Evidence on the effect of maternal mobile phone use on child behavioral development remains inconsistent, particularly regarding the relative importance of the prenatal and early childhood exposure periods. We aimed to examine associations between maternal mobile phone call duration during pregnancy and early childhood and behavioral problems in preschool-aged children. We analyzed data from the Mothers and Children's Environmental Health (MOCEH) prospective birth cohort. Maternal mobile phone use was measured by questionnaire during pregnancy and at ages 3-5 years, and child behavioral problems were assessed using the Korean Child Behavior Checklist (K-CBCL) at ages 4, 5, and 6 years. Maternal daily call duration (minutes/day), used as a proxy indicator of mobile phone use, was calculated from daily call frequency and average duration per call. Associations with behavioral problem scores were estimated using linear mixed-effects models in sub-cohorts with available exposure information for the whole period (n = 780), pregnancy (n = 763), and early childhood (n = 418). Mutually adjusted models accounted for maternal mobile phone use during the other exposure period, with missing information treated as a separate category. Early childhood maternal mobile phone use was significantly associated with higher total (β = 1.37, 95% CI: 0.46-2.28) and externalizing (β = 1.44, 0.54-2.33) problem scores, whereas prenatal use was not. Sex-stratified analyses showed associations for total and externalizing problems in males and internalizing problems in females. These findings suggest that maternal mobile phone use during early childhood, rather than pregnancy, is associated with child behavioral problems, pointing to the caregiving pathways, such as interruptions in parent-child interaction caused by technology use, as a plausible explanation.

The humidifier disinfectant disaster in Korea was one of the most severe environmental health disasters of recent decades. It showed that indoor household chemical products used in daily life can cause fatal health effects at the population level when inhalation risks are not adequately assessed before marketing. The disaster also reaffirmed the central role of epidemiology in detecting emerging environmental health threats and guiding public health responses. Fifteen years after the disaster was recognized, major challenges remain, including defining the full spectrum of health damage, providing compensation, and ensuring long-term support. The Special Act on Remedy for Damage Caused by Humidifier Disinfectants, fully amended in 2026, represents an important institutional advance. By explicitly defining the joint liability of the state and relevant companies, the amended Act reflects a shift toward a more public, state-administered system of compensation and health support. This disaster also highlights the roles of public health professionals in generating epidemiological evidence on delayed or newly recognized diseases and sequelae, applying that evidence in clinical and policy contexts, and establishing life-course–based lifelong health management programs. For the 2026 comprehensive amendment to produce meaningful progress, continued efforts are needed to clarify long-term health effects and refine health data–based surveillance systems so that scientific evidence can be translated effectively into policy.

Background This study assesses the national distribution of ambient fine particulate matter (PM2.5) exposure across socioeconomic status (SES) and its confounding on long-term PM2.5 mortality in Korea, aiming to minimize SES influence.Methods A nationwide cohort of 5% of Koreans, aged 30 or older, from 2007 to 2019, from the National Health Information Database, was analysed. PM2.5 exposure levels were estimated at the city level using the Community Multiscale Air Quality system. Mortality data were obtained from Statistics Korea. The study examined annual PM2.5 exposure by SES indicators and its confounding on mortality risks associated with PM2.5, using time-varying Cox proportional hazards models.Results The study followed 1 453 036 individuals from 2007 to 2019, totalling 17 760 227 person-years (PYs). The non-accidental (A00-R99), cardiovascular (I00-I99) and respiratory (J00-J99) mortality rates per 1000 PY were 7.6, 1.9 and 0.8, respectively. We observed a trend of decreasing PM2.5 exposure levels but increased mortality among medical aid beneficiaries, those with lower household incomes and those residing in neighbourhoods with a higher area deprivation index. When adjusting for these SES covariates, the long-term mortality effects of PM2.5 shifted in the direction of increased risk [hazard ratio (HR) for cardiovascular mortality in the unadjusted model = 0.968 (95% CI: 0.909-0.959); HR in the fully adjusted model = 1.053 (95% CI: 1.004-1.105)].Conclusion In regions where SES and PM2.5 concentrations are positively correlated, as in Korea, it is crucial to rigorously control for SES confounding to avoid underestimating the mortality effects associated with PM2.5.

