Range Of Activity Concentrations Research Articles

Radiological Impact Assessment of Mining on Soil, Water and Plant Samples from Okobo Coal Field, Nigeria

Anthropogenic, including mining activities leaves the environment contaminated with potentially toxic substances and remote hazards if not properly checked. The quest in this study is the levels of naturally occurring radionuclides in Okobo coal, Nigeria and their possible distribution in coal mine vicinity soils, water and plants (cassava). Samples were characterized for levels of radionuclides and radiological detriments using high resolution gamma spectrometer, Gamma ray liquid scintillation and applicable radiological hazard indices. The range of mean activity concentrations (Bq·kg-1) for the environmental samples are as follows: 226Ra (8.39 ± 1.0 to 77.6 ± 4.0), 232Th (0.470 ± 0.4 and 77.8 ± 2), and 40K (29.1 ± 0.4 and 289 ± 6), with their respective mean values of 32.7 ± 2.1, 54.0 ± 1.5 and 158.8 ± 3.1 (Bq·kg-1). Radiological detriments including radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), radioactivity level index or gamma index (Iγ) and the ELCR for coal sample is 96.94 Bq·kg-1, 0.26, 0.30, 0.69, and 1.56 respectively. Reported values were below the safety limits stipulated by UNSCEAR and implied that the environment is relatively safe with low levels of natural radioactivity. Overall, this background study has demonstrated that Okobo coal mine is a less radio-hazard contributor to environmental samples. Exceptions to this generalization are representative gamma index (Iγr) and annual effective dose equivalent values for some cassava and soil samples, which may call for future impact monitoring.

Radioactivity and Geochemistry of Wadi El Reddah Stream Sediments, North Eastern Desert, Egypt

Wadi El Reddah is considered as semi closed basin where the only open tributary is very narrow and has higher ground relative to the ground adjacent to the surrounding peaks. The 238U activity concentrations range between 101.24 and 347.96 with an average 214.63 Bq Kg-1, 234U activity concentrations range between 89.67 and 308.19 Bq Kg-1 with average 190.10 Bq Kg-1. 232Th activity concentrations vary between 96.42 and 463.71 Bq Kg-1 with 240.46 Bq Kg-1 as an average. 40K ranges between 1092.71 and 1227.25 Bq Kg-1 with an average 1153.82 Bq Kg-1. 235U activity concentration ranges between 4.66 and 17.38 Bq Kg-1 with average 10.19 Bq Kg-1. Most of stream sediment samples exhibit increase in SiO2, Fe2O3t, Na2O, P2O5 and K2O and L.O.I. However, trace elements in the studied samples show enrichment in Ni, Cu, Pb, Zn, Cd, Ta, Nb, Zr, Y, Rb, Cs, Ga, Hf, Sn, Th, Tl, U, W, Mo, Bi, As, Be, Li, Sb and Au whereas they are depleted in Co, Sr, V, Ag, Cr and Sc. Zr, Hf and Y are relatively immobile and essentially concentrated in the accessory minerals (zircon and its alteration product branirite, xenotime, thorite and uranothorite). Their REE patterns are well characterized by the M- and W-type tetrad effects. The M- type tetrad effect could be inherited from the surrounding granitic rocks whereas the positive Y anomalies intimately associating with the W-type tetrad effect of REE mainly occur in natural aquatic solutions including seawaters and in some hydrogenous deposits.

Experimental facility for the production of reference atmosphere of radioactive gases (Rn, Xe, Kr, and H isotopes)

Radioactive gases are of great interest for environmental measurements and can be distinguished in two categories. The natural radionuclides such as the isotopes of radon (222Rn and 220Rn), and the anthropogenic radionuclides coming from fission products (isotopes of Xe and 85Kr) and activation products (3H and 37Ar). Gas monitoring in the environment is an important issue for radioprotection and for the Comprehensive Nuclear-Test-Ban Treaty (CTBT), which both require metrological traceability of these gases. For this purpose, two gas chambers, of 42 L and 125 L, have been conceived and built at the LNE-LNHB to produce reference atmospheres of various gas mixtures. These chambers were created in order to provide any radioactive gas atmosphere with a wide range of activity concentrations (Bq·m−3 to MBq·m−3). The goal of this setup is to be representative of the different environmental conditions for detector qualification and to perform studies of radioactive gas absorption in materials of interest. As a result, the 2 chambers used in this experimental facility are designed to work from vacuum pressure to atmospheric pressure, with a constant activity concentration for any radioactive gas, and under dry to high humidity conditions. It can also be used in a static mode, in which the activity concentration will follow the radioactive decay of the gas. In this paper, the characterization of the chambers will be discussed. These two chambers are combined with different primary standards established by the LNE-LNHB. As the production of the reference atmosphere depends on the primary standard method, we present the details for each atmosphere production, which require a well-known volume, pressure or a direct activity concentration measurement.

