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.***
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
Characteristic
J62.0
J62.8
Underlying or contributing cause
Underlying cause
Underlying or contributing cause
Underlying cause
Total
17
11
38
27
Sex
Male
9
7
36
26
Female
8
4
2
1
Race
White
13
9
31
22
Black
3
2
6
4
Other
1
0
1
1
Ethnicity
Hispanic
2
1
10
8
Non-Hispanic
15
10
28
19
Education
≤8 grade
0
0
5
4
9–12
1
1
6
3
High school diploma
8
5
10
9
Some college
1
0
2
2
College degree
2
1
1
0
Unknown
5
4
14
9
Marital status
Married
6
5
18
13
Single/Divorced
11
6
19
13
Unknown
0
0
1
1
Place of birth
United States
17
11
27
18
Outside United States
0
0
11
9
Year of death
1999
1
1
2
1
2000
0
0
5
5
2001
0
0
1
1
2002
1
1
4
3
2003
3
2
3
3
2004
0
0
3
0
2005
0
0
2
1
2006
2
1
4
2
2007
0
0
1
1
2008
0
0
2
2
2009
0
0
1
1
2010
0
0
1
0
2011
1
1
3
2
2012
0
0
0
0
2013
5
3
3
3
2014
1
0
1
0
2015
3
2
2
2
p-value§
0.21
0.41
0.09
0.23
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).
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).
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
Year of death
Age (yrs)
Industry
Occupation
J62.8 code listed as the underlying cause
1999
40
Cut stone and stone product manufacturing
Crushing, grinding, and polishing machine setters, operators, and tenders
Yes
1999
43
Commercial and institutional building construction
Cement masons and concrete finishers
No
2000
32
Cut stone and stone product manufacturing
Etchers and engravers
Yes
2000
34
Unknown, blank, inadequate information
Sandblaster§
Yes
2000
41
Manufacturing
Production workers, all other
Yes
2000
41
Nonmetallic mineral mining and quarrying
Loading machine operators, underground mining
Yes
2000
43
Services to buildings and dwellings
Janitors and cleaners, except maids and housekeeping cleaners
Yes
2001
39
Construction of buildings
Brickmasons and blockmasons
Yes
2002
40
All other miscellaneous chemical product and preparation manufacturing
Industrial production managers
No
2002
41
Masonry contractors
Brickmasons and blockmasons
Yes
2002
43
Vitreous china, fine earthenware, and other pottery product manufacturing
Production workers, all other/Machine feeders
Yes
2002
44
Unknown, blank, inadequate information
Unknown, blank, inadequate information
Yes
2003
22
Construction
Construction laborers
Yes
2003
31
Retail trade
First-line supervisors of retail sales workers
Yes
2003
35
Unknown, blank, inadequate information
Unknown, blank, inadequate information
Yes
2004
41
Cut stone and stone product manufacturing
Laborers and freight, stock, and material movers, hand
No
2004
42
Nonmetallic mineral product manufacturing
Production workers, all other
No
2004
44
Ferrous metal foundries
Crushing, grinding, and polishing machine setters, operators, and tenders
No
2005
36
Tile and terrazzo contractors
Brickmasons and blockmasons
Yes
2005
41
Cement and concrete product manufacturing
Production workers, all other
No
2006
38
Unknown, blank, inadequate information
Unknown, blank, inadequate information
Yes
2006
41
Cut stone and stone product manufacturing
Crushing, grinding, and polishing machine setters, operators, and tenders
Yes
2006
42
Agencies, brokerages, and other insurance related activities
Social workers, all other
No
2006
43
Unknown, blank, inadequate information
Unknown, blank, inadequate information
No
2007
34
Electric power generation, transmission and distribution
Painting, coating, and decorating workers
Yes
2008
43
Cut stone and stone product manufacturing
Etchers and engravers
Yes
2008¶
34
Unknown, blank, inadequate information
Unknown, blank, inadequate information
Yes
2009
32
Janitorial services
Janitors and cleaners, except maids and housekeeping cleaners
Yes
2010
37
Nonpaid workers
Did not work
No
2011
34
General freight trucking
Heavy and tractor-trailer truck drivers
No
2011
35
Manufacturing
Production workers, all other
Yes
2011
44
Unknown, blank, inadequate information
Unknown, blank, inadequate information
Yes
2013
36
Construction
Industrial production managers
Yes
2013
41
Construction of buildings
Operating engineers and other construction equipment operators
Yes
2013
44
Other miscellaneous durable goods merchant wholesalers
Industrial truck and tractor operators
Yes
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
Year of death
Age (yrs)
Industry
Occupation
Multiple drug use or drug overdose codes listed
1999
37
Nonpaid workers
Homemakers
Yes
2002
41
Voluntary health organizations
Secretaries and administrative assistants, except legal, medical, and executive
No
2003
37
Glass and glass product manufacturing
Glaziers
Yes
2003
40
Offices of dentists
Dental laboratory technicians
Yes
2003
41
Ambulatory health care services
Emergency medical technicians and paramedics
Yes
2006
19
Nonpaid workers
Students
No
2006
40
Nonpaid workers
Did not work
Yes
2011
41
Construction
Operating engineers and other construction equipment operators
Yes
2013
34
Computer systems design and related services
Computer occupations, all other
No
2013
36
Unknown, blank, inadequate information
Driver/sales workers
Yes
2013
36
All other specialty trade contractors
Construction managers
Yes
2013
43
Nonpaid workers
Did not work
Yes
2013
44
General medical and surgical hospitals
Registered nurses
Yes
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.