Polyhexamethylene guanidine phosphate (PHMG-P) is a guanidine-based disinfectant previously used in household humidifiers in Korea. This study evaluated whether PHMG-P exposure is causally linked to pneumonitis by integrating epidemiological, toxicological, and mechanistic evidence. We prespecified an evidence-integration framework aligned with the Office of Health Assessment and Translation/Grading of Recommendations Assessment, Development and Evaluation approaches, and applied the Organisation for Economic Cooperation and Development adverse outcome pathway (AOP) guidance to organize mechanistic evidence. We systematically identified studies and synthesized findings across 3 domains: epidemiology (age-period-cohort [APC], difference-in-differences [DID], and interrupted time-series [ITS] analyses), toxicology (animal and in vitro studies), and mechanism (mapping key events to an AOP). We assessed internal and external validity, coherence, and strength of evidence within and across domains. Epidemiological analyses showed that pneumonitis incidence rose during humidifier disinfectant use and declined after the 2011-2012 withdrawal, with higher risks in children and reproductive-age females. APC, DID, and ITS, including PHMG-P–specific time-series analysis, indicated increased pneumonitis incidence and mortality during exposure periods. Toxicological studies demonstrated that PHMG-P exposure resulted in epithelial injury, inflammation, fibrosis, and impaired lung function consistent with chemical pneumonitis. Mechanistic evidence linked PHMG-P exposure to epithelial damage, oxidative stress, macrophage polarization, and fibrotic changes. Multiple lines of evidence support a causal link between PHMG-P exposure and pneumonitis, underscoring the value of integrating epidemiology and toxicology to strengthen risk assessment and inform policy.

We evaluated the association between the duration of exposure to three types of extreme heat-heat wave, heat warning, and tropical night-and mortality risk in people with disabilities (PWDs) by disability type and severity. Mortality data were obtained from the Korean National Health Insurance Service for PWDs (43.8 million person-years and 0.38 million deaths) and Statistics Korea for non-disabled individuals (NDs) (894 million person-years and 1.5 million deaths) from May to September in 2002-2021. Temperature data were collected from the Korea Meteorological Administration. Heat wave (Max T ≥ 33 °C), heat warning (Max T ≥ 35 °C), and tropical night (Min T ≥ 25 °C) were defined. Prolonged events (≥2 days) occurred in 4.5 % of heat waves, 1.2 % of heat warnings, and 2.1 % of tropical nights. All-cause mortality risks for ≥2 days of heat warning were the highest during extreme heat. Among severely disabled, all-cause mortality risks were highest with ≥2 days of heat warning (relative risk [RR] [95 % confidence interval (CI)]: 1.152 [1.058, 1.254]), exceeding risk on the first day of heat warning. However, on the first day of heat exposure, the mortality risks for an accidental cause on heat warning (RR [95 % CI]: 1.665 [1.162, 2.386]) and a respiratory cause on a tropical night (RR [95 % CI]: 1.266 [1.023, 1.567]) were high with no clear increase for longer durations. PWDs, especially those with severe or specific disabilities, face elevated mortality risk from prolonged extreme heat. These findings highlight the need for targeted health policies addressing the exposure duration of extreme heat among PWDs.

People with disabilities (PWD) may be more vulnerable to the adverse health effects of air pollution than the general population. This study examined the association between long-term exposure to ambient fine particulate matter (PM2.5) and mortality risk in PWD considering disability type and severity. Data from the Korean National Health Insurance Service and Statistics Korea were analyzed in this retrospective cohort study, including 2,880,265 individuals (41,501,709 person-years), of which 176,410 were PWD (2,011,231 person-years). PM2.5 exposure was estimated using simulated data from 2006 to 2019. Causes of death included all causes, non-accidental causes, respiratory disease, lung cancer, and cardiovascular disease. Cox proportional hazard models were used to estimate hazard ratios (HRs) for mortality associated with PM2.5 stratified by disability type and severity. PWD, particularly those with severe disabilities or specific impairments such as kidney problems or brain lesions, showed significantly high mortality risks from all causes, non-accidental causes, and cardiovascular diseases due to PM2.5 exposure. For individuals with kidney impairment, the HR (95

