Nuclear Tests Research Articles

Malignant neoplasms of the respiratory tract and thoracic organs in the remote period in males of Altai krai affected by first nuclear test at Semipalatinsk test site

BACKGROUND: The study of remote effects of radiation exposure on tumor-related morbidity in population remains a matter of great social significance in Altai Krai.
 AIM: To investigate the incidence rate for malignant neoplasms of respiratory tract and thoracic organs in the remote period in the male population born in 1932–1949 and located in the zone of influence of the first nuclear test.
 METHODS: This retrospective cohort study was based on the analysis of anonymized data and surgical records on morphologically verified cases of primary malignant neoplasms in a male cohort for the period from 2007 to 2016. In this paper, we studied a cohort fixed by the date of the first nuclear test, with a total of 6383 male individuals. The main (exposed) cohort included 2291 men, while the control (non-exposed) cohort included 4092 men who lived in rural communities of the region that were not affected during the first nuclear test. The cohort included 156 cases of morphologically verified diagnosis of primary malignant neoplasms of the respiratory tract and thoracic organs (codes C30–C39 according to the International Classification of Diseases). Person-time incidence rate (PtR), standard error (mPtR) and confidence intervals (95% CI) were calculated. The incidence of respiratory and thoracic malignant neoplasms, structure and relative risk (RR) were assessed. Statistical processing of the data was performed using licensed Microsoft Office 2016 software.
 RESULTS: The number of person-years spent at risk for respiratory and thoracic malignancies in the male population in the main cohort was 16 731 person-years, and in the control cohort — 30 747 person-years. In the main cohort, PtR was 436.32×105 person-years, with an mPtR of 51.07 and 95% CI of 334.18–538.45; in the control cohort the PtR was 269.95×105 person-years with an mPtR of 29.63 and 95% CI of 210.68–329.21. The leading localizations of malignant neoplasms of the respiratory and thoracic organs in men in the main and control cohorts were bronchial and lung malignancies and laryngeal malignancies.
 CONCLUSIONS: An increased relative risk of respiratory and thoracic malignant neoplasms manifesting in the remote period in the male population born and living in rural areas of Altai Krai during the first nuclear test conducted at the Semipalatinsk test site was revealed: RR=1.616, 95% CI 1.180–2.214, with the standard error of relative risk equal to 0.160.

The intramolecular SN2 reaction tautomeric ent-Kauranoids isolated from the aerial parts of Isodon amethystoides

As our ongoing searching for the bioactive natural terpenoids, nine ent-kauranoids (1–9), including three previously undescribed ones (1, 2, and 9), were isolated from the aerial parts of Isodon amethystoides. Their structures were elucidated on the basis of spectroscopic data analysis, including NMR, MS, and ECD. Compounds 1 and 2 were a pair of tautomeric compounds, which was confirmed by the HPLC analysis and low temperature NMR testing. The underlying mechanism of the tautomer was proposed as an intramolecular SN2 reaction, which was explained by quantum chemical calculation. The HOMO-LUMO gap and the free energy revealed the spontaneous of the tautomeric of the 1 and 2. Additionally, the similar phenomena were also found in the two groups of known compounds 3 and 4 and 6 and 7, respectively. Apart from the tautomer, compounds 3 and 4 can be hydrolyzed into 5 through ester hydrolysis in CDCl3, while compounds 6, 7 can be hydrolyzed into 8 through ester hydrolysis. These phenomena were also confirmed through HPLC analysis and low temperature nuclear magnetic resonance tests and the mechanism was studied using quantum chemical calculation.

Multicellular species environmental DNA (eDNA) research constrained by overfocus on mitochondrial DNA

Environmental DNA (eDNA) is becoming an established tool across the biological and medical sciences. Despite the evident successes and wide adoption of eDNA approaches, some fundamental questions remain. For instance, there is almost a dogma in the field around the superiority of mitochondrial DNA for use in eDNA studies, however robust comparison with nuclear eDNA is widely lacking. The dominance of mitochondrial-based eDNA for animal and plant studies appears to be largely settled, despite a widespread lack of rigorous nuclear eDNA testing. Outside of the source organism the protections conferred on eDNA by the cell, mitochondrial and nuclear membranes are poorly understood, including the contribution of each to eDNA persistence and degradation. Utilizing shotgun sequencing to unbiasedly assess the level of nuclear and mitochondrial eDNA across samples, we reveal stark differences in nuclear versus mitochondrial eDNA persistence and abundance. By focusing too heavily on mitochondrial DNA alone the field is underutilizing eDNA's full potential.