Assessment and mapping of the high background radiation anomaly associated with laterite utilization in the south coastal region of Kenya

Laterite is commonly used in Kenya and other tropical countries as an aggregate material for road paving. However, the use and relocation of laterite and other geological materials from high background radiation areas (HBRA) may increase exposure to ionizing radiation in areas that were originally at background radiation levels. We present the results of an in-situ radiometric survey conducted at sites associated with laterite utilization around the Mrima Hill HBRA and adjoining environs along a section of the main road in south coastal region of Kenya. The goal of this study was to determine the levels of primordial radionuclides, as well as to assess and map the associated radiation exposure due to the modified radiation field resulting from the use of laterite in the region. It was found that air absorbed gamma dose-rates on parts of the road and side road intersections (median values are 326 ± 52 and 987 ± 138 nGy h−1, respectively) range 4–14 times higher than the adjoining areas. This anomaly was attributed to elevated levels of 238U and 232Th (activity concentrations range 202–1452 Bq kg−1 and 315–1579 Bq kg−1, respectively) measured adjacent to the laterite roadbeds. In addition, results from the energy dispersive X-ray fluorescence analysis of lateritic soils showed that Th correlates positively with monazite constituent elements namely P, La, Ce and Nd suggesting that the laterite used for road paving in parts of the region was sourced from Mrima Hill.

Assessment of 210Po and 210Pb by moss biomonitoring technique in Thrace region of Turkey

This study presents the first data of 210Po and 210Pb activity concentrations using moss species Hypnum cupressiforme from Thrace region, the northwestern part of Turkey. The moss samples were systematically collected from 40 locations in the study area. The average with standard deviation and range of 210Po and 210Pb activity concentrations were found to be 409 ± 128, 188–777 and 494 ± 183, 178–852 Bq kg−1 at dry weight, respectively. Comparatively higher radionuclide activities were found in the northeastern Thrace, probably due to 222Rn daughters attached to aerosols through high rainfall in this part of the region. A significant positive correlation was found between 210Po and 210Pb, which shows that their source and/or bioaccumulation behavior are similar. The average and range of 210Po/210Pb ratio were calculated to be 0.89 and 0.47–2.67, respectively. Those levels were calculated to be mostly lower than unity that addressed the abundance of 210Pb, probably due to predominantly inorganic particles through atmospheric deposition.

The assessment of radioactivity and radiological hazards in soils of Bolu province, Turkey

The radioactivity levels in soil samples of Bolu province of north-western Turkey have been determined. There has been no information about radioactivity measurement reported in soil samples in Bolu province so far. For this reason, the activity concentrations of natural and artificial radionuclides (226Ra, 232Th, 40K, and 137Cs) were measured in soil samples collected from 40 different points in Bolu province of north-western Turkey using gamma spectrometry technique with a high-purity germanium detector. The average activity concentrations (range) of 226Ra, 232Th, 40K, and 137Cs were found to be 18.2 (3.8–49.9) Bq/kg, 17.3 (4.1–37.9) Bq/kg, 258.3 (64.6–518.9) Bq/kg, and 7.5 (0.6–43.6) Bq/kg, respectively. At the end of the analysis, the radioactivity values were lower than the world average values reported by United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR). In order to evaluate the radiological hazards resulting from natural radioactivity, radium equivalent activity (Raeq), gamma index (Iγ), external hazard index (Hex), absorbed dose rate in air (D), annual gonadal dose rate (AGDE), the annual effective dose rate (AEDE), and excess life time cancer risk (ELCR) were calculated and found in the range of 14.8–129.8 Bq/kg, 0.1–0.5, 0.0–0.4, 7.0–60.2 nGy/h, 49.8–417.5 µSv/y, 8.6–73.8 µSv/y, and 0.3 × 10−4 to 2.6 × 10−4, respectively. These results were compared with recommended values (370 Bq/kg for Raeq, <1 for Iγ, <1 for Hex, 55 nGy/h for D, 300 µSv/y for AGDE, 70 µSv/y for AEDE, and 2.9 × 10−4 for ELCR) by European Commission (EC), UNSCEAR and International Commission on Radiological Protection (ICRP). As a result, health hazards originated by natural radiation from soil samples of the Bolu province is low and insignificant.

