Pneumoconiosis is a chronic disease attributed to the long-term inhalation and deposition of inorganic mineral dust in the lungs during occupational activities, with serious harm and a large number of patients (1). The main pathological manifestations of pneumoconiosis include chronic pulmonary inflammation, persistent pulmonary fibrosis and other substantial irreversible changes that may occur after exposure cessation (2, 3). In 2017, silicosis was the most common type of pneumoconiosis worldwide, followed by coal worker pneumoconiosis (CWP) (4). In addition, known pneumoconiosis also include welder’s pneumoconiosis, graphite disease, carbon black pneumoconiosis and others (5). Pneumoconiosis is a chronic occupational disease that, due to its irreversible pathological changes, is difficult to recover from once contracted. At present, there is no effective treatment for pneumoconiosis, and prevention has always been the main means to reduce the incidence rate and mortality of pneumoconiosis, and causing significant economic burden and health losses to the country and patients.

In China, pneumoconiosis is the leading occupational diseases that need to pay more focus. China suffered from the world’s largest health loss from pneumoconiosis in 2019, accounting for two-thirds of the global health loss from pneumoconiosis (6). In 2023, a total of 12,087 new cases of various occupational diseases were reported nationwide, including 8,051 cases of occupational pneumoconiosis, accounting for 66.61% of the total cases (7). According to occupational history and the severity of radiographs, pneumoconiosis is divided into three stages in China (8), which is different from the classification of simple type (further divided into subtypes 1, 2, and 3) and complex type (further divided into subtypes A, B, and C) by the International Labor Organization (ILO) (9). However, there is a certain correlation between the two. The first, both using lung changes on radiographs as the main basis for diagnostic classification; the second, Stage I represents simple pneumoconiosis of the ILO, while Stage III represents complex pneumoconiosis of categories B and C of the ILO; the third, Stage II falls between the two stages mentioned above; the fourth, both can serve as important basis for occupational injury compensation. In addition, the classification of pneumoconiosis can be used as an important factor for the survival time of cases (3).

The industrial structure of Zhenjiang City, which is dominated by sectors such as metal and non-metal mining, metallurgy, coal mining, non-ferrous metal smelting and processing, high-end equipment manufacturing, new materials, automotive and parts, as well as shipbuilding and marine engineering, stands in sharp contrast to the export-oriented processing model centered on light industry and electronics in Southern China (10, 11), the foundational industrial model focused on energy and heavy chemicals in Northern China (12), the equipment manufacturing model supported by steel and automobiles in Central China (13), and the resource development model emphasizing mining and metallurgy in Southwest China (14). The industrial characteristics of Eastern China, including Zhenjiang, are marked by a combination of diversification and density (15). The region is home to numerous small and medium-sized manufacturing enterprises, leading to a more complex array of occupational hazards. Although no occupational disease incidents had occurred in the past, there are quite a few pneumoconiosis patients. This distinct context endows research on the survival status of pneumoconiosis in this area with unique representativeness and necessity.

To prevent pneumoconiosis, the ILO and the World Health Organization (WHO) have jointly launched a global plan to eliminate pneumoconiosis, with the goal of eradicating pneumoconiosis worldwide by 2030. China has invested a lot of energy and funds in the prevention and control of pneumoconiosis, and has included occupational health in the Healthy China 2030 Plan, and included in the Five-Year Plan for National Economic and Social Development and the State Council’s Safety Production Assessment. The aim of this study is to evaluate the key factors affecting the survival of pneumoconiosis patients in Zhenjiang City, reduce related complications, prolong survival, and provide evidence for improving patients’ quality of life. Therefore, follow-up was conducted on occupational pneumoconiosis patients reported in Zhenjiang City from 1965 to 2025, and the survival status of pneumoconiosis patients was analyzed, aiming to provide scientific basis for the prevention and treatment of pneumoconiosis.

