The team divided the lake into three hydrologically distinct groups based on dominant inflow sources and catchment characteristics. Group 1, influenced by urban development and agricultural runoff, showed significantly higher concentrations of most of the studied rare earth elements together with elevated radionuclide activities. Group 2, representing predominantly forested catchments, exhibited comparatively lower values across the board. Group 3, located near the dam outlet, displayed intermediate characteristics that the authors attribute to sediment mixing processes, where material from different parts of the catchment converges before settling.

Rare earth elements have become strategically critical materials for magnets, batteries, and electronics, so understanding where they accumulate in ordinary environments matters both for resource geology and for ecotoxicology. At the same time, radium-226, thorium-232, and potassium-40 are the principal natural contributors to gamma radiation in soils and sediments, and their concentrations determine whether an area poses any radiological concern. Because rare earth elements often travel geochemically with thorium and uranium decay chains in minerals like monazite, the co-occurrence of elevated REEs and radionuclides is not coincidental but reflects shared mineral hosts.

To quantify contamination, the researchers applied two widely used indices. The geoaccumulation index, or Igeo, compares measured concentrations against background levels and classifies enrichment from unpolluted to heavily polluted. The pollution load index, or PLI, aggregates multiple elements into a single value for each site. Both indices indicated generally low to moderate relative enrichment across the lake, with localized enrichment at several sites, particularly within Group 1. Enrichment factor calculations, however, suggested that the REE distributions are predominantly controlled by natural geological sources rather than by pollution, meaning the elevated values near developed shores likely reflect weathering of local bedrock and soils transported by runoff rather than industrial discharge.

The radiological assessment told a more nuanced story. Radium equivalent activity and the external hazard index, two standard measures used to gauge gamma dose potential from sediment or building materials, remained below recommended reference values at most sampling sites. However, several radiological indices exceeded commonly adopted global reference levels at some locations. The authors identify these spots as areas where continued environmental monitoring is warranted, not as immediate hazards but as signals that parts of the lakebed warrant periodic rechecking as land use evolves.

Multivariate statistical analyses added a key mechanistic insight: strong associations emerged between the rare earth elements and the radionuclides radium-226 and thorium-232, whereas potassium-40 behaved distinctly in space. This pattern is geochemically coherent. Radium-226 sits in the uranium decay chain and thorium-232 heads its own chain, and both tend to reside in the same refractory mineral phases that concentrate rare earths. Potassium-40, by contrast, tracks potassium-bearing minerals such as feldspars and micas, which weather and transport differently, explaining its decoupled spatial behavior.

The study’s spatial variability, the authors conclude, is consistent with the combined influence of the regional geological setting, sediment provenance, catchment-scale sediment transport processes, and recent land use disturbances. In practical terms, the lake is acting as an integrator: every inflow carries the chemical signature of its sub-catchment, and the lakebed preserves a mosaic of those signatures. Urbanized and agricultural areas deliver finer, more weathered, and chemically enriched particles, while forested catchments contribute comparatively pristine material.

For Da Lat, a city whose economy depends heavily on tourism, agriculture, and a clean mountain environment, the findings provide a valuable geochemical baseline for sustainable catchment management. Establishing reference concentrations now allows future monitoring to detect departures from natural variability, whether from expanding agriculture, construction, or changes in hydrology. The work also fits into a broader national effort, as Vietnamese researchers have recently published similar radiological assessments for the Red River, Ha Long Bay, and central coastal lagoons, building a country-wide picture of natural radioactivity in sediments.

Methodologically, the study demonstrates the value of combining nuclear analytical techniques with multivariate statistics and geographic information systems. By classifying sampling sites according to hydrological connectivity rather than arbitrary grid positions, the researchers could link chemical patterns to catchment processes, a design that other lake studies could replicate. The approach turns a routine monitoring exercise into a diagnostic tool for identifying which parts of a watershed contribute the most chemically distinctive sediment.

As demand for rare earth elements grows worldwide, and as awareness of naturally occurring radioactive materials in everyday environments increases, studies like this one fill an important gap. They show that even a seemingly pristine mountain lake carries measurable geochemical gradients shaped by both bedrock and human activity, and that careful baseline mapping is the first step toward protecting both environmental and public health in rapidly developing regions.

