95th Percentile Research Articles

Hemoglobin A1c Genetics and Disparities in Risk of Diabetic Retinopathy in Individuals of Genetically Inferred African American/African British and European Ancestries.

Individuals with diabetes who carry genetic variants that lower hemoglobin A1c (HbA1c) independently of glycemia may have higher real, but undetected, hyperglycemia compared with those without these variants despite achieving similar HbA1c targets, potentially placing them at greater risk for diabetes-related complications. We sought to determine whether these genetic variants, aggregated in a polygenic score, and the large-effect African ancestry-specific missense variant in G6PD (rs1050828) that lower HbA1c were associated with higher retinopathy risk. Using data from 29,828 type 2 diabetes cases of genetically inferred African American/African British and European ancestries, we calculated ancestry-specific nonglycemic HbA1c polygenic scores (ngA1cPS) composed of 122 variants associated with HbA1c at genome-wide significance, but not with glucose. We tested the association of the ngA1cPS and the G6PD variant with retinopathy, adjusting for measured HbA1c and retinopathy risk factors. Participants in the bottom quintile of the ngA1cPS showed between 20% and 50% higher retinopathy prevalence, compared with those above this quintile, despite similar levels of measured HbA1c. The adjusted meta-analytic odds ratio for the bottom quintile was 1.31 (95% CI 1.0, 1.73; P = 0.05) in African ancestry and 1.31 (95% CI 1.15, 1.50; P = 6.5 × 10-5) in European ancestry. Among individuals of African ancestry with HbA1c below 7% units, retinopathy prevalence was higher in individuals below, compared with above, the 50th percentile of the ngA1cPS regardless of sex or G6PD carrier status. Genetic effects need to be considered to personalize HbA1c targets and improve outcomes of people with diabetes from diverse ancestries.

Adverse Associations of Long-Term Exposure to PM2.5 and Its Components with Platelet Traits among Subway Shift-Workers without Air Purifier Use

Air purifier use, shift work, and long-term exposure to fine particulate matter (PM2.5) are linked to platelet abnormality. However, the role of air purifier use and shift work in the individual or joint associations of PM2.5 and its components with platelet indices are largely unknown. A total of 8772 participants were recruited from a population of subway workers in China. PM2.5 and its component data were obtained from the Tracking Air Pollution in China dataset. The role of air purifier use and shift work in the association between PM2.5 and its components and platelet indices were analyzed. Among shift workers without air purifier use, positive associations of PM2.5 and each component in PM2.5 with the mean platelet volume (MPV) or platelet counts (PLT) were observed, whereas negative associations of PM2.5 and each component in PM2.5 with the platelet distribution width (PDW) were observed. Furthermore, estimated changes (95%CIs) in PLT, MPV, and PDW in response to each 10th percentile increment in the mixture of PM2.5 and its components were 0.8657 (0.2496, 1.4819), 0.0192 (0.0054, 0.0329), and −0.0648 (−0.0945, −0.0351), respectively, and sulfate in PM2.5 was the major contributor to those associations. Long-term exposure to PM2.5 and its components was related to increased platelet disorders among shift workers without air purifier use, and those associations were mainly attributed to sulfate in PM2.5.

Small for Gestational Age Calves: Part I-Concept and Definition, Contributing Prenatal Factors and Neonatal Body Morphometrics in Holstein Friesian Calves.

