EnvironmetricsPub Date : 2026-07-31DOI: 10.1002/env.70125
Qingzhao Yu, Bin Li
{"title":"Bayesian Mediation Analysis With Bayesian Additive Regression Trees","authors":"Qingzhao Yu, Bin Li","doi":"10.1002/env.70125","DOIUrl":"https://doi.org/10.1002/env.70125","url":null,"abstract":"<div>\u0000 \u0000 <p>Understanding how environmental exposures influence health outcomes through biological pathways is critical for environmental risk assessment. We propose a Bayesian mediation analysis framework that integrates Bayesian Additive Regression Trees (BART) to model complex, nonlinear, and high-dimensional relationships among exposures, mediators, and outcomes. The method accommodates multiple mediators, interaction effects, and uncertainty quantification through posterior inference. We introduce two estimation strategies for direct and indirect effects and develop an algorithm for computing the Deviance Information Criterion (DIC) for model evaluation. An open-source R package, <i>bmabart</i>, implements the approach with visualization tools. Simulation studies demonstrate robustness in identifying significant mediators under challenging correlation structures. We apply the method to Louisiana Triple Negative Breast Cancer (TNBC) data, investigating microRNAs that mediate the association between air pollution burden, measured by the Environmental Justice Index, and cancer stage at diagnosis. Results highlight key biomarkers linking environmental exposures to disease progression, offering insights into mechanisms underlying health disparities. This framework provides a flexible and reproducible tool for environmental health research where complex mediation structures are common.</p>\u0000 </div>","PeriodicalId":50512,"journal":{"name":"Environmetrics","volume":"37 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148647818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EnvironmetricsPub Date : 2026-07-31DOI: 10.1002/env.70117
Ronny O. Vallejos
{"title":"Agreement Coefficients for Continuous Variables: A Review","authors":"Ronny O. Vallejos","doi":"10.1002/env.70117","DOIUrl":"https://doi.org/10.1002/env.70117","url":null,"abstract":"<div>\u0000 \u0000 <p>Agreement coefficients provide a fundamental framework for quantifying the concordance between two or more measurement methods applied to the same continuous variable. Unlike correlation, which measures the strength of a linear relationship, agreement focuses on assessing whether measurements are numerically similar, capturing both precision and accuracy. This review provides a comprehensive overview of the primary statistical approaches for assessing agreement between continuous variables. Such a synthesis is timely, as it has been 15–20 years since the last major review in the field. Beginning with the seminal contributions of Bland and Altman (1986) and Lin (1989), the paper discusses extensions of their methods to robust, multivariate, and repeated-measures settings, as well as recent developments like the probability of agreement and measures based on alternative distance functions measures. Special attention is given to probabilistic and spatial generalizations, including frameworks designed for geostatistical and areal data, which have become increasingly relevant in modern applications such as image analysis and environmental statistics. Through illustrative examples and comparative discussions, this review highlights the evolution, connections, and limitations of existing agreement measures, identifying open challenges and directions for future research.</p>\u0000 </div>","PeriodicalId":50512,"journal":{"name":"Environmetrics","volume":"37 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148647819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EnvironmetricsPub Date : 2026-07-30DOI: 10.1002/env.70110
Weiqiang Zheng, Shuguang Liu, Zhengzheng Zhou
{"title":"Quantile Estimation in Rainfall Frequency Analysis With Log-Logistic Distribution Using Pivotal Quantities: Method, Effect, and Application","authors":"Weiqiang Zheng, Shuguang Liu, Zhengzheng Zhou","doi":"10.1002/env.70110","DOIUrl":"https://doi.org/10.1002/env.70110","url":null,"abstract":"<div>\u0000 \u0000 <p>Rainfall frequency analysis commonly presents results as confidence intervals around quantile estimates to account for uncertainty. However, standard bootstrap methods can introduce considerable errors, particularly when sample sizes are small. Focusing on the widely used Log-logistic (LLO) distribution, this study proposes an approach based on pivotal quantities. By generating realizations from three joint pivotal quantities, the method enables the estimation of distribution parameters and return levels along with their associated uncertainties. Its performance is assessed through simulation experiments involving LLO distributions with varying shape parameters, and compared with the basic percentile bootstrap and the bias-corrected and accelerated (BCa) bootstrap methods. The results indicate that the pivotal quantity method generally provides more accurate quantile estimates for both parameters and return levels, while showing lower sensitivity to the characteristics of the underlying distribution. The advantages are particularly evident under conditions commonly encountered in rainfall frequency analysis, such as small sample sizes, high return periods, and extreme confidence levels. The practical utility of the method is illustrated through a case study in Suzhou City, China, which highlights spatial variations in rainfall intensity and underscores the importance of accounting for heavy-tail behavior at rain gauges with large values of the diagnostic variable <i>Q</i><sub><i>k</i></sub>. Overall, the proposed pivotal quantity method provides a promising alternative for improving the reliability of statistical inference in rainfall frequency analysis.</p>\u0000 </div>","PeriodicalId":50512,"journal":{"name":"Environmetrics","volume":"37 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
EnvironmetricsPub Date : 2026-07-29DOI: 10.1002/env.70126
Pierdomenico Duttilo, Francesco Lisi
{"title":"Short-Term CO\u0000 \u0000 \u0000 \u0000 \u0000 \u0000 2\u0000 \u0000 \u0000 \u0000 $$ {}_2 $$\u0000 Emissions Forecasting: Insight From the Italian Electricity Market","authors":"Pierdomenico Duttilo, Francesco Lisi","doi":"10.1002/env.70126","DOIUrl":"https://doi.org/10.1002/env.70126","url":null,"abstract":"<p>This study investigates the short-term forecasting of carbon emissions from electricity generation in the Italian power market. Using hourly data from 2021 to 2023, several statistical models and forecast combination methods are evaluated and compared at the national and zonal levels. Four main model classes are considered: (i) linear parametric models, such as seasonal autoregressive integrated moving average (SARIMA) and its exogenous variable extension; (ii) functional parametric models, including seasonal functional autoregressive models, with and without exogenous variables; (iii) (semi) nonparametric and possibly nonlinear models, notably the generalized additive model (GAM) and TBATS (trigonometric seasonality, Box-Cox transformation, ARMA errors, trend, and seasonality); and (iv) a semi-functional approach based on the K-nearest neighbors. Forecast combinations include simple averaging, the optimal Bates and Granger weighting scheme, and a selection-based strategy that chooses the best model for each hour. The results show that the GAM produces the most accurate forecasts during the daytime hours, while the functional parametric models perform best in the early morning. Among the combination methods, the simple average and the selection-based approaches consistently outperform all individual models. The findings underscore the value of hybrid forecasting frameworks in improving the accuracy and reliability of short-term carbon emissions predictions in power systems. In addition, they highlight the importance of considering zonal specificities when implementing flexible energy demand strategies. The timing of low-carbon emissions varies between market zones throughout the day.</p>","PeriodicalId":50512,"journal":{"name":"Environmetrics","volume":"37 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2026-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/env.70126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148616908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}