Nuclear Testing in French Polynesia: After Fifty Years of Lies and State Secrets How to Calm Our Anger and Rebuild Ourselves

The essay discusses, from an Indigenous perspective, the French nuclear weapon tests in the southern Pacific islands. It presents a vivid scenario of the detrimental effects and social inequalities produced by the dynamic of ‘industrialization without industry’ brought about by militarisation and extraction.

The marine reservoir age of Greenland coastal waters

Abstract. Knowledge of the marine reservoir age is fundamental for creating reliable chronologies of marine sediment archives based on radiocarbon dating. This age difference between the 14C age of a marine sample and that of its contemporaneous atmosphere is dependent on several factors (among others, ocean circulation, water mass distribution, terrestrial runoff, upwelling, and sea-ice cover) and is therefore spatially heterogeneous. Anthropogenic influence on the global isotopic carbon system, mostly through atmospheric nuclear tests, has complicated the determination of the regional reservoir age correction ΔR, which therefore can only be measured in historic samples of known age. In this study we expand on the few existing measurements of ΔR for the coastal waters around Greenland, by adding 92 new radiocarbon dates on mollusks from museum collections. All studied mollusk samples were collected during historic expeditions of the late 19th and early 20th centuries, and besides coastal sites around Greenland, the new measurements also include localities from the western Labrador Sea, Baffin Bay, and the Iceland Sea. Together with existing measurements, the new results are used to calculate average ΔR values for different regions around Greenland, all in relation to Marine20, the most recent marine radiocarbon calibration curve. To support further discussions and comparison with previous datasets, we use the term ΔR13, where the suffix 13 refers to the previous calibration curve Marine13. Our study explores the links between the marine reservoir age and oceanography, sea-ice cover, water depth, mollusk feeding habits, and the presence of carbonate bedrock. Although we provide regional averages, we encourage people to consult the full catalogue of measurements and determine a suitable ΔR for each case individually, based on the exact location including water depth. Despite this significant expansion of the regional reservoir age database around Greenland, data from the northern coast, directly bordering the Arctic Ocean, remain missing.

The Rise and Fall of Radioactive Carbon in the Atmosphere

The level of radioactive carbon dioxide in the atmosphere has shifted dramatically since the middle of the twentieth century. At that time, nuclear weapons tests resulted in considerably raised levels of the radioactive molecule. The impact peaked in the early 1960s and, since then, the radioactive level has come back almost to where it was before the nuclear test period. The ambition here is to discuss the character of the carbon dioxide curve in its different phases with an emphasis on what has happened after the atmospheric tests stopped. The curve’s behaviour seems to raise an interesting question for climate change theory.

The Postnuclear Ecosystem of Central Asia: Hamid Ismailov’s Vunderkind Erzhan

The core of this article consists in an ecocritical reading of a Russian language work from Central Asia: Vunderkind Yerzhan (2011) by Hamid Ismailov (b.1954). Based on the recognition that the Anthropocene calls for an emphasis on the complex interrelationships of ecological systems, the article underscores the urgency of an ecocritical reading in understanding the impact of human agency on the environment, particularly in relation to the history of Central Asia. The article traces the origins of environmental problems in Central Asia, including the Aral Sea crisis and nuclear testing in Semipalatinsk, illustrating the contradictions in Soviet ecological policies that simultaneously advanced and degraded the environment. Vunderkind Erzhan unfolds in a post-nuclear wasteland, where the protagonist, Erzhan, encapsulates the ecological legacy of Stalinist times. The article focuses on the interconnectedness of Erzhan’s life with the environmental abuses perpetrated during the implementation of nuclear power. Ismailov conveys the environmental sadness provoked by the region’s ecological degradation; his povest’ is an outcry against the Soviet myth of progress and sheds light on the environmental consequences that developmentalist policies had in Kazakhstan. Ismailov’s work becomes a lens through which the article examines the environmental challenges in the region, providing a nuanced understanding of the intersections between literature, culture, and the environment. Vunderkind Erzhan emerges as an exemplary ecological tale, illustrating the profound interconnection between all earthly beings, all affected by the far-reaching consequences of human agency.