Low birth weight (BW) calves exhibit higher mortality rates, reduced body weights at parturition, lower first-lactation milk yields, and longer parturition to first insemination intervals. In human medicine, small for gestational age (SGA) births are associated with increased perinatal morbidity and long-term metabolic risks. This study aimed to define SGA in Holstein Friesian (HF) calves, evaluate their body measurements and proportions, and identify its prenatal risk factors. Four linear regression models were built with weight as a function for gestation length for bull and heifer calves born from nulli- or multiparous dams. Calves with a BW below the 10th percentile were classified as SGA. Differences in body measurements were analyzed using ANOVA, and logistic regression models identified prenatal risk factors to be born SGA. Gestation length, calf sex, and dam parity were crucial variables in defining SGA. SGA calves had significantly smaller body measurements (p < 0.001) and larger body proportions (p < 0.001) compared to average and large calves. For nulliparous dams, a higher 2nd trimester temperature-humidity index (p = 0.032) and older age at parturition (>26 months, p = 0.026) significantly increased the birth of SGA calves. For multiparous dams, both low (<5800 kg, p = 0.049) and high (6700-8600 kg, p = 0.027) milk yields during gestation lead to more SGA births, although very high-yielding dams (>8600 kg) did not birth more SGA calves. This study establishes SGA in HF calves, suggests SGA calves are asymmetrical with evidence of "brain sparing", and highlights the impact of prenatal factors on calf size at birth. Further research is needed to determine the long-term effects of being born SGA on growth, reproductive performance, and productivity.

High Healthcare Costs in Childhood Inflammatory Bowel Disease: Development of a Prediction Model Using Linked Clinical and Health Administrative Data.

The incidence of pediatric-onset inflammatory bowel disease (IBD) and the costs of caring for individuals with IBD are both increasing. We calculated the direct healthcare costs of pediatric IBD in the first year after diagnosis and developed a model to predict children who would have high costs (top 25th percentile). Using data from the Canadian Children IBD Network inception cohort (≤16 years of age, diagnosed between 2013 and 2019) deterministically linked to health administrative data from Ontario, Canada, we estimated direct healthcare and medication costs accrued between 31 and 365 days after diagnosis. Candidate predictors included age at diagnosis, sex, rural/urban residence location, distance to pediatric center, neighborhood income quintile, IBD type, initial therapy, disease activity, diagnostic delay, health services utilization or surgery around diagnosis, regular primary care provider, and receipt of mental health care. Logistic regression with stepwise elimination was used for model building; 5-fold nested cross-validation optimized and improved model accuracy while limiting overfitting. The mean cost among 487 children with IBD was CA$15 168±15 305. Initial treatment (anti-tumor necrosis factor therapy, aminosalicylates, or systemic steroids), having a mental health care encounter, undergoing surgery, emergency department visit at diagnosis, sex, and age were predictors of increased costs, while having a regular primary care provider was a predictor of decreased costs. The C-statistic for our model was 0.71. The cost of caring for children with IBD in the first year after diagnosis is immense and can be predicted based on characteristics at diagnosis. Efforts that mitigate rising costs without compromising quality of care are needed.

Electroconvulsive Therapy With Brain Cyst: A Simulation Study.

Electroconvulsive therapy (ECT) is effective in treating severe depression and other neuropsychiatric disorders, but how the presence of an anatomical anomaly affects the electrical pathways between the electrodes remains unclear. We investigate the difference in electric field (E-field) distribution during ECT in the brain of a patient with an arachnoid cyst relative to hypothetical condition where the cyst was not present. Magnetic resonance imaging scans of the head of a patient with a large left frontal cyst were segmented to construct a finite element model to study the E-field distribution during ECT. Five electrode configurations were investigated: right unilateral, left unilateral, bifrontal, and bitemporal and left anterior right temporal. The E-field distributions for all montages were compared with a hypothetical condition where brain tissue and electrical conductivity from the right frontal region was mirrored across the longitudinal fissure into the cyst. Differences in mean E-field and 90th percentile E-fields were mainly observed in brain regions closest to the cyst including the left inferior frontal gyrus and left middle frontal gyrus. This trend was most pronounced in montages where the electrodes were closest to the cyst such as left unilateral and bitemporal. The presence of a highly conductive cyst close to the ECT electrode tended to attract current into the cyst region, altering current pathways, with potential implications for therapeutic efficacy and safety. Placing electrodes farther away from the cyst is likely to minimize any effects on the E-field distribution and potentially clinical outcomes.

Coagulation profiles and percentiles in neonates with hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia: A step toward more accurate transfusion thresholds.