Pneumoconiosis is still a threat to public health (16–20). From the global perspective, in 2017, pneumoconiosis had the prevalent cases of 527,500 and over 60,000 new reported cases (21), and its prevalence had increased since 1990 from 0.0054 to 0.0069% (22). An updated report showed, pneumoconiosis was estimated to account for 0.9 million collectively DALYs (Disability-Adjusted Life Years) and 3.1 million prevalent cases in 2019. Pneumoconiosis prevalence has remained comparable from 1990 to 2019 while the ASR (age-standardized rates) of DALYs, deaths, and incidence have decreased by 44.4, 53.3, and 13.7%, respectively. Although the overall trend of the above indicators is declining, the ASR of incidence slightly rose by 5.4% from 1990 to 2019 in women globally, and men have had significantly higher ASR of DALYs, deaths, prevalence, and incidence throughout the investigated period (23). According to recent studies, the number of global pneumoconiosis cases increased by approximately 66.0% from 1990 to 2017, and by 61.5% from 1990 to 2019 (23, 24), and the mortality rate of pneumoconiosis patients has been at a high level in recent years, with over 21,000 deaths each year since 2015 (2), and the rate of pneumoconiosis mortality decreased by 41% from 1990 to 2016 (17).

Different countries or regions still face severe challenges in the prevention and treatment of pneumoconiosis. Pneumoconiosis has re-emerged in the United States and Australia, countries with highly developed healthcare systems, high standards of workplace safety procedures, and highly mechanized mining practices that reduce workers’ exposure to particles (2, 20). In 2018, a study reported that the national prevalence of pneumoconiosis in long-tenured working miners exceeded 10% (25, 26). During the same period, National Institute for Occupational Safety and Health (NIOSH) data showed a sharp increase trend in the incidence of coal worker’s pneumoconiosis (CWP) and progressive massive fibrosis (PMF) (26, 27), and the estimated prevalence of coal workers pneumoconiosis in the 2000s exceeded that in the 1990s (28). Other underdeveloped countries, especially those with inadequate reporting systems, may have many patients who have not yet been diagnosed and reported.

Some reports showed that the age distribution was concentrated in the 60–69 age group, with a higher number of deaths and a greater disease burden. And, the other relevant indicators of older workers were higher than those of younger workers, indicating that the disease burden of employees increases with the increase of dust exposure years (29). In males, the mortality rate of pneumoconiosis increases with age, and the disease burden of middle-aged and older adult people is significantly higher than that of young people (30). The extension of working years leads to the accumulation of dust exposure, increased lung tissue damage, and increased risk of disease (31), with age effects having a greater impact on silicosis and coal worker pneumoconiosis (32).

A survival analysis was conducted in a cohort of 4,103 pneumoconiosis patients diagnosed in an industrial city of China. The study encompassed major pneumoconiosis types, including silicosis, coal worker’s pneumoconiosis, welder’s pneumoconiosis, and other variants (e.g., asbestosis, cement pneumoconiosis, foundry worker’s pneumoconiosis, and potter’s pneumoconiosis). The study was predominantly male, a demographic pattern consistent with established epidemiological characteristics reported in multiple previous studies (1, 13, 24). This demographic distribution reflects significant gender-based occupational segregation within the labor market, wherein high-risk, dust-exposed occupations are predominantly held by males. Survival analysis revealed that patients diagnosed with Stage III pneumoconiosis exhibited a significantly shorter mean survival time and life expectancy compared to those in Stages I and II. Furthermore, Cox proportional hazards regression identified several factors significantly associated with increased mortality risk among pneumoconiosis cases: employment in the manufacturing sector, medium-sized mining enterprises, diagnosis at Stage III at initial presentation, and older age at onset. Of these, the manufacturing industry was associated with the highest hazard ratio, followed by medium-sized mining enterprises, initial diagnosis at Stage III, and older age at onset.

