytotherapeutic agents such as chamomile (Matricaria recutita), lilies (Lilium lancifolium), clover (Trifolium pratense), and mallow roots (Malva sylvestris), accompanied by a large amounts of water.ConclusionsThere is scientific evidence that could explain the anti-inflammatory and antioxidant effects of all plant-derived medicines used in this prescription. Abundant water intake to increase urine volume was an essential part of treatment. However, the lack of more precise data related to the prescription and the evolution of the patients makes it difficult to analyze its therapeutic efficacy. (AU)

Una mirada histórica a la menstruación a través de una receta médica del siglo xix en el Nuevo Reino de Granada / A historical look at menstruation through a 19th century medical prescription in the New Kingdom of Granada

La menstruación ha tenido diferentes significados en diversas culturas a lo largo de la historia. Desde Regnier de Graaf en el siglo xvii hasta la fecha, pasando por la médica norteamericana Mary Putnam Jacobi a finales del sigloxix, un buen número de pioneros científicos estudiaron el sistema reproductor femenino con el fin de entender la fisiología del ciclo menstrual. En el Nuevo Reino de Granada, durante los siglos xviii yxix, se desarrolló por parte de médicos y boticarios una receta médica a base de agentes herbarios y de origen animal con el fin de regular el ciclo menstrual, disminuyendo de esta forma síntomas asociados a esta condición para evitar el estigma sociocultural que esta condición implicaba para la mujer en aquel entonces. Esta receta se encuentra en la actualidad consignada en el archivo histórico Cipriano Rodríguez Santamaría en la biblioteca Octavio Arizmendi Posada de la Universidad de La Sabana en Chía, Colombia. La redacción y autoría de esta receta no es del todo clara, y su uso se basa eventualmente en la experiencia y observación de quienes en esa época la utilizaron, sin bases científicas para respaldar su eventual efecto modulador y terapéutico.(AU)

Menstruation has had different meanings in various cultures throughout history. From Regnier de Graaf in the 17th century to the American physician Mary Putnam Jacobi in the late 19th century, a number of pioneering scientists have studied the female reproductive system in order to understand the physiology of the menstrual cycle. In the New Kingdom of Granada, during the eighteenth and nineteenth centuries, doctors and apothecaries developed a medical prescription based on herbal and animal products in order to regulate the menstrual cycle. In this way the symptoms associated with this condition were reduced in order to avoid the socio-cultural stigma that it implied for women at that time. This prescription is currently stored in the Cipriano Rodríguez Santamaría Historical Archives at the Octavio Arizmendi Posada Library at La Sabana University in Colombia, South America. The writing and authorship of this prescription is not entirely clear, and its use is based on the experience and observation of those who used it at that time, with no scientific basis to support its eventual modulating and therapeutic effect.(AU)

Management of "stone pain" between the 18th and 19th centuries: A brief history of a medical prescription in the Viceroyalty of New Granada.

INTRODUCTION: The presence of stones in the urinary tract is a condition that has accompanied humans since ancient times. In colonial times, this condition was known as "stone pain" and its non-surgical management was based on the use of medicines derived from plants, animals and minerals. OBJECTIVE: To contextualize a medical prescription used to modulate stone pain in the 18th century in the New Kingdom of Granada. Additionally, to analyze its components and evaluate the basis of its possible phytotherapeutic effects on the disease and pain. MATERIAL AND METHOD: Document search in the Cipriano Rodríguez Santamaría Historical Archive of the Octavio Arizmendi Posada Library at Universidad de La Sabana. The document entitled "Prescription for bladder or kidney stone pain" was analyzed, and a complementary review of current scientific literature and original texts was performed with no time limits, in order to compare this prescription to related findings in the history of medicine. RESULTS: The transcription of the source document revealed several phytotherapeutic agents such as chamomile (Matricaria recutita), lilies (Lilium lancifolium), clover (Trifolium pratense), and mallow roots (Malva sylvestris), accompanied by a large amounts of water. CONCLUSIONS: There is scientific evidence that could explain the anti-inflammatory and antioxidant effects of all plant-derived medicines used in this prescription. Abundant water intake to increase urine volume was an essential part of treatment. However, the lack of more precise data related to the prescription and the evolution of the patients makes it difficult to analyze its therapeutic efficacy.

Investigación médico-antropológica documental: prescripciones enfocadas al manejo del dolor / Medical-anthropological research: prescriptions focused on pain management

Introducción: Las recetas médicas o prescripciones históricas en el territorio de la Nueva Granada (hoy Colombia) revelan la evolución del manejo de la enfermedad en función de los efectos benéficos de administrar algún tipo de agente medicinal de origen vegetal, animal o mineral. Objetivo: Describir el tratamiento del reumatismo en los siglos XVIII y XIX, con base en dos recetas médicas de la época con base en la fundamentación contemporánea de su interacción fisiológica. Materiales y métodos: Búsqueda documental en el archivo Histórico de la Biblioteca Octavio Arizmendi Posada de la Universidad de La Sabana, donde se encontraron las recetas tituladas "Reumatismo" y "Rehumas". Resultados: Se describen cuatro clases de tratamientos para las enfermedades reumáticas utilizados en los siglos XVIII y XIX y orientados principalmente a la disminución del dolor. Este artículo presenta las bases fisiológicas de estos tratamientos, y cómo pudieron o no haber tenido algún efecto calmante al examinar su fisiología. Conclusiones: Estos medicamentos coloniales neogranadinos no ameritan su uso en el contexto actual de la medicina, pero pudieron representar una ayuda terapéutica en su momento.

Introduction: the medical prescriptions or historical prescriptions in the territory of New Granada (present-day Colombia) reveal the evolution of disease management given the beneficial effects of administering some type of medicinal agent of plant, animal or mineral origin. Objective: To describe the treatment of rheumatism in the 18th and 19th centuries based on two medical prescriptions of the time based on the contemporary rationale of their physiological interactions. Materials and methods: Documentary search in the Historical Archive of the Octavio Arizmendi Posada Library at Universidad de La Sabana in Colombia, where the prescriptions entitled "Reumatismo" and "Rehuma" were found. Results: Four classes of treatments for rheumatic diseases used in the 18th and 19th centuries and mainly oriented to pain reduction are described. This article presents the physiological basis of these treatments, and how they may or may not have had some calming effect when examining their physiology. Conclusions: These Neogranadian colonial drugs do not deserve their use in the current context of medicine, but they may have represented a therapeutic aid at the time.

How the distribution coefficient of 238U in natural soils is affected by the method used to obtain the soil solution and its dependency on structural characteristics.

A systematic study on desorption of uranium in a natural soil has been carried out to reduce the level of uncertainty associated with the method employed to determine the values of the distribution coefficient (Kd). Generally, the operating method used to extract and analyze the soil solution determines the Kd values. Here, the centrifugation method has been used to obtain soil solution extracts. Several procedural parameters have been considered such as incubation time, the level of soil moisture relative to saturation (saturation degree) and centrifugation speed (equivalent to effective suction). In order to analyze the influence of soil structural characteristics, this study considers three grain-size fractions of soil: loamy coarse sand, loamy fine sand, and loam, all of which are obtained from a natural soil collected in a uranium mineralized area. Our results indicate that neither incubation time nor centrifugation speed influence the determination of Kd for uranium. The results also indicate that the level of soil moisture is the most important factor for determining 238U-Kd. It has been shown that the influence of moisture on Kd also depends on the structural characteristic of the soil. For the loamy coarse sand subsample, the moisture level during the incubation period showed a significant influence on the Kd. In addition, through the use of regression analysis, the pH was identified as the cofactor with the greatest influence on Kd of uranium.

Influence of soil conditions on the distribution coefficients of 226Ra in natural soils.

In order to clarify some of the assumptions and approximations about the use of the distribution coefficient Kd for 226Ra in soils, a systematic study has been performed using centrifugation to extract the soil solution. The separated fractions of the soil solution have different kinetics with respect to the sorption process in the soil, which may in turn condition the final chemical composition and even the speciation of the radionuclides in solution. In the experimental design of this study three factors were considered: the moisture level in the incubation process, incubation time and the speed of centrifugation. Also, three levels were chosen for each factor. In order to analyze the influence of the structural characteristics of the soil, this study was performed with three textural fractions: coarse sand, fine sand, and silt and clay, obtained from an only soil. Also, the soil was naturally enriched with radionuclides of the 238U series. An analysis of variance (ANOVA) was performed in order to assess the influence of the factors studied on the distribution coefficient of 226Ra. The results indicate that different behaviors can be observed depending on the structural characteristic of the soil. In the case of particle size, the soil with the largest grain size showed that the incubation process parameters influence the equilibrium level achieved, while in the case of the smallest edaphic particles, radium is not homogeneously distributed in the soil solution and the Kd value is dependent on the speed of centrifugation.

Mazinger, a γ-ray spectrometry system of high efficiency and very low background for paloeoclimate applications.

