Workers' Compensation Costs for Occupational Hearing Loss Claims in the United States, 2009-2013.

This study estimated the average annual number of U.S. workers' compensation (WC) claims for occupational hearing loss (OHL) and their associated cost and identified the industry/occupation classifications with the highest numbers of OHL claims. The most recent U.S. cost estimate ($242 million) was based on data from one state in 1 year (1991). WC data from the National Council on Compensation Insurance, Inc. (35 states) and two additional individual states were examined, incorporating data from 37 states and the District of Columbia. Costs and numbers of claims were estimated for the 13 missing states to develop estimates for the United States. Sensitivity analyses were also performed to develop ranges for the point estimates. The estimated U.S. average annual OHL claim cost fell within the range of $49 to $67 million during 2009-2013, with a point estimate of $60 million (2013 dollars). The estimated average annual number of OHL claims ranged from 4,114 to 5,986, with a point estimate of 4,965 claims. Based on data available from 36 states and DC, 18 of the 40 industry/occupation classifications with ≥50 OHL claims were in the manufacturing sector. WC data underestimate the true burden of OHL. Most OHL cases are not compensated. WC laws, industry composition and other factors vary widely by state, so estimates must employ data for many states. This study incorporated data from most states and utilized sensitivity and comparative analyses to obtain estimates. Workers in a wide range of industry/occupation classifications need special attention to prevent OHL.

Infrared spectra of isoquinolinium (iso-C9H7NH+) and isoquinolinyl radicals (iso-C9H7NH and 1-, 3-, 4-, 5-, 6-, 7- and 8-iso-HC9H7N) isolated in solid para-hydrogen.

Protonated polycyclic aromatic nitrogen heterocycles (H+PANH) are prospective candidates that may contribute to interstellar unidentified infrared (UIR) emission bands because protonation enhances the relative intensities of the bands near 6.2, 7.7 and 8.6 µm, and the presence of the N atom induces a blue shift of the ring-stretching modes so that the spectra of H+PANH match better with the 6.2 µm feature in class-A UIR spectra. We report the infrared (IR) spectra of protonated isoquinoline (the 2-isoquinolinium cation, iso-C9H7NH+), its neutral counterpart (the 2-isoquinolinyl radical, iso-C9H7NH), and another mono-hydrogenated product (the 6-isoquinolinyl radical, 6-iso-HC9H7N), produced on the electron-bombardment of a mixture of isoquinoline (iso-C9H7N) with excess para-hydrogen (p-H2) during matrix deposition at 3.2 K. To generate additional isomers of hydrogenated isoquinoline, we irradiated iso-C9H7N/Cl2/p-H2 matrices at 365 nm to generate Cl atoms, followed by IR irradiation to generate H atoms via Cl + H2 (v = 1) → HCl + H; the H atoms thus generated reacted with iso-C9H7N. In addition to iso-C9H7NH and 6-iso-HC9H7N observed in the electron-bombardment experiments, we identified six additional hydrogenated isoquinoline species, 1-, 3-, 4-, 5-, 7- and 8-iso-HC9H7N, via their IR spectra; hydrogenation on the N atom and all available carbon atoms except for the two sharing carbon atoms on the fused ring was observed. Spectral groupings were achieved according to their behaviors after maintenance of the matrix in darkness and on secondary photolysis at various wavelengths. The assignments were supported via comparison of the experimental results with the vibrational wavenumbers and IR intensities of possible isomers predicted using the B3LYP/6-311++G(d,p) method. The implications in the identification of the UIR band are discussed.

Infrared Spectra of 1-Quinolinium (C9H7NH+) Cation and Quinolinyl Radicals (C9H7NH and 3-, 4-, 7-, and 8-HC9H7N) Isolated in Solid para-Hydrogen.

