Work-Related Lung Disease (WoRLD) Surveillance System

Annual Survey of Occupational Injuries and Illnesses, BLS
After passage of the Occupational Safety and Health Act of 1970, the responsibility for collecting statistics on occupational injuries and illnesses was delegated to the Bureau of Labor Statistics (BLS). The BLS Annual Survey of Occupational Injuries and Illnesses, done in cooperation with participating State agencies, involves data collection by mail from a sample of approximately 250,000 establishments each calendar year. Nearly all industries in the private sector (employers covered by the Occupational Safety and Health Act of 1970) are included. Annual BLS reports of these data incorporate corresponding data from mine operators, provided to BLS by the Mine Safety and Health Administration (MSHA), and from railroad transportation employers, provided to BLS by the Federal Railroad Administration. National estimates of injury and illness incidence rates by industry are developed from the survey data. Beginning in 1992, the survey was expanded to provide more information on illnesses resulting in days away from work, allowing for more detailed classification of respiratory system diseases. For this report, annual summary data on respiratory illnesses were abstracted from BLS annual reports on occupational injuries and illnesses.

In contrast with injury data, illness data presented in the BLS annual reports are quite limited because employers typically do not recognize and report illnesses, particularly illnesses with a long latency. Also, the survey does not cover all workers since it excludes the self-employed; farm operators with fewer than 11 employees; private households; employees in federal, state, and local government agencies; and independent mining contractors.

For more information refer to annual reports: Occupational Injuries and Illnesses: Counts, Rates, and Characteristics, Office of Safety, Health and Working Conditions, U.S. Department of Labor, Bureau of Labor Statistics; and www.bls.gov/iif/home.htm.

Black Lung Benefit Awards, SSA and DOL
Title IV of the Coal Mine Health and Safety Act of 1969 authorizes a benefits program, providing medical payments and cash stipends for miners totally disabled because of pneumoconiosis arising out of employment in underground coal mining, as well as for widows of coal miners whose death resulted from the disease or who were entitled to Black Lung benefits at the time of death. The Social Security Administration (SSA) was assigned initial responsibility for operating the benefits program. The Black Lung Benefits Act of 1972 continued SSA responsibility for payments to miners granted claims before July 1973, assigned the Department of Labor responsibility for claims filed after July 1973, and extended eligibility for benefits to surface coal miners and to surviving children of miners. This latter provision allowed children to receive benefits if both parents were deceased, or if a widow ceased to qualify for benefits through remarriage. (In September 1997, in an effort to enhance customer service to Black Lung program beneficiaries, the responsibility for managing all active SSA Black Lung claims was assigned to DOL.)

For more information refer to annual reports: Social Security Bulletin, Annual Statistical Supplements,2000 at www.ssa.gov/policy/docs/statcomps/supplement/2000/index.html; annual reports to Congress: Office of Workers' Compensation Programs, U.S. Department of Labor, Employment Standards Administration; and U.S. Department of Labor, Black Lung Home Page at www.dol.gov/esa/regs/compliance/owcp/bltable.htm.

Coal Mine Employment Data, MSHA
Initiated in 1970, annual informational reports from the Mine Safety and Health Administration (MSHA) summarize occupational injury and illness experience of United States miners, based on data reported by mine operators. Each operator subject to the Federal Mine Safety and Health Act of 1977 is required to submit annual reports of all injuries and occupational illnesses (see section on Annual Survey of Occupational Injuries and Illnesses, above), as well as related data, including average number of employees during the year. The MSHA informational reports on coal mining provide annual estimates for size of the mining workforce, including separate figures for underground mines. Similar estimates are provided based on data reported by contractors performing certain work at mining operations.

For more information refer to annual reports: Injury Experience in Coal Mining, U.S. Department of Labor, Mine Safety and Health Administration; and www.msha.gov/stats/part50/p50y2k/aetable.htm.

Coal Workers' X-ray Surveillance Program, NIOSH
The Coal Workers' X-ray Surveillance Program (CWXSP) is a NIOSH-administered occupational health program mandated by the Coal Mine Health and Safety Act of 1969. The primary objective of the CWXSP is to screen miners for coal workers' pneumoconiosis (CWP). Since 1970, coal mine operators have been required to offer a chest radiograph to all underground coal miners at the time of hire and again three years later. Subsequently, miners can volunteer for radiographs at approximately five-year intervals. The chest x-rays are taken at no cost to the miners. In addition to the posterior-anterior chest x-ray, other information is collected, including miner identification, age, tenure, and specific job in the mine.