In the literature, there are no studies about the transfusion threshold for neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). In order to facilitate accurate interpretation of coagulation results in these neonates, we aimed to generate specific reference intervals in this specific population. This retrospective study included all HIE neonates admitted from 2014 to 2022 to undergo TH. All infants during TH underwent blood exams, including the coagulation profile. Our primary outcome was to assess the estimates of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles for each parameter on admission (before transfusion). By the receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) and the best cut-off point were used to evaluate the ability of the prothrombin time expressed as international normalized ratio (PT-INR) to predict the risk of any bleeding. A total of 143 infants were included in this study. On admission, the median fibrinogen value was 205mg/dL, prothrombin time 18.6seconds, PT-INR 1.50, activated partial thromboplastin time 38.3seconds, thrombin time 18.6seconds, antithrombin 57.0%. The optimal cut-off of PT-INR in predicting the risk of any bleeding was greater than 1.84 (AUC.623, p=.024). For the first time, we proposed the percentiles of coagulation parameters in our cohort of neonates with HIE. Furthermore, we found that a PT-INR greater than 1.84 can significantly predict the risk of any bleeding. Further studies are needed to determine if a restrictive versus a liberal transfusion approach can be equally safer for these high-risk infants.

Association between lipoprotein(a), fibrinogen and their combination with all-cause, cardiovascular disease and cancer-related mortality: findings from the NHANES

BackgroundThere is evidence indicating that both lipoprotein(a) [Lp(a)] and fibrinogen (FIB) are associated with mortality, However, the impact of their combination on mortality has not been determined. Thus, the aim of this study was to examine the association between the combination of Lp(a) and FIB with all-cause and cause-specific mortality.MethodsThis prospective cohort study enrolled 4,730 participants from the third National Health and Nutrition Examination Survey. The exposure variables included Lp(a), FIB and their combination, while the outcome variables consisted of all-cause, cardiovascular disease (CVD) and cancer-related mortality. Multivariate COX regression, subgroup analysis, sensitivity analysis and restricted cubic spline (RCS) were used to investigate the association between Lp(a), FIB and their combination with all-cause, CVD and cancer-related mortality.ResultsOver a median follow-up period of 235 months, 2,668 individuals died, including 1,051 deaths attributed to CVD and 549 deaths due to cancer. Multivariate Cox regression analyses revealed independent associations between both Lp(a) and FIB with all-cause, CVD, and cancer-related mortality. Compared to participants in the 1st to 50th percentiles of both Lp(a) and FIB, those in the 90th to 100th percentiles exhibited multivariable adjusted HRs of 1.813 (95% CI: 1.419–2.317, P < 0.001), 2.147 (95% CI: 1.483–3.109, P < 0.001) and 2.355 (95% CI: 1.396, 3.973, P = 0.001) for all-cause, CVD and cancer-related mortality, respectively. Subgroup and sensitivity analyses did not substantially attenuate the association between the combination of high Lp(a) and high FIB with the risk of all-cause and CVD-related mortality. Additionally, the RCS analysis showed that the relationship between Lp(a) and the risk of all-cause and cancer-related mortality, as well as the relationship between FIB and the risk of cancer-related mortality, were linear (P for nonlinearity > 0.05). Conversely, the relationship between Lp(a) and the risk of CVD-related mortality, as well as the relationship between FIB and the risk of all-cause and CVD-related mortality, were nonlinear (P for nonlinearity < 0.05).ConclusionsHigh levels of Lp(a) and FIB together conferred a greater risk of mortality from all-cause, CVD and cancer.