An analysis of the distribution of pneumoconiosis cases in the region identified silicosis, coal worker’s pneumoconiosis, cement pneumoconiosis, and welder’s pneumoconiosis as the four most prevalent types. This disease profile differs notably from the patterns reported in Guangdong and Hunan provinces (33), consistent with Liaoning Province (34), reflecting distinct local industrial structures and associated occupational dust exposures. By disease stage, pneumoconiosis cases were predominantly diagnosed at Stage I (77.8%), with Stage II and Stage III comprising the remaining cases. This stage distribution pattern is consistent with epidemiological findings reported from other regions of China, including Shanghai, Hubei, and Tianjin (35–39). The high proportion of cases diagnosed at Stage I suggests that occupational health surveillance policies, including regular physical examinations, may have played a critical role in early detection. Significant differences were observed in the mean age of onset and dust exposure duration across different disease stages. These variations are associated with several exposure-related and host factors, including cumulative dust exposure time, dust concentration, free silica content, individual susceptibility, and timeliness of medical examination and diagnosis among pneumoconiosis cases (40).

Furthermore, even after cessation of dust exposure, pneumoconiosis demonstrates persistent progression, characterized by further deterioration of lung pathology and progressive decline in pulmonary function, leading to escalation in disease stage. Compared with other types of pneumoconiosis, silicosis progresses faster and more severely (41). Therefore, the diagnosis of stage II or III pneumoconiosis was not only associated with the timing of initial diagnosis but also reflects disease progression from earlier stages. The analysis in this study identified that cases diagnosed at Stage II or Stage III were predominantly concentrated in small and medium-sized enterprises (SMEs) within the mining and manufacturing sectors, which were associated with lower regional economic levels. The contributing factors can be summarized as follows: first, poor working conditions, lack of protective engineering controls, and inadequate implementation of occupational health management systems in these enterprises; second, a general lack of occupational safety training among dust-exposed workers, resulting in insufficient awareness of the health risks posed by dust, particularly silica; and finally, failure to effectively implement relevant occupational health supervision measures, including non-compliance with regular workplace dust monitoring and periodic occupational health examinations for at-risk workers (1). Thus, a significantly shorter dust exposure duration was observed among cases diagnosed at Stage II, and particularly at Stage III, when compared to Stage I cases. This pattern suggests a more aggressive disease progression in these patients.

Silicosis is widely recognized as the most prevalent, rapidly progressive, and clinically severe form of pneumoconiosis (42, 43). This study confirms that silicosis (65.56% of all cases) constitutes the principal component of the pneumoconiosis disease burden. Stratified by disease stage, silicosis accounted for 61.63% (1,968/3,193) of Stage I cases, 79.15% (615/777) of Stage II, and 80.45% (107/133) of Stage III. This study revealed significantly shorter median survival time in Stage III compared to Stages I and II, a pattern potentially explained by the substantially higher proportion of silicosis cases in Stage III. Disease progression analysis demonstrated shorter time to progression to Stage II and Stage III among silicosis patients compared to other pneumoconiosis types. Specifically, 66.92% (520/777) of Stage II cases progressed from Stage I, while 56.07% (60/133) of Stage III cases evolved from earlier stages. The overall and stage-specific mortality rates in this study substantially exceeded those reported in multiple previous studies (3, 44). The high proportion of silicosis across all disease stages may represent a key epidemiological factor underlying this discrepancy, further supporting evidence that silicosis carries higher mortality than other pneumoconiosis types (32). Notably, diagnosis at Stage III was associated with shorter dust exposure duration (1, 45). Despite their relatively brief exposure history, a substantial proportion of these patients were directly classified as Stage III at initial diagnosis. Given the highest proportion of silicosis cases was observed in Stage III, this subgroup may represent distinct exposure patterns or disease progression characteristics compared to other stages.

