Deaths From Pneumoconiosis — Dust Diseases of the Lungs — in the U.S., 1999–2018

Pneumoconioses are preventable occupational lung diseases caused by breathing in dust — coal dust, asbestos, silica and other mineral dusts, and some organic dusts. From 1968 to 2000, deaths from them fell for every type except asbestosis. A CDC team looked at what happened next, using death certificates for people 15 and older from 1999 to 2018, and industry and job data from 26 states for selected years.

The types

The trend

Over the 20 years, 43,366 people had pneumoconiosis on their death certificate, and for 17,578 of them it was the underlying cause of death. Nearly all were men (96.3%); 41.0% were aged 75–84.

• Asbestosis accounted for about three-fifths of the deaths (60.1%), then coal workers’ pneumoconiosis (25.8%) and unspecified pneumoconiosis (7.9%).
• Deaths fell 40.4%, from 2,738 in 1999 to 1,632 in 2018, with a significant decline from 2002. The age-adjusted death rate fell from 12.8 to 5.3 per million.
• The steepest drops were in coal workers’ pneumoconiosis (69.6%, from 1,002 to 305 deaths) and silicosis (53.0%, from 185 to 87).
• The one exception: deaths from other inorganic dusts rose significantly, from 12 to 25 — though no single disease in that group, mostly berylliosis and siderosis, rose significantly on its own.

The highest death rates over the period were in West Virginia for black lung (59.8 per million) and for unspecified pneumoconiosis (24.1), Montana for asbestosis (20.0), and Vermont for silicosis (2.3).

Who was exposed

Among deaths with job data from 26 states:

• Coal workers’ pneumoconiosis — 74.2% worked in coal mining; 65.0% were mining machine operators.
• Asbestosis — most often in construction (25.0%), and among pipe layers, plumbers, pipefitters and steamfitters (8.0%).
• Silicosis — most often in construction (18.9%), and among mining machine operators (12.3%).

Why deaths fell

• Black lung. A shrinking coal mining workforce and laws such as the 1969 Federal Coal Mine Health and Safety Act, which required federal inspections of all coal mines, set enforceable safety measures and created federal benefits for black lung. A 2014 Mine Safety and Health Administration rule cut the dust limit from 2.0 to 1.5 mg per cubic meter, expanded medical monitoring and added continuous personal dust monitors — too recent, given the disease’s long latency, to explain the decline, but expected to help in future.
• Silicosis. National silica exposure standards from 1971, prevention programs and changes in industry. In 2016 OSHA lowered the exposure limit to 50 µg per cubic meter and added requirements for exposure control, respirators, hazard communication, medical surveillance and records.
• Asbestosis. Deaths began falling in 2001, reflecting the end of U.S. asbestos mining and of asbestos product manufacturing, emission controls, and ever-lower exposure limits — from 12.0 fibers per cubic centimeter in 1971 down to 0.1 in 1994.

The 2018 total of 1,632 deaths was 32.8% below the Healthy People 2020 baseline of 2,430 in 2005, beating its goal of a 10% reduction.

Why vigilance still matters

People are still dying of these preventable diseases, and new risks are emerging: the return of progressive massive fibrosis, the most severe form of black lung; new jobs that expose workers to silica, such as quartz countertop installation and hydraulic fracturing; continued imports of asbestos-containing materials and rising rates of other asbestos diseases such as mesothelioma. A 2019 Environmental Protection Agency rule still allows asbestos imports, its use in gaskets, brakes and chemical manufacturing, and asbestos mining. The authors call for continued dust controls, early detection and surveillance — with more attention to the “other inorganic dust” diseases.

Limitations

• Death certificates were not checked against medical records.
• Some silicosis deaths, such as those from talc linked to illicit drug use, may not be work-related.
• The usual job on a death certificate may not be where exposure happened.
• Rates use the whole population, including people never at occupational risk.
• Small numbers prevented analyzing the “other inorganic dust” diseases individually.

Sources

Based on Bell JL, Mazurek JM, "Trends in Pneumoconiosis Deaths — United States, 1999–2018," Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention; a work of the United States government in the public domain.