Industry-specific prevalence of elevated blood lead levels among Pennsylvania workers, 2007-2018.

OBJECTIVES: To use industry-specific denominators to more accurately examine trends in prevalence rates for occupational cases of elevated blood lead levels (eBLLs) in Pennsylvania. METHODS: We used adult (aged ≥16 years) blood lead level data from Pennsylvania (2007-2018) and industry-specific denominator data from the US Census Bureau's County Business Patterns to calculate prevalence rates for eBLLs, defined as ≥25 µg/dL. RESULTS: Of the 19 904 cases with eBLLs, 92% were due to occupational lead exposure, with 83% from workers in the battery manufacturing industry. In 2018, the prevalence rate of eBLLs for battery manufacturing (8036.4 cases per 100 000 employed battery manufacturing workers) was 543 times the overall Pennsylvania prevalence rate. The prevalence rate for battery manufacturing steeply declined 71% from 2007 to 2018. CONCLUSIONS: The battery manufacturing industry had the highest burden of occupational lead exposure in Pennsylvania, illustrating the importance of using industry-specific denominators to accurately identify sources of lead exposure. Although the prevalence rate of eBLLs declined over time, lead exposure remains a major concern among battery manufacturing workers.

Occupational exposure to high-level disinfectants and risk of miscarriage among nurses.

OBJECTIVES: To examine the association of occupational exposure to high-level disinfectants (HLDs) with risk of miscarriage among nurses. METHODS: Our study included women who enrolled in the Nurses' Health Study 3 (2010-2020) and had at least one pregnancy during follow-up. Occupational exposure to HLDs was self-reported at baseline. Every 6 months, a follow-up questionnaire was sent to participants asking for detailed information on pregnancies. We used a discrete-time Cox model to calculate the HRs and 95% CIs of miscarriage according to exposure to HLDs. RESULTS: Our study included 2579 nurses with a median of 5.6 years of follow-up (range: 1-9 years), and we documented 768 (19%) cases of miscarriage among 3974 pregnancies. Compared with women with no HLD exposure, the HRs of miscarriage were 1.08 (95% CI: 0.87 to 1.34) for past users and 0.84 (95% CI: 0.68 to 1.04) for HLD users. Compared with women with no HLD exposure, duration, frequency, and type of HLD and use of exposure controls were not associated with risk of miscarriage. When restricting to pregnancies that occurred within 12 months of HLD use, occupational exposure to unspecified types of HLD was significantly associated with higher risk of miscarriage (HR=1.78; 95% CI: 1.08 to 2.93). CONCLUSIONS: We observed no associations between occupational use of HLDs and miscarriage, except when we restricted to pregnancies occurring within 12 months of assessed baseline exposure. Given the observational design and limited sample size, results should be interpreted cautiously.

Occupational use of high-level disinfectants and asthma incidence in early- to mid-career female nurses: a prospective cohort study.

OBJECTIVES: Occupational use of disinfectants among healthcare workers has been associated with asthma. However, most studies are cross-sectional, and longitudinal studies are not entirely consistent. To limit the healthy worker effect, it is important to conduct studies among early- to mid-career workers. We investigated the prospective association between use of disinfectants and asthma incidence in a large cohort of early- to mid-career female nurses. METHODS: The Nurses' Health Study 3 is an ongoing, prospective, internet-based cohort of female nurses in the USA and Canada (2010-present). Analyses included 17 280 participants without a history of asthma at study entry (mean age: 34 years) and who had completed ≥1 follow-up questionnaire (sent every 6 months). Occupational use of high-level disinfectants (HLDs) was evaluated by questionnaire. We examined the association between HLD use and asthma development, adjusted for age, race, ethnicity, smoking status and body mass index. RESULTS: During 67 392 person-years of follow-up, 391 nurses reported incident clinician-diagnosed asthma. Compared with nurses who reported ≤5 years of HLD use (89%), those with >5 years of HLD use (11%) had increased risk of incident asthma (adjusted HR (95% CI), 1.39 (1.04 to 1.86)). The risk of incident asthma was elevated but not statistically significant in those reporting >5 years of HLD use and current use of ≥2 products (1.72 (0.88 to 3.34)); asthma risk was significantly elevated in women with >5 years of HLD use but no current use (1.46 (1.00 to 2.12)). CONCLUSIONS: Occupational use of HLDs was prospectively associated with increased asthma incidence in early- to mid-career nurses.

Envisioning the future of work to safeguard the safety, health, and well-being of the workforce: A perspective from the CDC's National Institute for Occupational Safety and Health.

The future of work embodies changes to the workplace, work, and workforce, which require additional occupational safety and health (OSH) stakeholder attention. Examples include workplace developments in organizational design, technological job displacement, and work arrangements; work advances in artificial intelligence, robotics, and technologies; and workforce changes in demographics, economic security, and skills. This paper presents the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health's Future of Work Initiative; suggests an integrated approach to address worker safety, health, and well-being; introduces priority topics and subtopics that confer a framework for upcoming future of work research directions and resultant practical applications; and discusses preliminary next steps. All future of work issues impact one another. Future of work transformations are contingent upon each of the standalone factors discussed in this paper and their combined effects. Occupational safety and health stakeholders are becoming more aware of the significance and necessity of these factors for the workplace, work, and workforce to flourish, merely survive, or disappear altogether as the future evolves. The future of work offers numerous opportunities, while also presenting critical but not clearly understood difficulties, exposures, and hazards. It is the responsibility of OSH researchers and other partners to understand the implications of future of work scenarios to translate effective interventions into practice for employers safeguarding the safety, health, and well-being of their workers.

Carbon monoxide exposures among U.S. wildland firefighters by work, fire, and environmental characteristics and conditions.

Carbon monoxide (CO) exposure levels encountered by wildland firefighters (WLFs) throughout their work shift can change considerably within a few minutes due to the varied tasks that are performed and the changing environmental and fire conditions encountered throughout the day. In a U.S. Forest Service study during the 2009-2012 fire seasons, WLFs from 57 different fires across the U.S. were monitored for CO using CO data-logging detectors while an observer recorded worker tasks, fire characteristics, and environmental conditions at scheduled intervals. Exposures to CO for 735 WLF's work shifts were analyzed to assess the effect of variations among work tasks, fire characteristics, and environmental conditions. Geometric mean full shift time-weighted averages were low at 2.4 parts per million (ppm) and average length of work shift was 11 hr and 15 min. The task with the highest mean CO exposure was sawyer/swamper at 6.8 ppm; workers performing that task had an estimated 9 times higher odds of a having a 1-min CO measurement exceeding 25 ppm than the referent pump task (OR = 8.89, 95% CI = 1.97, 40.24). After adjusting CO exposure limits for shift length, elevation, and work level, 2% and 4% of the WLF's work shifts exceeded the National Institute for Occupational Safety and Health's recommended exposure level and the American Conference of Governmental Industrial Hygienist's threshold limit value, respectively. In regression modeling, variables that were significantly associated with elevated levels of CO exposure included: task, fuel model, wind orientation, crew type, relative humidity, type of attack, and wind speed. In the absence of instruments such as CO detectors that can determine and alert WLFs to elevated CO levels, recognition of the conditions that lead to elevated levels of CO exposure can assist WLFs to effectively use administrative controls, such as work rotations, to minimize exposures.

Occupational use of high-level disinfectants and fecundity among nurses.

Objective This study aimed to examine the relationship between occupational use of high-level disinfectants (HLD) and fecundity among female nurses. Methods Women currently employed outside the home and trying to get pregnant (N=1739) in the Nurses' Health Study 3 cohort (2010-2014) were included in this analysis. Occupational exposure to HLD used to disinfect medical instruments and use of protective equipment (PE) was self-reported on the baseline questionnaire. Every six months thereafter women reported the duration of their ongoing pregnancy attempt. Multivariable accelerated failure time models were used to estimate time ratios (TR) and 95% confidence intervals (95% CI). Results Nurses exposed to HLD prior to and at baseline had a 26% (95% CI 8-47%) and 12% (95% CI -2-28%) longer median duration of pregnancy attempt compared to nurses who were never exposed. Among nurses exposed at baseline to HLD, use of PE attenuated associations with fecundity impairments. Specifically, women using 0, 1, and ≥2 types of PE had 18% (95% CI -7-49%), 16% (95% -3-39%), and 0% (95% -22-28%) longer median durations of pregnancy attempt compared to women who were never exposed. While the use of PE varied greatly by type (9% for respiratory protection to 69% for protective gloves), use of each PE appeared to attenuate the associations of HLD exposure with reduced fecundity. Conclusion Occupational use of HLD is associated with reduced fecundity among nurses, but use of PE appears to attenuate this risk.

Precautionary practices of healthcare workers who disinfect medical and dental devices using high-level disinfectants.

BACKGROUND High-level disinfectants (HLDs) are used throughout the healthcare industry to chemically disinfect reusable, semicritical medical and dental devices to control and prevent healthcare-associated infections among patient populations. Workers who use HLDs are at risk of exposure to these chemicals, some of which are respiratory and skin irritants and sensitizers. OBJECTIVE To evaluate exposure controls used and to better understand impediments to healthcare workers using personal protective equipment while handling HLDs. DESIGN Web-based survey. PARTICIPANTS A targeted sample of members of professional practice organizations representing nurses, technologists/technicians, dental professionals, respiratory therapists, and others who reported handling HLDs in the previous 7 calendar days. Participating organizations invited either all or a random sample of members via email, which included a hyperlink to the survey. METHODS Descriptive analyses were conducted including simple frequencies and prevalences. RESULTS A total of 4,657 respondents completed the survey. The HLDs used most often were glutaraldehyde (59%), peracetic acid (16%), and ortho-phthalaldehyde (15%). Examples of work practices or events that could increase exposure risk included failure to wear water-resistant gowns (44%); absence of standard procedures for minimizing exposure (19%); lack of safe handling training (17%); failure to wear protective gloves (9%); and a spill/leak of HLD during handling (5%). Among all respondents, 12% reported skin contact with HLDs, and 33% of these respondents reported that they did not always wear gloves. CONCLUSION Findings indicated that precautionary practices were not always used, underscoring the importance of improved employer and worker training and education regarding HLD hazards.

Occupational carbon monoxide fatalities in the US from unintentional non-fire related exposures, 1992-2008.

OBJECTIVE: To analyze characteristics of, and trends in, work-related carbon monoxide (CO) fatalities in the US. METHODS: Records of unintentional, non-fire related fatalities from CO exposure were extracted from the Bureau of Labor Statistics' Census of Fatal Occupational Injuries and the Occupational Safety and Health Administration's Integrated Management Information System for years 1992-2008 and analyzed separately. RESULTS: The average number of annual CO fatalities was 22 (standard deviation=8). Fatality rates were highest among workers aged≥65, males, Hispanics, winter months, the Midwest, and the Fishing, Hunting, and Trapping industry subsector. Self-employed workers accounted for 28% of all fatalities. Motor vehicles were the most frequent source of fatal CO exposure, followed by heating systems and generators. CONCLUSIONS: CO has been the most frequent cause of occupational fatality due to acute inhalation, and has shown no significant decreasing trend since 1992. The high number of fatalities from motor vehicles warrants further investigation.

Characterization of lead in US workplaces using data from OSHA's integrated management information system.

BACKGROUND: Lead hazards continue to be encountered in the workplace. OSHA's Integrated Management Information System (IMIS) is the largest available database containing sampling results in US workplaces. METHODS: Personal airborne lead sampling results in IMIS were extracted for years 1979-2008. Descriptive analyses, geographical mapping, and regression modeling of results were performed. RESULTS: Seventy-nine percent of lead samples were in the manufacturing sector. Lead sample results were highest in the construction sector (median = 0.03 mg/m(3) ). NORA sector, year, OSHA region, number of employees at the worksite, federal/state OSHA plan, unionization, advance notification, and presence of an employee representative were statistically associated with having a lead sample result exceed the PEL. CONCLUSIONS: Lead concentrations within construction have been higher than any other industry. Lead hazards have been most prevalent in the north and northeastern US. IMIS data can be useful as a surveillance tool and for targeting prevention efforts toward hazardous industries.

A cohort mortality study of chemical laboratory workers at Department of Energy Nuclear Plants.