Analysis of social security coverage among pneumoconiosis patients in this study revealed statistically significant differences across disease stages (p < 0.05). While most of Stage I and Stage II patients were enrolled in at least one type of social security scheme—either occupational injury insurance or basic medical insurance—the coverage dropped markedly in Stage III patients. Less than 40% of Stage III patients had dual insurance coverage, and over 60% lacked any form of social security. Among Stage I, Stage II and Stage III patients, this coverage gap was consistent with findings reported by Li et al. (46). Notably, 27% of all patients had not undergone disability assessment, a figure that rose to nearly 60% among Stage III patients. This directly disqualifies a significant number of patients, particularly those with advanced disease, from receiving statutory occupational injury benefits. Existing evidence suggests that comprehensive social security can facilitate timely medical service utilization by improving relevant support mechanisms (4). Furthermore, Wang et al. identified poor economic status as a key barrier to healthcare-seeking among pneumoconiosis patients (47). From a public health perspective, these findings highlight the need for targeted policy interventions: first, to expand social security coverage, particularly for occupational groups at high risk of disease progression; second, to optimize a systematic disability assessment system ensuring patients receive entitled benefits in a timely manner; and finally, strengthen the employer’s main responsibility in occupational disease prevention through multi departmental cooperation.

This study revealed a mean survival time among all patients, which demonstrated significant associations with both dust exposure duration and age at first diagnosis. The combination of shorter dust exposure duration and older age at diagnosis contributed to reduced survival time, further highlighting the long-term health hazards associated with occupational dust exposure. From the perspective of disease natural history, pneumoconiosis typically exhibits a prolonged latency period ranging from 10 to 40 years (6). The powerful compensatory capacity of the pulmonary system, coupled with the non-specific nature of early clinical manifestations, often leads to insufficient healthcare-seeking awareness among patients and consequent delays in diagnosis, thereby creating challenges for early detection and intervention (32). Consequently, most cases are diagnosed at an advanced age and have already progressed to relatively severe stages. Furthermore, the generally declined immune function in older adult patients increases their susceptibility to comorbidities such as tuberculosis and chronic obstructive pulmonary disease (48). Such comorbid conditions significantly elevate both the complexity of clinical management and mortality risk (49). Therefore, it is necessary to conduct timely intervention and treatment for patients with pneumoconiosis to delay the disease progression and prevent potential infections and complications (4).

Life-table analysis of the 4,103 pneumoconiosis patients demonstrated an increasing overall mortality probability and median survival time with advancing age. This positive association between age and mortality probability has been consistently documented in numerous survival analyses. Some studies on occupational-attributable deaths and DALYs from pneumoconiosis indicated that age-standardized mortality rates were highest in older age groups, with the peak DALY rate observed in the 75–84 year age group (17, 41), and another study showed that mortality and DALYs rates peak between the ages of 85 and 89 (29). The observed increase in median survival time may be attributed to the predominance of older age groups within the observed patients, which often represent relatively healthier survivors, thereby contributing to an overall reduction in mortality rates (32), and the risk rate had decreased. Existing research has shown that patients with Stage I pneumoconiosis can receive free standardized rehabilitation treatment after being diagnosed with pneumoconiosis, and their survival time can reach the level of normal individuals (46, 50). The present study involved a substantial proportion of subjects from older age groups, characterized by their advanced age at onset and the fact that approximately 80% of cases were initially diagnosed at Stage I.

Stratified by age and disease stage, mortality demonstrated a progressive increase across the three pneumoconiosis stages, accompanied by corresponding declines in life expectancy. Stage III, characterized by the most severe pulmonary function impairment and a spectrum of comorbidities, exhibited significantly elevated mortality risk compared to Stage I and Stage II. Furthermore, a positive correlation was observed between patient age, disease stage, and comorbidity burden, collectively contributing to reduced survival time (48, 51). The disease burden was substantially higher in middle-aged and older adult populations compared to younger groups (32). As illustrated by the cumulative survival curves, survival probabilities decreased with advancing disease stage. This pattern contrasts with findings reported by Ortmeyer et al., which indicated comparable overall life expectancy between miners and the general population (50). A 20-year follow-up study of South Welsh miners and ex-miners revealed similar survival patterns among subjects with simple pneumoconiosis, category A pneumoconiosis, and those without radiological evidence of the disease (52). Notably, elevated mortality was exclusively documented among miners with category B and C complicated pneumoconiosis. These collective findings underscore that preventing and delaying disease progression represent critical interventions for significantly extending survival time in pneumoconiosis patients (53).