Discussion
Among 55 deaths in young adults reported for 1999–2015 with ICD-10 code J62 assigned
as either the underlying or a contributing cause of death, 13 were coded as subcategory
J62.0, indicating exposure to talc dust, and in most of these cases, the underlying
or contributing cause-of-death codes also indicated multiple drug use or drug overdose.
These deaths likely represent nonoccupational pulmonary talcosis caused by illicit
inhalation or intravenous administration of talc-contaminated drugs (
3
,
5
–
7
). Eight of the 13 pneumoconiosis deaths attributed to talc dust were associated with
multiple drug use and drug overdose occurred during 2010–2015, and coincided with
the expanding epidemic of drug overdose deaths in the United States (
8
).
The remaining two thirds of silicosis deaths were coded as J62.8. Among silicosis
deaths reported for 1999–2013, manufacturing or construction industries, both of which
are known to be associated with exposures to silica-containing dust, were frequently
listed on death certificates for these decedents. Three decedents had a history of
subcutaneous silicone injections and likely were erroneously assigned code J62.8 as
the underlying cause of death.
The findings in this report are subject to at least five limitations. First, no information
on silica exposure intensity or duration is listed on death certificates. Silicosis-associated
deaths in young adults should be considered sentinel cases, potentially resulting
from high exposures that cause short latency to disease onset and rapid disease progression.
Second, lifetime occupational histories of decedents were not collected, and the usual
industry and occupation listed on death certificates might not accurately represent
the industry or occupation where the hazardous silica exposure occurred. However,
there is a generally good agreement of industry and occupation information on death
certificates compared with that from other sources (
9
). Third, industry and occupation information was only available for 40 (83%) and
42 (88%) decedents, respectively, who were included in reports during 1999–2013. Fourth,
pneumoconiosis as a cause of death might have been misclassified or under- or overreported.
Finally, increased recognition of drug-related deaths, improvements in testing, and
reporting of deaths involving drug use might have contributed to the high frequency
of reported multiple drug use and drug overdose among pneumoconiosis deaths due to
talc. The continuing occurrence of pneumoconiosis deaths due to other dust containing
silica indicates the need for maintaining measures to limit workplace exposure to
respirable crystalline silica. Primary prevention of pneumoconioses relies on elimination
or effective control of exposures (https://www.cdc.gov/niosh/topics/hierarchy/). Effective
silicosis prevention strategies for employers are available from the Occupational
Safety and Health Administration (https://www.osha.gov/silica/) and CDC (https://www.cdc.gov/niosh/topics/silica).
The occurrence of pneumoconiosis deaths due to talc associated with multiple drug
use and drug overdose reinforces the need for a multifaceted, collaborative clinical,
public health, public safety, and law enforcement approach to the drug overdose epidemic
(
8
). Examining detailed information on causes of death, including external causes, along
with industry and occupation of decedents, is essential for identifying silicosis
deaths associated with occupational exposures and reducing misclassification of silicosis
mortality.
Summary
What is already known about this topic?
Various preventable occupational pulmonary diseases are associated with exposure to
respirable particles of crystalline silica and other silicate materials, one of which
is talc (hydrous magnesium silicate). Detailed information on the circumstances surrounding
deaths of silicosis decedents is needed to better target intervention and prevention
measures.
What is added by this report?
During 1999–2015, among 55 decedents aged 15–44 years who had pneumoconiosis due to
dust containing silica assigned as either the underlying or contributing cause of
death, 38 (69%) were assigned pneumoconiosis due to other dust containing silica,
and 17 (31%) were assigned pneumoconiosis due to talc dust. Decedents with pneumoconiosis
due to other dust containing silica had manufacturing or construction industry frequently
listed as the occupation on their death certificates; both industries are well known
to be associated with exposures to silica-containing dust. Among 17 decedents with
pneumoconiosis due to talc dust, 13 (76%) involved multiple drug use or drug overdose
and none worked in talc exposure-associated jobs.
What are the implications for public health practice?
Among deaths in persons aged 15–44 years attributed to pneumoconiosis due to dust
containing silica, nearly one third had pneumoconiosis due to talc dust. Most of these
cases likely represent nonoccupational exposure to talc. Examining detailed information
on causes of death, including external causes, along with industry and occupation
of decedents is essential for identifying silicosis deaths associated with occupational
exposures and reducing misclassification of silicosis mortality.