OBJECTIVES: Humidifier disinfectants (HDs) were sold in Korea from 1994 until their recall in 2011. We examined the incidence patterns of 8 respiratory diseases before and after the HD recall and estimated the attributable risk in the Korean population. METHODS: Using National Health Insurance data from 2002 to 2019, we performed age-cohort-period and differences-indiffference analyses (comparing periods before vs. after the recall) to estimate the population-attributable fraction and the excess number of episodes. The database comprised 51 million individuals (99% of the Korean population). The incidence of 8 diseases-acute upper respiratory infection (AURI), acute lower respiratory infection (ALRI), asthma, pneumonia, chronic sinusitis (CS), interstitial lung disease (ILD), bronchiectasis, and chronic obstructive pulmonary disease (COPD)-was defined by constructing episodes of care based on patterns of medical care and the clinical characteristics of each disease. RESULTS: The relative risks (RRs) for AURI, ALRI, asthma, pneumonia, CS, and ILD were elevated among younger individuals (with an RR as high as 82.18 for AURI in males), whereas chronic conditions such as bronchiectasis, COPD, and ILD showed higher RRs in older individuals. During the HD exposure period, the population-attributable risk percentage ranged from 4.6% for bronchiectasis to 25.1% for pneumonia, with the excess number of episodes ranging from 6,218 for ILD to 3,058,861 for CS. Notably, females of reproductive age (19-44 years) experienced 1.1-9.2 times more excess episodes than males. CONCLUSIONS: This study provides epidemiological evidence that inhalation exposure to HDs affects the entire respiratory tract and identifies vulnerable groups.

This study examined the associations between exposure to heavy metals, bisphenol A (BPA), and phthalates and precocious or delayed puberty. This study was a cross-sectional study using the data obtained from the Korea Environmental Exposure and Health Survey in Children and Adolescents. Blood samples were collected to measure lead, mercury, and cadmium levels, whereas spot urine samples were analyzed for BPA, phthalate metabolites, and creatinine levels. Sexual maturation status was assessed using self-measured Tanner stages. Our analyses involved single- and multi-exposure binomial logistic regression models adjusted for age, body mass index, presence of siblings, urban residence, and socioeconomic status. In the multi-exposure models, we applied quantile g-computation mixture analysis to calculate odds ratios (ORs) for precocious and delayed puberty. In the study cohort of 1,424 individuals, precocious puberty was identified in 50 (3.5%) individuals, whereas delayed puberty was identified in 54 (3.8%) individuals. In the single-exposure models, a higher mono-benzyl phthalate concentration was associated with a higher risk of delayed puberty in girls (OR = 2.75, 95% confidence interval: 1.34, 5.66). In the mixture exposure models, exposure to a mixture of BPA and phthalate metabolites was associated with precocious puberty in boys and delayed puberty in both sexes, although the risk estimates were imprecise. Our findings add to the increasing evidence suggesting that exposure to environmental chemicals may contribute to delayed puberty.

Human health has improved dramatically, but biodiversity is in crisis, with over 1 million species at risk of extinction. Human activities, such as deforestation and resource overuse, have accelerated environmental changes, known as Anthropocene Acceleration. The Planetary Boundaries framework identifies nine ecological limits, including climate change and biodiversity loss. By 2023, six of these boundaries had been exceeded, threatening human survival. Climate change, driven by greenhouse gas (GHG) emissions, is causing extreme weather, rising sea levels, and ecosystem disruptions. The IPCC warns that surpassing 1.5°C will have severe consequences. Climate inequality is worsening, as the wealthiest 10% produce nearly half of global emissions, while low-income populations bear most climate-related economic and health burdens. Biodiversity loss further increases infectious disease risks, necessitating a One Health approach that integrates human, animal, and environmental health. The healthcare sector contributes 4.6% of global emissions, requiring urgent action to become carbon-neutral. South Korea’s climate-health policies need to expand beyond infectious diseases to chronic conditions and vulnerable populations including future generations. While WHO advocates integrating climate resilience with emission reductions, ensuring a sustainable, health-centered response to the climate crisis, South Korea lacks GHG reduction targets for healthcare sectors. To address this, South Korea should mandate carbon reporting for healthcare, integrate emissions reduction in hospital accreditation, provide sustainability incentives. Improving high-emission medical practices requires healthcare awareness, behavioral change, and scientific evidence for safety.