The chest films are read by physicians certified by NIOSH as proficient in use of the International Labour Office (ILO) classification system for radiographs of the pneumoconioses. Each film is read by at least two readers, and a consensus rule is used to reach a final determination for each film. The CWXSP defines CWP as small opacity profusion category of at least 1/0 or large opacities (i.e., larger than one centimeter in diameter). Miners with radiographic evidence of CWP on their chest radiographs are offered the option to work in an area of the mine with a respirable coal mine dust level of 1 mg/m3 or less and have personal dust exposures monitored at frequent intervals.

The large number of chest x-ray examinations since 1970 provide a means of monitoring the prevalence of CWP among active underground coal miners. However, coal miner participation rates have generally decreased since 1970 to less than 30% of working underground coal miners. Thus, tenure-specific prevalence estimates may be biased due to selective participation. Also, overall crude prevalence estimates may reflect over-representation of newly employed miners. Inferences regarding the entire coal mine work force that are based on CWXSP data should be drawn with caution. Tabulations of CWXSP data presented in this report vary from those presented in some earlier editions of the Work-Related Lung Disease Surveillance Report due to revised criteria for categorizing tenure and round.

For more information: Coal Workers' Health Surveillance Program, Surveillance Branch, Division of Respiratory Disease Studies, NIOSH, 1095 Willowdale Road, Morgantown, WV 26505, phone (304) 285-5724 at www.cdc.gov/niosh/topics/surveillance/ORDS/CoalWorkersHealthSurvProgram.html.

Integrated Management Information System, OSHA
The Integrated Management Information System (IMIS) includes most of the industrial hygiene sample data from Occupational Safety and Health Administration (OSHA) compliance inspections and consultation surveys conducted since May 1979. The data are reported by OSHA compliance safety and health officers and OSHA state consultants. Each IMIS record includes sample date, substance code, airborne concentration, sample type and exposure type, occupation, OSHA permissible exposure limit (PEL), and standard industrial classification (see Methods, Appendix B). OSHA consultation data were not included in previous NIOSH Work-Related Lung Disease Surveillance Reports. Therefore, most numbers of samples reported for a given year, or period of years, are greater than reported previously.

For more information: Directorate of Information Technology, Occupational Safety and Health Administration, 200 Constitution Avenue, NW, Washington, DC 20210, phone (202) 693-1700.

Metal/Nonmetal Mine Data, MSHA
The metal/nonmetal mine data (MNMD) are records of industrial hygiene samples collected by Mine Safety and Health Administration (MSHA) inspectors in non-coal surface and underground mines and mills since 1974. This report presents data since 1979, which represent both personal and area samples. Each MNMD record includes sample date, contaminant code, airborne concentration, occupation, MSHA permissible exposure limit (PEL), percent silica and silica concentration where available, standard industrial classification, and the mine and/or mill at which the sample was obtained. In 1982, Congress temporarily removed the surface stone and sand and gravel industries from MSHA's jurisdiction. During this year the number of respirable dust samples collected are fewer than in other years. The quartz reference standard used for MNMD samples changed in 1988. As a result, the reported percent quartz content, quartz concentrations, and the percentage of samples exceeding the PEL increased in 1988 from 1987. MSHA occasionally revises and updates MNMD files, so the number of records reported for a given year, or period of years, may differ from previous reports.

For more information: Metal and Nonmetal Health Division, Mine Safety and Health Administration, Room 2453, 1100 Wilson Blvd., Arlington, VA 22209, phone (202) 693-9630.

For more information on the quartz reference standard used for the MNMD samples: Dust Division, Pittsburgh Safety and Health Technology Center, Mine Safety and Health Administration, P.O. Box 18233, Pittsburgh, PA 15236, phone (412) 386-6858 at www.msha.gov/techsupp/pshtcweb/dust.htm.

Multiple Cause-of-Death Data, NCHS
The National Center for Health Statistics (NCHS) has made available annual public-use multiple cause-of-death data files since 1968. These files contain records of all deaths in the United States (approximately two million annually) that are reported to state vital statistics offices. Each death record includes codes for up to 20 conditions listed on the death certificate, including both underlying and contributing causes of death in two fields: the entity axis, which preserves diagnostic detail for all listed conditions and their placement on the death certificate; and the record axis, which reorders the codes, removes redundancies, and (infrequently) combines some associated conditions (see "Detail Record Layout" at www.cdc.gov/nchs/about/major/dvs/mcd/1998mcd.htm). Other data include age, race, sex, and state and county of residence at time of death. In addition, usual industry and occupation codes are available for decedents from some states since 1985. NCHS annually determines that certain quality criteria have been met by usual industry and occupation data from selected states (see Appendix E).

