Pneumoconiosis progression patterns in US coal miner participants of a job transfer programme designed to prevent progression of disease

Assessment of the Respiratory Health of Working US Coal Miners Since 2014-Radiography, Spirometry, and Symptom Assessments

OBJECTIVE

The aim of the study is to summarize Coal Workers' Health Surveillance Program findings since 2014, focusing on prevalence of radiographic pneumoconiosis and abnormal spirometry by region.

METHODS

Analysis included the most recent Coal Workers' Health Surveillance Program encounter for working miners during October 1, 2014-June 30, 2022. Central Appalachia consists of Kentucky, Virginia, and West Virginia.

RESULTS

Pneumoconiosis prevalence was highest among underground miners, with 318 (6.2%) having radiographic evidence of disease. Central Appalachian miners were more likely to have evidence of pneumoconiosis (relative risk = 4.1 [3.4-5.0]) and abnormal spirometry (relative risk = 1.4 [1.2-1.6]) compared with all others.

CONCLUSIONS

Central Appalachia is a hotspot for pneumoconiosis, as well as for other indicators of respiratory impairment in coal miners. Outreach for occupational respiratory health surveillance should focus on those areas most heavily affected, ensuring that miners are not hindered by perceived or actual barriers to this secondary intervention.

Active Surveillance of Engineered Stone Workers Facilitates Early Identification of Silicosis: A Discussion of Surveillance of Occupational Lung Diseases

Silicosis in workers exposed to respirable crystalline silica while fabricating engineered stone products is an emerging respiratory health issue. We describe silicosis in engineered stone workers in California and examine clinical features by the source of identification. Cases were identified passively using hospital-based patient discharge data or actively through outreach and medical testing following enforcement investigation. Outcomes were examined based on the source of case identification. We identified 18 cases diagnosed between 2006 and 2020. Cases identified passively compared to other identification methods were associated with lower percent predicted forced vital capacity (FVC) (P ≤ .01), forced expiratory volume in 1 s (FEV1) (P ≤ .01), and diffusing capacity of the lungs for carbon monoxide (DLCO) (P < .01) at the time of diagnosis and were more likely to be identified following death or lung transplant (P = .01). Our experience demonstrates delays in diagnosis and case identification when relying on passive surveillance methods. Enhanced public health surveillance systems can improve the early detection of occupational lung disease and inform future prevention policies.

Submission of mandatory respiratory health examinations among US coal miners participating in the Coal Workers' Health Surveillance Program

BACKGROUND

Mandatory examination requirements for US coal miners newly entering the workforce have been in place since the 1969 Coal Act mandated chest radiographs and were updated to include spirometry with promulgation of the 2014 Mine Safety and Health Administration Dust Rule. Compliance with the mandatory respiratory screening series is described using data from the National Institute for Occupational Safety and Health Coal Workers' Health Surveillance Program (CWHSP).

METHODS

Among all radiographic and spirometry submissions to the CWHSP during 30 June 1971-15 March 2022, new underground coal miners who began work in the industry after 30 June 1971, and new underground, surface miners and contractors who began work after new regulations were implemented 1 August 2014, were identified and included in analysis.

RESULTS

Of the 115 093 unique miners who participated in the CWHSP and whose estimated entry into mining occurred during 30 June 1971-15 March 2019, 50 487 (43.9%) received their initial mandatory radiograph, and 15 452 (13.4%) submitted their initial and 3-year mandatory radiographs. Since new regulations were implemented, compliance with initial radiographs appeared to improve (80%) but compliance with 3-year radiographs remained low (11.6%). Compliance with spirometry testing was also low for initial (17.1%) and follow-up screenings (2.7%).

CONCLUSIONS

The majority of new coal miners eligible for health surveillance did not receive a baseline radiograph or spirometry test through the CWHSP even though coal mine operators are required by law to provide these. Ensuring coal miners' regular participation in health surveillance from early in their careers is an important way to monitor and protect their respiratory health.

Postexposure progression of pneumoconiosis among former Appalachian coal miners

BACKGROUND

The prevalence of pneumoconiosis among working United States underground coal miners has been increasing for the past two decades, with the highest rates of disease observed among miners in the central Appalachian states of Kentucky, Virginia, and West Virginia. Surveillance for this disease in the United States focuses on working coal miners, who continue to be occupationally exposed to dust. This study examines the radiographic evidence for postexposure progression of pneumoconiosis in a population of former coal miners no longer occupationally exposed to coal mine dust who were seen at a community radiology clinic in eastern Kentucky.