Prenatal exposure to climate factors, air pollution, and green space has been linked to respiratory diseases in infants. However, the role of the combined effects of exposure to these factors on respiratory ailments remains unclear. Here we investigate the association of combined exposure to traffic-related air pollution (TRAP), climate factors, and green space during the prenatal period with respiratory diseases in infants. We enrolled 454 participants from the ongoing prospective birth cohort known as the Mothers and Children's Environmental Health study. Data on infant respiratory diseases were collected from parents or guardians. Average exposure values of TRAP, climate factors, and green spaces for the study population were calculated based on geocoded residential addresses. Multiple logistic regression and quantile-based g-calculation models were utilized to examine the association of exposure to environmental factors and green space with respiratory diseases. The combined exposure to climate factors and TRAP during the first trimester of pregnancy was associated with an increased risk of respiratory diseases in infants. High levels of particulate matter with a diameter less than 2.5 μm (PM2.5) and temperature increased the risk of respiratory diseases (adjusted odds ratio (AOR): 1.615, 95% confidence interval (CI): 1.001, 2.658). Additionally, the risk of respiratory diseases from exposure to air pollution and temperature was associated with lower tertiles of residential green spaces. The AOR was 1.064 (95% CI: 1.001, 1.133) per 1 µg/m3 increase in PM2.5, 1.057 (95% CI: 1.001, 1.116) per 1 ppb increase in NO2, and 1.108 (95% CI: 1.001, 1.176) per 1 ℃ increase in temperature. Incorporating green space into the analysis of joint exposure to climate factors and air pollution reduced the risk of respiratory disease. This study proposes that combined exposures to climate factors, TRAP, and green spaces during pregnancy are associated with infant respiratory diseases. Fewer residential green spaces could enhance the association of climate factors and air pollution with respiratory diseases.

Following widespread use of humidifier disinfectants (HDs) in South Korea from the late 1990s until their recall in 2011, clusters of respiratory illnesses emerged. While causality has been established for severe cases, evidence linking non-specific or chronic respiratory diseases to HD exposure remains insufficient for recognition or compensation. We aimed to assess the relationship between HD exposure and a broad spectrum of respiratory diseases and determine the latency of disease onset. We linked national health insurance data to self-reported exposure records for 6061 individuals who filed compensation claims for HD-related health damage. We conducted individual-level interrupted time series (ITS) analysis over a 15-year period (60 months before and 120 months after first HD use). We evaluated eight respiratory diseases and calculated excess rate ratios (ERRs) and latency patterns by disease type, severity, and HD chemical ingredients. Significantly elevated risks were observed for all eight diseases post-HD exposure. The strongest associations were observed for pneumonia (ERR=14.04), asthma (ERR=8.54), and interstitial lung disease (ERR=8.26). Most disease onset was typically concentrated within the first few years post-exposure but extended up to a decade for chronic conditions. ERRs stratified by chemical type revealed distinct ingredient-specific risk profiles. Despite potential collider bias, comparative analyses using national population data showed consistency in relative risk estimates. This study provides robust epidemiologic evidence for the long-term health consequences of HD exposure. The findings support revisions in compensation policies and underscore the need for extended health surveillance of affected individuals. However, the results should be interpreted with caution due to potential collider bias and possible overrepresentation of affected individuals.

Background Allergic diseases (ADs) have been increasingly reported in infants and children over the last decade. Diet, especially the inclusion of fish intake, may help to lower the risk of ADs. However, fish also, can bioaccumulate environmental contaminants such as mercury. Hence, our study aims to determine what effects the type and frequency of fish intake have on ADs in six-month-old infants, independently and jointly with mercury exposure. Methods This study is part of the prospective birth cohort: Mothers and Children’s Environmental Health (MOCEH) study in South Korea. Data was collected on prenatal fish intake, prenatal mercury concentration and ADs for infants aged six months for 590 eligible mother-infant pairs. Logistic regression analysis was conducted to evaluate the risk of prenatal fish intake and mercury concentration on ADs in infants. Finally, interaction between fish intake and mercury concentration affecting ADs in infants was evaluated. Hazard ratios of prenatal fish intake on ADs in 6 month old infants were calculated by prenatal mercury exposure. Results Logistic regression analysis showed that white fish (OR: 0.53; 95% CI 0.30–0.94; P < 0.05) intake frequency, once a week significantly decreased the risk of ADs in infants. Stratification analysis showed that consuming white fish once a week significantly reduced the hazard of ADs (HR: 0.44; 95% CI 0.21–0.92; P < 0.05) in infants in the high-mercury (≥ 50th percentile) exposure group. Conclusion The result indicates that prenatal white fish intake at least once a week reduces the risk of ADs in infants, especially in the group with high prenatal mercury exposure.