The Cox proportional hazards model identified several independent risk factors for reduced survival in pneumoconiosis patients: employment in the mining sector (HR = 2.676, 95% CI: 2.050–3.493), manufacturing industry (HR = 9.856, 95% CI: 1.724–56.338), medium-sized enterprises (HR = 2.493, 95% CI: 1.478–4.204), diagnosis at Stage III at initial presentation (HR = 1.781, 95% CI: 1.281–2.476), and age at onset (HR = 1.097, 95% CI: 1.088–1.105). The consistent concentration of pneumoconiosis cases in mining and manufacturing sectors, as documented in multiple studies (54–58), reflects the elevated occupational health risks in these industries, including high exposure concentrations to respirable crystalline silica, inadequate engineering controls, and insufficient occupational health surveillance systems. Especially, the patients worked in the mining industry had a worse survival than those worked in other industries (4). Medium-sized enterprises (55, 59, 60), while functioning as crucial contributors to socioeconomic stability through employment generation, exhibit distinct occupational health risk patterns. Epidemiologic analysis revealed that compared to large corporations, these enterprises demonstrated structural disadvantages in allocating resources for occupational health protections. Conversely, when compared with micro-scale economic entities, they encompassed larger workforce populations with broader occupational exposure profiles. This intermediate risk pattern positions medium-sized enterprises as critical observation units in pneumoconiosis disease burden research, carrying significant public health implications for overall working population health. The associations between initial diagnosis at Stage III, age at onset, and patient survival observed in this study align with established risk patterns documented in previous epidemiological study (61). Patients who received a disability rating—especially at level 7 or below, or within levels 7–4—exhibited a significantly reduced mortality risk. This suggests that enrollment in a systematic occupational disease management network may provide patients with more regular medical follow-up and targeted interventions, thereby contributing to improved clinical outcomes.

To date, no survival analysis focusing on pneumoconiosis patients has been conducted in Zhenjiang. This study addresses this gap through a retrospective cohort study designed to systematically examine survival patterns and determinants in this population. Moving beyond descriptive epidemiological characterization, we employed Kaplan–Meier methodology for survival probability estimation and Cox proportional hazards regression to identify independent risk factors. Unlike cross-sectional studies limited to describing disease distribution, survival analysis enables the investigation of factors influencing disease prognosis. Methodologically, this retrospective follow-up study inherits limitations inherent to its design, including potential information bias and loss to follow-up. Furthermore, the absence of precise historical dust exposure metrics, together with the recall bias associated with retrospectively collected behavioral data (e.g., smoking history), constrains the analysis. These gaps highlight the critical importance of designing future studies with prospective, systematic data capture to strengthen the evidence base.

This study elucidates the key determinants of mortality risk in pneumoconiosis, and its findings offer critical insights into the severe challenges currently facing occupational health in China. The extended latency period of pneumoconiosis and China’s accelerating population aging pose substantial challenges to disease control. This is particularly relevant for the estimated 280 million migrant workers who are predominantly employed in high-risk sectors such as mining, construction, and manufacturing (62). The high mobility of this population contributes to fragmented occupational health supervision systems. Against this backdrop, our findings demonstrate that the risk of death from pneumoconiosis is closely associated with occupational environment (manufacturing, mining, medium-sized enterprises), late-stage detection (Stage III at initial diagnosis), and earlier age at onset. In contrast, the specific etiological type of pneumoconiosis (e.g., silicosis or coal worker’s pneumoconiosis) showed no independent association with mortality. Furthermore, enrollment in the occupational disease disability management system may have a protective effect on patient prognosis.

With ongoing industrial expansion and improvements in diagnostic capabilities, reported pneumoconiosis incidence was projected to rise (25). Therefore, based on these findings, public health interventions should focus on dust control in high-risk workplaces, early diagnostic screening, and prioritized health management for older adult patients and those with advanced disease. Concurrently, it is essential to enhance occupational health surveillance mechanisms and implement differentiated prevention and management strategies tailored to specific industries, populations, and disease stages (63).

We propose a comprehensive public health approach comprising the following evidence-based interventions: