Severe Silicosis in Engineered Stone Fabrication Workers - California, Colorado, Texas, and Washington, 2017-2019.

Silicosis is an incurable occupational lung disease caused by inhaling particles of respirable crystalline silica. These particles trigger inflammation and fibrosis in the lungs, leading to progressive, irreversible, and potentially disabling disease. Silica exposure is also associated with increased risk for lung infection (notably, tuberculosis), lung cancer, emphysema, autoimmune diseases, and kidney disease (1). Because quartz, a type of crystalline silica, is commonly found in stone, workers who cut, polish, or grind stone materials can be exposed to silica dust. Recently, silicosis outbreaks have been reported in several countries among workers who cut and finish stone slabs for countertops, a process known as stone fabrication (2-5). Most worked with engineered stone, a manufactured, quartz-based composite material that can contain >90% crystalline silica (6). This report describes 18 cases of silicosis, including the first two fatalities reported in the United States, among workers in the stone fabrication industry in California, Colorado, Texas, and Washington. Several patients had severe progressive disease, and some had associated autoimmune diseases and latent tuberculosis infection. Cases were identified through independent investigations in each state and confirmed based on computed tomography (CT) scan of the chest or lung biopsy findings. Silica dust exposure reduction and effective regulatory enforcement, along with enhanced workplace medical and public health surveillance, are urgently needed to address the emerging public health threat of silicosis in the stone fabrication industry.

Fragrances and work-related asthma-California surveillance data, 1993-2012.

OBJECTIVE: Fragrance chemicals are used in a large array of products. Workers may be exposed to these chemicals in the workplace directly when used as air fresheners, or indirectly in personal care products used by coworkers or others. This study characterizes work-related asthma (WRA) cases associated with fragrance exposures in California workplaces from 1993 through 2012. METHODS: We used the California Work-Related Asthma Prevention Program's surveillance database to identify individuals with physician-diagnosed WRA associated with the use of air fresheners and scented personal care products (perfumes, colognes, etc.). Cases were classified using previously published, standardized surveillance methods. RESULTS: Perfume was the ninth most common exposure identified from 1993 through 2012. A total of 270 WRA cases associated with fragrance exposure were reported during this period, representing 3.8% of all confirmed cases. These 270 cases included 242 associated with perfume or cologne, 32 associated with air freshener, and 4 associated with both. Similar to non-fragrance cases, nearly a quarter of fragrance-associated cases were classified as new-onset asthma. Fragrance-associated cases were significantly more likely to be in office, health, and education jobs than non-fragrance-associated cases. When compared to non-fragrance cases, fragrance cases were significantly more likely to be female (94% vs 62%) and be classified as having work-aggravated asthma (38% vs 20%), yet had similar outcomes compared with cases associated with other exposures. CONCLUSIONS: Our surveillance data show that fragrance use in the workplace is associated with WRA. Prevention methods include employee education, enforced fragrance-free policies, well-designed ventilation systems, and good building maintenance.

Swimming facilities and work-related asthma.

BACKGROUND: Exposure to chlorinated water in swimming facilities may aggravate preexisting asthma or cause new onset asthma. This may be a particular problem for individuals who work and therefore spend prolonged time at swimming facilities. Chloramines formed by the interaction of chlorine-based disinfection products with the nitrogen in water from human sweat, urine and skin cells are the suspected causal agents. METHODS: Cases were reviewed from the state surveillance systems in California (CA), Michigan (MI) and New Jersey (NJ) to identify individuals with confirmed work-related asthma (WRA) attributed to exposures in swimming pools, water parks or hydrotherapy spas. A standardized method was used to confirm cases. RESULTS: A total of 44 confirmed cases of WRA were identified; 17 from 1994 to 2011 in CA, 15 from 1991 to 2012 in MI and 12 from 1990 to 2011 in NJ. A majority (52.2%) of the cases were new onset; 31.8% secondary to an acute exposure incident and 20.4% to repeated exposure. These represented 0.3-1.6% of all confirmed cases of WRA received during these time periods. Maintenance workers (34.9%) and lifeguards (31.8%) were the most common occupations. CONCLUSIONS: Swimming pool workers were identified from three states where the pool environment was either a trigger of preexisting asthma or associated with new onset of WRA. Regulations to require air monitoring and improvements in ventilation are recommended to reduce exposure levels of chloramines, the presumed etiologic agents. Clinical assessment of patients with asthma should include consideration of the effect on respiratory symptoms from exposures in a swimming pool environment.

Isocyanates and work-related asthma: Findings from California, Massachusetts, Michigan, and New Jersey, 1993-2008.

BACKGROUND: Isocyanates remain a leading cause of work-related asthma (WRA). METHODS: Two independent data systems were analyzed for the period 1993-2008: (1) State-based WRA case surveillance data on persons with isocyanate-induced WRA from four states, and (2) Occupational Safety and Health Administration (OSHA) Integrated Management Information System (IMIS) isocyanate air sampling results. RESULTS: We identified 368 cases of isocyanate-induced WRA from 32 industries and 678 OSHA isocyanate air samples with detectable levels from 31 industries. Seventeen industries were unique to one or the other dataset. CONCLUSION: Isocyanate-induced WRA continues to occur in a wide variety of industries. Two data systems uncovered industries with isocyanate exposures and/or illness. Improved control measures and standards, including medical surveillance, are needed. More emphasis is needed on task-specific guidance, spill clean-up procedures, skin and respiratory protection, and targeted medical monitoring to mitigate the hazards of isocyanate use.

Gender differences in work-related asthma: surveillance data from California, Massachusetts, Michigan, and New Jersey, 1993-2008.

OBJECTIVE: To characterize work-related asthma by gender. METHODS: We analyzed state-based sentinel surveillance data on confirmed work-related asthma cases collected from California, Massachusetts, Michigan, and New Jersey during 1993-2008. We used Chi-square and Fisher's Exact Test statistics to compare select characteristics between females and males. RESULTS: Of the 8239 confirmed work-related asthma cases, 60% were female. When compared to males with work-related asthma, females with work-related asthma were more likely to be identified through workers' compensation (14.8% versus 10.6%) and less likely to be identified through hospital data (14.2% versus 16.9%). Moreover, when compared to males, females were more likely to have work-aggravated asthma (24.4% versus 13.5%) and less likely to have new-onset asthma (48.0% versus 56.5%). Females were also more likely than males with work-related asthma to work in healthcare and social assistance (28.7% versus 5.2%), educational services (11.8% versus 4.2%), and retail trade (5.0% versus 3.9%) industries and in office and administrative support (20.0% versus 4.0%), healthcare practitioners and technical (13.4% versus 1.6%), and education training and library (6.2% versus 1.3%) occupations. Agent groups most frequently associated with work-related asthma were miscellaneous chemicals (20.3%), cleaning materials (15.3%), and indoor air pollutants (14.9%) in females and miscellaneous chemicals (15.7%), mineral and inorganic dusts (13.2%), and pyrolysis products (12.7%) in males. CONCLUSIONS: Among adults with work-related asthma, males and females differ in terms of workplace exposures, occupations, and industries. Physicians should consider these gender differences when diagnosing and treating asthma in working adults.

Occupational Contributions to Respiratory Health Disparities.

Occupation is an important contributor to disparities in respiratory disease, affecting financial status, health-care access, and exposure to hazardous substances. Although occupation and associated exposures are included in the socioecological models, work exposures remain persistently absent from research on health inequities and their contribution to health. This article focuses on the occupational contribution to disparities in asthma, chronic obstructive pulmonary disease, silicosis, coronavirus disease 2019, and lung cancer. Because occupational exposures are largely preventable through proper workplace controls, the recognition of occupational causes of disease can provide an opportunity for interventions to bring about health equity.

Silicosis Among Immigrant Engineered Stone (Quartz) Countertop Fabrication Workers in California.

Importance: Silicosis associated with inhalation of respirable crystalline silica among engineered stone countertop fabrication workers is an emerging health concern. Objective: To describe clinical, socioeconomic, and occupational characteristics of patients diagnosed with silicosis associated with engineered stone in California. Design, Setting, and Participants: This case series included reported cases of silicosis associated with fabrication of engineered stone countertops, as identified by statewide surveillance by the California Department of Public Health (2019-2022). Data analysis was performed from October 2022 to March 2023. Exposures: Patient interviews and medical record abstractions were used to assess occupational exposure to respirable crystalline silica, including duration of work tenure and preventive measures undertaken. Main Outcomes and Measures: Demographics, clinical characteristics, health care utilization, and clinical outcomes were obtained, including vital status, hypoxia, and lung transplant. Results: This case series identified 52 male patients meeting inclusion criteria; median (IQR) age was 45 (40-49) years, and 51 were Latino immigrants. Ten (19%) were uninsured, and 20 (39%) had restricted-scope Medi-Cal; 25 (48%) presented initially to an emergency department. A delay in diagnosis occurred in 30 (58%) patients, most commonly due to alternative initial diagnoses of bacterial pneumonia (9 [30%]) or tuberculosis (8 [27%]). At diagnosis, 20 (38%) patients had advanced disease (progressive massive fibrosis) with severely or very severely reduced forced expiratory volume in 1 second in 8 (18%) and 5 (11%), respectively. Of the cases, 10 (19%) were fatal; median (IQR) age at death was 46 (38-51) years, and 6 patients (12%) were alive with chronic resting hypoxia. Eleven were referred for lung transplant: 3 underwent transplant with 1 fatality; 7 were declined transplant, with 6 fatalities; and 1 died prior to listing. Median (IQR) work tenure was 15 (10-20) years; 23 (45%) reported use of water suppression for dust mitigation, and 25 (48%) continued to fabricate stone after being diagnosed with silicosis. Conclusions and Relevance: In this case series performed in California, silicosis associated with occupational exposure to dust from engineered stone primarily occurred among young Latino immigrant men. Many patients presented with severe disease, and some cases were fatal.

Active Surveillance of Engineered Stone Workers Facilitates Early Identification of Silicosis: A Discussion of Surveillance of Occupational Lung Diseases.

Silicosis in workers exposed to respirable crystalline silica while fabricating engineered stone products is an emerging respiratory health issue. We describe silicosis in engineered stone workers in California and examine clinical features by the source of identification. Cases were identified passively using hospital-based patient discharge data or actively through outreach and medical testing following enforcement investigation. Outcomes were examined based on the source of case identification. We identified 18 cases diagnosed between 2006 and 2020. Cases identified passively compared to other identification methods were associated with lower percent predicted forced vital capacity (FVC) (P ≤ .01), forced expiratory volume in 1 s (FEV1) (P ≤ .01), and diffusing capacity of the lungs for carbon monoxide (DLCO) (P < .01) at the time of diagnosis and were more likely to be identified following death or lung transplant (P = .01). Our experience demonstrates delays in diagnosis and case identification when relying on passive surveillance methods. Enhanced public health surveillance systems can improve the early detection of occupational lung disease and inform future prevention policies.

Occupational COVID-19 Exposures and Illnesses among Workers in California-Analysis of a New Occupational COVID-19 Surveillance System.

Little is known about occupational SARS-CoV-2 exposures and COVID-19 outcomes. We established a Doctor's First Reports of Occupational Injury or Illness (DFR)-based surveillance system to study cases of work-related COVID-19 exposures and disease. The surveillance data included demographics, occupation, industry, exposure, and illness, details including hospitalization and lost work. We classified workers into 'healthcare', non-healthcare 'public-facing', or 'other' worker groups, and rural-urban commuting areas (RUCAs). We describe worker exposures and outcomes overall by worker group and RUCA. We analyzed 2848 COVID-19 DFRs representing workers in 22 detailed occupation groups and 19 industry groups. Most DFRs were for workers in metropolitan RUCAs (89%) and those in healthcare (42%) and public-facing (24%) worker groups. While DFRs were from 382 unique worksites, 52% were from four hospitals and one prison. Among 1063 DFRs with a suspected exposure, 73% suspected exposure to a patient or client. Few DFRs indicated hospitalization (3.9%); however, the proportion hospitalized was higher among nonmetropolitan (7.4%) and public-facing (6.7%) workers. While 56% of DFRs indicated some lost work time, the proportion was highest among public-facing (80%) workers. Healthcare and prison workers were the majority of reported occupational COVID-19 exposures and illnesses. The risk of COVID-19 hospitalization and lost work may be highest among nonmetropolitan and public-facing workers.