Climate change has caused extreme weather events, including frequent summer heat waves. We examined how the effects of high air temperatures on mortality have changed between the two study periods (1991-1995 and 2015-2019), including 1994 and 2018, the worst heat wave years in the meteorological history of South Korea. Temperature data from the Korea Meteorological Administration and mortality data from Statistics Korea were used in this study. We used distributed lag nonlinear models to estimate the cumulative relative risks (CRRs) to determine the association between daily maximum temperature in summer (June to September) and mortality. CRRs were estimated for each province and pooled using a random-effects meta-analysis for all provinces. Maximum temperature and annual average days in heat wave were 37.7 degrees C and 11.8 in 1991-1995 and 38.3 degrees C and 18.8 in 2015-2019. The slope of the CRR for mortality increases with increasing temperature and has been steeper in the past than in recent years and steeper in those over 65 than in those under 65. Excess mortality has recently declined compared with that in the past. The impact of high summer temperatures on mortality changed between the two periods, suggesting improved population resilience.

Objectives: : Outbreak reports are essential for documenting the spread of and responses to disease outbreaks. However, there is a lack of standardized reporting guidelines that encompass broader perspectives on outbreaks. We aimed to develop a universal reporting guideline applicable to diverse outbreak reports and community epidemic interventions, the "Guidelines for Community Outbreak Investigation Reporting (G- CORE)." Methods: : G-CORE is designed to address the challenges in documenting various outbreak scenarios, including infectious diseases and non-infectious environmental hazards. The development of G-CORE involved a structured process, including a comprehensive literature review of recent outbreak reports from leading journals and an analysis of existing reporting guidelines. The process also involved project registration with the EQUATOR Network and collaboration with experts in various fields. Following the initial drafting, an internal (team) review was conducted to evaluate the guidelines' robustness and relevance. Subsequently, the guidelines underwent revision based on feedback from external experts and potential users, including authors with experience in outbreak reporting. The project also includes plans for widespread dissemination and periodic revisions to adapt to developments and user feedback. Results: : G-CORE will provide a structured framework for reporting outbreak investigations, comprising a detailed checklist and Explanation & Elaboration documents. Conclusion: : G-CORE establishes a new standard in outbreak reporting, facilitating comprehensive, clear, and actionable public health communications. Its development marks a significant advance in the documentation and management of public health outbreaks.

Early childhood is important for neurodevelopment, and exposure to endocrine disruptors such as bisphenol A (BPA) and phthalates in this period may cause neurodevelopmental disorders and delays. The present study examined the association between exposure to mixtures of BPA and three metabolites of phthalates in early childhood and IQ at 5 years of age. The Mother and Children's Environmental Health (MOCEH) study is a prospective birth cohort study conducted in Korea with 1751 pregnant women enrolled from 2006 to 2010. After excluding those without relevant data, 47 children were included in the final analysis. We measured children's urinary concentrations of metabolites of endocrine-disrupting chemicals (Bisphenol A, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate and mono-(2-ethyl-5-butyl) phthalate) at ages of 24 and 36 months. We evaluated the children's IQ with the Korean Wechsler Intelligence Test at the age of 5 years. After adjusting for potential confounders, a multiple linear regression was conducted to examine the associations between individual endocrine-disrupting chemicals and the IQ of the children. Weighted Quantile Sum (WQS) regression and quantile-based g-computation were used to assess the association between IQ at age 5 and exposure to mixtures of BPA and phthalates. In the single-chemical analyses, mono-(2-ethyl-5-butyl) phthalate exposure at 36 months was adversely associated with children's IQ (β = −4.93, 95% confidence interval (CI): -9.22, −0.64). In the WQS regression and quantile-based g-computation analyses, exposure to the mixture of BPA and phthalates was associated with lower IQ [β = −9.13 (P-value = 0.05) and β = −9.18 (P-value = 0.05), respectively]. The largest contributor to the overall association was exposure to mono-(2-ethyl-5-butyl) phthalate at 36 months. In the present study, postnatal exposure to mixtures of BPA and three metabolites of phthalates was associated with decreased IQ of children at age 5.

