Indirect Damage Research Articles

CTA Imaging of Peripheral Arterial Injuries.

Traumatic vascular injuries consist of direct or indirect damage to arteries and/or veins and account for 3% of all traumatic injuries. Typical consequences are hemorrhage and ischemia. Vascular injuries of the extremities can occur isolated or in association with major trauma and other organ injuries. They account for 1-2% of patients admitted to emergency departments and for approximately 50% of all arterial injuries. Lower extremities are more frequently injured than upper ones in the adult population. The outcome of vascular injuries is strictly correlated to the environment and the time background. Treatment can be challenging, notably in polytrauma because of the dilemma of which injury should be prioritized, and treatment delay can cause disability or even death, especially for limb vascular injury. Our purposes are to discuss the role of computed tomography angiography (CTA) in the diagnosis of vascular trauma and its optimized protocol to achieve a definitive diagnosis and to assess the radiological signs of vascular injuries and the possible pitfalls.

Review of Sulfate Removal in Low Concentration Brine Solutions

Sulfate is a common ion present in natural water bodies at low concentrations and as effluent in different metallurgical processes. The discharge of sulfate in rivers and waterbodies can cause direct and indirect damage to the environment. Regulatory agencies have been increasing the constraints in sulfate content limit for discharge focused on human equity and environmental protection. A common practice is the precipitation of sulfate with lime, but the remaining solution still has ca. 1,500 mg L-1 of sulfate, which is not acceptable for disposal or reuse. This work describes the main routes for sulfate removal such as chemical precipitation, biological degradation, ion exchange, and separation through membranes and discusses the main advantages and issues of each approach. One of the main challenges is to scale up the tests and show the performances at the industrial level. The subject must be the focus of constant study to obtain relevant results so that usual technologies are replaced by more innovative, cheap and efficient methods.

Examining direct and indirect flood damages in residential and business sectors through an empirical lens.

Investment to reduce flood risk for social and economic wellbeing requires quantitative evidence to guide decisions. Direct and indirect flood damages at individual household and business building levels were assessed in this study using multivariate analysis with three groups of flood damage attributes, i.e., flood characteristics, socioeconomic conditions, and building types. A total of 172 and 45 respondents from residential and commercial buildings were gathered through door-to-door interviews at areas in Peninsular Malaysia that were pre-identified to have frequently flooded. Two main findings can be drawn from this study. First, flood damage is greatly contributed by high-income households and businesses, despite them being less exposed to floods than low-income earners. This supports the current use of mean economic damage in engineering-based flood intervention analysis. Second, indirect damages increase with the increase in family size, indicating the importance of strengthening preparedness and social support to those with great social responsibility. Overall, the study highlights the importance of holistic flood management accounting for both direct and indirect losses.

Deciphering the mechanisms of carcinogens: Unravelling the pathways of cancer initiation and progression: An insight into DNA damage, genotoxicity, and epigenetic changes

Carcinogens are substances known to induce cancer by altering the genetic material and cellular processes within the human body. Understanding the mode of action of carcinogens is critical for developing effective prevention and intervention strategies against cancer. Cancer remains a significant global health challenge, with carcinogens posing a continuous threat to human well-being. This study explores into the intricate mechanisms by which carcinogens induce cancer, focusing on the interplay of DNA damage, genotoxicity, and epigenetic alterations. Through an analysis of direct and indirect-acting carcinogens, the study elucidates how these agents disrupt cellular DNA, leading to mutations and chromosomal abnormalities. Additionally, the role of genotoxicity in driving oncogenesis is explored, highlighting the importance of assessing carcinogenic risk through cytogenetic genotoxicity methods. The study focused into the direct and indirect DNA damage, genotoxicity, epigenetic changes, inflammation, hormonal effects, and immune system suppression induced by different carcinogens. It intends insight on the intricate interplay between environmental factors and the molecular foundation of carcinogenesis by thoroughly investigating these pathways. By comprehensively examining these pathways, which hope to focus on the complex interplay of carcinogenesis. By understanding these mechanisms, this study aims to inform preventive strategies and therapeutic interventions, ultimately mitigating the global burden of cancer.