Potential limitations of multiple cause-of-death data include: under- or over-reporting of conditions on the death certificate by certifying physicians; incomplete or unclassified reporting of usual occupation and industry; and non-specificity of codes.

For more information: Mortality Statistics Branch, Division of Vital Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, 6525 Belcrest Road, Room 820, Hyattsville, Maryland 20782. Phone (301) 458-4666; and www.cdc.gov/nchs/products/elec_prods/subject/mortmcd.htm. Also refer to the annual reports: Vital Statistics of the United States, Vol. II Mortality (Parts A and B), Public Health Service, National Center for Health Statistics; and www.cdc.gov/nchs/products/pubs/pubd/vsus/vsus.htm.

For more information on usual industry and occupation codes: see "Technical Appendix for 1995" at www.cdc.gov/nchs/about/major/dvs/mcd/1998mcd.htm.

National Health Interview Survey, NCHS
The National Center for Health Statistics (NCHS) makes available public-use data from the National Health Interview Survey (NHIS), an annual health survey that has been conducted since 1960. NHIS is a cross-sectional household interview survey on the health of the civilian non-institutionalized population of the United States. The main objective of the NHIS is to monitor the health of the United States population through the collection and analysis of data on a broad range of health topics. NHIS data are collected annually from approximately 40,000 households and include about 100,000 persons. The households selected for interview in the NHIS are a probability sample representative of the target population. The annual response rate of the NHIS is near 90% of the eligible households in the sample.

For more information: Division of Health Interview Statistics, National Center for Health Statistics, 6525 Belcrest Road, Hyattsville, MD 20782; and www.cdc.gov/nchs/nhis.htm.

National Hospital Discharge Survey, NCHS
Estimated numbers of hospital discharges presented in this report have been abstracted from National Hospital Discharge Survey (NHDS) reports published by the National Center for Health Statistics (NCHS). The NHDS, conducted yearly by NCHS, collects data on the use of short-stay non-Federal hospitals in the United States. Federal, military, and Department of Veterans Affairs hospitals were excluded in the survey. In recent years, data have been abstracted from approximately 300,000 records from about 500 hospitals. Each discharge record includes information on patient age, race, sex, ethnicity (since 1985), marital status, length of stay, source of payment (since 1977), diagnoses and surgical procedures, hospital size, ownership, and region of the United States.

Only hospitals with six or more beds for patient use and those in which the average length of stay for all patients is less than 30 days are included in the survey. One limitation of NHDS data is that they represent number of discharges, not number of patients. In addition, information is available only nationally and by region, but not by state. The NHDS relies on the completeness of hospital medical records, and findings can be influenced by diagnostic practices.

For more information: National Hospital Discharge Survey: Annual Summary with Detailed Diagnosis and Procedure Data, Division of Health Care Statistics, National Center for Health Statistics at www.cdc.gov/nchs/about/major/hdasd/nhdsdes.htm.

Occupational and Environmental Disease Surveillance Database, AOEC
A database for occupational and environmental diseases and chronic injuries has been developed by the Association of Occupational and Environmental Clinics (AOEC). For inclusion in the database, a case must have at least one diagnosed condition that, in the physician's judgment, is more likely than not to be related to occupational or environmental exposure. Twenty-four AOEC member clinics contributed cases for the period 1991-2000. Six clinics participated over the entire 10-year period and contributed 80% of the cases. An additional seven clinics contributed over 125 cases each and submitted 14% of the cases. While not necessarily representative of all patients with work-related conditions, these case reports provide insight into the types of occupational conditions being treated by occupational medicine specialists, as well as into the types of exposures that are causing or exacerbating these diseases.

For more information: Association of Occupational and Environmental Clinics, 1010 Vermont Ave., NW, #513, Washington, DC 20005, phone (202) 347-4976 at www.aoec.org.

Population Data Estimates, BoC and CDC
National population estimates used in this report are based on national and state level data from the United States Bureau of the Census (BoC). All population estimates used to compute rates in this report have been those obtainable through the CDC computer system. BoC decennial census population data were used for 1970, 1980, and 1990. In all other years prior to 1990, estimates from intercensal Demo Detail files were used. Estimates from postcensal Demo Detail files were used for 1991-1995. Since 1996, comparable postcensal population estimates prepared by the BoC were used. [Note: Comparing population statistics from Demo-Detail and BoC postcensal estimates for each year from 1990 through 1995, we observed a maximum annual difference of less than 0.05 percent, and a difference of 0.01 percent or less in a majority of years. State-specific differences for the same years were less than one percent for all states, with very rare exceptions.]