Subject of Research: Distribution of rare earth elements and natural radionuclides in lake sediments

Article Title: Assessment and spatial distribution of natural radionuclides and some rare earth elements in the surface sediments of TuyenLam Lake, Central Highlands, Vietnam

Article References: Nguyen, M.-D., Le, X.-T., Tran, Q.-T., Vo, T.-Q.-T., Tran, T.-A., Nguyen, T.-H.-L., Tuong, T.-T.-H., Vo, T.-M.-T., Phan, Q.-T., Chau, T.-N.-Q., Tran, T.-T.-P., Nguyen, D.-K., & Nguyen, H.-N. (2026). Assessment and spatial distribution of natural radionuclides and some rare earth elements in the surface sediments of TuyenLam Lake, Central Highlands, Vietnam. Environmental Monitoring and Assessment, 198(9), Article 998. https://doi.org/10.1007/s10661-026-15854-5

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15854-5

Keywords: rare earth elements, natural radionuclides, lake sediments, radiological risk, Vietnam, TuyenLam Lake, sediment contamination, geochemistry, environmental monitoring, land use, radium-226, thorium-232

The research team, led by geologists from Ekiti State University and collaborating institutions in Nigeria and China, collected 274 samples in December 2023—137 soils and 137 stream sediments—using a hand auger at depths of zero to ten centimeters, the layer where human contact with radionuclides is most direct. The sampling grid covered more than seventy percent of the study area, which lies between the towns of Gana, Pako, Korgadzhi, and Mokwa, and spans terrain underlain by granite gneiss, quartzo-feldspathic gneiss, quartz mica schist, quartzite, and metagraywacke, all intruded by Neoproterozoic Pan-African granitic rocks. These metamorphic and igneous units contain varying amounts of radioactive minerals, which weathering steadily releases into nearby soils and drainage systems.

Analysis was performed using high-performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry at the Bureau Veritas Minerals Laboratory in Vancouver, Canada, with quality assurance anchored to the IAEA-375 reference material. Concentrations measured in parts per million were converted to becquerels per kilogram using standard International Atomic Energy Agency conversion factors. The results showed that uranium-238 activity in soils ranged from 2.11 to 77.38 Bq/kg with a mean of 12.95 Bq/kg, thorium-232 ranged from 8.08 to 66.25 Bq/kg with a mean of 26.87 Bq/kg, and potassium-40 spanned 1.57 to 178.41 Bq/kg with a mean of 39.77 Bq/kg. All three soil averages fell below the UNSCEAR worldwide benchmarks, painting Jebba’s farmland in a comparatively reassuring light.

The stream sediments, however, were a different matter entirely. Uranium-238 in sediments averaged 26.21 Bq/kg, roughly double the soil value, and thorium-232 averaged 109.39 Bq/kg—more than four times the soil mean and well above the international standard limit, with individual samples reaching a remarkable 572.47 Bq/kg. Potassium-40 remained modest at an average of 48.16 Bq/kg. The radium equivalent activity, a composite index that weights the three radionuclides according to their gamma-emission potential, averaged 54.44 Bq/kg in soils but 186.34 Bq/kg in sediments, with a maximum of 926.17 Bq/kg—far beyond the 370 Bq/kg ceiling considered acceptable for construction materials.

The dose metrics reinforce this divide. The average absorbed gamma dose rate was 24.23 nGy/h for soils but 82.05 nGy/h for sediments, against a global outdoor average of 57 nGy/h. The internal hazard index, which captures the respiratory risk from inhaling radon and thoron gases released by building materials, averaged 0.41 for soils—comfortably below the safety threshold of one—but 1.44 for sediments, meaning that if these sediments were quarried and used in home construction, occupants could face meaningful internal exposure. External hazard indices followed the same pattern, with sediments approaching the unity limit at a mean of 0.94 while soils sat at just 0.26.

Perhaps the most consequential finding concerns long-term cancer risk. The excess lifetime cancer risk values ranged from 0.33 to 2.43 for soils but from 0.71 to 18.10 for stream sediments, exceeding UNSCEAR thresholds across both media but dramatically so in the depositional environments. The annual effective dose equivalent for indoor scenarios built on sediment-derived material also surpassed global averages. Organ-specific calculations identified the testes as the most vulnerable tissue, followed by bone marrow, lungs, and ovaries, with total effective dose rates reaching 8.16 mSv per year for sediments compared with 2.30 mSv per year for soils.