Macrophages release miRNAs in response to Doxorubicin with a potential role in indirect cardiac damage

Macrophages release miRNAs in response to Doxorubicin with a potential role in indirect cardiac damage

What to do With Cross-Border Environmental Pollution: Legislative Aspects

Abstract – Environmental torts and possibility of trans-border dispute settlement thereof has gained significant prominence in the recent years. Cases such as Urgenda foundation v the State of the Netherlends, Milieudefensie et al. v. Royal Dutch Shell plc., ClientEarth v. Enea, Neubauer et al. v. Germany demonstrate that environmental tort cases can be brought by stakeholders globally rather than relying on involvement of a relevant national responsible authority. EU climate policy of decreasing GHG emissions and the ambitious target of reaching climate neutrality by 2050 has resulted in a rapid development of environmental law. Thus, environmental regulation is becoming increasingly complex and possible breaches may cause serious legal consequences affecting everyone not just selected individuals or states. These developments could possibly lead to a necessity of a forum or rules where any natural person or an NGO could bring a claim against a state or multinational corporation which engages in illegal activities causing harm the environment on a global scale. Using litigation as a tool to empower society to stand against environmental wrongdoers may serve as a deterring factor to maintain order when it comes to environmental regulation. While such reasoning may seem farfetched and extreme, nevertheless it still raises a question of current regulation on determination of jurisdiction and the applicable law and whether it would be possible to benefit from developing these rules. By engaging in a systematic literature analysis identifying the relevant terms, the research shall explore the basic principles of private international law in relation to assigning jurisdiction and determining applicable law in claims concerning environmental torts. The research shall develop a methodology with the aim of covering and identifying a wider range of problems related to the determination of jurisdiction and application of law in cross-border environmental tort claims. Some of the main issues concern the determination of defendants in cases involving multinational corporations, multi-claimant cases, and the compensation of indirect damages. An exploration of material aspects in the developments of the current EU regulation and guidelines shall be analysed in conjunction with the aforementioned notion. The result of the study not only will reflect the specifics of the application of the Brussels Ibis Regulation and Rome II regulation in cross-border environmental torts, but also how the EU environmental regulation could potentially promote corporate responsibility and environmental protection. Thus, developing research on interaction between private international law and environmental law. Keywords - environmental tort, SEG emissions, jurisdiction, applicable law, cross-border pollution

IMPACTS OF TOBACCO USE AND EXPOSURE TO TOBACCO SMOKE ON HEALTH, SOCIETY, ECONOMY, AND ENVIRONMENT

Smoking represents a significant global public health challenge and is the primary preventable cause of disease and death. This problem is accentuated by the fact that a substantial 80% of adult smokers worldwide come from low- or middle-income countries. The aim of this paper is twofold: first, to highlight the health impacts associated with tobacco use, and second, to delineate the indirect damage caused to the environment during the life cycle of tobacco products - from production and distribution to consumption and waste generation. The reluctance of some countries to take decisive action, together with intense pressure from tobacco corporations, is hindering progress towards reducing the number of adult smokers and curbing tobacco use among minors. State interventions, supported by strict laws, are necessary to enforce the ban on indoor smoking, the ban on the sale of tobacco to minors, and the establishment of permanent interstate cooperation in the fight against cigarette smuggling. Educational initiatives aimed at raising awareness of the dangers of smoking and tobacco consumption are key to fostering a smoke-free culture. A strong media campaign, supported by state measures, could contribute to faster and more comprehensive targeting of target groups, especially younger age categories.

The concept of rationalising damage and the scope of insurer’s liability

The concept of indirect violation of rights and interestsholds an important place in the system of liability for damages.Therefore, the analysis of that subject matter should focus not on whether the damage is compensable but on the basis and extent of compensation.The diversity of events that may give rise to an “indirect damage” does not make it easy to identify its prerequisites. On top of that, the actions taken do not go in pair with harmonisation of terminology and do not lead to the introduction of one consistent liability model. An answer to the doubts arising in context of compensating for “indirect damage” is the concept of rationalising damage. It covers a set of directives that serve to determine if a given detriment qualifies as “indirect damage” and if a given person is an indirect victim. Not all violations are compensable, but only violations to legally protected interests. As a result, compensation does not cover all inconveniences, or inconveniences forming a part of risk associated with everyday life. Determination of the scope of compensating for indirect damage has a significant impact on the scope of liability of the insurer.This is the case as the model of compensation for indirect violations should be “economically efficient. Keywords

Theoretical and Experimental Investigations of Identifying Bridge Damage Using Instantaneous Amplitude Squared Extracted from Vibration Responses of a Two-Axle Passing Vehicle