Distribution of organically bound tritium (OBT) activity concentrations in aquatic biota from eastern Canada

A survey of eastern Canadian biota was conducted to determine the distribution of activity concentrations of organically bound tritium (OBT). Fish samples were collected from Lake Ontario and the St. Lawrence River in areas continuously receiving inputs of tritiated water (HTO) from operating nuclear power plants, and from Lake Nipissing, a background area. Components of their aquatic environments were sampled. The data collected also provides some insight on how tritium activity concentrations in ambient water influence tissue free water tritium (TFWT) and OBT activity concentrations in biological tissues.Using an ALOKA liquid scintillation system, fish TFWT and OBT were quantified. Fish TFWT averaged 1.6 ± 0.1 Bq/L in Lake Nipissing and 3.1 ± 0.3 Bq/L in Lake Ontario. In contrast, TFWT ranged from 11.1 to 80.8 Bq/L in the St. Lawrence River near the Gentilly-2 Canada Deuterium Uranium (CANDU) site. Fish tissue OBT levels were 4.0 ± 0.4 Bq/L and 5.3 ± 0.2 Bq/L for Lake Nipissing and Lake Ontario, respectively, and between 18.1 and 134.2 Bq/L for CANDU sites.The activity concentrations of TFWT and OBT were reviewed for algae, freshwater mussel and various fish samples collected near Gentilly-2, Pickering and Darlington Nuclear Power Generating Stations. TFWT in aquatic biota was found to correlate with the tritium activity concentrations measured in waters at the time of sampling (TFWT/HTO of ambient water was 0.3–4.3). The OBT concentration factors (OBT/HTO of ambient water) were found to be higher in freshwater mussels (between 17 and 47) compared to algae and fish (0.3–10). These results point to a heterogeneous distribution of biota OBT content in these aquatic ecosystems. It was also noted that all fish and algae samples were found to be within the range of tritium activity concentrations that has been historically measured in the same waters. Values in freshwater mussels were above this range.

Complete dissolution of solid matrices using automated borate fusion in support of nuclear decommissioning and production of reference materials

Accurate measurement of natural and anthropogenic radionuclide concentrations is of critical importance to end users in the nuclear sector to ensure correct classification prior to storage, recycling, reprocessing or disposal. Uncertainties in the characterisation of solid matrices and materials could lead to safety, quality and financial implications. Robust sample preparation methods are vital, in particular effective sample digestion, as under-estimated chemical yield recovery results in a corresponding under-estimation of activity levels. Borate fusion has been proven to effectively digest a range of complex sample matrices in the geosciences but is not used routinely elsewhere. In this study, we describe an automated procedure for borate fusion of multiple matrices encountered in nuclear decommissioning, containing diverse radionuclides over a range of activity concentrations. The impact of digestion flux, sample mass and sample to flux ratios are described, as well as the subsequent separation and measurement techniques. The results contribute to accurate and precise measurement of radionuclides in various matrices, as well as to characterisation of reference materials, providing greater confidence in nuclear industry programmes worldwide.

Natural radioactivity measurements in drinking water and ingestion dose assessment: case of the uranium bearing region of Poli, Cameroon

This study aimed at measuring radioactivity in drinking water and to assess corresponding ingestion dose to the public and the uranium toxicity. Twenty samples were collected in the uranium bearing region of Poli, Cameroon. α- and γ-spectrometry were used for radioactivity measurements. The range of activity concentrations for each radionuclide is 0.7 ± 0.3-3.5 ± 0.5 mBq.l−1 for 238U, 0.07 ± 0.03-2.1 ± 0.9 mBq.l−1 for 235U, 0.6 ± 0.2-5.1 ± 0.6 mBq.l−1 for 234U, 10 ± 1 mBq.l−1 for 226Ra, 10 ± 2-16.8 ± 2.2 mBq.l−1 for 210Po. Ingestion dose due to intake of 238U, 235U, 234U, 226Ra and 210Po in water was assessed for six age groups. The mean ingestion dose ranges from 8.8 μSv.yr−1 for adult to 123 μSv.yr−1 for infant, higher than the reference level of the committed effective dose (100 μSv.yr−1) recommended by the World Health Organisation (WHO). The uranium mass ranges between 0.014 μg.l−1 and 0.18 μg.l−1, below the reference mass which is 30 μg.l−1 showing that the uranium toxicity is low. 234U/238U isotopic ratio in water was observed with values near the equilibrium on 70% of collected samples and far from equilibrium reaching 3.09 in a borehole.

Natural radioactivity measurements in drinking water and ingestion dose assessment: case of the uranium bearing region of Poli, Cameroon

This study aimed at measuring radioactivity in drinking water and to assess corresponding ingestion dose to the public and the uranium toxicity. Twenty samples were collected in the uranium bearing region of Poli, Cameroon. α- and γ-spectrometry were used for radioactivity measurements. The range of activity concentrations for each radionuclide is 0.7 ± 0.3-3.5 ± 0.5 mBq.l−1 for 238U, 0.07 ± 0.03-2.1 ± 0.9 mBq.l−1 for 235U, 0.6 ± 0.2-5.1 ± 0.6 mBq.l−1 for 234U, 10 ± 1 mBq.l−1 for 226Ra, 10 ± 2-16.8 ± 2.2 mBq.l−1 for 210Po. Ingestion dose due to intake of 238U, 235U, 234U, 226Ra and 210Po in water was assessed for six age groups. The mean ingestion dose ranges from 8.8 μSv.yr−1 for adult to 123 μSv.yr−1 for infant, higher than the reference level of the committed effective dose (100 μSv.yr−1) recommended by the World Health Organisation (WHO). The uranium mass ranges between 0.014 μg.l−1 and 0.18 μg.l−1, below the reference mass which is 30 μg.l−1 showing that the uranium toxicity is low. 234U/238U isotopic ratio in water was observed with values near the equilibrium on 70% of collected samples and far from equilibrium reaching 3.09 in a borehole.

Micronuclei frequency in peripheral blood lymphocytes and levels of anti-p53 autoantibodies in serum of residents of Kowary city regions (Poland) with elevated indoor concentrations of radon

IntroductionNinety four residents of Kowary city (Poland) have been investigated for environmental radon exposure that ranged from 0.24 WLM to 9.6 WLM (activity concentration range: 35–2700 Bq/m3). Kowary was chosen because of uranium mineralisation in its close vicinity. MethodWhole population studied was divided into two groups: exposed to low radon activity concentrations resulting in the exposure of ≤0.55 WLM (value corresponding to the exposure to 100 Bq/m3 during whole year), and exposed to high radon activity concentration (>0.55 WLM). In the two groups two selected biomarkers in blood were assessed: the cytokinesis-block micronucleus assay (CBMN) on peripheral blood lymphocytes (PBL), and the levels of anti-p53 antibodies in serum measured because some data indicate increased expression of the antibodies in individuals after exposure to DNA damaging agents including radon. The potential confounding factors known to influence micronuclei (MN) frequency were also measured in serum: vitamin B12, folic acid, as well as total calcium. ResultsIn the present study no significant correlation was found between MN frequency in PBL and radon exposure. Among all persons investigated only 11 had detectable levels of the anti-p53 antibodies, whereas only 3 persons had positive result. Therefore, the group was too small to perform any meaningful statistical analysis and to conclude on any association. Cigarette smoking did not significantly influence the number of MN. There was a significant positive correlation observed between MN frequency and age, as well as higher MN frequency was detected in women. ConclusionThe problem of the radon exposure is still unresolved and needs further studies on bigger human cohorts in order to search for more sensitive biomarkers.

Assessment of lifetime cancer risk from natural radioactivity levels in Kadikoy and Uskudar District of Istanbul

The activity concentrations of 226Ra, 232Th, and 40K are measured in soil samples from various locations in the Kadikoy and Uskudar district of Istanbul (Turkey). The 226Ra activity concentrations range from 19.97 Bqkg−1 to 50.80 Bqkg−1 and average 226Ra concentration value 31.40 Bqkg−1 was calculated. The 232Th activity concentrations range from 21.38 Bqkg−1 to 52.61 Bqkg−1 and average 232Th concentration value 34.44 Bqkg−1 was calculated. The 40K activity concentrations range from 464.06 Bqkg−1 to 711.27 Bqkg−1 and average 40K concentration value 619.59 Bqkg−1 was calculated. In addition, radium equivalent (Raeq), absorbed gamma dose rate (D), annual effective dose equivalent, (AEDE), excess lifetime cancer risk (ELCR) were calculated in this study. All of the calculations have been compared with both national and international standards and similar studies. As a result of this comparison, levels of natural radioactivity and radiological effects were slightly higher than the World average and Turkey.

Natural radionuclide survey in the coastal strip of the 290 Ramsar site, Uruguay

An initial on-going survey of the activity concentrations of 226Ra, 232Th and 40K for sand samples collected within the coastal strip of 290 Ramsar site evaluated the external hazard index, the outdoor annual effective dose equivalent and the radium equivalent activity, to elucidate potential risks for the resident inhabitants. The range of mean activity concentrations in the whole area for 226Ra, 232Th and 40K were between 4.12 ± 0.26 and 48.3 ± 1.4, 5.47 ± 0.55 and 194 ± 13, 77.7 ± 4.2 and 445 ± 18 Bq kg−1, respectively. The Barra de Valizas–Aguas Dulces region had the highest activity concentrations of 226Ra and 232Th. The annual effective dose equivalent for this region was higher than the mean worldwide value, whereas it is lower than the recommended values for public exposure.

Assessment of natural radioactivity levels and the associated radiological hazards in some building materials from Mayo-Kebbi region, Chad

In order to assess the levels of natural radioactivity and the associated radiological hazards in some building materials of the Mayo-Kebbi region (Chad), a total of nineteen samples were collected on the field. Using a high resolution γ-ray spectrometry system, the activity concentrations of radium (226Ra), thorium (232Th) and potassium (40K) in these samples have been determined. The measured average activity concentrations range from 0.56 ± 0.37 Bq kg−1 to 435 ± 7 Bq kg−1, 1.3 ± 0.6 Bq kg−1 to 50.6 ± 1.1 Bq kg−1 and 4.3 ± 2.0 Bq kg−1 to 840 ± 9 Bq kg−1, for 226Ra, 232Th and 40K, respectively. The highest 226Ra average activities is found in soil brick samples of Zabili. The highest mean value of 232Th and 40K concentrations are found in soil brick samples of Madajang. The activity concentration and the radium equivalent activity (Raeq) have been compared to other studies done elsewhere in the world. Their average values are lower than most of those of countries with which the comparison has been made. Were also evaluated, the external radiation hazard index, the internal radiation hazard index, the indoor air absorbed dose rate, the outdoor air absorbed dose rate, the activity utilization index, the annual effective dose, the annual gonadal dose equivalent, the representative level index, as well as, the excess lifetime cancer risk. In accordance with the criterion of the Organization for Economic Cooperation and Development, our results show that soil brick samples of Zabili and Madajang increases the risk of radiation exposure, thereby the possibility of developing cancer by people living in this environment. Based on these findings, brick samples from Zabili and Madajang are not recommended for construction purposes. All other sample materials have properties that are acceptable for use as building materials in terms of radiation hazard.

Performance evaluation of the LightPath imaging system for intra-operative Cerenkov luminescence imaging

The performances of an intra-operative optical imaging system for Cerenkov luminescence imaging of resected tumor specimens were evaluated with phantom studies. The spatial resolution, the linearity of the measured signal with the activity concentration and the minimum detectable activity concentration were considered. A high linearity was observed over a broad range of activity concentration (R2⩾0.99 down to ∼40 kBq/ml of 18F-FDG). For 18F-FDG activity distributions 2 mm deep in biological tissue, the measured detection limit was 8 kBq/ml and a spatial resolution of 2.5 mm was obtained. The detection limit of the imaging system is comparable with clinical activity concentrations in tumor specimens, and the spatial resolution is compatible with clinical requirements.

Assessment of radioactivity levels and radiological-hazard indices in plant fertilizers used in Iraqi Kurdistan Region

The present study is to determine the activity concentration of radioactive nuclide in plant fertilizers used in agriculture in Iraqi Kurdistan region using high- purity germanium detector (HPGe) gamma spectrometer. The results showed that the range of activity concentrations for 226Ra, 232Th, 40K and 137Cs in chemicals and organic fertilizers are (0.1–134), (0.1–74), (1–12,000) and (0–1) Bq/kg respectively, based on the measured activities that were used to assess the radiological hazards. Radium equivalent activity in some samples exceeds the value (370 Bq/kg) which recommended by the OECD.

