Surveillance for Silicosis Deaths Among Persons Aged 15–44 Years — United States, 1999–2015

Silicosis is usually a disease of long latency affecting mostly older workers; therefore, silicosis deaths in young adults (aged 15–44 years) suggests acute or accelerated disease.* To understand the circumstances surrounding silicosis deaths among young persons, CDC analyzed the underlying and contributing causes^† of death using multiple cause-of-death data (1999–2015) and industry and occupation information abstracted from death certificates (1999–2013). During 1999–2015, among 55 pneumoconiosis deaths of young adults with International Classification of Diseases, Tenth Revision (ICD-10) code J62 (pneumoconiosis due to dust containing silica),^§ 38 (69%) had code J62.8 (pneumoconiosis due to other dust containing silica), and 17 (31%) had code J62.0 (pneumoconiosis due to talc dust) listed on their death certificate. Decedents whose cause of death code was J62.8 most frequently worked in the manufacturing and construction industries and production occupations where silica exposure is known to occur. Among the 17 decedents who had death certificates listing code J62.0 as cause of death, 13 had certificates with an underlying or a contributing cause of death code listed that indicated multiple drug use or drug overdose. In addition, 13 of the 17 death certificates listing code J62.0 as cause of death had information on decedent’s industry and occupation; among the 13 decedents, none worked in talc exposure–associated jobs, suggesting that their talc exposure was nonoccupational. Examining detailed information on causes of death (including external causes) and industry and occupation of decedents is essential for identifying silicosis deaths associated with occupational exposures and reducing misclassification of silicosis mortality.

Various occupationally associated pulmonary diseases are linked to exposure to silica and silicates, a large class of minerals that includes talc (hydrous magnesium silicate) and other nonfibrous silicate minerals (1). Silicosis is caused by inhaling respirable crystalline silica. Occupational exposure to airborne respirable silica particles has been associated with work in mining, quarrying, tunneling, construction, sandblasting, masonry, foundry operations, glass manufacture, ceramic and pottery production, and cement and concrete production and with work with certain materials in dental laboratories (2). Newly emerging occupations and tasks, including fabricating and installing quartz-containing engineered stone products and extracting natural gas by hydraulic fracturing also place workers at risk for silicosis.^¶ Approximately 2.3 million workers might be exposed to respirable crystalline silica in the United States.**

Exposure to talc causes talcosis (talco-silicosis or talco-asbestosis if talc is contaminated with silica or asbestos fibers, respectively); inhalation of talc usually results from occupational exposures during talc mining and milling and during production of ceramics, pharmaceuticals, paint, paper, cosmetics, plastics, roofing, rubber, insecticides, and other products (3). Although only 240 workers were employed in talc mining in the United States during 2015 (the number of workers exposed to talc in milling and secondary industries is unknown), 803,000 metric tons of talc were used in various products that year.^†† Nonoccupational exposure to talc dust has been associated with use of cosmetic talcum powder (4) and, importantly, with illicit intravenous or inhalation administration of talc-containing legal or illegal drugs, including marijuana, methamphetamine, methadone, promethazine, cocaine, diazepam, acetaminophen, meperidine, pentazocine, oxymorphone, and heroin (3,5–7).

To investigate silicosis deaths among young adults, ICD-10 codes for underlying and contributing causes of death from the 1999–2015 National Center for Health Statistics’ multiple cause-of-death mortality data were analyzed to provide detailed information on the circumstances surrounding pneumoconiosis deaths among young adults caused by dust containing silica. Time trends were assessed using a linear regression model. Twenty-one states provided copies of actual death certificates^§§ from 1999 through 2013; usual industry and occupation entries were abstracted from these certificates and were coded using the National Institute for Occupation Safety and Health’s Industry and Occupation Computerized Coding System.^¶¶