&lt;i&gt;IGF1R&lt;/i&gt; rs907806 and &lt;i&gt;GHSR&lt;/i&gt; rs572169 genetic variants in fetal macrosomia

BACKGROUND: Being strongly affected by maternal and fetal genetic factors, intrauterine environment plays a critical role in fetal growth. Intrauterine conditions, in turn, are largely determined by the genetic factors. AIM: The aim of this study was to evaluate the effect of the IGF1R rs907806 and GHSR rs572169 genetic variants on the weight of newborns. MATERIALS AND METHODS: This prospective study included 221 mother-newborn pairs. The inclusion criteria were singleton pregnancy and informed consent to participate in the study. The exclusion criteria were severe somatic, oncological and acute illnesses three months prior or during pregnancy, gestational diabetes mellitus, refusal to participate in the study at any stage, and insufficient data. The study groups included patients with type 1 diabetes mellitus (group I), type 2 diabetes mellitus (group II), and no carbohydrate metabolism disorders (group III). Cord blood samples were obtained after delivery. The IGF1R rs907806 and GHSR rs572169 genotypes were determined by polymerase chain reaction with restriction fragment length polymorphism analysis. The main outcomes were delivery of a large for gestational age fetus (weight of more than the 90th percentile INTERGROWTH-21st). The secondary outcomes were diabetic fetopathy, diabetic cardiomyopathy, and neonatal hypoglycemia. RESULTS: In group III, the minor G allele of the IGF1R rs907806 variant was more frequent in large-for-gestational-age newborns (p = 0.017; odds ratio 3.039; 95% confidence interval 1.244–7.424) than in those with a weight of less than 90th percentile. For the GHSR rs572169 variant, no similar trend was observed. This pattern was pronounced in the male newborns only (rs907806 AA vs. AG+GG; p = 0.046; odds ratio 4.229, 95% confidence interval 1.181–15.139). In newborns with hypoglycemia, a higher frequency of the GG genotype of the GHSR rs572169 (GA) variant was observed in the total sample (p = 0.004) and the type 1 diabetes mellitus group (p = 0.0496). CONCLUSIONS: The IGF1R rs907806 variant may affect birthweight in the male newborns of mothers without carbohydrate metabolism disorders. The observed association of neonatal hypoglycemia with the GG genotype of the GHSR rs572169 variant requires further investigation. Genetic factors can contribute to prognostic models of perinatal complications, while improving their early diagnosis opportunities.

Population-wide eGFR percentiles in younger adults and clinical outcomes.

Identifying meaningful estimated glomerular filtration rate (eGFR) reductions in younger adults (<65 years) could guide prevention efforts. To aid in interpretation and identification of young adults at risk, we examined the association of population-level eGFR percentiles relative to the median by age and clinical outcomes. We conducted a retrospective cohort study of 8.7 million adults from Ontario, Canada from age 18 to 65 from 2008 to 2021 with an eGFR measure (both single outpatient value and repeat measures). We calculated median eGFR values by age and examined the association of reduced eGFR percentiles (≤10th, 5th, 2.5th and 1st) with outcomes using time to event models. Outcomes were a composite of all-cause mortality, major adverse cardiac outcomes (MACE) with/without heart failure (MACE+) and kidney failure as well as each component individually. From age 18 to 65, the median eGFR declined with age (range 128 to 90) and across percentiles [eGFR ranges 102 to 68 for ≤10th, 96 to 63 for ≤5th, 90 to 58 for ≤2.5th and 83 to 54 for 1st]. The adjusted rate for any adverse outcome was elevated at ≤ 10th percentile (HR 1.14 95%CI 1.10-1.18) and was consistent for all-cause mortality, MACE, MACE+ and predominant for kidney failure (HR 5.57 95%CI 3.79-8.19) compared to the median eGFR for age. Young adults with an eGFR in the lower percentiles were less likely to be referred to a specialist, have a repeat eGFR or albumin to creatinine ratio measure. eGFR values at the 10th percentile or lower based on a population-level distribution are associated with adverse clinical outcomes and in younger adults (18 to 39) this corresponds to a higher level of eGFR that may be underrecognized. Application of population-based eGFR percentiles may aid interpretation and improve identification of younger adults at risk.

Assessment of Gross Motor Skills in Ponseti-treated Children With Idiopathic Clubfoot at 3 Years Old: Insights from the Peabody Developmental Motor Scale 2.