Identifying bridge damage using a movable test vehicle is highly regarded for its mobility, cost-effectiveness, and broad monitoring coverage. Previous studies have shown that the residual contact-point (CP) response between connected vehicles is free of the impact of vehicle self-vibrations and road roughness, making it particularly suitable for the indirect extraction of bridge modal properties. However, most experimental campaigns regarding contact-point (CP) responses focus on a single-axle testing vehicle within a non-moving state. This study aims to theoretically and experimentally identify bridge damage using the instantaneous amplitude squared (IAS) extracted from the residual CP response of a two-axle passing vehicle. First, the closed-form solution of the residual CP acceleration was derived for a two-axle vehicle interacting with a simply supported beam. The IAS index was constructed from the driving frequency of the residual CP acceleration. Then, numerical investigations using finite element simulation were conducted to validate using the IAS index for indirect bridge damage identification. The application scope of the approach under various vehicle speeds and road roughness grades was examined. Finally, a laboratory vehicle–bridge interaction system was tested to validate the approach. Numerical studies demonstrated that bridge damage could be directly determined by observing the IAS abnormalities, which were baseline-free. The IAS from the residual CP response outperformed the IAS from CP responses in identifying bridge damage. However, it was better to use the IAS when the vehicle speed was no greater than 2 m/s and the grade of the road surface roughness was not high. Laboratory tests showed that it was possible to identify bridge damage using the IAS extracted from the residual CP acceleration under perfect road surfaces. However, it fell short under rough road surfaces. Hence, further experiments are required to fully examine the capacity of the IAS for bridge damage identification in practical applications.

Inhibition of Let-7b-5p maturation by LIN28A promotes thermal skin damage repair after burn injury

Burn injuries, especially severe ones, result in direct and indirect thermal damage to skin tissues, with a complex and slow wound healing process. Improper treatment can induce sustained inflammatory responses, causing systemic damage. Lin28A, a highly conserved RNA binding protein, was found to exert a significant effect on cell proliferation and wound repair. Lin28A exerts the functions through inhibiting the maturation of the let-7 family miRNAs. Herein, the roles of Lin28A and let-7b in thermal injury repair were investigated using a mouse thermal injury model and a human skin fibroblast (HSF) model for thermal injuries. Lin28A could inhibit the maturation of let-7b, thus participating in skin repair after burns. In the animal model, Lin28A was highly expressed after thermal injury. In the HSF model for thermal injuries, downregulation of Lin28A inhibited the proliferation, migration, and extracellular matrix (ECM) generation of fibroblasts. When let-7b was knocked down in HSFs, the impacts on fibroblast functions caused by downregulation of Lin28A were partially reversed. Moreover, let-7b overexpression might significantly attenuate the promotive effects of Lin28A upon thermal injury repair. Finally, AKT2 and IGF1R were the let-7b target genes within cells. These findings reveal that Lin28A might promote thermal injury repair in burn-injured skin by inhibiting the maturation of let-7b and improving HSF viability and functions, thus illustrating the critical effect of let-7b on burn wound healing and providing new therapeutic targets and strategies for burn treatment.

Tunnel indirect damage identification algorithm based on service train dynamic response time series

In this study, a tunnel indirect damage identification algorithm based on a service train dynamic response time series was proposed. First, the principles and processes of the proposed algorithm are introduced. The instantaneous frequency and spectral entropy of the trend and seasonal terms of the train dynamic response decomposed by Seasonal and Trend decomposition using Loess are calculated, respectively, to further extract the time-frequency features of the signal. The calculated sequence is input into the Bi-directional Long Short-Term Memory network, and the type of damage case is the output. Second, the feasibility of the algorithm is verified using a model test. Finally, the key links in the algorithm are discussed. The results indicate that the proposed algorithm can identify damage cases with a small number of training and test sets, and the accuracy of the test set can reach 83.33%. Through time-frequency feature extraction and normalization processing, the length of the network input sequence is reduced, the training speed is increased, and damage identification can be realized without a deep network.

Exploring the pathogenetic mechanisms of Mycoplasmapneumoniae (Review).