Cleaning Products and Work-Related Asthma, 10 Year Update.

OBJECTIVE: To describe the frequency of work-related asthma (WRA) and characteristics of individuals with exposure to cleaning products 1998 to 2012, compared with 1993 to 1997. METHODS: Cases of WRA from products used for cleaning or disinfecting surfaces were identified from California, Massachusetts, Michigan (1998 to 2012), New Jersey (1998 to 2011), and New York (2009 to 2012). RESULTS: There were 1199 (12.4%) cleaning product cases among all 9667 WRA cases; 77.8% women, 62.1% white non-Hispanic, and average age of 43 years. The highest percentages worked in healthcare (41.1%), and were building cleaners (20.3%), or registered nurses (14.1%). CONCLUSIONS: The percentage of WRA cases from exposure to cleaning products from 1998 to 2012 was unchanged from 1993 to 1997 indicating that continued and additional prevention efforts are needed to reduce unnecessary use, identify safer products, and implement safer work processes.

Primary prevention of occupational asthma: identifying and controlling exposures to asthma-causing agents.

BACKGROUND: Primary prevention of occupational asthma requires timely identification and regulation of asthma-causing agents. METHODS: We examined 39 substances identified as causing allergic occupational asthma in the US to determine the basis for their identification and their regulatory status. We compared them with occupational asthmagens identified and regulated in the UK and Germany. RESULTS: US regulatory agencies have not established consistent, evidence-based methods to identify and control exposures to substances that cause occupational asthma. Occupational asthmagens are identified primarily by non-regulatory US organizations, and most are not regulated to prevent asthma. CONCLUSIONS: Implementing an evidence-based identification and regulatory process for occupational asthmagens will help to ensure primary prevention of occupational asthma in the US. This should include: establishing consistent identification criteria; publishing a list of occupational asthmagens; collecting use, exposure, and health effects information on asthma-causing substances; requiring medical surveillance and medical removal protection in addition to exposure limits; and stimulating development of safer alternatives.

Work-related reactive airways dysfunction syndrome cases from surveillance in selected US states.

The objective was to elaborate the descriptive epidemiology of work-related cases of reactive airways dysfunction syndrome (RADS). Cases of work-related asthma (WRA) were identified in four states in the United States during 1993-1995 as part of the Sentinel Event Notification Systems for Occupational Risks (SENSOR). Information gathered by follow-back interview was used to describe 123 work-related RADS cases and to compare them to 301 other WRA cases whose onset of disease was associated with a known asthma inducer. RADS represented 14% of all new-onset WRA cases identified by the state SENSOR surveillance systems. RADS cases had significant adverse medical and occupational outcomes identified by follow-back interview. In particular, 89% still had breathing problems, 78% had ever sought emergency care and 39% had ever been hospitalized for work-related breathing problems, 54% had applied for worker compensation benefits, and 41% had left the company where they experienced onset of asthma. These values equaled or exceeded the comparable figures for those WRA cases whose onset was attributed to a known inducer. Work-related RADS represents a minority of all WRA cases, but the adverse impact of this condition appears to equal that of other WRA cases.

Cleaning products and work-related asthma.

To describe the characteristics of individuals with work-related asthma associated with exposure to cleaning products, data from the California-, Massachusetts-, Michigan-, and New Jersey state-based surveillance systems of work-related asthma were used to identify cases of asthma associated with exposure to cleaning products at work. From 1993 to 1997, 236 (12%) of the 1915 confirmed cases of work-related asthma identified by the four states were associated with exposure to cleaning products. Eighty percent of the reports were of new-onset asthma and 20% were work-aggravated asthma. Among the new-onset cases, 22% were consistent with reactive airways dysfunction syndrome. Individuals identified were generally women (75%), white non-Hispanic (68%), and 45 years or older (64%). Their most likely exposure had been in medical settings (39%), schools (13%), or hotels (6%), and they were most likely to work as janitor/cleaners (22%), nurse/nurses' aides (20%), or clerical staff (13%). However, cases were reported with exposure to cleaning products across a wide range of job titles. Cleaning products contain a diverse group of chemicals that are used in a wide range of industries and occupations as well as in the home. Their potential to cause or aggravate asthma has recently been recognized. Further work to characterize the specific agents and the circumstances of their use associated with asthma is needed. Additional research to investigate the frequency of adverse respiratory effects among regular users, such as housekeeping staff, is also needed. In the interim, we recommend attention to adequate ventilation, improved warning labels and Material Safety Data Sheets, and workplace training and education.