Silver Nanobiocomposites Based on Humic Substances As Highly Efficient Stimulators of Seed Germination

Silver-containing nanocomposites are synthesized from humic peloid substances in an environmentally friendly way. The growth-stimulating activity of ultralow concentrations of humic substances of therapeutic muds and silver-containing compounds on their basis is studied. The stimulator active concentration range upon wheat seed generation is determined to be 4 × 10–3–4 × 10–16%. The fastest (almost double) growth of the main roots of sprouts is found to be for silver nanocomposites based on humic substances. The established activity of nanocomposites is a prerequisite for the development of novel highly efficient growth-stimulating drugs.

Radioactive Contamination Control by Atmospheric Dispersion Assessment of Airborne Indicator Contaminants: Numerical Model Validation

In this work, a numerical model is proposed to estimate air concentration of released airborne radioactive contaminants 131I and 137Cs. A Gaussian dispersion model is used to assess the atmospheric dispersion of radioactive contaminants released continuously from a nuclear power plant as a result of an accident. The model uses various input parameters such as source height, release rate, stability class, wind speed, and wind direction. The validation of the model was carried out by comparing its predicted values with published experimental data. The model was extensively tested by simulating several accidental situations. The main conclusion drawn from these tests is that for large downwind distances from the release point, the contaminant concentrations predicted by the model diverge drastically from measured data, while for short distances, the predicted values generally agree quite well with experimental data. The obtained activity concentrations range from 1.57 × 102 to 6.43 × 103 Bq/m3 for 131I and from 3.18 × 10−2 to 9.72 × 102 Bq/m3 for 137Cs. The estimated standard deviation coefficients values range of 7.2 to 6847.7 m, and the maximum absolute error predicted by the model for these parameters was less than 5%.

137Cs in mushrooms from Croatia sampled 15–30 years after Chernobyl

The aim of this study was to select species with higher potential to accumulate 137Cs among the available mushroom species, by determining the activity concentrations of 137Cs in mushrooms collected along north and north-western part of Croatia. A total of 55 samples of 14 different species were analyzed and the potential of mycorrhizal and saprotrophic species to accumulate 137Cs was compared. A wide range of the dry weight activity concentrations of 137Cs was detected, ranging from 0.95 to 1210 Bq/kg (154 Bq/kg mean value; 52.3 Bq/kg geometric mean) in mycorrhizal and 1.05–36.8 Bq/kg (8.90 Bq/kg mean value; 5.49 Bq/kg geometric mean) in saprotrophic species. Statistical analyses showed that mycorrhizal species accumulate significantly higher concentrations of 137Cs and thus could perform better as long-term bioindicators of environmental pollution by radiocaesium then saprotrophic species. The comparison of Boletus sp. and Hydnum repandum (both mycorrhizal species commonly found in Croatia) showed, in general order of magnitude, higher accumulation in Hydnum repandum. Clearly, mushrooms, especially mycorrhizal species, can be used as significant indicators even decades after the occurrence of any serious 137Cs contamination event. However, as a wide range of values indicates that various parameters may influence the total uptake of the 137Cs into the mushroom fruit bodies, it is necessary to emphasize that 137Cs activity detected in a single mushroom sample is very site-specific.

Inhibition of Herpes Simplex Viruses by Cationic Dextran Derivatives.

Human herpesviruses are among the most prevalent pathogens and currently there are no drugs available that could cure diseases induced by them. The most widely utilized antiherpes drugs, acyclovir and its derivatives, have serious limitations, such as low bioavailability and severe side effects. The current paper reports on the synthesis and characterization of cationic dextran derivatives (DEXxDSy) of various molecular weights and various degrees of substitution with ammonium groups, which were tested as antiherpes agents. DEXxDSy showed high effectiveness against HSV-1 and HSV-2 viruses, as found using a variety of techniques. Importantly, no toxicity was observed for these compounds in the range of active concentrations, demonstrating their potential as antivirals. The mechanism of action of DEXxDSy was assessed. We hypothesize that they may limit virus transmission, as extensive examination showed that they hamper the interaction between the virus and the cellular attachment receptor.