Mycoplasmas, the smallest self-replicating prokaryotes without a cell wall, are the most prevalent and extensively studied species in humans. They significantly contribute to chronic respiratory tract illnesses and pneumonia, with children and adolescents being particularly vulnerable. Mycoplasma pneumoniae (M. pneumoniae) infections typically tend to be self-limiting and mild but can progress to severe or even life-threatening conditions in certain individuals. Extrapulmonary effects often occur without pneumonia, and both intrapulmonary and extrapulmonary complications operate through separate pathological mechanisms. The indirect immune-mediated damage of the immune system, vascular blockages brought on by vasculitis or thrombosis and direct harm from invasion or locally induced inflammatory cytokines are potential causes of extrapulmonary manifestations due to M. pneumoniae. Proteins associated with adhesion serve as the primary factor crucial for the pathogenicity of M. pneumoniae, relying on a specialized polarized terminal attachment organelle. The type and density of these host receptors significantly impact the adhesion and movement of M. pneumoniae, subsequently influencing the pathogenic mechanism and infection outcomes. Adjacent proteins are crucial for the proper assembly of the attachment organelle, with variations in the genetic domains of P1, P40 and P90 surfaces contributing to the variability of clinical symptoms and offering new avenues for developing vaccines against M. pneumoniae infections. M. pneumoniae causes oxidative stress within respiratory tract epithelial cells by adhering to host cells and releasing hydrogen peroxide and superoxide radicals. This oxidative stress enhances the vulnerability of host cells to harm induced by oxygen molecules. The lack of superoxide dismutase and catalase of bacteria allows it to hinder the catalase activity of the host cell, leading to the reduced breakdown of peroxides. Lung macrophages play a significant role in managing M. pneumoniae infection, identifying it via Toll-like receptor 2 and initiating the myeloid differentiation primary response gene 88-nuclear factor κΒ signaling cascade. However, the precise mechanisms enabling M. pneumoniae to evade intracellular host defenses remain unknown, necessitating further exploration of the pathways involved in intracellular survival. The present comprehensive review delves into the pathogenesis of M. pneumoniae infection within the pulmonary system and into extrapulmonary areas, outlining its impact.

Resistance to Cassava Whitefly (Bemisia tabaci) among Eastern and Southern African Elite Cassava Genotypes.

Cassava whitefly, Bemisia tabaci, directly damages cassava leaves by feeding on phloem, causing chlorosis and abscission, leading to a yield loss of up to 50%. The pest also causes indirect damage through sooty mold formation. Most Ugandan cassava varieties resist cassava mosaic disease (CMD) and tolerate cassava brown streak disease (CBSD), but little is known about their response to whitefly infestation. The main objective of this study was to identify cassava genotypes with putative resistance to whitefly in Uganda. This was conducted on 24 improved cassava varieties in three agro-ecological zones during the second rains of 2016. Monthly data were taken for adult and nymph counts, whitefly and sooty mold damage, and CMD and CBSD severities from 2 to 9 months after planting (MAPs). The results show that the whitefly population is highly significantly (p < 0.000) amongst varieties across the three agro-ecological zones. Mkumba consistently supported the low adult numbers and nymphs. The findings demonstrate the potential of the improved cassava varieties as sources of whitefly resistance for sustainable management.

Proton relative biological effectiveness for the induction of DNA double strand breaks based on Geant4

Uncertainties in the relative biological effectiveness (RBE) of proton remains a major barrier to the biological optimization of proton therapy. A large amount of experimental data suggest that proton RBE is variable. As an evolving Monte Carlo code toolkit, Geant4-DNA is able to simulate the initial DNA damage caused by particle beams through physical and chemical interactions at the nanometer scale over a short period of time. This contributes to evaluating the radiobiological effects induced by ionizing radiation. Based on the Geant4-DNA toolkit, this study constructed a DNA geometric model containing 6.32Gbp, simulated the relationship between radiochemical yields (G-values) and their corresponding chemical constructors, and calculated a detailed calculation of the sources of damage and the complexity of damage in DNA strand breaks. The damage model constructed in this study can simulate the relative biological effectiveness (RBE) in the proton Bragg peak region. The results indicate that: (1) When the electron energy is below 400 keV, the yield of OH· account for 18.1% to 25.3% of the total water radiolysis yields. (2) Under the influence of histone clearance function, the yield of indirect damage account for over 72.93% of the yield of DNA strand breaks (SBs). When linear energy transfer (LET) increased from 29.79 (keV/μm) to 64.29 (keV/μm), the yield of double strand breaks (DSB) increased from 17.27% to 32.65%. (3) By investigating the effect of proton Bragg peak depth on the yield of direct DSB (DSBdirect) and total DSB (DSBtotal), the RBEDSBtot and RBEDSBdir levels of cells show that the RBE value of protons reaches 2.2 in the Bragg peak region.

