Smokers' utilization of quitting methods and vaping during pregnancy: an empirical cluster analysis of 2016-2018 Pregnancy Risk Assessment Monitoring System (PRAMS) data in seven US states.

BACKGROUND: Patterns of utilization of numerous smoking cessation methods among pregnant women amidst the increasing popularity of vaping (use of e-cigarettes) remains unknown. METHODS: This study included 3,154 mothers who self-reported smoking around the time of conception and delivered live births in 2016-2018 in seven US states. Latent class analysis was used to identify subgroups of smoking women based on their utilization of 10 surveyed quitting methods and vaping during pregnancy. RESULTS: We identified four subgroups of smoking mothers with different utilization patterns of quitting methods during pregnancy: 22.0% reported "not trying to quit"; 61.4% tried to "quit on my own" without any behavioral or pharmacological assistance; 3.7% belonged to the "vaping" subgroup; and 12.9% utilized "wide-ranging methods" with higher use rate of multiple approaches, such as quit line and nicotine patch. Compared to mothers "not trying to quit," the subgroup trying to "quit on my own" were more likely to be abstinent (adjusted OR 4.95, 95% CI 2.82-8.35) or to reduce the number of cigarettes smoked daily (adjusted OR 2.46, 95% CI 1.31-4.60) in late pregnancy, and these improvements lasted into early postpartum. We did not observe a measurable reduction in smoking among the "vaping" subgroup or women trying to quit with "wide-ranging methods". CONCLUSIONS: We identified four subgroups of smoking mothers with different utilization patterns of eleven quitting methods during pregnancy. Pre-pregnancy smokers who tried to "quit on my own" were most likely to be abstinent or to reduce smoking amount.

The evolution of workplace risk for Covid-19 in Canadian healthcare workers and its relation to vaccination: A nested case-referent study.

BACKGROUND: During the early months of the Covid-19 pandemic, studies demonstrated that healthcare workers (HCWs) were at increased risk of infection. Few modifiable risks were identified. It is largely unknown how these evolved over time. METHODS: A prospective case-referent study was established and nested within a cohort study of Canadian HCWs. Cases of Covid-19, confirmed by polymerase chain reaction, were matched with up to four referents on job, province, gender, and date of first vaccination. Cases and referents completed a questionnaire reporting exposures and experiences in the 21 days before case date. Participants were recruited from October 2020 to March 2022. Workplace factors were examined by mixed-effects logistic regression allowing for competing exposures. A sensitivity analysis was limited to those for whom family/community transmission seemed unlikely. RESULTS: 533 cases were matched with 1697 referents. Among unvaccinated HCWs, the risk of infection was increased if they worked hands-on with patients with Covid-19, on a ward designated for care of infected patients, or handled objects used by infected patients. Sensitivity analysis identified work in residential institutions and geriatric wards as high risk for unvaccinated HCWs. Later, with almost universal HCW vaccination, risk from working with infected patients was much reduced but cases were more likely than referents to report being unable to access an N95 mask or that decontaminated N95 masks were reused. CONCLUSIONS: These results suggest that, after a rocky start, the risks of Covid-19 infection from work in health care are now largely contained in Canada but with need for continued vigilance.

Duration of employment within occupations and incident stroke in a US general population cohort 45 years of age or older (REGARDS study).

BACKGROUND: The work environment can contribute to the risk of cardiovascular diseases (CVD) including stroke. Our objective was to identify occupations with elevated risk of stroke within the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort. METHODS: We analyzed incident stroke outcomes (ischemic and hemorrhagic strokes) from 2003 to 2020 and employment characteristics of 13,659 adults aged ≥45 years enrolled in a national population-based cohort study. Using a modified Poisson regression approach, we estimated the relative risks (RRs) and the associated 95% confidence intervals (CI) of stroke in relation to years of employment within each occupation coded using the US Census two-digit Standard Occupation Code. Models were adjusted for Framingham Stroke Risk Score, region, race, age, and body mass index. We conducted stratified analysis by sex, employment time period (pre-1975 vs. post-1975), and region. RESULTS: Workers in the following occupations had a greater risk of stroke with longer duration of employment (per decade): protective service (RR: 2.35, 95% CI: 1.11, 4.97), food preparation and service (RR: 1.51, 95% CI: 1.05, 2.19), and transportation and material moving (RR: 1.30, 95% CI: 1.00, 1.69). The stroke risk in these occupations was disproportionately elevated in men, and differed by region and employment time period. CONCLUSIONS: Longer employment in protective service, food preparation and serving, and transportation and materials moving occupations may increase the risk of stroke. Surveillance may uncover specific work-related risk factors in these occupations, leading to interventions to reduce the burden of stroke among US workers.

Pride and adversity among nurses and physicians during the pandemic in two US healthcare systems: a mixed methods analysis.