Congenital talipes equinovarus, or clubfoot, can lead to lifelong functional impairments, including diminished gross motor skills (GMS), if left untreated. The Ponseti method corrects idiopathic clubfoot through casting and bracing. Given the importance of GMS in childhood development, this technique must be optimized to support childhood and long-term health outcomes. This study examined immediate posttreatment GMS in 3-year-old children treated with Ponseti, hypothesizing that they would perform on par with their nonclubfoot peers. Data from 45 children (33 to 46mo of age) treated for idiopathic clubfoot were analyzed. The Peabody Developmental Motor Scales, 2nd edition, was used to assess GMS, and logistic regression identified factors influencing Gross Motor Quotient (GMQ) scores. Approximately half (n=22) of the patients exhibited below-average GMS (11th to 25th percentile), with 11 scoring below the 10th percentile. Initial deformity severity, gender, and cast numbers did not impact GMQ. Repeat percutaneous tenotomy was associated with lower GMQs. Brace compliance significantly reduced odds of low GMQs by up to 80%. Age at testing and additional surgery were also linked to below-average and poor GMQs. GMS appeared to be impaired in almost half of the 3-year-old patients treated for idiopathic clubfoot, so our hypothesis was disproven. Repeat percutaneous tenotomy was associated with lower GMS, necessitating future recognition of patients who might be at risk of relapse. Brace noncompliance emerged as a significant risk factor, emphasizing early identification of these patients and education for their parents. This study offers a benchmark for clinicians and parents, but research on long-term outcomes is needed. Level II, prospective cohort study.

Phonological assessment for Greek (PAel) test: Reliability and validity in 4-to 6-year-old preschool children

ABSTRACT Single-word phonological tests are widely used for detecting children at risk for Speech Sound Disorders (SSDs). However, specific conceptual and operational criteria should be evaluated to ensure that these assessments are valid and reliable and can serve as diagnostic tools. The current study aimed to investigate the validity and reliability of the screener of a phonological Greek instrument, named the Phonological Assessment for Greek (PAel) comparing the phonological performance of typically developing (TD) children and children with SSDs, aged 4 to 6 years. The participants were 20 TD children and 40 children with SSDs. All participants completed the screener of PAel, the 70-word list of the standardised Test of Phonetic and Phonological Development (TPPD), and a language test, namely the Action Picture Test. Participants who scored below the 25th percentile on the language test were excluded. Phonological analysis revealed that PAel has high content validity. The participants who had received a diagnosis of SSDs presented restricted consonant and cluster inventories and significantly lower whole-word match levels in comparison to their TD peers. The overall Spearman’s correlation coefficients between PAel and TPPD were 0.611 for TD children (p < 0.001) and 0.875 for children with SSDs (p < 0.001), indicating good criterion validity. The tool demonstrated strong test-retest reliability and inter-rater reliability with Spearman values exceeding 0.85, and Intra-class correlation coefficients over 0.90. Overall, the results suggest that PAel has satisfactory reliability and validity and can be used as an assessment tool to detect children at risk for SSDs.

Determining cut-off scores for simulated tasks in Brazilian Air Force military personnel

IntroductionCombat readiness assessments through simulated tasks (STs) have been developed for the Brazilian Air Force (BAF) to establish physical employment standards. Previous research has established BAF critical combat tasks with...

Argentine and World Health Organization head circumference standards: A comparison study.

Introduction. Several studies have shown population differences in head circumference (HC) that question the universal validity of the World Health Organization (WHO) standard to assess head growth. Objectives. To compare the Argentine reference charts for HC from 0 to 5 years of age with the WHO standards. Population and methods. The 3rd and 97th percentiles for HC based on the Argentine reference charts were compared with the corresponding WHO standard and the percentage of children classified as having microcephaly (HC < 3rd percentile of the WHO) and macrocephaly (HC > 97th percentile of the WHO) at specific ages between 0 and 5 years were estimated. Results. The comparison of the Argentine reference charts with the WHO standards shows that, in both males and females, at the 3rd percentile, the Argentine reference charts are below the WHO standards from 1 to 6 months of age, similar from 9 to 18 months of age, and then above until 60 months old. In relation to the 97th percentile, the Argentine reference charts are above the WHO standards from birth to 60 months in both boys and girls. Conclusions. The head size of Argentine children is different from that established by the WHO standards. The adoption of the WHO standards for our population increases the percentage of macrocephaly diagnosis at all ages.

