Janet M. Hale

Rapidly progressive coal workers' pneumoconiosis in the United States: geographic clustering and other factors

Background: Despite significant progress made in reducing dust exposures in underground coal miners in the United States, severe cases of coal workers’ pneumoconiosis (CWP), including progressive massive fibrosis (PMF), continue to occur among coal miners. Aims: To identify US miners with rapidly progressive CWP and to describe their geographic distribution and associated risk factors. Methods: Radiographic evidence of disease progression was evaluated for underground coal miners examined through US federal chest radiograph surveillance programmes from 1996 to 2002. A case of rapidly progressive CWP was defined as the development of PMF and/or an increase in small opacity profusion greater than one subcategory over five years. County based prevalences were derived for both CWP and rapidly progressive cases. Results: A total of 886 cases of CWP were identified among 29 521 miners examined from 1996 to 2002. Among the subset of 783 miners with CWP for whom progression could be evaluated, 277 (35.4%) were cases of rapidly progressive CWP, including 41 with PMF. Miners with rapidly progressive CWP were younger than miners without rapid progression, were more likely to have worked in smaller mines (<50 employees), and also reported longer mean tenure in jobs involving work at the face of the mine (in contrast to other underground mining jobs), but did not differ with respect to mean underground tenure. There was a clear tendency for the proportion of cases of rapidly progressive CWP to be higher in eastern Kentucky, and western Virginia. Conclusions: Cases of rapidly progressive CWP can be regarded as sentinel health events, indicating inadequate prevention measures in specific regions. Such events should prompt investigations to identify causal factors and initiate appropriate additional measures to prevent further disease.

Surveillance of respirable crystalline silica dust using OSHA compliance data (1979–1995)

BACKGROUND The objective of this work was to estimate the percentage of workers by industry that are exposed to defined concentrations of respirable crystalline silica dust. METHODS An algorithm was used to estimate the percentage of total workers exposed to crystalline silica in 1993 at concentrations of at least 1, 2, 5, and 10 times the National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL) of 0.05 mg/m3. Respirable crystalline silica air sampling data from regulatory compliance inspections performed by the Occupational Safety and Health Administration (OSHA), for the years 1979-1995, and recorded in the Integrated Management Information System (IMIS) were used to estimate exposures. Therefore, this work does not include industries such as mining and agriculture that are not covered by OSHA. The estimates are stratified by Standard Industrial Classification (SIC) codes. RESULTS This work found that some of the highest respirable crystalline silica dust concentrations occurred in construction (masonry, heavy construction, and painting), iron and steel foundries (casting), and in metal services (sandblasting, grinding, or buffing of metal parts). It was found that 1.8% (13,800 workers) of the workers in SIC 174--Masonry, Stonework, Tile Setting, and Plastering--were exposed to at least 10 times the NIOSH REL. For SIC 162--Heavy Construction, Except Highway and Street Construction--this number is 1.3% (6,300 workers). SIC 172--Painting and Paper Hanging--which includes construction workers involved in sandblasting was found to have 1.9% (3,000 workers) exposed to at least 10 times the NIOSH REL. The industry that was found to have the highest percentage of workers (6%) exposed to at least the NIOSH REL was the cut stone and stone products industry. CONCLUSION Not enough is being done to control exposure to respirable crystalline silica. Engineering controls should be instituted in the industries indicated by this work.

National Occupational Health Survey of Mining Query System

Abstract The National Institute for Occupational Safety and Health (NIOSH) conducted a project called the National Occupational Health Survey of Mining (NOHSM) from 1984 to 1989. The NOHSM consisted of 491 mine surveys. The mines were selected so as to be statistically representative of the entire U.S. mining industry. At each mine, NIOSH employees obtained data regarding occupational hygiene programs, potential exposure to chemical and physical agents, and bulk dust samples. The NOHSM survey data have been automated in the NOHSM Query System. This system allows queries to be processed against the data collected during the NOHSM survey. The NOHSM Query System was developed to be user friendly so that end-users can process their own queries against the NOHSM data. This was accomplished by making the system key driven with on-line help, and simplifying the query formulation process by minimizing the selections. There are two steps in formulating a query. Step one is deciding which data to retrieve or how to...

Radiographic features of importance in the National Institute for Occupational Safety and Health-administered Coal Workers’ Health Surveillance Program: characterising the use of the ‘other symbols’

Objective The National Institute for Occupation Safety and Health-administered Coal Workers’ Health Surveillance Program (CWHSP) provides radiographic pneumoconiosis screening for US coal miners. Radiographs are classified by readers according to International Labour Office criteria. In addition to pneumoconiotic parenchymal and pleural lung abnormalities, readers document radiographic features of importance (other symbols). Other symbols are not meant to imply a diagnosis or interpretation but are relevant as they provide information beyond a pneumoconiosis classification for features related to dust exposure and other aetiologies. Our objective was to summarise other symbol data from 48 years of CWHSP participants. Methods Chest radiograph classifications obtained from CWHSP participants between July 1968 and July 2016 were analysed. Any ‘other symbol’ indication from any of the readings were counted. Frequencies were tabulated by individual reader and those identified by any reader. Results Of the 469 922 radiographs included in this study, nearly 15% had at least one reader identify a radiographic feature of importance. The most commonly identified other symbol was cancer (excluding mesothelioma) (6.83%), followed by emphysema (1.68%). Some features were rarely identified over the 48 years of data collection such as rheumatoid pneumoconiosis (n=46), pneumothorax (n=32), mesothelioma (n=12) and rounded atelectasis (n=4). Conclusions This is the largest study to date describing radiographic features of importance as part of routine chest radiographic surveillance. While these symbols are not diagnostic they can be used to describe features associated with dust exposure. One of the most commonly identified radiographic features in our population is emphysema which is associated with respirable dust exposure. These results can be compared with other dust exposed populations.

Respiratory health services reported by U.S. mining facilities in the National Occupational Health Survey of Mining (1984–1989)

This report describes the involvement of mine management personnel at U.S. mines in providing environmental and medical services related to respiratory health. The data were obtained by means of a questionnaire that was administered to mine management personnel at 491 mines and mills during May 1984 to August 1989. The data indicate that 62% of U.S. miners worked at facilities that provided at least a portion of workers with chest X-rays, and 41% worked at facilities that provided at least a portion of workers with pulmonary function tests. Eighty-five percent of miners worked at facilities in which the company required a medical examination of all new employees; the majority were required by company policy to have a medical examination before returning to work after an illness. However, only 2% of miners were required by company policy to have an exit medical examination when their employment ended. This report underscores the need for respiratory health to remain a primary concern of all persons who provide occupational health services to miners.