OBJECTIVE: This study evaluates the mortality experience of 6,157 chemical laboratory workers employed at United States Department of Energy facilities. METHODS: All cause, all cancer and cause-specific standardized mortality ratios were calculated. Cox regression analyses were conducted to further evaluate the relation between chemical exposure and mortality risk due to selected cancers. RESULTS: The mortality due to all causes combined and all cancers combined were below expectation for the cohort. There were no statistically significant elevations reported among males for any specific cancer or non-cancer outcome. There no statistically significant elevations among females for any specific non-cancer and most specific cancers; however, multiple myeloma deaths were significantly elevated (SMR = 3.56; 95% CI = 1.43-7.33; number of observed deaths, n = 7). Statistically significant elevations were seen among workers employed 20+ years for leukemia using both 2- and 5-year lag periods. Also, a statistically significant positive trend of elevated lung cancer mortality with increasing employment duration was seen using both 5- and 10-year lags. A similar trend was seen for smoking related cancers among men. CONCLUSION: While lymphatic and hematopoietic cancer mortality was below expectation, a significant elevation of multiple myeloma deaths among females and an elevation of leukemia among workers employed 20+ years (possibly due to radiation and benzene exposure) were observed. A NIOSH case-control study is underway to examine more closely the relation between multiple myeloma and a variety of chemical exposures among workers employed at the Oak Ridge K-25 facility.

Task- and time-dependent weighting factors in a retrospective exposure assessment of chemical laboratory workers.

A chemical exposure assessment was conducted for a cohort mortality study of 6157 chemical laboratory workers employed between 1943 and 1998 at four Department of Energy sites in Oak Ridge, Tennessee, and Aiken, South Carolina. Previous studies of chemical laboratory workers have included members within professional societies where exposure assessment was either limited or not feasible, or chemical processing employees where laboratory and production workers were combined. Because sufficient industrial hygiene records were unavailable for all four sites, weighted duration of employment was used as a surrogate for the magnitude of exposure. Potential exposure indices were calculated for each worker using number of days employed and weighting factors for frequency of contact and year of employment. A total of 591 unique laboratory job titles indicative of a chemical laboratory worker were collapsed into 18 general job title categories. Through discussions with current and retired workers, along with examination of historical organizational charts and job descriptions, the percentage of time with activities involving the direct handling of chemicals in the laboratory was estimated for each job title category. Scaled weighting factors of 1, 0.6, 0.3, and 0.05 were assigned to the job title categories representing 100%, 60%, 30%, and 5% of daily activities handling chemicals, respectively. Based on limited industrial hygiene monitoring data, personal radiation monitoring records, and professional judgment, weighting factors that declined 4% annually were applied to each year to account for improvements in laboratory technique, advancements in instrumentation, improvement in engineering controls, and increased safety awareness through time. The study cohort was separated into three categories of chemical exposures based on department level information: (1) inorganic, (2) mixed inorganic and organic, and (3) unknown. Potential exposure indices ranged from 0.15 to 6824.5 with a median value of 377.5 and a mean equal to 884.2. This exposure assessment method is useful for epidemiologic analyses when quantitative exposure data are absent or insufficient.

Carcinogen biomonitoring in human exposures and laboratory research: validation and application to human occupational exposures.

A multiple biomarker approach is required to integrate for metabolism, temporal response and exposure-response kinetics, biological relevance, and positive predictive value. Carcinogen DNA adduct analysis can be used in animal and in vitro studies to detect absorption permutations caused by mixture interactions, and to control metabolic variation when specific CYP450 genes (1A1 or 1A2) are knocked out. These enzymes are not critical to the metabolic activation of model Polycyclic Aromatic Compounds (PAC) and aromatic amines, respectively, as suggested by in vitro analysis. Several human studies have been carried out where multiple biomarkers have been measured. In a study of benzidine workers, the similarities in elimination kinetics between urinary metabolites and mutagenicity is likely responsible for a better correlation between these markers than to BZ-DNA adducts in exfoliated cells. In a study of rubber workers, the relationship between specific departments, urinary 1 HP and DNA adducts in exfoliated cells coincided with the historical urinary bladder cancer risk in these departments; the same relationship did not hold for urinary mutagenicity. In a study of automotive mechanics, biomarkers were used to monitor the effectiveness of exposure interventions. These data reinforce the notion that carcinogen biomarkers are useful to monitor exposure, but that a complementary approaches involving effect and perhaps susceptibility biomarkers is necessary to obtain the necessary information.