METHODS

Data were obtained and analyzed from clinical records of former coal miners who had a clinic encounter during January 1, 2017-August 1, 2019, a recorded final year of employment, and ≥2 postemployment digital chest radiographs. Radiographs were classified according to the International Labour Office guidelines by at least two B Readers. A final summary pneumoconiosis severity score (range, 0-13), accounting for both small and large opacities, was assigned to each chest radiograph. Progression was defined as an increase in severity score between a miner's radiographs over time.

RESULTS

Data for 130 former coal miners were analyzed. All miners were male and most (n = 114, 88%) had worked primarily in Kentucky. Information on race/ethnicity was not available. The most common job types were roof bolters (n = 51, 39%) and continuous miner operators (n = 46, 35%). Forty-one (31.5%) miners had evidence of radiographic disease progression after leaving the workforce, with a median of 3.6 years between first and latest postretirement radiograph. A total of 80 (62%) miners had evidence of pneumoconiosis on their latest radiograph, and two-thirds (n = 53) of these were classified as progressive massive fibrosis (PMF), the most severe form of the disease.

CONCLUSIONS

Postexposure progression can occur in former coal miners, emphasizing the potential benefits of continued radiographic follow-up postemployment. In addition to participating in disease screening throughout their careers to detect pneumoconiosis early and facilitate intervention, radiographic follow-up of former coal miners can identify new or progressive radiographic findings even after workplace exposure to respirable coal mine dust ends. Identification of progressive pneumoconiosis in former miners has potential implications for clinical management and eligibility for disability compensation.

Cost-effectiveness of comprehensive preventive measures for coal workers' pneumoconiosis in China

Background

Coal workers’ pneumoconiosis (CWP) remains one of the most severe occupational diseases in China. Despite the implementation of CWP comprehensive preventive measures, the unreasonable allocation of investment by coal enterprises limits the effect of preventing CWP, especially when the health resources are inadequate. This study aims to evaluate the cost-effectiveness of comprehensive measures for CWP from the perspective of coal enterprises.

Methods

Comprehensive measures and two primary interventions (engineering controls and individual protective equipment) were selected. A time-dependent Markov model was developed to evaluate cost and quality-adjusted life-years (QALYs). The input data were collected from the survey and literature. A hypothetical null situation, in which the currently implemented interventions were eliminated, was used as a comparator based on the generalised cost-effectiveness analysis (GCEA) recommended by the World Health Organization (WHO). The primary outcomes of the model were reported in terms of incremental cost-effectiveness ratios (ICERs). Uncertainty was verified using one-way and probabilistic sensitivity analyses.

Results

The QALYs of the comprehensive measures, engineering controls, and individual protective equipment were 17.60, 17.50, and 16.85 years, respectively. Compared with null, the ICERs of the interventions were 65,044.73, 30,865.15, and 86,952.41 RMB/QALY, respectively. Individual protective equipment was dominated by an ICER of -11,416.02 RMB/QALY compared to engineering controls. Sensitivity analysis suggested the robustness of the results.

Conclusions

The comprehensive preventive measures for CWP that are currently implemented in Chinese state-owned mines are cost-effective. In comprehensive measures, engineering controls are more cost-effective than individual protective equipment. Investment in engineering controls should be increased to improve the cost-effectiveness of preventing CWP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07654-7.

Analyzing Characteristics of Particulate Matter Pollution in Open-Pit Coal Mines: Implications for Green Mining

The particulate pollution in the open-pit coal mines of China is particularly severe in winter. The aim of this study is to understand the pollution characteristics of particulate matter (PM) in winter and provide a basis for the prevention and control of particulate pollution. We took the problem of PM concentration at the bottom of the Haerwusu Open-pit Coal Mine (HOCM) as the research object. Dust monitoring equipment at two measurement points at different heights were positioned for continuous monitoring of the PM concentration. The data for three months were gathered. Statistical analyses were performed to analyze the variation characteristics of the PM and its relationship with meteorological factors. The results show that the average PM concentration in the study area is below the average daily limit of the China National Ambient Air Quality Standard (GB 3095-2012). However, the average concentration of PM10 exceeded the national limit in December. The order of PM concentration is observed as December > January > February. The correlation of PM is found to be positive with humidity and negative with wind speed. Temperature is found to be positively correlated with PM in December, while it is negative in January. At the same time, the temperature difference in December is negatively correlated with PM concentration. Under the combined action of multiple meteorological factors, the magnitude of the impact on the PM concentration at the bottom of the pit in winter is humidity > temperature > wind speed > temperature difference (inverse temperature intensity). In conclusion, PM2.5 is found to be more sensitive to environmental factors. The results of this study are particularly useful to progress in green mining.