Materials qualification through the Nuclear Science User Facilities (NSUF): a case study on irradiated PM-HIP structural alloys

This article presents neutron irradiation and post-irradiation examination (PIE) capabilities available to the nuclear materials research community through the US Department of Energy’s Nuclear Science User Facilities (NSUF). The pressing need to deploy advanced nuclear reactors to combat climate change requires qualification of new fuels and materials. Among advanced manufacturing processes, powder metallurgy with hot isostatic pressing (PM-HIP) is nearest to becoming qualified for nuclear applications. This article provides examples from a recent irradiation and PIE program on a series of structural alloys fabricated by PM-HIP to illustrate how NSUF capabilities can be used to generate qualification data. The neutron irradiation experiments are described, and a sampling of results from tensile testing, nanoindentation, transmission electron microscopy, and atom probe tomography are presented, showing the favorable performance of PM-HIP alloys compared to their cast or forged counterparts under irradiation. This article provides a perspective on leveraging NSUF for future nuclear fuels and materials testing and qualification.

Experimental Studies on Pore Structure and the Gas Content Evolution Mechanisms of Shale Gas Reservoirs at Different Burial Depths in the Longmaxi Formation, Southern Sichuan Basin

Micro- and nano-scale pores develop in shale reservoirs, and the associated pore structure controls the occurrence state, gas content, seepage capacity, and micro-migration and accumulation mechanisms of shale gas. For this study, we mainly conducted tests, using field emission-scanning electron microscopy, of the isothermal methane adsorption of powder-sized samples under high temperatures (60–130 °C) and pressures (0–45 MPa), along with methane-saturated nuclear magnetic resonance tests of plug-sized samples under different temperatures (60–100 °C) and pressures (0–35 MPa). These samples were from Longmaxi shale cores from strata at different burial depths from the Zhaotong, Weiyuan, and Luzhou areas. As the burial depth increases, organic pores transform from complex networks to relatively isolated and circular pore-like structures, and the proportion of organic matter-hosted pores increases from 25.0% to 61.2%. The pore size is influenced by the pressure difference inside and outside the pores, as well as the surface tension of organic matter in situ. As the burial depth increases to 4200 m, the main peak of the pore size first increases from 5–30 nm to 200–400 nm and then decreases to 50–200 nm. This work establishes an NMR method of saturated methane on plug-sized samples to test the free gas content and develop a prediction model of shale reservoirs at different burial depths. The gas content of a shale reservoir is influenced by both burial depths and pore structure. When the burial depth of the shale gas reservoir is less than 2000 m, inorganic pores and microfractures develop, and the self-sealing ability of the reservoir in terms of retaining shale gas is weak, resulting in low gas content. However, due to the small pore size of organic pores and the low formation temperature, the content of adsorbed gas increases, accounting for up to 60%. As the burial depth increases, the free gas and total gas content increase; at 4500 m, the total gas content of shale reservoirs is 18.9 m3/t, and the proportion of free gas can be as high as 80%. The total gas content predicted by our method is consistent with the results of the pressure-holding coring technique, which is about twice our original understanding of gas content, greatly enhancing our confidence in the possibility of accelerating the exploration and development of deep shale gas.

Examining the potential for detecting simultaneous noble gas and aerosol samples in the international monitoring system radionuclide network

The purpose of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is to establish a legally binding ban on nuclear weapon test explosions or any other nuclear explosions. The Preparatory Commission for the CTBT Organization (CTBTO PrepCom) is developing the International Monitoring System (IMS) that includes a global network of 80 stations to monitor for airborne radionuclides upon entry into force of the CTBT. All 80 radionuclide stations will monitor for particulate radionuclides and at least half of the stations will monitor for radioxenon. The airborne radionuclide monitoring is an important verification technology both for the detection of a radionuclide release and in the determination of whether the release event originates from a nuclear explosion as opposed to an industrial use of nuclear materials.Nuclear power plants and many medical isotope production facilities release radioxenon into the atmosphere. Low levels of a few particulate isotopes, such as iodine, may also be released. Detections of multiple isotopes are useful for screening the radionuclide samples for relevance to the Treaty. This paper examines the anticipated joint detections in the IMS of noble gas and particulate isotopes from underground nuclear explosions where breaches in the underground containment vents from low levels to up to 1% of the radionuclide inventory of the resulting fission products to the atmosphere. Detection probabilities are based on 844 simulated release events spaced out at 17 release locations and one year in time. Six different release (venting) scenarios, including two fractionated scenarios, were analyzed.When ranked by detection probability, 11 particulate isotopes and one noble gas isotope (133Xe) appear in the top 20 isotopes for all six release scenarios. Using the 11 particulate isotopes and the one noble gas isotope, the IMS has nearly the same detection probability as when 45 particulate and 4 noble gas isotopes are used. Thus, a limited list of relevant radionuclides may be sufficient for treaty verification purposes. The probability that at least one particulate and at least one radioxenon isotope would be detected in the IMS from the release events ranged from 0.15 to 0.86 depending on the release scenario.

AN EXPERIENCE WITH ID‐NAT AND IT’S ROLE TO REFINE BLOOD SAFETY AGAINST THE TRANSFUSION‐TRANSMITTED INFECTIONS: A 3 YEAR RETROSPECTIVE STUDY

Safety of blood is a daunting task, particularly in India, where HBV infection is highly prevalent (2-4%), HCV infection (2%) and HIV .infection (0.29%) among blood donors. The objective of this research is to assess the impact of donor nuclear acid testing (ID‐NAT) on individuals in addition to Chemiluminescence. Immunoassay (ChLIA) on safety of blood transfusion currently in India. In order to assess the data from three years of extra NAT testing at Blood and Component Bank, J.N. Medical College and Hospital, AMU, Aligarh, a retrospective observational study was done. 2.11% (2431 of 115298) units were ID-NAT reactive while only 1.86% (2147 of 115298) units were reactive by ChLIA.AID-NAT yield (NAT only reactive i.e sero-negative with ChLIA) of 0.25% (284 of 115298) was detected. 1 in 398 was the overall ID-NAT yield rate. In 3 years, ID‐NAT testing prevented 284 probable .ID-NAT implementation for TTIs up to 1136 (assuming 100% component separation) and recipients of transfusions.in addition to Chemiluminescence Immunoassay (ChLIA) has improved the outcome in terms of safety of blood transfusion.

Sperm chromatin structure assay (SCSA®) and flow cytometry-assisted TUNEL assay provide a concordant assessment of sperm DNA fragmentation as a function of age in a large cohort of approximately 10,000 patients

BackgroundSperm DNA integrity is increasingly seen as a critical characteristic determining reproductive success, both in natural reproduction and in assisted reproductive technologies (ART). Despite this awareness, sperm DNA and nuclear integrity tests are still not part of routine examinations for either infertile men or fertile men wishing to assess their reproductive capacity. This is not due to the unavailability of DNA and sperm nuclear integrity tests. On the contrary, several relevant but distinct tests are available and have been used in many clinical trials, which has led to conflicting results and confusion. The reasons for this are mainly the lack of standardization between different clinics and between the tests themselves. In addition, the small number of samples analyzed in these trials has often weakened the value of the analyses performed. In the present work, we used a large cohort of semen samples, covering a wide age range, which were simultaneously evaluated for sperm DNA fragmentation (SDF) using two of the most frequently used SDF assays, namely the TUNEL assay and the sperm chromatin structure assay (SCSA®). At the same time, as standard seminal parameters (sperm motility, sperm morphology, sperm count) were available for these samples, correlations between age, SDF and conventional seminal parameters were analyzed.ResultsWe show that the SCSA® and TUNEL assessments of SDF produce concordant data. However, the SDF assessed by TUNEL is systematically lower than that assessed by SCSA®. Regardless of the test used, the SDF increases steadily during aging, while the HDS parameter (High DNA stainability assessed via SCSA®) remains unchanged. In the cohort analyzed, conventional sperm parameters do not seem to discriminate with aging. Only sperm volume and motility were significantly lower in the oldest age group analyzed [50–59 years of age].ConclusionsIn the large cohort analyzed, SDF is an age-dependent parameter, increasing linearly with aging. The SCSA® assessment of SDF and the flow cytometry-assisted TUNEL assessment are well correlated, although TUNEL is less sensitive than SCSA®. This difference in sensitivity should be taken into account in the final assessment of the true level of fragmentation of the sperm nucleus of a given sample. The classical sperm parameters (motility, morphology, sperm count) do not change dramatically with age, making them inadequate to assess the fertility potential of an individual.

Global Seismic Networks Operated by the U.S. Geological Survey

Abstract The U.S. Geological Survey (USGS) Global Seismographic Network (GSN) Program operates two thirds of the GSN, a network of state-of-the-art, digital seismological and geophysical sensors with digital telecommunications. This network serves as a multiuse scientific facility and a valuable resource for research, education, and monitoring. The other one third of the GSN is funded by the National Science Foundation (NSF), and the operations of this component are overseen by EarthScope. This collaboration between the USGS, EarthScope, and NSF has allowed for the development and operations of the GSN to be a truly multiuse network that provides near real-time open access data, facilitating fundamental discoveries by the Earth science community, supporting the earthquake hazards mission of the USGS, benefitting tsunami monitoring by the National Oceanic and Atmospheric Administration, and contributing to nuclear test monitoring and treaty verification. In this article, we describe the installation and evolution of the seismic networks operated by the USGS that ultimately led to the USGS portion of the GSN (100 stations under network codes IU, IC, and CU) as they are today and envision technological advances and opportunities to further improve the utility of the network in the future. This article focuses on the USGS-operated component of the GSN; a companion article on the GSN stations funded by the NSF and operated by the Cecil and Ida Green Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography, University of California at San Diego by Davis et al. (2023) appears in this volume.

Classification of nuclear activity types for neighboring countries of South Korea using machine learning techniques with xenon isotopic activity ratios

The discrimination of the source for xenon gases' release can provide an important clue for detecting the nuclear activities in the neighboring countries. In this paper, three machine learning techniques, which are logistic regression, support vector machine (SVM), and k-nearest neighbors (KNN), were applied to develop the predictive models for discriminating the source for xenon gases’ release based on the xenon isotopic activity ratio data which were generated using the depletion codes, i.e., ORIGEN in SCALE 6.2 and Serpent, for the probable sources. The considered sources for the neighboring countries of South Korea include PWRs, CANDUs, IRT-2000, Yongbyun 5 MWe reactor, and nuclear tests with plutonium and uranium. The results of the analysis showed that the overall prediction accuracies of models with SVM and KNN using six inputs, all exceeded 90%. Particularly, the models based on SVM and KNN that used six or three xenon isotope activity ratios with three classification categories, namely reactor, plutonium bomb, and uranium bomb, had accuracy levels greater than 88%. The prediction performances demonstrate the applicability of machine learning algorithms to predict nuclear threat using ratios of xenon isotopic activity.

Evaluation of the Genotoxic and Histological Effects in Neotropical Fish Prochilodus Lacustris (Pisces, Prochilodontidae) in Conservation Area of the Brazilian Northeast.

Human activities significantly impact the aquatic biota in lacustrine environments, leading to negative environmental consequences. Due to this, this study was carried out to evaluate the genotoxic and histological biomarkers in the gills and kidneys of Prochilodus lacustris. The collection of fish and water was conducted in three distinct stations (S1, S2, S3) in an international protected area in northeast Brazil. The histological alterations index was used to assess changes in the gills and kidneys at a histological level. In addition, micronucleus and nuclear abnormalities tests were employed to examine damage to the genetic material. According to the frequency of Micronucleus, nuclear injuries, and the histopathology of gills and kidneys, it can be inferred that station S1 had the highest impact on the fish, causing significant harm. Based on our findings, the organisms residing in Lake Açu are adversely affected by the poor environmental conditions. This raises doubts about the effectiveness of the Protection Area by Humid Zone of International Interest in Northeast Brazil.

The Microfoundations of Nuclear Proliferation: Evidence from South Korea

Abstract How do South Koreans shape their nuclear proliferation beliefs? Despite growing scholarly research on public attitudes toward nuclearization, we do not fully understand the underlying factors that influence mass opinion on nuclear weapon acquisition. This study tests the effects of structural- and individual-level factors on South Korean public support for nuclear weapon acquisition by creating a novel time-series dataset. Contrary to conventional wisdom, structural variables did not immediately shift South Koreans’ proliferation beliefs. Instead, the effects accumulated over time. North Korea’s ballistic missile launches and nuclear tests gradually increased South Koreans’ support for proliferation. Also, within a short time period, South Korea–U.S. summits had null effects but progressively dampened the armament preferences. Interestingly, North Korea’s denuclearization summits instantly reduced the proliferation beliefs, but, the support for nuclearization surged over time. Regarding individual-level factors, South Koreans’ fear of nuclear imbalance, desire to decide on their own nuclear war, and conservative party identification were positively associated with the support for proliferation. This study enriches existing literature by offering new empirical evidence and contributes to the scholarly debate on the impact of U.S. security assurances on South Koreans’ nuclear proliferation attitudes.