For more information: 1990 Census of the Population, General Population Characteristics, U.S. Bureau of the Census, Series 1900, CP-1; and www.census.gov/prod/www/abs/decenial.html. For more information on population estimates: www.census.gov/popest/estimates.php.

Respirable Coal Mine Dust Data, MSHA
The data consist of respirable coal mine dust measurements collected by MSHA inspectors and mine operators at surface and underground coal mines and preparation plants since 1974. Each record includes sample date, duration, and airborne concentration, as well as occupation and the mine or preparation plant at which the sample was obtained.

For more information: Information Resource Center, Mine Safety and Health Administration, P.O. Box 25367, Denver, CO 80225, phone (303) 231-5475; and www.msha.gov/techsupp/pshtcweb/dust.htm

Respirable Coal Mine Quartz Dust Data, MSHA
The data consist of respirable quartz measurements collected by MSHA inspectors and mine operators at surface and underground coal mines and preparation plants since 1982. Each record includes sample date, duration, percent quartz, and airborne concentration, as well as occupation and the mine or preparation plant at which the sample was obtained.

For more information: Dust Division, Pittsburgh Safety and Health Technology Center, Mine Safety and Health Administration, P.O. Box 18233, Pittsburgh, PA 15236, phone (412) 386-6858 at www.msha.gov/techsupp/pshtcweb/dust.htm

Sentinel Event Notification Systems for Occupational Risks (SENSOR), NIOSH
Since 1987, NIOSH has awarded cooperative agreements to various state health departments to develop models for state-based and condition-specific surveillance and preventive intervention. Two of the conditions for which states have been funded through the SENSOR program are silicosis and work-related asthma. States and years funded for these two conditions are shown in Table A-1.

SENSOR Silicosis. A total of three states (MI, NJ, OH) maintained silicosis surveillance programs during the 10-year period covered by the SENSOR tables included in this report (1989-1998). All three states identified potential cases using a variety of sources: review of state death certificate data, case reports from physicians, review of hospital discharge data or direct hospital reporting to the state health department. In addition, Michigan and Ohio review workers' compensation records.

In all three states, demographic, work history, and medical information used for case confirmation and description was obtained through a combination of the initial case ascertainment source, a review of medical records, and follow-up telephone interview with the reported cases or their surviving next of kin. For SENSOR surveillance purposes, silicosis case confirmation requires a history of occupational exposure to airborne silica dust and either: (a) a chest radiograph interpreted as characteristic of silicosis, or (b) lung histopathology characteristic of silicosis (see Appendix G).

For more information: Maxfield R, Alo C, Reilly MJ, et al. Surveillance for silicosis, 1993-Illinois, Michigan, New Jersey, North Carolina, Ohio, Texas, and Wisconsin. MMWR CDC Surveill Summ 1997 Jan 31;46:13-28 at www.cdc.gov/mmwr/preview/mmwrhtml/00046046.htm.

SENSOR Work-Related Asthma (WRA). A total of four states (CA, MA, MI, NJ) maintained WRA surveillance programs during the seven-year period covered by the SENSOR tables included in this report (1993-1999). Physician case reports represented the primary ascertainment source in all four states. Massachusetts, Michigan, and New Jersey actively solicited physicians for case reports, whereas California identified potential cases by reviewing data from Doctor's First Reports (DFR) of Occupational Injury or Illness, a longstanding statewide physician reporting system linked to physician reimbursement for medical services. In addition, Michigan and New Jersey actively solicited hospital reports and reviewed hospital discharge records for potential WRA cases. In 1993, Massachusetts also began supplementing case ascertainment with review of state-wide hospital discharge data.

In all four states, surveillance staff collected demographic, work history, and medical information used for case confirmation, classification, and description through a combination of the initial case ascertainment source, a review of medical records, and follow-up telephone interview with reported cases. For SENSOR surveillance purposes, WRA surveillance case confirmation requires a healthcare professional's diagnosis of asthma (or a related diagnosis consistent with asthma) and an association between symptoms of asthma and work. Confirmed WRA cases are classified according to established criteria (see Appendix G). To facilitate consistency in agent coding across states, putative causes of WRA are coded using the Association of Occupational and Environmental Clinics (AOEC) exposure coding scheme (www.aoec.org/aoeccode.htm), which flags "known asthma inducers."

For more information: Jajosky RA, Harrison R, Reinisch F, et al. Surveillance of work-related asthma in selected U.S. states using surveillance guidelines for state health departments-California, Massachusetts, Michigan, and New Jersey, 1993-1995. MMWR CDC Surveill Summ 1999 Jun 25;48:1-20 at www.cdc.gov/mmwr/preview/mmwrhtml/ss4803a1.htm.