Statistical analysis pinpointed the culprit behind these hazards. Pearson correlation matrices revealed that thorium-232 correlated almost perfectly with nearly every radiological index—r values exceeding 0.99 for radium equivalent, hazard indices, and the annual gonadal dose equivalent in sediments—while potassium-40 showed weak correlations below 0.1, reflecting its comparatively low gamma emission. Principal component analysis confirmed the pattern: in soils, the first component explained 90.91 percent of total variance and grouped thorium with all the integrated hazard indices, while uranium and potassium clustered separately. In sediments, the first component accounted for 92.58 percent of variance and pulled thorium, radium equivalent, and the hazard metrics into a single dominant cluster.

The spatial distribution of the radionuclides maps directly onto the region’s geology and hydrology. Uranium activities peaked in the southeastern sector around the Jebba Hills, consistent with weathering of uranium-bearing minerals, while thorium concentrated in the southwestern and northern zones near Shika and the Moga Hills. Potassium-40 showed a gradient toward the south and southwest, reflecting the distribution of feldspar- and mica-rich rocks. Elevated radium equivalent values near the hills suggest geochemical leaching from elevated terrain into surrounding soils, and sediment enrichment around Bajijo and the southern areas points to the decisive role of erosion, transport, and deposition in concentrating fine-grained, radionuclide-bearing particles in stream channels. The authors also note that agricultural practices may contribute: phosphate-based NPK fertilizers, derived from naturally enriched phosphate rocks, can accumulate uranium and thorium in soils through repeated application, while irrigation water carrying dissolved potassium-40 and uranium adds to the radiological load.

Why do sediments outperform soils as radiation reservoirs? The physics and chemistry of sorption provide the answer. Fine-grained particles offer large surface areas and chemically reactive mineral surfaces onto which dissolved radionuclides adsorb readily, promoting their deposition and accumulation in bottom sediments. Once trapped, however, these radionuclides are not permanently immobilized: shifts in pH, redox potential, or organic matter content can remobilize them—under reducing conditions, for instance, uranium can convert to more soluble forms and diffuse back into the water column—while flooding, dredging, and storm events can resuspend contaminated particles and increase their bioavailability. Benthic organisms that ingest contaminated particles can then carry radionuclides into the aquatic food web, opening pathways for bioaccumulation and trophic transfer to humans.

The study’s implications extend beyond Jebba. Across much of West Africa, rural communities routinely draw sand and sediment from streams and riverbeds for building construction, and the finding that Jebba’s sediments exceed internal hazard thresholds sounds a cautionary note for any similar geological setting. The authors recommend continuous monitoring, denser spatial sampling to refine hotspot maps, measurement of additional radionuclides such as cesium-137 and cobalt-60, evaluation of radon emissions from soils and sediments, and the integration of radiological assessments into Nigeria’s national environmental management frameworks. They acknowledge limitations—a single-season snapshot, no epidemiological linkage to actual health outcomes, and limited treatment of hydrodynamic transport—but the core message stands: in this corner of the Niger River basin, thorium-232 is the primary risk driver, and the sediments that quietly collect it in the region’s waterways deserve far closer attention than the ground above them.

Subject of Research: Distribution and radiological health risks of natural radionuclides in soils and stream sediments in Jebba, Nigeria

Article Title: Distribution of 238U, 232Th, and 40K in soils and stream sediments in the Jebba area, Nigeria-an integrated environmental, health and radiological risk assessment

Article References: OlaOlorun, O. A., Popoola, O. J., Oyebamiji, A. O., Abdu‑Raheem, Y. A., & Ukaogo, P. (2025). Distribution of 238U, 232Th, and 40K in soils and stream sediments in the Jebba area, Nigeria-an integrated environmental, health and radiological risk assessment. BMC Environmental Science, 2(1), Article 21. https://doi.org/10.1186/s44329-025-00035-5

Image Credits: AI Generated

DOI: 10.1186/s44329-025-00035-5

Keywords: radionuclides, uranium-238, thorium-232, potassium-40, stream sediments, radiological risk, Nigeria, Jebba, natural radioactivity, cancer risk, soil contamination, environmental health

Radon-222 is a chemically inert noble gas produced continuously in the decay chain of uranium-238, which occurs naturally in rocks and soils. Because it is a gas, radon can migrate through fractures, faults, and porous formations, dissolving in groundwater along the way. When that water is drawn to the surface and consumed, the gas can deliver a radiation dose in two distinct ways: through ingestion, when radon dissolved in water passes through the digestive tract, and through inhalation, when radon degasses from water during showering, cooking, or other household activities and is breathed into the lungs. Inhaled radon and its short-lived progeny are the second leading cause of lung cancer after tobacco smoking in many countries, making accurate assessments of exposure a public health priority worldwide.

The measurement campaign in Kribi relied on a RAD7 electronic radon detector, an instrument that uses a passivated implanted planar silicon detector to capture alpha particles emitted by radon and its decay products. Water samples were collected from a range of drinking water sources across the study area, each reflecting the local geological conditions of its catchment. The concentrations recorded spanned a wide range, from as low as 0.07 becquerels per liter to a maximum of 11.42 becquerels per liter, with a geometric mean of 0.81 becquerels per liter. Nearly all of the measured values fell below the reference levels established by the United States Environmental Protection Agency, which recommends an action threshold of 11.1 becquerels per liter, and the World Health Organization, which suggests 100 becquerels per liter as a guideline for drinking water. This pattern suggests that for the average resident of Kribi, the radon burden in the water supply is unlikely to pose a significant radiological hazard under normal consumption habits.

Converting concentration measurements into meaningful estimates of radiation dose requires careful accounting of how much water different age groups consume and how their bodies absorb or retain radon. The researchers calculated annual effective doses for three categories: infants, children, and adults. For ingestion, the dose estimates were 10.19 microsieverts for infants, 4.35 microsieverts for children, and 3.10 microsieverts for adults per year. These figures reflect the fact that infants, despite consuming less water by volume than adults, receive proportionally higher doses because of their smaller body mass and the higher sensitivity of developing tissues to ionizing radiation. For inhalation, the doses were more evenly distributed across age groups: 7.48 microsieverts for infants, 7.03 microsieverts for children, and 6.42 microsieverts for adults. All of these values remained well below the WHO reference limits, which cap the acceptable annual effective dose at 100 microsieverts for adults and 200 microsieverts for children, suggesting that the combined ingestion and inhalation pathways in Kribi do not currently represent a significant health concern.

What makes the study particularly interesting from a geological perspective is its investigation of how lithology, the physical character of the underlying rock layers, and proximity to volcanic faults influence radon behavior. Statistical tests comparing radon concentrations across different lithological units and across different water source types produced p-values greater than 0.05, meaning no statistically significant differences emerged. This finding is notable because it challenges the assumption that rock type alone can predict radon levels in groundwater. Instead, the researchers found that both lithological setting and water source type together shape radon concentrations in this particular coastal environment, highlighting the complexity of radon migration through heterogeneous geological terrain.

Proximity to the Kribi volcanic fault did appear to play a role, but not in a simple or uniform way. Some locations situated near the fault exhibited elevated radon concentrations in their water supplies, consistent with the idea that fault zones serve as preferential pathways for radon-rich fluids rising from deeper in the crust. However, other locations equally close to the fault showed comparatively low concentrations. This inconsistent pattern suggests that factors beyond fault proximity alone are at work, possibly including local variations in rock uranium content, aquifer permeability, water residence time, and the degree of fracturing at specific sites. The study’s authors emphasize that these local factors may collectively override any simple relationship between distance from a fault and radon concentration, complicating efforts to predict exposure based on geological maps alone.

One of the most striking results of the investigation was the strong statistical correlation between radon concentrations in drinking water and radon concentrations in soil gas measured at the same locations. The correlation coefficient of r = 0.78, with a p-value below 0.001, indicates a robust association that is extremely unlikely to have arisen by chance. This relationship points to a common geogenic source for radon in both media, meaning that the uranium-bearing minerals in the underlying bedrock are simultaneously releasing radon into the soil atmosphere and into the groundwater. The finding has practical implications because it suggests that soil gas radon measurements, which are relatively quick and inexpensive to perform, could serve as a useful screening tool for identifying areas where groundwater radon concentrations might be elevated. This correlation also underscores the influence of broader environmental characteristics, including soil permeability, moisture content, and structural geology, on the diffusion and transport of radon through the subsurface.

The Kribi study adds to a growing body of research from Cameroon and other African nations examining natural radiation exposure in settings where uranium-bearing rocks, volcanic activity, and extensive fault networks create conditions favorable for radon accumulation. Earlier investigations in the Adamawa region, the Poli uranium-bearing area, the bauxite-rich zones of western Cameroon, and the coastal Bakassi Peninsula have all documented elevated radon in various environmental compartments. What distinguishes the current study is its focus on a tropical coastal aquifer system, an environment where the interaction between saline intrusion, weathered basement rocks, and fractured volcanic formations creates a distinct geochemical setting that has been underrepresented in the global radon literature. By providing baseline data for Kribi, the researchers have established a reference point that can inform future monitoring programs and public health interventions across similar tropical coastal environments elsewhere in West and Central Africa.

The implications of this research extend beyond academic interest. In many rural and peri-urban communities across sub-Saharan Africa, groundwater from wells, boreholes, and springs constitutes the primary source of drinking water, and the geological conditions controlling radon transport are rarely mapped in detail. The Kribi findings suggest that blanket assumptions about radon risk, whether based on rock type, fault proximity, or water source category, may be misleading without site-specific measurement. The strong water-to-soil-gas correlation offers a pragmatic approach for resource-limited settings: a rapid soil gas survey could help prioritize water sources for more expensive and time-consuming water sampling and dose assessment. As climate change, population growth, and urbanization place increasing pressure on coastal aquifers worldwide, understanding the geological controls on naturally occurring radionuclides in drinking water will become ever more important for protecting public health in vulnerable communities.

Subject of Research: Assessment of age-dependent radiological health risks from radon-222 in drinking water and soil gas in a volcanic fault region of Kribi, Cameroon

Article Title: Age-dependent health risks assessment due to 222Rn in drinking water depending on lithology and volcanic faults

Article References: Juste, B. N., Dieu Souffit, G., Joseph Emmanuel, N. N. I., François, K., Modibo, O. B., Saïdou, & Motapon, O. (2026). Age-dependent health risks assessment due to 222Rn in drinking water depending on lithology and volcanic faults. Environmental Geochemistry and Health, 48(14), Article 585. https://doi.org/10.1007/s10653-026-03432-0

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03432-0

Keywords: radon-222, drinking water, soil gas, volcanic fault, lithology, Kribi Cameroon, annual effective dose, ingestion dose, inhalation dose, groundwater, radiological risk, tropical coastal aquifer

The research, conducted by Blessing N. Ben-Festus and Festus Ben of the Centre for Advanced Materials Research and Development at Federal Polytechnic Ede in Nigeria, with Ben also affiliated with the Centre for Nanoengineering and Advanced Materials at the University of Johannesburg, focused on sediments within a tropical river estuarine system in southwestern Nigeria. The fieldwork was carried out in a waterway shaped by seasonal rainfall and runoff, artisanal and urban pressures, and the steady downstream delivery of weathered material from the surrounding landscape. Regions of this kind are often underrepresented in global radiological databases, which historically have emphasized temperate environments, making the new dataset a valuable reference point not only for Nigeria but for comparative assessments of depositional environments worldwide.

Technically, the study relied on gamma-ray spectrometry, the workhorse technique of environmental radiochemistry. Sediment samples collected from the estuary were prepared, sealed to allow radioactive equilibrium to be established, and then quantified using a calibrated sodium iodide detector, a scintillation-based instrument that records the characteristic gamma-ray energies emitted by decaying nuclides. Sodium iodide spectrometers are prized in field-adjacent laboratories for their high detection efficiency and relatively low cost, although they demand careful energy and efficiency calibration to resolve the photopeaks of interest. The authors followed established calibration practice, drawing on the well-documented performance characteristics of 3-inch by 3-inch NaI(Tl) detectors, to convert counts into activity concentrations expressed in becquerels per kilogram, a unit that describes the number of radioactive decays per second in each kilogram of dry sediment.

The measured activity concentrations told a consistent story. Potassium-40, the primordial isotope that has persisted since the formation of the Earth and pervades virtually all crustal material, averaged 490.50 plus or minus 7.66 becquerels per kilogram across the samples. Uranium-238, the head of the uranium decay series, averaged just 5.67 plus or minus 0.20 becquerels per kilogram, and thorium-232, the progenitor of the thorium series, registered 4.81 plus or minus 0.26 becquerels per kilogram. Benchmarked against the reference values published by the United Nations Scientific Committee on the Effects of Atomic Radiation, the potassium result ran about 16.79 percent above the global average, a modest elevation the authors attribute to the potassium-rich minerals weathered from the catchment’s bedrock and soils. By contrast, the uranium and thorium figures sat far below the corresponding global thresholds, at 82.82 percent and 89.31 percent below them, respectively, underscoring how strongly the local geology, rather than industrial contamination, controls the radiological signature of these deposits.