Source Spectra of Pg and Lg Waves from North Korean Nuclear Tests Estimated Using a Nonmodel-Based Approach

ABSTRACT In this article, we demonstrate that source spectra for regional seismic waves generated by an underground explosion may be uniquely extracted using a simple linear regression method between the geometrical spreading corrected displacement spectra and epicentral distances as long as the recording stations are well distributed in distances. Using this method, source spectra of Pg and Lg waves from North Korean nuclear tests conducted between 2009 and 2017 are estimated, respectively, and are compared to test the conjecture of Fisk (2006) as well as to determine the relative size between the seismic moment of Lg waves and that of compressional waves. For a specified explosion, the resultant Pg and Lg source spectra approximately have equal low-frequency source level. Based on this result, it is estimated that for the explosions seismic moment of Lg waves would be about 35% of that of compressional waves. In addition, it is shown the Fisk conjecture approximately stands, as for a specified explosion the observed Pg and Lg source spectra share the same manner of high-frequency rolloff as f−2, the source corner frequency of Lg waves is smaller than that of Pg waves by a factor of about 1/3, and the Pg source spectrum exhibits a prominent overshoot, whereas it is not obvious in corresponding Lg source spectrum. The new method for source spectra estimation may have a promising application prospect in monitoring studies. As an example, it is shown that the yield and even buried depths of the North Korean nuclear explosions may be reasonably estimated by fitting the observed Pg source spectra using an MM71- (Mueller and Murphy, 1971) and DJ91 (Denny and Johnson, 1991)-based hybrid source model suggested by Ford and Walter (2013).

Comparison of external dose estimates using different retrospective dosimetry methods in the settlements located near Semipalatinsk Nuclear Test Site, Republic of Kazakhstan.

For correct assessment of health risks after low-dose irradiation, calculation of radiation exposure estimates is crucial. To verify the calculated absorbed doses, instrumental methods of retrospective dosimetry are used. We compared calculated and instrumental-based estimates of external absorbed doses in the residents of Dolon, Mostik and Cheremushki villages, Kazakhstan, affected by the first nuclear weapon test performed at the Semipalatinsk Nuclear Test Site (SNTS) on August 29, 1949. The 'instrumental' doses were retrospectively estimated using the Luminescence Retrospective Dosimetry (LRD) and Electron Spin Resonance (ESR) methods. Correlation between the calculated individual cumulative external absorbed whole-body doses based on typical input data and ESR-based individual doses in the same people was strong (r = 0.782). It was even stronger between the calculated doses based on individual questionnaires' input data and the ESR-based doses (r = 0.940). Application of the LRD method is useful for validation of the calculated settlement-average cumulated external absorbed dose to air. Reconstruction of external exposure can be supplemented with the data from later measurements of soil contamination with long-lived radionuclides, such as, 137Cs. Our results show the reliability of the calculational method used for the retrospective assessment of individual external doses.

Compression damage mechanism and damage detection of Aronia melanocarpa based on nuclear magnetic resonance tests

Compression damage mechanism and damage detection of Aronia melanocarpa based on nuclear magnetic resonance tests

Coronary and Extra-coronary Subclinical Atherosclerosis to Guide Lipid-Lowering Therapy.

To discuss and review the technical considerations, fundamentals, and guideline-based indications for coronary artery calcium scoring, and the use of other non-invasive imaging modalities, such as extra-coronary calcification in cardiovascular risk prediction. The most robust evidence for the use of CAC scoring is in select individuals, 40-75 years of age, at borderline to intermediate 10-year ASCVD risk. Recent US recommendations support the use of CAC scoring in varying clinical scenarios. First, in adults with very high CAC scores (CAC ≥ 1000), the use of high-intensity statin therapy and, if necessary, guideline-based add-on LDL-C lowering therapies (ezetimibe, PCSK9-inhibitors) to achieve a ≥ 50% reduction in LDL-C and optimally an LDL-C < 70 mg/dL is recommended. In patients with a CAC score ≥ 100 at low risk of bleeding, the benefits of aspirin use may outweigh the risk of bleeding. Other applications of CAC scoring include risk estimation on non-contrast CT scans of the chest, risk prediction in younger patients (< 40 years of age), its value as a gatekeeper for the decision to perform nuclear stress testing, and to aid in risk stratification in patients presenting with low-risk chest pain. There is a correlation between extra-coronary calcification (e.g., breast arterial calcification, aortic calcification, and aortic valve calcification) and incident ASCVD events. However, its role in informing lipid management remains unclear. Identification of coronary calcium in selected patients is the single best non-invasive imaging modality to identify future ASCVD risk and inform lipid-lowering therapy decision-making.