Large protonated polycyclic aromatic hydrocarbons (H+PAH) and the corresponding nitrogen heterocycles (H+PANH) have been proposed as possible carriers of unidentified infrared (UIR) emission bands from galactic objects. The nitrogen atom in H+PANH is expected to induce a blue shift of the band associated with the CC-stretching mode of H+PAH near 6.3 µm so that their emission bands might agree better with the UIR band near 6.2 µm. We report the IR spectrum of protonated quinoline (1-quinolinium cation, C9H7NH+) and its neutral species (1-quinolinyl radical, C9H7NH) measured upon electron bombardment during the deposition of a mixture of quinoline (C9H7N) and para-hydrogen (p-H2) at 3.2 K, indicating that the protonation and hydrogenation occur mainly at the N atom site. Additional experiments on the irradiation of C9H7N/Cl2/p-H2 matrices at 365 nm to generate Cl atoms, followed by irradiation with IR light to generate H atoms via Cl + H2 (v = 1), were performed to induce the reaction H + C9H7N. This method proved to be efficient for hydrogenation reactions in solid p-H2; we identified, in addition to C9H7NH observed in electron-bombardment experiments, four radicals with hydrogenation at the C-atom site─3-, 4-, 7-, and 8-HC9H7N. Spectral assignments were achieved according to the behavior upon secondary photolysis and a comparison of experimental results with vibrational wavenumbers and IR intensities predicted with the B3LYP/6-311++G(d,p) method. The observed lines at 1641.4, 1598.4, and 1562.0 cm-1 associated with the CC-stretching mode of C9H7NH+ are blue-shifted from those at 1618.7, 1580.8, 1556.7, and 1510.0 cm-1 of the corresponding protonated naphthalene (C10H9+).

Workers' compensation claim counts and rates by injury event/exposure among state-insured private employers in Ohio, 2007-2017.

INTRODUCTION: This study analyzed workers' compensation (WC) claims among private employers insured by the Ohio state-based WC carrier to identify high-risk industries by detailed cause of injury. METHODS: A machine learning algorithm was used to code each claim by U.S. Bureau of Labor Statistics (BLS) event/exposure. The codes assigned to lost-time (LT) claims with lower algorithm probabilities of accurate classification or those LT claims with high costs were manually reviewed. WC data were linked with the state's unemployment insurance (UI) data to identify the employer's industry and number of employees. BLS data on hours worked per employee were used to estimate full-time equivalents (FTE) and calculate rates of WC claims per 100 FTE. RESULTS: 140,780 LT claims and 633,373 medical-only claims were analyzed. Although counts and rates of LT WC claims declined from 2007 to 2017, the shares of leading LT injury event/exposures remained largely unchanged. LT claims due to Overexertion and Bodily Reaction (33.0%) were most common, followed by Falls, Slips, and Trips (31.4%), Contact with Objects and Equipment (22.5%), Transportation Incidents (7.0%), Exposure to Harmful Substances or Environments (2.8%), Violence and Other Injuries by Persons or Animals (2.5%), and Fires and Explosions (0.4%). These findings are consistent with other reported data. The proportions of injury event/exposures varied by industry, and high-risk industries were identified. CONCLUSIONS: Injuries have been reduced, but prevention challenges remain in certain industries. Available evidence on intervention effectiveness was summarized and mapped to the analysis results to demonstrate how the results can guide prevention efforts. Practical Applications: Employers, safety/health practitioners, researchers, WC insurers, and bureaus can use these data and machine learning methods to understand industry differences in the level and mix of risks, as well as industry trends, and to tailor safety, health, and disability prevention services and research.

Workers' Compensation Claim Rates and Costs for Musculoskeletal Disorders Related to Overexertion Among Construction Workers - Ohio, 2007-2017.