Normative data for the squat, bench press and deadlift exercises in powerlifting: Data from 809,986 competition entries

ObjectivesStrength assessment and comparison to normative values are an important benchmarking and diagnostic tool in human health and performance. However, population specific normative data are often several decades old, often lack information about adolescent and adult strength levels and are not representative of the strength levels of strength trained individuals. The purpose of this study was to develop contemporary strength norms for the squat, bench press, and deadlift using powerlifters competing in un-equipped, drug-tested competitions. DesignRetrospective cross-sectional analysis. MethodsRetrospective data from global drug-tested, unequipped powerlifting competitions were collated with 809,986 samples (571,650 males, 238,336 females) included. Strength was assessed according to sex, United Nations age classifications, and competitive powerlifting weight class. Strength was expressed relatively (ratio of weight lifted/bodyweight) and computed for the 10th–90th percentile for each of the above categories. ResultsRelative strength was greatest for young adults (18–35 years; 90th percentile for squat [male: 2.83 × bodyweight, female: 2.26], bench press [male: 1.95, female: 1.35], deadlift [male: 3.25, female: 2.66]) before declining thereafter for all three exercises. Although lower than their younger counterparts, very old adults (>80 years) had 90th percentile data for the squat of male: 1.72 and female: 1.01, bench press: male: 1.31 and female: 0.92, and deadlift: male: 2.30 and female: 1.68. Relative strength was also greatest for the lightest female and male weight classes, respectively. ConclusionsThese findings provide a comprehensive, accurate and precise representation of strength for drug-tested, unequipped powerlifters in each category and serve as a point of reference for other trained population groups. To facilitate uptake and ease of comparison, we have developed a freely available online tool.

Estimation of Individual Positive Anti-Islet Autoantibodies from 3 Screen ICA Titer.

The 3 Screen ICA ELISA is a novel assay capable of simultaneously measuring autoantibodies to glutamic acid decarboxylase (GADA), insulinoma-associated antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A), making it a valuable tool for screening type 1 diabetes. Despite its advantages, it cannot specify which individual autoantibodies are positive or negative. This study aimed to estimate individual positive autoantibodies based on the 3 Screen ICA titer. Six hundred seventeen patients with type 1 diabetes, simultaneously measured for 3 Screen ICA and three individual autoantibodies, were divided into five groups based on their 3 Screen ICA titer. The sensitivities and contribution rates of the individual autoantibodies were then examined. The study had a cross-sectional design. Sixty-nine percent (424 of 617) of patients with type 1 diabetes had 3 Screen ICA titers exceeding the 99th percentile cut-off level (20 index). The prevalence of GADA ranged from 80% to 100% in patients with a 3 Screen ICA over 30 index and 97% of patients with a 3 Screen ICA ≥300 index. Furthermore, the prevalence of all individual autoantibodies being positive was 0% for ≤80 index and as high as 92% for ≥300 index. Significant associations were observed in specific titer groups: the 20-29.9 index group when all the individual autoantibodies were negative, the 30-79.9 index group when positive for GADA alone or IA-2A alone, the 30-299.9 index group when positive for ZnT8A alone, the 80-299.9 index group when positive for both IA-2A and ZnT8A, the 300-499.9 index group when positive for both GADA and ZnT8A, and the ≥300 index group when positive for all individual autoantibodies. These results suggest that the 3 Screen ICA titer may be helpful in estimating individual positive autoantibodies.