Protection of children’s personal data in social networks in the context of the right to be forgotten

The article is devoted to a legal analysis of the protection of the confidentiality of children’s personal data on social networks in the context of the right to be forgotten and the General Data Protection Regulation. It is established that most social networks have their own usage rules, but their priority is to attract more users and company profit rather than the security of users’ personal data. Legal mechanisms for the implementation and protection of human rights in the digital environment are in the process of formation and improvement. It is proven that the application of the right to be forgotten has become one of the forms of personal data protection in social networks and on the Internet in general. Although initially the right to erasure emerged only at the level of the judicial practice of the Court of Justice of the EU, an effective mechanism has now been created to protect the individual’s right to delete outdated information about themselves, taking into account the balance between the right to privacy and the right to freedom of expression. Due to psychological immaturity and limited life experience, children and adolescents may casually disclose sensitive personal information, increasing the likelihood of abuse by both social networks and third parties. Therefore, minors receive special protection as vulnerable user categories according to the General Data Protection Regulation. It is argued that the incorporation of the right to be forgotten into EU legislation helps eliminate undesirable consequences of oversharing and restores minors’ ability to control their digital footprint. The terms of service of most social networks ensure additional protection of minors’ data and provide several options for deleting already disseminated information. Obstacles to the application of the right to be forgotten in social networks are identified, such as the lack of a developed mechanism for deleting photos or videos with minors published without the consent of the child or their parents by another user, the limited ability of users under 13 years old to request deletion without intermediaries, and the limited liability of social networks for the loss of information, data, and direct or indirect damages from such actions.

Alternative and Classical Processes for Disinfection of Water Polluted by Fungi: A Systematic Review

The introduction of the first list of priority pathogenic fungi by the World Health Organization stresses the need to research and develop public health actions to mitigate infections caused by fungi. One of those actions involves the water disinfection systems, which comprise classical and alternative methods that have been developed in the last decades. Thereby, this work reviews the disinfection of fungi by classical methods such as chlorination, ozonation, and ultraviolet (UV) treatments and alternative advanced oxidation processes (AOPs) such as photo-Fenton, photocatalysis, or couplings of UV with peroxides. The matrices of aquatic systems (sewage, groundwater, drinking water, among others) were considered. A bibliometric analysis is performed initially, and then some aspects of the resistance to antifungals are presented, and the efficiency of the diverse processes in the reduction in fungal loading is also revised. Herein, it is shown the role of the disinfecting agents (e.g., chlorine, hydroxyl radical, or light) and their effects on fungi structures (e.g., direct DNA damage, or indirect damage due to the action of radicals). Moreover, gaps, such as the treatment of antifungal-resistant fungi and limited information about combinations among AOPs, related to the disinfection of water polluted by fungi, were identified.

Assessment of early DNA damage induced in human fibroblasts by four therapeutic radionuclides using Geant4-DNA

PurposeQuantifying the initial damage induction is necessary to understand the dependence of the late effects on radiation quality. This study was conducted to better understand the effects of therapeutic radionuclides on human cells and to improve the therapeutic efficacy of TRT. MethodsIn this study, early direct and indirect DNA damage induced by four widely used therapeutic radionuclides (Y-90, I-131, Lu-177, and I-125) in human fibroblasts was investigated using Geant4 DNA. The relative effects of direct and indirect damage induction on DNA and human cells were evaluated using complexity and source classification. In addition, we performed an analysis of the histogram of fragment length distribution for therapeutic radionuclides. ResultsThe results of this study showed that the highest single-strand break (SSB) and double-strand break (DSB) yields based on source classification are due to the relative effects of indirect damage induction on DNA and human cells. Radionuclide I-131 has the highest yield of SSB, while I-125 has the highest yield of DSB. On the other hand, Y-90 has the lowest SSB and DSB yield values. The study also revealed that I-125 has the highest fragment length distribution, while Y-90 has the lowest. ConclusionAmong the therapeutic radionuclides, I-131 and I-125 had the greatest effect on SSB and DSB yield values, respectively, while Y-90 had little effect.