Overexertion is a leading cause of work-related musculoskeletal disorders (WMSDs) among construction workers. Nearly 90% of construction jobs require manual handling of materials for approximately one half of the worker's time (1). In 2015, overexertion from lifting and lowering materials caused 30% of WMSDs among construction workers; overexertion involving pushing, pulling, holding, carrying, and catching materials caused an additional 37% of WMSDs (1). This study examined the rate and cost of WMSD claims from overexertion among Ohio construction workers during 2007-2017. Workers' compensation claims related to overexertion that were submitted to the Ohio Bureau of Worker's Compensation (OHBWC) by workers in the construction industry for injuries and illnesses occurring during 2007-2017 were analyzed. Rates and costs of allowed claims were measured by age group. Workers aged 35-44 years experienced the highest claim rate: 63 per 10,000 full-time employees (FTEs) for WMSDs from overexertion. However, claims by workers aged 45-54 years and 55-64 years were more costly on average and resulted in more days away from work. Ergonomic design improvements and interventions are needed to ensure that the majority of construction workers can safely perform jobs throughout their careers. Age-specific WMSD prevention and risk communication efforts also might be helpful.

Workers' compensation claims among private skilled nursing facilities, Ohio, 2001-2012.

INTRODUCTION: Skilled nursing facilities have one of the highest rates of occupational injury and illness among all industries. This study quantifies the burden of occupational injury and illness in this industry using data from a single state-based workers' compensation (WC) system. METHODS: Ohio Bureau of Workers' Compensation claims from 2001 to 2012 were analyzed among privately owned, state-insured skilled nursing facilities and are presented as claim counts and rates per 100 full-time equivalents (FTE). Worker, employer, incident, and injury characteristics were examined among all claims and by medical-only (medical care expenses and/or less than eight days away from work) and lost-time (eight days or more away from work) claim types. RESULTS: There were 56,442 claims in this population of Ohio skilled nursing facilities from 2001 to 2012. Overexertion and bodily reaction, slips, trips, and falls, and contact with objects and equipment accounted for the majority of all WC claims (89%). Overexertion and bodily reaction, and slips, trips, and falls comprised 85% of the 10,793 lost-time claims. The highest injury event/exposure rates for all claims were for overexertion and bodily reaction (3.7 per 100 FTE for all claims), followed by slip, trips, and falls (2.1), and contact with objects and equipment (1.9). CONCLUSION: Understanding the details surrounding injury events and exposures resulting in WC claims can help better align prevention efforts, such as incorporation of safe patient handling policies and lifting aids, improvement in housekeeping practices, and employee training within skilled nursing facilities to prevent worker injury and mitigate related expenses.

The effectiveness of ergonomic interventions in material handling operations.

This study evaluated the effectiveness of ergonomic interventions in material handling operations involving 33 employers and 535 employees from 2012 to 2017. Outcomes included employee-reported low back/upper extremity pain and safety incidents at baseline, every three months, and annually for up to two years. A total of 32.5% of employees completed at least one survey, while 13.6% completed all nine surveys over two years. Among highly exposed employees (who reported handling >= 50 lbs. > 33% of the time), upper extremity pain frequency and severity were lower among those who reported using the intervention routinely versus those that reported using their body strength alone to handle objects >= 50 lbs. After excluding from analyses one employer that used anti-fatigue mats, low back pain frequency was also significantly lower among highly exposed intervention users. In conclusion, there was some evidence that the interventions were effective in reducing employee-reported pain for highly exposed employees.

Workers' compensation claims for traumatic brain injuries among private employers-Ohio, 2001-2011.

BACKGROUND: The purpose of this analysis was to identify and prioritize high-risk industry groups for traumatic brain injury (TBI) prevention efforts. METHODS: Workers with TBI from 2001 to 2011 were identified from the Ohio Bureau of Workers' Compensation data. To prioritize industry groups by claim type (lost-time (≥8 days away from work) and total claims) and injury event categories, we used a prevention index (PI) that averaged TBI counts and rate ranks (PI = (count rank + rate rank)/2). TBI rates per 10 000 estimated full-time equivalent (FTE = 2000 h/y) workers were calculated. RESULTS: From 2001 to 2011, 12 891 TBIs were identified among private employers, resulting in a rate of 5.1 TBIs per 10 000 FTEs. Of these, 40% (n = 5171) were lost-time TBIs, at a rate of 2.0 per 10 000 FTEs. Spectator Sports had the highest lost-time TBI rate (13.5 per 10 000 FTEs), whereas General Freight Trucking had the greatest number of lost-time TBIs (n = 293). Based on PIs, General Freight Trucking ranked first for lost-time TBIs for all injury events combined. Several industry groups within Construction, General and Specialized Freight Trucking, Services to Building and Dwellings, Employment Services, and Restaurants and Other Eating Places ranked high across multiple injury event categories for lost-time TBIs. CONCLUSIONS: The high-ranking industry groups identified from our study can be used to effectively direct occupational TBI prevention efforts.

Degree of Integration Between Occupational Safety and Health Programs and Wellness Programs: First-year Results From an Insurer-Sponsored Wellness Grant for Smaller Employers.

OBJECTIVE: The aim of this study was to describe levels of integration between occupational safety and health (OSH) and workplace wellness programs/practices/policies ("programs") among participants in an insurer-sponsored wellness grant program. METHODS: We analyzed survey responses about year 1 of an insurer-sponsored grant to start a wellness program from 220 small- and medium-sized employers. Responses yielded 25 indicators of OSH-wellness integration, and 10 additional indicators to summarize multiple responses. RESULTS: At least half of the employers (N = 220) reported some level of integration within five of seven categories of OSH-wellness integration. Employers sometimes considered ergonomics, safety, or substance exposure hazards while designing their wellness program (15%) or reduced such hazards to support their wellness program (24%). Few meaningful differences were observed by employer size. CONCLUSIONS: Although high levels of integration were unusual, some degree of integration was common for most indicator categories.

Workers' compensation injury claims among workers in the private ambulance services industry-Ohio, 2001-2011.

BACKGROUND: Ambulance service workers frequently transfer and transport patients. These tasks involve occupational injury risks such as heavy lifting, awkward postures, and frequent motor vehicle travel. METHODS: We examined Ohio workers' compensation injury claims among state-insured ambulance service workers working for private employers from 2001 to 2011. Injury claim counts and rates are presented by claim types, diagnoses, and injury events; only counts are available by worker characteristics. RESULTS: We analyzed a total of 5882 claims. The majority were medical-only (<8 days away from work). The overall injury claim rate for medical-only and lost-time cases was 12.1 per 100 full-time equivalents. Sprains and strains accounted for 60% of all injury claims. Overexertion from patient handling was the leading injury event, followed by motor vehicle roadway incidents. CONCLUSIONS: Study results can guide the development or improvement of injury prevention strategies. Focused efforts related to patient handling and vehicle incidents are needed.

Applying Machine Learning to Workers' Compensation Data to Identify Industry-Specific Ergonomic and Safety Prevention Priorities: Ohio, 2001 to 2011.

OBJECTIVE: This study leveraged a state workers' compensation claims database and machine learning techniques to target prevention efforts by injury causation and industry. METHODS: Injury causation auto-coding methods were developed to code more than 1.2 million Ohio Bureau of Workers' Compensation claims for this study. Industry groups were ranked for soft-tissue musculoskeletal claims that may have been preventable with biomechanical ergonomic (ERGO) or slip/trip/fall (STF) interventions. RESULTS: On the basis of the average of claim count and rate ranks for more than 200 industry groups, Skilled Nursing Facilities (ERGO) and General Freight Trucking (STF) were the highest risk for lost-time claims (>7 days). CONCLUSION: This study created a third, major causation-specific U.S. occupational injury surveillance system. These findings are being used to focus prevention resources on specific occupational injury types in specific industry groups, especially in Ohio. Other state bureaus or insurers may use similar methods.

Spectroscopy of prospective interstellar ions and radicals isolated in para-hydrogen matrices.

para-Hydrogen (p-H2) serves as a new host in matrix-isolation experiments for an investigation of species of astrochemical interest. Protonated and mono-hydrogenated species are produced upon electron bombardment during deposition of p-H2 containing a precursor in a small proportion. The applications of this novel technique to generate protonated polycyclic aromatic hydrocarbons (H+PAH), protonated polycyclic nitrogen heterocycles (H+PANH), and their neutral counterparts, which are important in the identification of interstellar unidentified infrared emission bands, demonstrate its superiority over other methods. The clean production with little fragmentation, ease of distinction between protonated and neutral species, narrow lines and reliable relative infrared intensities of the lines, and broad coverage of the spectral range associated with this method enable us to assign the isomers unambiguously. The application of this method to the protonation of small molecules is more complicated partly because of the feasible fragmentation and reactions, and partly because of the possible proton sharing between the species of interest and H2, but, with isotopic experiments and secondary photolysis, definitive assignments are practicable. Furthermore, the true relative infrared intensities are critical to a comparison of experimental results with data from theoretical calculations. The spectra of a proton-shared species in solid p-H2 might provide insight into a search for spectra of proton-bound species in interstellar media. Investigations of hydrogenated species involving the photolysis of Cl2 or precursors of OH complement those using electron bombardment and provide an improved ratio of signal to noise. With careful grouping of observed lines after secondary photolysis and a comparison with theoretical predictions, various isomers of these species have been determined. This photolytic technique has been applied in an investigation of hydrogenated PAH and PANH, and the hydrogenation reactions of small molecules, which are important in interstellar ice and the evolution of life. The electronic transitions of molecules in solid p-H2 have been little investigated. The matrix shift of the origins of transitions and the spectral width seem to be much smaller than those of noble-gas matrices; these features might facilitate a direct comparison of matrix spectra with diffuse interstellar bands, but further data are required to assess this possibility. The advantages and disadvantages of applying these techniques of p-H2 matrix isolation to astrochemical research and their future perspectives are discussed.

Exposure to Recycled Uranium Contaminants in Gaseous Diffusion Plants.

As part of an ongoing study of health effects in a pooled cohort of gaseous diffusion plant workers, organ dose from internal exposure to uranium was evaluated. Due to the introduction of recycled uranium into the plants, there was also potential for exposure to radiologically significant levels of 99Tc, 237Np and 238,239Pu. In the evaluation of dose response, these radionuclide exposures could confound the effect of internal uranium. Using urine bioassay data for study subjects reported in facility records, intakes and absorbed dose to bone surface, red bone marrow and kidneys were estimated as these organs were associated with a priori outcomes of interest. Additionally, 99Tc intakes and doses were calculated using a new systemic model for technetium and compared to intakes and doses calculated using the current model recommended by the International Commission on Radiological Protection. Organ absorbed doses for the transuranics were significant compared to uranium doses; however, 99Tc doses calculated using the new systemic model were significant as well. Use of the new model resulted in an increase in 99Tc-related absorbed organ dose of a factor of 8 (red bone marrow) to 30 (bone surface).

Mortality in a combined cohort of uranium enrichment workers.

OBJECTIVE: To examine the patterns of cause-specific mortality and relationship between internal exposure to uranium and specific causes in a pooled cohort of 29,303 workers employed at three former uranium enrichment facilities in the United States with follow-up through 2011. METHODS: Cause-specific standardized mortality ratios (SMRs) for the full cohort were calculated with the U.S. population as referent. Internal comparison of the dose-response relation between selected outcomes and estimated organ doses was evaluated using regression models. RESULTS: External comparison with the U.S. population showed significantly lower SMRs in most diseases in the pooled cohort. Internal comparison showed positive associations of absorbed organ doses with multiple myeloma, and to a lesser degree with kidney cancer. CONCLUSION: In general, these gaseous diffusion plant workers had significantly lower SMRs than the U.S. POPULATION: The internal comparison however, showed associations between internal organ doses and diseases associated with uranium exposure in previous studies. Am. J. Ind. Med. 60:96-108, 2017. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Development of methods for using workers' compensation data for surveillance and prevention of occupational injuries among State-insured private employers in Ohio.

BACKGROUND: Workers' compensation (WC) claims data may be useful for identifying high-risk industries and developing prevention strategies. METHODS: WC claims data from private-industry employers insured by the Ohio state-based workers' compensation carrier from 2001 to 2011 were linked with the state's unemployment insurance (UI) data on the employer's industry and number of employees. National Labor Productivity and Costs survey data were used to adjust UI data and estimate full-time equivalents (FTE). Rates of WC claims per 100 FTE were computed and Poisson regression was used to evaluate differences in rates. RESULTS: Most industries showed substantial claim count and rate reductions from 2001 to 2008, followed by a leveling or slight increase in claim count and rate from 2009 to 2011. Despite reductions, there were industry groups that had consistently higher rates. CONCLUSION: WC claims data linked to employment data could be used to prioritize industries for injury research and prevention activities among State-insured private employers. Am. J. Ind. Med. 59:1087-1104, 2016. © 2016 Wiley Periodicals, Inc.

Occupational risk factors for endometriosis in a cohort of flight attendants.

OBJECTIVES: This study aimed to (i) compare odds of endometriosis in a cohort of flight attendants against a comparison group of teachers and (ii) investigate occupational risk factors for endometriosis among flight attendants. METHODS: We included 1945 flight attendants and 236 teachers aged 18-45 years. Laparoscopically confirmed endometriosis was self-reported via telephone interview, and flight records were retrieved from airlines to obtain work schedules and assess exposures for flight attendants. We used proportional odds regression to estimate adjusted odds ratios (OR adj) and 95% confidence intervals (95% CI) for associations between exposures and endometriosis, adjusting for potential confounders. RESULTS: Flight attendants and teachers were equally likely to report endometriosis (OR adj1.0, 95% CI 0.5-2.2). Among flight attendants, there were no clear trends between estimated cosmic radiation, circadian disruption, or ergonomic exposures and endometriosis. Greater number of flight segments (non-stop flights between two cities) per year was associated with endometriosis (OR adj2.2, 1.1-4.2 for highest versus lowest quartile, P trend= 0.02) but block hours (taxi plus flight time) per year was not (OR adj1.2, 95% CI 0.6-2.2 for highest versus lowest quartile, P trend=0.38). CONCLUSION: Flight attendants were no more likely than teachers to report endometriosis. Odds of endometriosis increased with number of flight segments flown per year. This suggests that some aspect of work scheduling is associated with increased risk of endometriosis, or endometriosis symptoms might affect how flight attendants schedule their flights.

Internal exposure to uranium in a pooled cohort of gaseous diffusion plant workers.

Intakes and absorbed organ doses were estimated for 29 303 workers employed at three former US gaseous diffusion plants as part of a study of cause-specific mortality and cancer incidence in uranium enrichment workers. Uranium urinalysis data (>600 000 urine samples) were available for 58 % of the pooled cohort. Facility records provided uranium gravimetric and radioactivity concentration data and allowed estimation of enrichment levels of uranium to which workers may have been exposed. Urine data were generally recorded with facility department numbers, which were also available in study subjects' work histories. Bioassay data were imputed for study subjects with no recorded sample results (33 % of pooled cohort) by assigning department average urine uranium concentration. Gravimetric data were converted to 24-h uranium activity excretion using department average specific activities. Intakes and organ doses were calculated assuming chronic exposure by inhalation to a 5-µm activity median aerodynamic diameter aerosol of soluble uranium. Median intakes varied between 0.31 and 0.74 Bq d(-1) for the three facilities. Median organ doses for the three facilities varied between 0.019 and 0.051, 0.68 and 1.8, 0.078 and 0.22, 0.28 and 0.74, and 0.094 and 0.25 mGy for lung, bone surface, red bone marrow, kidneys, and liver, respectively. Estimated intakes and organ doses for study subjects with imputed bioassay data were similar in magnitude.

Cancer Mortality through 2005 among a Pooled Cohort of U.S. Nuclear Workers Exposed to External Ionizing Radiation.

UNLABELLED: Nuclear workers worldwide have been studied for decades to estimate associations between their exposure to ionizing radiation and cancer. The low-level exposure of these workers requires pooling of large cohorts studied over many years to obtain risk estimates with appropriate latency and good precision. We assembled a pooled cohort of 119,195 U.S. nuclear workers at four Department of Energy nuclear weapons facilities (Hanford site, Idaho National Laboratory, Oak Ridge National Laboratory and Savannah River site) and at the Portsmouth Naval Shipyard. The cohort was followed at the start of the workers beginning their radiation work (at earliest, between 1944 and 1952) through 2005, and we compared its mortality to that of the U.S. POPULATION: We also conducted regression-modeling analysis to evaluate dose-response associations for external radiation exposure and outcomes: all cancers, smoking- and nonsmoking-related cancers, all lymphatic and hematopoietic cancers, leukemia (excluding chronic lymphocytic), multiple myeloma, cardiovascular disease and others. The mean dose observed among the cohort was 20 mSv. For most outcomes, mortality was below expectation compared to the general population, but mesothelioma and pleura cancers were highly elevated. We found an excess relative risk (ERR) per 10 mSv of 0.14% [95% confidence interval (CI): -0.17%, 0.48%] for all cancers excluding leukemia. Estimates were higher for nonsmoking-related cancers (0.70%, 95% CI: 0.058%, 1.5%) and lower for smoking-related cancers (-0.079%, 95% CI: -0.43%, 0.32%). The ERR per 10 mSv was 1.7% (95% CI: -0.22%, 4.7%) for leukemia, which was similar to the estimate of 1.8% (95% CI: 0.027%, 4.4%) for all lymphatic and hematopoietic cancers. The ERR per 10 mSv for multiple myeloma was 3.9% (95% CI: 0.60%, 9.5%). The ERR per 10 mSv for cardiovascular disease was 0.026% (-0.25%, 0.32%). Little evidence of heterogeneity was seen by facility, birth cohort or sex for most outcomes. The estimates observed here are similar to those found in previous large pooled nuclear worker studies and also (with the exception of multiple myeloma) to those conducted in the Life Span Study of Japanese atomic bomb survivors. The tendency of observed risks to persist many years after exposure for most outcomes illustrates the importance of continued follow-up of nuclear worker cohorts.

Miscarriage among flight attendants.

BACKGROUND: Cosmic radiation and circadian disruption are potential reproductive hazards for flight attendants. METHODS: Flight attendants from 3 US airlines in 3 cities were interviewed for pregnancy histories and lifestyle, medical, and occupational covariates. We assessed cosmic radiation and circadian disruption from company records of 2 million individual flights. Using Cox regression models, we compared respondents (1) by levels of flight exposures and (2) to teachers from the same cities, to evaluate whether these exposures were associated with miscarriage. RESULTS: Of 2654 women interviewed (2273 flight attendants and 381 teachers), 958 pregnancies among 764 women met study criteria. A hypothetical pregnant flight attendant with median first-trimester exposures flew 130 hours in 53 flight segments, crossed 34 time zones, and flew 15 hours during her home-base sleep hours (10 pm-8 am), incurring 0.13 mGy absorbed dose (0.36 mSv effective dose) of cosmic radiation. About 2% of flight attendant pregnancies were likely exposed to a solar particle event, but doses varied widely. Analyses suggested that cosmic radiation exposure of 0.1 mGy or more may be associated with increased risk of miscarriage in weeks 9-13 (odds ratio = 1.7 [95% confidence interval = 0.95-3.2]). Risk of a first-trimester miscarriage with 15 hours or more of flying during home-base sleep hours was increased (1.5 [1.1-2.2]), as was risk with high physical job demands (2.5 [1.5-4.2]). Miscarriage risk was not increased among flight attendants compared with teachers. CONCLUSIONS: Miscarriage was associated with flight attendant work during sleep hours and high physical job demands and may be associated with cosmic radiation exposure.

Flight attendant radiation dose from solar particle events.

INTRODUCTION: Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. METHODS: Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. RESULTS: Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 µGy (18 µSv) and 3.1 µGy (8.3 µSv) for the first and second study periods, respectively. Maximum doses were as high as 440 µGy (1.2 mSv) and 20 flight segments had doses greater than 190 µGy (0.5 mSv). DISCUSSION: During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.