BACKGROUND:Cancer is a leading cause of death worldwide, posing a significant threat to human health and life expectancy. Numerous existing studies explored the correlation between coal-fired power plants and cancer development. Currently, Chungcheongnam-do Province hosts 29 coal-fired power plants, constituting half of the total 58 plants across South Korea. METHODS:This study assessed the cancer incidence by proximity to coal-fired power plants in Chungcheongnam-do Province, Korea. In this study, the exposed group comprised individuals residing within a 2-km radius of the coal-fired power plants, whereas the control group comprised individuals who had no prior residency within the 2-km radius of such plants or elsewhere in the province. Standardized incidence ratios were calculated using the cancer incidence cases retrieved from the National Health Insurance System data from 2007 to 2017. RESULTS:The study found that exposed men had a 1.11 (95% confidence interval [CI], 1.09-1.21) times higher risk of developing all cancer types and a 1.15 (95% CI, 1.09-1.22) times higher risk of developing cancers excluding thyroid cancer compared with control men. Exposed women had a 1.05 (95% CI, 1.00-1.14) times higher risk of developing all cancer types and a 1.06 (95% CI, 0.98-1.13) times higher risk of developing cancers excluding thyroid cancer than did control women. The colorectal, liver, prostate, and bladder cancer incidence rates were significantly higher in exposed men than that in all control groups. The incidence of esophageal, stomach, liver, and lung cancers were significantly higher in exposed women compared with all control groups. CONCLUSION:The residents near coal-fired power plants had a higher risk of developing cancer than did those living in other areas. In the future, long-term follow-up investigations in residents living in the vicinity of power plants are warranted.

Objectives: : The objective of this study was to develop the Guidelines for Recommendation Reporting (G-RECO) for use in the Public Health Weekly Report (PHWR) in Korea, aiming to improve the standardization, scientific accuracy, and practical applicability of recommendation reports in clinical practice guidelines. Methods: : The methodology of this study aligned with the EQUATOR Network standards. A multidisciplinary research committee was formed, comprising experts in various relevant fields. The development process included a comprehensive literature review, analysis of existing guidelines, and formulation of a structured G-RECO framework with 21 key items. This was supplemented with Explanation & Elaboration documents for each item. The draft underwent rigorous revisions and evaluations by both internal and external experts. Results: : By November 2023, significant progress had been made in developing a detailed GRECO checklist and accompanying E&E documents. These tools are designed to guide authors in clear and consistent reporting of recommendation reports. The team is poised to finalize and publish the checklist and E&E documents by December 2024. Conclusion: : The G-RECO guidelines represent a significant advancement in the formalization and standardization of recommendation reports for the PHWR. They are expected to improve the quality of research and publications in clinical practice guidelines, contributing to the evolution of the field and enriching public health discourse. The guidelines, with their comprehensive nature and user-friendly design, will become an invaluable resource for researchers, editors, and peer reviewers in public health and epidemiology.

OBJECTIVES: Exposure to humidifier disinfectants has been linked to respiratory diseases, including interstitial lung disease, asthma, and pneumonia. Consequently, numerous toxicological studies have explored respiratory damage as both a necessary and sufficient condition for these diseases. We systematically reviewed and integrated evidence from toxicological studies by applying the evidence integration method established in previous research to confirm the biological plausibility of the association between exposure and disease. METHODS: We conducted a literature search focusing on polyhexamethylene guanidine phosphate (PHMG) and chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT), the primary ingredients in humidifier disinfectants. We selected relevant studies based on their quality and the population, exposure, comparator, outcome (PECO) statements. These studies were categorized into three lines of evidence: hazard information, animal studies, and mechanistic studies. Based on a systematic review, we integrated the evidence to develop an aggregate exposure pathway-adverse outcome pathway (AEP-AOP) model for respiratory damage. The reliability and relevance of our findings were assessed by comparing them with the hypothesized pathogenic mechanisms of respiratory diseases. RESULTS: By integrating toxicological evidence for each component of the AEP-AOP framework for PHMG and CMIT/MIT, we developed an AEP-AOP model that elucidates how disinfectants released from humidifiers expose target sites, triggering molecular initiating events and key events that ultimately lead to respiratory damage. This model exhibits high reliability and relevance to the pathogenesis of respiratory diseases. CONCLUSIONS: The AEP-AOP model developed in this study provides strong evidence, based on evidence-based toxicology, that exposure to humidifier disinfectants causes respiratory diseases. This model demonstrates the pathways leading to respiratory damage, a hallmark of these conditions.