Processes of care for individuals with work related asthma: treatment characteristics and impact of asthma on work.

The prevalence of asthma among working adults continues to rise each year. The California Department of Health Services conducts surveillance of work related asthma (WRA) to classify each work related exposure using Doctor's First Reports of Occupational Illness and Injury (DFRs). Using a cross-sectional, descriptive, comparative design, additional interviews were conducted and medical records were reviewed to explore workers' and providers' perceptions of follow up care. Two cohorts were compared: workers with WRA who belonged to a large, single HMO (n = 79) and workers with WRA who underwent follow up outside this HMO (n = 76). The interview asked about providers seen, tests ordered, and the impact of asthma on work. The HMO clients were significantly more likely than the non-HMO clients to see occupational medicine specialists (p = .004) and have pulmonary function testing (p = .049) during initial treatment. Twenty-four percent of clients currently working reported missed workdays caused by asthma in the past 6 months. The findings indicate management of WRA varies by health care system in California.

Work-related asthma in the educational services industry: California, Massachusetts, Michigan, and New Jersey, 1993-2000.

OBJECTIVES: To characterize work-related asthma (WRA) cases working in the educational services industry identified by state-based occupational disease surveillance systems. METHODS: We examined 2,995 WRA cases reported from 1993 to 2000 to four states: California, Massachusetts, Michigan, and New Jersey. RESULTS: A total of 265 (9%) WRA cases were employed in the educational services industry; 69% of cases were classified as new-onset asthma and 31% as work-aggravated asthma. New-onset asthma cases were further classified as occupational asthma (61%) or as reactive airways dysfunction syndrome (8%). The most frequently reported occupation was teachers and teachers' aides (54%). The most frequently reported agents were indoor air pollutants (28%), unspecified mold (16%), dusts (14%), and cleaning products (7%). CONCLUSIONS: Asthma within the educational services industry is an occupational health problem. The health of school employees should also be considered when initiatives addressing asthma among schoolchildren are instituted. The identification, elimination, and/or control of respiratory hazards are important factors for the protection of staff and students alike.

Glutaraldehyde exposures among workers making bioprosthetic heart valves.

Exposure to glutaraldehyde is a recognized cause of work-related asthma. An investigation was undertaken to describe exposure to glutaraldehyde among workers making bioprosthetic heart valves and to make recommendations for prevention. At the two largest heart valve manufacturing facilities in California, the work process was observed; employer representatives and glutaraldehyde-exposed workers were interviewed; and employer written records, including company-generated industrial hygiene data, were analyzed. Approximately 600 female workers had continuous airborne exposure to glutaraldehyde over the course of every work shift and the routine potential for skin and eye contact with glutaraldehyde while making heart valves. Employee short-term (15-min) glutaraldehyde exposures were all well below the current regulatory ceiling level (0.20 ppm). Overall, approximately 40% of the glutaraldehyde-related job tasks involved exposures above the American Conference of Industrial Hygienists threshold limit value ceiling of 0.05 ppm; the majority (71.4% and 83.3%, depending on the company) involved exposures greater than 0.015 ppm. At one company, two cases of physician-diagnosed asthma were recorded by the employer in the previous 5-year period; these reports met the surveillance case definition for new-onset, work-related asthma associated with a known asthma inducer. Factors that contributed to worker exposure included large exposed surface areas of glutaraldehyde under agitation; working with glutaraldehyde-treated tissue in proximity to workers' breathing zones; manual pouring and disposal of glutaraldehyde solutions without local exhaust ventilation, eye protection, and waste neutralization; and prolonged use of latex gloves. Workers making bioprosthetic heart valves are at risk for occupationally acquired asthma. Employers should implement additional engineering controls to minimize workers' exposures to at least below a level of 0.015 ppm, an appropriate glove to prevent workers' skin exposure to glutaraldehyde, consistent and universal use of eye protection, and a medical surveillance program for glutaraldehyde-exposed workers.