Utility of block-matching and 3D filter for reproducibility of lung density and denoising in low-dose chest CT: A pilot study

PurposeThis study aimed to acquire an image quality consistent with that of full-dose chest computed tomography (CT) when obtaining low-dose chest CT images and to analyze the effects of block-matching and 3D (BM3D) filters on lung density measurements and noise reduction in lung parenchyma. MethodsUsing full-dose chest CT images, we evaluated lung density measurements and noise reduction in lung parenchyma images for low-dose chest CT. Three filters (median, Wiener, and the proposed BM3D) were applied to low-dose chest CT images for comparison and analysis with images from full-dose chest CT. To evaluate lung density measurements, we measured CT attenuation at the 15th percentile of the lung CT histogram. The coefficient of variation (COV) and contrast-to-noise ratio (CNR) were used to evaluate the noise level. ResultsThe 15th percentile of the lung CT histogram showed the smallest difference between full- and low-dose CT when applying the BM3D filter, and the highest difference between full- and low-dose CT without filters (full-dose = − 926.28 ± 0.32, BM3D = − 926.65 ± 0.32, and low-dose = − 959.43 ± 0.95) (p < 0.05). The COV was smallest when applying the BM3D filter, whereas the CNR was the highest (p < 0.05). ConclusionsThe results of the study prove that the BM3D filter can reduce image noise while increasing the reproducibility of the lung density, even for low-dose chest CT.

Evaluation of concentration and characterization of potential toxic elements and fluorine in ambient air dust from Iran’s industrial capital: A health risk assessment using Monte Carlo simulation

The emission and adsorption of mineral elements to dust from geogenic and anthropogenic sources are health challenges in residential areas. This study investigated, for the first time to the best of our knowledge, the presence of potentially toxic elements (PTEs), rare earth elements (REE) and fluorine (F) in collected dust samples from central Iran. Their associated health risks were estimated based on the Monte Carlo simulation. Results show that the morphology of the collected dust was uniform spherical particles and the predominant elements were Si and Ca. The highest concentration of PTEs was for Ca (mean: 36574 mg/kg) and Fe (mean: 30189 mg/kg) and the mean concentrations of As, Ni, Pb, Mn and Zn exceeded World Health Organization (WHO) guidelines, likely due to the anthropogenic activities such as metal melt factories. Fluorine averaged 159.4 mg/kg, and some detected elements originated from industrial and natural sources. The 5th, 50th, and 95th percentiles of the estimated Hazard Index (HI) were 0.13, 0.43, and 0.77, respectively, in adults and 1.00, 3.03, and 5.99, respectively, in children. The carcinogenic risk (LTCR) for adults and children exceeded the safety range (1 × 10−4), and their highest percentile was calculated at about 2.03 × 10−4 and 1.83 × 10−4, respectively. Furthermore, Ni was the most effective elements in LTCR. As a consequence, findings suggest a high potential carcinogenic risk due to the emission of dust in central Iran, especially for children, and the controlling of possible sources would benefit public health.

Merging TROPOMI and eddy covariance observations to quantify 5-years of daily CH4 emissions over coal-mine dominated region

A simple and flexible mass balance approach was applied to observations of XCH4 from TROPOMI to estimate CH4 emissions over Shanxi Province, including the impacts of advective transport, pressure transport, and atmospheric diffusion. High-frequency eddy-covariance flux observations were used to constrain the driving terms of the mass balance equation. This equation was then used to calculate day-to-day and 5 km × 5 km grided CH4 emissions from May 2018 to July 2022 based on TROPOMI RPRO column CH4 observations. The Shanxi-wide emissions of CH4, 126 ± 58.8 ug/m2/s, shows a fat tail distribution and high variability on a daily time scale (the 90th percentile is 2.14 times the mean and 2.74 times the median). As the number of days in the rolling average increases, the change in the variation decreases to 128 ± 35.7 ug/m2/s at 10-day, 128 ± 19.8 ug/m2/s at 30-day and 127 ± 13.9 ug/m2/s at 90-day. The range of values of the annual mean emissions on coal mine grids within Shanxi for the years 2018 to 2022 was 122 ± 58.2, 131 ± 71.2, 111 ± 63.6, 129 ± 87.1, and 138 ± 63.4 ug/m2/s, respectively. The 5-year average emissions from TROPOMI are 131 ± 68.0 ug/m2/s versus 125 ± 94.6 ug/m2/s on the grids where the EDGAR bottom-up database also has data, indicating that those pixels with mines dominate the overall emissions in terms of both magnitude and variability. The results show that high-frequency observation-based campaigns can produce a less biased result in terms of both the spatial and temporal distribution of CH4 emissions as compared with approaches using either low-frequency data or bottom-up databases, that coal mines dominate the sources of CH4 in Shanxi, and that the observed fat tail distribution can be accounted for using this approach.