The study of changes in climate on the scale of the entire history of Earth requires absolute dating methods that cover the total time period. 230Th and 234U disequilibria, as well as 231Pa and 235U, have shown as good candidates to provide ages older than 50ky. Therefore, they are the basis for a method that allows extending the 14C dating up to 500ky or even further. The wide variety of samples, their high number and the fact that several radionuclides are needed to obtain samples' chronology make γ spectrometry to be a suitable technique in this task. However, its low efficiency and high background, therefore, high detection limits in comparison with α spectrometry, need to be improved to become a real alternative in samples with very low activity levels. With this purpose, Mazinger, a new γ spectrometry system based on two HPGe detectors, which are surrounded by active and passive shieldings and placed 12m underground, has been set up in the Ionizing Radiation Laboratory of the University of Salamanca. In this work, the Mazinger's performance is studied at the full energy range useful for natural radionuclides. In composite detectors, energy resolution is a consequence of the electronics adjustments, which have to enable the raw spectra to be summed without resolution worsening. Therefore, the method used to set up electronics and add spectra is described. Detector background is also analysed and compared with the one of a single low-background HPGe detector as a function of the different shielding elements, obtaining gross values of order 10-4cps. Efficiency and figure of merit are obtained for the main natural radionuclides in marine sediments belonging to the Mediterranean MD99-2348 core. Special focus is made on the 230Th determination whose results are compared with the ones provided by α spectrometry. Results show that Mazinger´s performance, in terms of figure of merit, is four times better than the one of a low-level background HPGe detector, specially suited to detect natural radionuclides, being comparable to the performance of α spectrometry in the 230Th determination, which is the radionuclide of lower γ intensity, and doing Mazinger a first class in radiometry of natural radionuclides.

Influence of soil structure on the "Fv approach" applied to 238U and 226Ra.

The soil-to-plant transfer factors were determined in a granitic area for the two long-lived uranium series radionuclides 238U and 226Ra. With the aim to identify a physical fraction of soil whose concentration correlates linearly with the plant concentration, the soil compartment was analyzed in various stages. An initial study identified the soil compartments as being either bulk soil or its labile fraction. The bulk soil was subsequently divided into three granulometric fractions consisting of: coarse sand, fine sand, and silt and clay. The soil-to-plant transfer of radionuclides for each of these three texture fractions was analyzed. Lastly, the labile fraction was extracted from each textural part, and the activity concentration of the radionuclides 238U and 226Ra was measured. In order to assess the influence of soil texture on the soil-to-plant transfer process, we sought to identify possible correlations between the activity concentration in the plant compartment and those found in the different fractions within each soil compartment. The results showed that the soil-to-plant transfer process for uranium and radium depends on soil grain size, where the results for uranium showed a linear relationship between the activity concentration of uranium in the plant and the fine soil fraction. In contrast, a linear relation between the activity concentration of radium in the plant and the soil coarse-sand fraction was observed. Additionally, the presence of phosphate and calcium in the soil of all of the compartments studied affected the soil-to-plant transfer of uranium and radium, respectively.

Assessment of the vertical distribution of natural radionuclides in a mineralized uranium area in south-west Spain.

Low-level alpha spectrometry techniques using semiconductor detectors (PIPS) and liquid scintillation (LKB Quantulus 1220™) were used to determine the activity concentration of (238)U, (234)U, (230)Th, (226)Ra, (232)Th, and (210)Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were sampled from areas with different levels of influence from the installation and hence had different levels of contamination. The vertical profiles of the soils (down to 40 cm depth) were studied in order to evaluate the vertical distribution of the natural radionuclides. To determine the origin of these natural radionuclides the Enrichment Factor was used. Also, study of the activity ratios between radionuclides belonging to the same radioactive series allowed us to assess the different types of behaviors of the radionuclides involved. The vertical profiles for the radionuclide members of the (238)U series were different at each sampling point, depending on the level of influence of the installation. However, the profiles of each point were similar for the long-lived radionuclides of the (238)U series ((238)U, (234)U, (230)Th, and (226)Ra). Moreover, a major imbalance was observed between (210)Pb and (226)Ra in the surface layer, due to (222)Rn exhalation and the subsequent surface deposition of (210)Pb.

Enhancing radium solubilization in soils by citrate, EDTA, and EDDS chelating amendments.