Impact of COVID-19 on healthcare utilization among chronic disease patients in South Korea

BackgroundFrom 2020 to 2022, South Korea has experienced significant direct and indirect damage because of the coronavirus pandemic. Preventive measures aimed at controlling the spread of the virus have inadvertently limited healthcare accessibility for patients without COVID-19, leading to detrimental consequences, particularly for patients with chronic diseases. Hence, there is a growing need to comprehensively examine the changes in healthcare utilization among patients with chronic diseases owing to the COVID-19 pandemic, along with the associated factors and health outcomes. MethodsTo examine changes in healthcare utilization among patients with chronic diseases and their impact on health outcomes, we used the NHIS database. Logistic regression analysis was used to investigate changes in healthcare utilization, and a two-part model was applied to explore the effects of reduced healthcare utilization on hospitalization status and length of hospital stay. ResultsSince the onset of the pandemic, the likelihood of hospitalization has been 1.10 times higher than that during pre-pandemic times in the population groups with a 20 % decrease in outpatient healthcare utilization. Notably, individuals belonging to the low-income group exhibited a 1.77-fold higher likelihood of hospitalization than those in the high-income group. Furthermore, in cases where hospitalization could have been avoided, low-income individuals had an extended hospital stay of 16.7 days compared with high-income individuals. ConclusionThere is a need for a more proactive approach for classifying patients with chronic diseases based on various vulnerability factors to effectively respond to future novel infectious diseases and reduce the long-term burden on the nation.

Thyroiditis and COVID-19: focus on pediatric age. A narrative review.

In light of the growing concern over the possible link between SARS-CoV2 infection and autoimmune diseases, we conducted a review to investigate the impact of the pandemic outbreak on thyroid diseases. We carried out a narrative review of all pediatric cases described in the literature, mainly focusing on the possible association of COVID-19 with the incidence of autoimmune and post-infective thyroid diseases (namely Hashimoto's Thyroiditis (HT), Grave's Disease (GD) and Sub-Acute Thyroiditis (SAT)). We also felt it was necessary to provide a brief review of Non-thyroidal Illness Syndrome (NTIS) and Multisystem Inflammatory Syndrome in Children (MIS-C) because of their overlap with thyroiditis. There is currently no conclusive evidence linking SARS-CoV-2 infection with an increased incidence of autoimmune thyroiditis (AT) in pediatric age. However, SAT may be a mild complication of SARS-CoV-2 infection, as is the case with other viral infections. SAT typically resolves on its own and does not require treatment. NTIS may be associated with inflammatory complications, such as MIS-C, and admission to intensive care. It may also be considered a prognostic risk factor for severe disease. The hypothesized pathogenetic mechanisms of thyroid damage in COVID-19 include direct damage due to the significant expression of angiotensin-converting enzyme 2 (ACE2) in the thyroid gland, which is a ligand for the virus, and indirect damage due to immune dysregulation, such as the overproduction of IL-6, which is thought to be part of the pathogenesis of thyroiditis. However, due to the limited evidence available, further prospective longitudinal studies are required to clarify the relationship between COVID-19 and thyroid disease in children and adolescents, as well as to investigate any potential long-term consequences.

The Surprising Diversity of UV‐Induced Mutations

AbstractUltraviolet (UV) light is the most pervasive environmental mutagen and the primary cause of skin cancer. Genome sequencing of melanomas and other skin cancers has revealed that the vast majority of somatic mutations in these tumors are cytosine‐to‐thymine (C&gt;T) substitutions in dipyrimidine sequences, which, together with tandem CC&gt;TT substitutions, comprise the canonical UV mutation “signature”. These mutation classes are caused by DNA damage directly induced by UV absorption, namely cyclobutane pyrimidine dimers (CPDs) or 6‐4 pyrimidine‐pyrimidone photoproducts (6‐4PP), which form between neighboring pyrimidine bases. However, many of the key driver mutations in melanoma do not fit this mutation signature, but instead are caused by T&gt;A, T&gt;C, C&gt;A, or AC&gt;TT substitutions, frequently occurring in non‐dipyrimidine sequence contexts. This article describes recent studies indicating that UV light causes a more diverse spectrum of mutations than previously appreciated, including many of the mutation classes observed in melanoma driver mutations. Potential mechanisms for these diverse mutation signatures are discussed, including UV‐induced pyrimidine‐purine photoproducts and indirect DNA damage induced by UVA light. Finally, the article reviews recent findings indicating that human DNA polymerase eta normally suppresses these non‐canonical UV mutation classes, which can potentially explain why canonical C&gt;T substitutions predominate in human skin cancers.