Raw concentrations, however, are only the starting point of a radiological risk assessment. Because potassium-40, uranium-238 and thorium-232 differ in the energy and intensity of the gamma radiation they emit, regulators and researchers combine them into derived indices that better approximate real-world exposure. The study calculated the radium equivalent activity, a composite quantity that weights the three nuclides according to their relative gamma dose contributions, and obtained a mean value of 50.32 becquerels per kilogram, well under the widely cited 370 becquerels per kilogram ceiling that marks the threshold above which structural or land-use restrictions might be considered. This single number already suggests that neither beachcombers nor construction workers handling dredged sediment would encounter unusual radiation fields at the site.

The dose-based indicators reinforce that conclusion. The absorbed gamma dose rate in air at one meter above the sediment surface averaged 26.13 nanogray per hour, translating into an annual effective dose of roughly 0.03 millisievert per year for a member of the public spending typical time near or on the sediments. For context, the global average outdoor terrestrial dose attributable to natural radionuclides is generally estimated at around 0.07 millisievert per year, meaning the Nigerian estuary delivers less than half of that conventional background. The team also evaluated the annual gonadal dose, a quantity used to approximate the genetically significant dose to reproductive organs, obtaining 191.64 microsieverts per year, again comfortably below the internationally recognized screening level of about 300 microsieverts per year. Taken together, these parameters indicate that external exposure pathways linked to the estuary’s sediments pose no significant radiological risk to the surrounding communities.

The findings matter for reasons that extend beyond a single river. Sediments are the memory of a river system: they trap not only radionuclides but also heavy metals, nutrients and pollutants, and their radioactive inventory reflects the interplay of bedrock composition, weathering intensity, grain-size sorting and hydrodynamic energy. In tropical climates, intense rainfall and episodic flooding periodically resuspend and redistribute these deposits, meaning that a baseline established today is the essential yardstick against which future disturbance, whether from mining, dredging, dam construction or land-use change, can be judged. Comparable investigations along the Arvand River in Iran, the Pashur River in Bangladesh, the Ravi River in Pakistan and the coastal wetlands of southern Taiwan have revealed that fluvial radioactivity can vary enormously with geology, and in some industrialized estuaries technogenic nuclides from mining discharges or phosphogypsum releases dominate the picture. Against that backdrop, the low uranium and thorium readings in this Nigerian system signal an environment whose radiological profile remains essentially natural.

The study also contributes methodological value to the radiological sciences. Gamma spectrometry with sodium iodide detectors requires meticulous attention to detection efficiency, coincidence summing effects and source-to-detector geometry, and the growing literature on detector calibration offers practical guidance for laboratories working with modest infrastructure. By demonstrating that credible, standards-aligned hazard assessments can be produced with such instrumentation, the research lowers the barrier for similar monitoring programs in other data-poor tropical basins. The authors acknowledge research assistants Miss Daud Ajarat Olaide and Mr. Adeyeni Tunmise Afolabi for their contributions during the field study, and the work was funded by the Centre for Advanced Materials Research and Development, highlighting the role of institutionally supported, locally grounded science in filling global environmental data gaps.

Looking ahead, the researchers position their dataset as a foundation for longitudinal monitoring. Natural radioactivity is not static: sediments are eroded, redeposited and chemically transformed, and the same estuary measured after a decade of accelerated development could present a different signature. The measured values, now archived in the peer-reviewed literature and available upon reasonable request, give regulators in Osun State and beyond a defensible pre-disturbance benchmark. They also give residents a rare piece of quantified good news: the muds beneath their river, far from being a hidden radiological hazard, are among the quieter sediments on the planet, holding only a whisper of the uranium and thorium that Earth’s crust normally carries, and a dose burden that any international safety authority would judge unremarkable.

Subject of Research: Measurement of natural radionuclide activity concentrations and radiological hazard indices in sediments of a tropical river estuarine system

Article Title: Sediment-associated natural radionuclide and radiological risk indicators in a tropical river estuarine system

Article References: Ben-Festus, B. N., & Ben, F. (2026). Sediment-associated natural radionuclide and radiological risk indicators in a tropical river estuarine system. Environmental Monitoring and Assessment, 198(10), Article 1069. https://doi.org/10.1007/s10661-026-15895-w

Image Credits: AI Generated

DOI: 10.1007/s10661-026-15895-w

Keywords: natural radionuclides, gamma spectrometry, estuarine sediments, radiological risk, potassium-40, uranium-238, thorium-232, tropical river, environmental monitoring, radiation dose, Nigeria, radium equivalent activity