The effect of three chelating agents (citrate, EDTA, and EDDS) on the solubilization of radium from a granitic soil was studied systematically, considering different soil pH values, chelating agent concentrations, and leaching times. For all the chelating agents tested, the amount of radium leached proved to be strongly dependent on the pH of the substrate: only for acidic conditions did the amount of radium released increase significantly relative to the controls. Under the best conditions, the radium released from the amended soil was greater by factors of 20 in the case of citrate, 18 for EDTA, and 14 for EDDS. The greatest improvement in the release of radium was obtained for the citrate amendment at the highest concentration tested (50 mmol kg(-1)). A slightly lower amount of radium was leached with EDTA at 5 mmol kg(-1) soil, but the solubilization over time was very different from that observed with citrate or EDDS. With EDTA, a maximum in radium leaching was reached on the first day after amendment, while with citrate, the maximum was attained on the fourth day. With EDDS, radium leaching increased slightly but steadily with time (until the sixth day), but the net effect for the period tested was the lowest of the three reagents.

Improvement of a method for the sequential determination of 210Pb, 226Ra, and uranium isotopes by LSC and alpha-particle spectrometry.

In a previous paper the authors proposed a sequential method for the determination of isotopes of uranium, thorium, radium, and lead from environmental samples using alpha-particle spectrometry and LSC techniques. Although the radiochemical yields were suitable when the assays were performed on synthetic samples, application to real environmental samples caused a major decrease in the radiochemical yield, especially for uranium in inorganic samples (soils). A modification of the procedure is described that overcomes this drawback.

Enhancing uranium solubilization in soils by citrate, EDTA, and EDDS chelating amendments.

A systematic study was made of the effects of three soil amendments on the solubilization of uranium from a granitic soil. The aim was to optimize solubilization so as to enhance bioavailability for the purposes of remediation. The three amendments tested were with citrate, EDTA, and EDDS as chelating agents. The effects of pH, chelator concentration, and leaching time were studied. The most important factor in uranium solubilization was found to be the pH. In the absence of chelating agents, the greatest solubilization was obtained for alkaline conditions, with values representing about 15% of the total uranium activity in the bulk soil. There were major differences in uranium solubilization between the different amendments. The citrate treatment was the most efficient at acidic pH, particularly with the greatest concentration of citrate tested (50 mmol kg(-1)) after 6 days of treatment. Under these conditions, the uranium concentration in solution was greater by a factor of 356 than in the control suspension, and represented some 63% of the uranium concentration in the bulk soil. Under alkaline conditions, the EDTA and EDDS treatments gave the greatest uranium activity concentrations in solution, but these concentrations were much lower than those with the citrate amendment, and were not very different from the control results. The uranium extraction yield with EDDS amendment was greater than with EDTA.

Transfer of 238U, 230Th, 226Ra, and 210Pb from soils to tree and shrub species in a Mediterranean area.

The soil-to-plant transfer factors of natural uranium isotopes ((238)U and (234)U), (230)Th, (226)Ra, and (210)Pb were studied in a disused uranium mine located in the Extremadura region in the south-west of Spain. The plant samples included trees (Quercus ilex, Quercus suber, and Eucalyptus cameldulensis) and one shrub (Cytisus multiflorus). All of them are characteristic of Mediterranean environments. The activity concentrations in leaves and fruit were determined for the tree species at different stages of growth. For the shrub, the total above-ground fraction was considered in three seasons. For old leaves and fruit, the highest activity concentrations were found in Eucalyptus cameldulensis for all the radionuclides studied, except in the case of (230)Th that presented similar activity concentrations in all of the tree species studied. In every case, the transfer to fruit was less than the transfer to leaves. In the shrub, the results depended on the season of sampling, with the highest value obtained in spring and the lowest in autumn. Important correlations were obtained for (238)U and (226)Ra between the activity ratio in soils with that in leaves or fruit.

A sequential method for the determination of 210Pb, 226Ra, and uranium and thorium radioisotopes by LSC and alpha-spectrometry.

A procedure for the determination of (210)Pb, and alpha-emitting radioisotopes of uranium, thorium, and radium from the same aliquot of a sample has been proposed. The key step consisted in the recovery of Pb(II) and Ra by precipitation of insoluble Pb(NO(3))(2), the uranium and thorium radioisotopes remaining in solution. Afterwards, the fractions were handled by specific, well consolidated procedures. Lead-210 was determined by the LSC technique while the uranium, thorium, and radium radioisotopes were measured with silicon alpha-spectrometers. The procedure was applied to a reference sample and several environmental samples obtaining satisfactory results.

The ability of Helianthus annuus L. and Brassica juncea to uptake and translocate natural uranium and 226Ra under different milieu conditions.