During 1999–2015, a total of 55 young adult decedents had ICD-10 code J62 assigned as either the underlying or a contributing cause of death, including 38 (69%) with ICD-10 subcategory J62.8 listed as the underlying (27) or a contributing (11) cause of death. The mean age of these 38 decedents was 38.6 years; most were males (95%), white (82%), non-Hispanic (74%), and born in the United States (71%) (Table 1). None of these 38 deaths involved multiple drug use or drug overdose; three (8%) had received subcutaneous silicone injections.***

Seventeen (31%) of the 55 decedents had subcategory J62.0 listed as the underlying (11) or contributing (6) cause of death. The mean age of these decedents was 37.5 years; slightly more than half (9) were male, 13 were white, 15 were non-Hispanic, and all were born in the United States. Thirteen of these 17 deaths involved multiple drug use and drug overdose. ^††† The number of pneumoconiosis deaths due to other dust containing silica and due to talc dust among young adults remained stable during 1999–2015 (Table 1).

To evaluate industry and occupation of decedents with a diagnosis of silicosis, CDC obtained death certificates for 47 young adult decedents reported during 1999–2013 from 21 states^§§§ who had ICD-10 code J62 assigned as the underlying or contributing cause of death. Industry and occupation entries recorded on death certificates were reviewed, including 34 (97%) certificates for 35 deaths with any mention of pneumoconiosis due to other dust containing silica and all certificates for 13 deaths with any mention of pneumoconiosis due to talc dust during 1999–2013. Among the 35 decedents with a diagnosis of pneumoconiosis due to other dust containing silica, the majority were associated with working in the manufacturing (e.g., cut stone and stone product manufacturing industry) (12 [34%]) and construction (7 [20%]) industry sectors; 11 (31%) were working in production (e.g., crushing, grinding, polishing, mixing, and blending workers) occupations; five (14%) in construction and extraction occupations; and three (9%) as brickmasons and blockmasons (Table 2). These industries and occupations have well-established associations with exposure to crystalline silica (2). Among the 13 decedents whose death certificates included any mention of pneumoconiosis due to dust containing talc, none was employed in an industry or occupation traditionally associated with exposure to talc. Ten of these 13 decedents were assigned codes indicating multiple drug use or drug overdose. Among these 10 decedents, three worked in the health care and social assistance industry (offices of dentists, ambulatory health care services, and general medical and surgical hospitals) (Table 3).

Acknowledgments

Center for Health Statistics, Alabama Department of Public Health; Bureau of Vital Records, Arizona Department of Health; Vital Records Branch, Arkansas Department of Health; Center for Health Statistics and Informatics, California Department of Public Health; State Office of Vital Records, Georgia Department of Public Health; Division of Vital Records, Illinois Department of Public Health; Division of Vital Records, Indiana State Department of Health; Kansas Department of Health and Environment; Office of Vital Statistics, Kentucky Department for Public Health; Center for Records and Statistics, Louisiana Department of Health and Hospitals; Division for Vital Records and Health Statistics, Michigan Department of Health and Human Services; Office of Vital Records, Minnesota Department of Health; Office of Vital Records and Health Statistics, Mississippi State Department of Health; Office of Vital Statistics and Registry, New Jersey Department of Health; Bureau of Vital Records and Health Statistics, New Mexico Department of Health; Vital Records, North Carolina Department of Health and Human Services; Vital Statistics, Ohio Department of Health; Bureau of Health Statistics and Registries, Pennsylvania Department of Health; Bureau of Health Statistics and Registries, Pennsylvania Department of Health; Office of Healthcare Statistics, Tennessee Department of Health; Texas Department of State Health Services; Center for Health Statistics, Washington State Department of Health; Rose A. Rudd, Division of Unintentional Injury Prevention, National Center for Injury Prevention and Control, CDC; Carole A. Rehm, Respiratory Health Division, National Institute for Occupational Safety and Health, CDC.

Corresponding author: Jacek M. Mazurek, jmazurek1@cdc.gov, 304-285-5983.