Merging TROPOMI and eddy covariance observations to quantify 5-years of daily CH4 emissions over coal-mine dominated region

A simple and flexible mass balance approach was applied to observations of XCH4 from TROPOMI to estimate CH4 emissions over Shanxi Province, including the impacts of advective transport, pressure transport, and atmospheric diffusion. High-frequency eddy-covariance flux observations were used to constrain the driving terms of the mass balance equation. This equation was then used to calculate day-to-day and 5 km × 5 km grided CH4 emissions from May 2018 to July 2022 based on TROPOMI RPRO column CH4 observations. The Shanxi-wide emissions of CH4, 126 ± 58.8 ug/m2/s, shows a fat tail distribution and high variability on a daily time scale (the 90th percentile is 2.14 times the mean and 2.74 times the median). As the number of days in the rolling average increases, the change in the variation decreases to 128 ± 35.7 ug/m2/s at 10-day, 128 ± 19.8 ug/m2/s at 30-day and 127 ± 13.9 ug/m2/s at 90-day. The range of values of the annual mean emissions on coal mine grids within Shanxi for the years 2018 to 2022 was 122 ± 58.2, 131 ± 71.2, 111 ± 63.6, 129 ± 87.1, and 138 ± 63.4 ug/m2/s, respectively. The 5-year average emissions from TROPOMI are 131 ± 68.0 ug/m2/s versus 125 ± 94.6 ug/m2/s on the grids where the EDGAR bottom-up database also has data, indicating that those pixels with mines dominate the overall emissions in terms of both magnitude and variability. The results show that high-frequency observation-based campaigns can produce a less biased result in terms of both the spatial and temporal distribution of CH4 emissions as compared with approaches using either low-frequency data or bottom-up databases, that coal mines dominate the sources of CH4 in Shanxi, and that the observed fat tail distribution can be accounted for using this approach.

Validation of cool-season snowfall forecasts at a high-elevation site in Utah’s Little Cottonwood Canyon

Abstract Producing a quantitative snowfall forecast (QSF) typically requires a model quantitative precipitation forecast (QPF) and snow-to-liquid ratio (SLR) estimate. QPF and SLR can vary significantly in space and time over complex terrain, necessitating fine-scale or point-specific forecasts of each component. Little Cottonwood Canyon (LCC) in Utah’s Wasatch Range frequently experiences high-impact winter storms and avalanche closures that result in substantial transportation and economic disruptions, making it an excellent testbed for evaluating snowfall forecasts. In this study, we validate QPFs, SLR forecasts, and QSFs produced by or derived from the Global Forecast System (GFS) and High-Resolution Rapid Refresh (HRRR) using liquid precipitation equivalent (LPE) and snowfall observations collected during the 2019/20 – 2022/23 cool seasons at the Alta–Collins snow-study site (2945 m MSL) in upper LCC. The 12-h QPFs produced by the GFS and HRRR underpredict the total LPE during the four cool seasons by 33% and 29%, respectively, and underpredict 50th, 75th, and 90th percentile event frequencies. Current operational SLR methods exhibit mean absolute errors of 4.5 – 7.7. In contrast, a locally trained random forest algorithm reduces SLR mean absolute errors to 3.7. Despite the random forest producing more accurate SLR forecasts, QSFs derived from operational SLR methods produce higher critical success indices since they exhibit positive SLR biases that offset negative QPF biases. These results indicate an overall underprediction of LPE by operational models in upper LCC and illustrate the need to identify sources of QSF bias to enhance QSF performance.