Seedlings of Helianthus annuus L. (HA) and Brassica juncea (BJ) were used to test the effect of the pH, the presence of phosphates, and the addition of ethylene-diamine-tetraacetic acid (EDTA) or citrate on the uptake and the translocation of uranium isotopes ((238)U, (235)U, and (234)U) and (226)Ra. The results indicated that the presence of phosphates generally reduces the uptake and transfer of uranium from the roots to the shoots of HA. In the case of BJ, while phosphate enhanced the retention of uranium by roots, the translocation was poorer. Likewise, for (226)Ra, the best translocation was in the absence of phosphates for both species. The addition of citrate increased the translocation of uranium for both species, but had no clear effect on the transfer of (226)Ra. The effect of EDTA was much more moderate both for uranium and for (226)Ra, and for both plant species. Only noticeable was a slightly better uptake of (226)Ra by BJ at neutral pH, although the translocation was lower.

Influence of soil texture on the distribution and availability of 238U, 230Th, and 226Ra in soils.

The influence of soil texture on the distribution and availability of (238)U, (230)Th, and (226)Ra in soils was studied in soil samples collected at a rehabilitated uranium mine located in the Extremadura region in south-west Spain. The activity concentration (Bqkg(-1)) in the soils ranged from 60 to 750 for (238)U, from 60 to 260 for (230)Th, and from 70 to 330 for (226)Ra. The radionuclide distribution was determined in three soil fractions: coarse sand (0.5-2mm), medium-fine sand (0.067-0.5mm), and silt and clay (<0.067 mm). The relative mobility of the natural radionuclides in the different fractions was studied by comparison of the activity ratios between radionuclides belonging to the same radioactive series. The lability of these radionuclides in each fraction was also studied through selective extraction from the soils using a one-step sequential extraction scheme. Significant correlations were found for (238)U, (230)Th, and (226)Ra between the activity concentration per fraction and the total activity concentration in the bulk soil. Thus, from the determination of the activity concentration in the bulk soil, one could estimate the activity concentration in each fraction. Correlations were also found for (238)U and (226)Ra between the labile activity concentration in each fraction and the total activity concentration in bulk soil. Assuming that there is some particle-size fraction that predominates in the process of soil-to-plant transfer, the parameters obtained in this study should be used as correction factors for the transfer factors determined from the bulk soil in previous studies.

Elimination of natural uranium and (226)Ra from contaminated waters by rhizofiltration using Helianthus annuus L.

The elimination of natural uranium and (226)Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and (226)Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and (226)Ra from the solution: about 50% of the natural uranium and 70% of the (226)Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution.

Linearity assumption in soil-to-plant transfer factors of natural uranium and radium in Helianthus annuus L.

The linearity assumption of the validation of soil-to-plant transfer factors of natural uranium and (226)Ra was tested using Helianthus annuus L. (sunflower) grown in a hydroponic medium. Transfer of natural uranium and (226)Ra was tested in both the aerial fraction of plants and in the overall seedlings (roots and shoots). The results show that the linearity assumption can be considered valid in the hydroponic growth of sunflowers for the radionuclides studied. The ability of sunflowers to translocate uranium and (226)Ra was also investigated, as well as the feasibility of using sunflower plants to remove uranium and radium from contaminated water, and by extension, their potential for phytoextraction. In this sense, the removal percentages obtained for natural uranium and (226)Ra were 24% and 42%, respectively. Practically all the uranium is accumulated in the roots. However, 86% of the (226)Ra activity concentration in roots was translocated to the aerial part.

Polymorphisms in the promoter regions of FAS and FASL genes as candidate genetic factors conferring susceptibility to endometriosis.

Although the pathophysiological mechanisms leading to endometriosis remain unknown, several hypothesis have been proposed, including a dysregulation of the normal apoptotic process which takes place in the endometrium. One of the apoptotic pathways playing a crucial role in the programmed cell death within the endometrium is the Fas-FasL system. In this study we have performed a case-control analysis in order to evaluate three polymorphisms located within FAS (-1377G>A and -670A>G) and FASL (-843C>T) genes, as susceptibility factors for endometriosis. We have analysed a series of women with endometriosis compared respectively to a group of women without symptoms of the disease, and to a group of confirmed unaffected women. The genotyping of the three variants was carried out by Fluorescence Resonance Energy Transfer (FRET) technology, and statistical analysis was performed using chi2 test with Yates correction. Our results show that the differences in the distribution of the polymorphic variants were not statistically significant when the group of patients was compared to the other groups. Thus, it seems to indicate that the variants here analysed are not involved in the pathogenesis of the disease in our population. However this does not let us to completely exclude such genes as potential candidates for the disease. A complete genetic analysis of the genes involved in the intricate regulatory system of the apoptosis may lead to the identification of susceptibility factors for the disease and a better understanding of its etiology.