¹Respiratory Health Division, National Institute for Occupational Safety and Health, CDC.

References

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TABLE 1. Pneumoconiosis deaths due to dust containing silica (ICD-10 category J62),* among persons aged 15–44 years (n = 55), by patient characteristics, year of death, and ICD-10 subcategory (J62.0 or J62.8^†) — United States, 1999–2015

Abbreviation: ICD-10 = International Classification of Diseases, Tenth Revision.
* Decedents with the ICD-10 code J62, pneumoconiosis due to dust containing silica category assigned to their underlying or contributing causes of death.
^† ICD-10 code J62 is further divided into subcategories: J62.0 = pneumoconiosis due to talc dust; J62.8 = pneumoconiosis due to other dust containing silica.
^§ For 1999–2015 time trend (time trends examined using a first-order autoregressive linear regression model).

TABLE 2. Deaths due to other dust containing silica (ICD-10 subcategory J62.8),* among persons aged 15–44 years (n = 35), by year of death, age, industry and occupation,^† and assignment of code J62.8 as the underlying cause — United States, 1999–2013

Abbreviation: ICD-10 = International Classification of Diseases, Tenth Revision.
* Assigned as either the underlying or contributing cause of death in the National Center for Health Statistics (NCHS) multiple cause-of-death data.
^† Usual industry and occupation entries on death certificates for 34 (97%) of 35 pneumoconiosis deaths caused by other dust containing silica reported for 1999–2013 were available for review and coded using North American Industry Classification System and 2010 Standard Occupational Classification codes (https://wwwn.cdc.gov/niosh-nioccs/default.aspx).
^§ Because industry was not known, this occupation could be coded as 1) cleaners of vehicles and equipment, 2) crushing, grinding, and polishing machine setters, or 3) operators, and tenders construction laborers.
^¶ Death certificate was unavailable for review; information on year of death, age, and codes assigned as the underlying cause of death from the NCHS multiple cause-of-death data.

TABLE 3. Deaths due to talc dust (ICD-10 subcategory J62.0)* among persons aged 15–44 years (n = 13), by year of death, age, industry and occupation,^† and assignment of code indicating multiple drug use or drug overdose^§ — United States, 1999–2013

Abbreviation: ICD-10 = International Classification of Diseases, Tenth Revision.
* Assigned as either the underlying or contributing cause of death in the National Center for Health Statistics (NCHS) multiple cause-of-death data.
^† Usual industry and occupation entries on death certificates for all 13 (100%) pneumoconiosis deaths due to talc dust reported for 1999–2013 were available for review and coded using North American Industry Classification System and 2010 Standard Occupational Classification codes (https://wwwn.cdc.gov/niosh-nioccs/default.aspx).
^§ ICD-10 codes indicating multiple drug use of drug overdose: X42 (accidental poisoning by and exposure to narcotics and psychodysleptics [hallucinogens], not elsewhere classified); X44 (accidental poisoning by and exposure to other and unspecified drugs, medicaments and biologic substances); F19 (multiple drug use and use of other psychoactive substances [F19.1 (harmful use)], [F19.9 (unspecified mental and behavioral disorder)]); T39 (poisoning by nonopioid analgesics, antipyretics and antirheumatics, including T39.8 [other nonopioid analgesics and antipyretics, not elsewhere classified]); T40 (poisoning by narcotics and psychodysleptics [hallucinogens] [T40.2 (other opioids), T40.3 (methadone), T40.6 (other and unspecified narcotics)]); T42 (poisoning by antiepileptic, sedative-hypnotic and antiparkinsonism drugs, including T42.4 [benzodiazepines]) and T42.6 [other antiepileptic and sedative-hypnotic drugs]); X40 (accidental poisoning by and exposure to nonopioid analgesics, antipyretics, and antirheumatics) listed as the underlying or a contributing cause in the NCHS multiple cause-of-death data.