BACKGROUND: Our aims were to examine themes of the most difficult or distressing events reported by healthcare workers during the first wave of COVID-19 pandemic in two US health care systems in order to identify common themes and then to relate them to both behavioral theory and measures of anxiety and depression. METHODS: We conducted a cross-sectional survey of nurses and physicians during the early phases of the COVID-19 pandemic in the US. An emailed recruitment letter was sent, with about half choosing to supply open-ended responses relevant to thematic analysis. We measured symptoms of anxiety and depression separately, captured demographics, and asked two open-ended questions regarding events that were the most difficult or stressful, and reinforced pride. We reported descriptive statistics and coded thematic categories for their continuum "pride" and "distress" the factors related to fostering well-being according to the Self-Determination Theory. RESULTS: Themes that emerged from these narratives were congruent with prediction of Self-Determination theory that autonomy-supportive experiences will foster pride, while autonomy-thwarting experiences will cause distress. Those who reported distressful events were more anxious and depressed compared to those who did not. Among those who reported incidences that reinforced pride in the profession, depression was rarer compared to those who did not. These trends were evident after allowing for medical history and other covariates in logistic regressions. CONCLUSION: Causal claims from our analysis should be made with caution due to the cross-sectional research design. Understanding perceptions of the pandemic by nurses and physicians may help identify and manage sources of distress, and suggest means of mitigating the risk of mental health distress through autonomy-supportive policies.

Effect of Adjustment for Case Misclassification and Infection Date Uncertainty on Estimates of COVID-19 Effective Reproduction Number.

BACKGROUND: Surveillance data captured during the COVID-19 pandemic may not be optimal to inform a public health response, because it is biased by imperfect test accuracy, differential access to testing, and uncertainty in date of infection. METHODS: We downloaded COVID-19 time-series surveillance data from the Colorado Department of Public Health & Environment by report and illness onset dates for 9 March 2020 to 30 September 2020. We used existing Bayesian methods to first adjust for misclassification in testing and surveillance, followed by deconvolution of date of infection. We propagated forward uncertainty from each step corresponding to 10,000 posterior time-series of doubly adjusted epidemic curves. The effective reproduction number (Rt), a parameter of principal interest in tracking the pandemic, gauged the impact of the adjustment on inference. RESULTS: Observed period prevalence was 1.3%; median of the posterior of true (adjusted) prevalence was 1.7% (95% credible interval [CrI]: 1.4%, 1.8%). Sensitivity of surveillance declined over the course of the epidemic from a median of 88.8% (95% CrI: 86.3%, 89.8%) to a median of 60.8% (95% CrI: 60.1%, 62.6%). The mean (minimum, maximum) values of Rt were higher and more variable by report date, 1.12 (0.77, 4.13), compared to those following adjustment, 1.05 (0.89, 1.73). The epidemic curve by report date tended to overestimate Rt early on and be more susceptible to fluctuations in data. CONCLUSION: Adjusting for epidemic curves based on surveillance data is necessary if estimates of missed cases and the effective reproduction number play a role in management of the COVID-19 pandemic.

Smoking and use of electronic cigarettes (vaping) in relation to preterm birth and small-for-gestational-age in a 2016 U.S. national sample.

Women who smoke may be motivated to switch to vaping (use electronic cigarettes, e-cigs) around pregnancy in seeking to alleviate known hazards of smoking. E-cigs typically contain nicotine but either eliminates or greatly reduces exposure to the combustion products of tobacco. We studied a U.S.-wide representative sample of 31,973 live singleton births in 2016. In the three months before pregnancy, 5029 (14%) mothers exclusively smoked tobacco ("sole smokers") and 976 (3%) used both tobacco and e-cigs ("dual-users"). Among pre-pregnancy sole smokers, 44% continued to only smoke while 1% became dual-users in late pregnancy. Logistic regression models were used to assess the adjusted odds ratios (aOR) for preterm and small-for-gestational-age (SGA) by reported smoking or vaping in late pregnancy. Compared to women who used neither product ("non-users"), late-pregnancy sole smokers had increased risks for preterm birth (aOR 1.6, 95% CI 1.2-2.0) and SGA (aOR 2.4, 95% CI 1.8-2.9), after adjusting for their pre-pregnancy smoking or vaping status and other confounders. The adjusted models also showed that late-pregnancy sole vapers had similar risk of preterm birth as non-users (aOR 1.2, 95% CI 0.5-2.7). Late-pregnancy dual-users also had similar risk of preterm birth as non-users (aOR 1.3, 95% CI 0.8-2.3). However, late-pregnancy sole vapers and dual-users had increased risk of SGA compared to non-users (aOR 2.4, 95% CI 1.0-5.7 for sole vapers, and aOR 2.3 95% CI 1.3-4.1 for dual-users). These findings suggest that vapers during pregnancy had similar risk of preterm as non-users but still had elevated risk for restricted fetal growth.

Towards reduction in bias in epidemic curves due to outcome misclassification through Bayesian analysis of time-series of laboratory test results: case study of COVID-19 in Alberta, Canada and Philadelphia, USA.

BACKGROUND: Despite widespread use, the accuracy of the diagnostic test for SARS-CoV-2 infection is poorly understood. The aim of our work was to better quantify misclassification errors in identification of true cases of COVID-19 and to study the impact of these errors in epidemic curves using publicly available surveillance data from Alberta, Canada and Philadelphia, USA. METHODS: We examined time-series data of laboratory tests for SARS-CoV-2 viral infection, the causal agent for COVID-19, to try to explore, using a Bayesian approach, the sensitivity and specificity of the diagnostic test. RESULTS: Our analysis revealed that the data were compatible with near-perfect specificity, but it was challenging to gain information about sensitivity. We applied these insights to uncertainty/bias analysis of epidemic curves under the assumptions of both improving and degrading sensitivity. If the sensitivity improved from 60 to 95%, the adjusted epidemic curves likely falls within the 95% confidence intervals of the observed counts. However, bias in the shape and peak of the epidemic curves can be pronounced, if sensitivity either degrades or remains poor in the 60-70% range. In the extreme scenario, hundreds of undiagnosed cases, even among the tested, are possible, potentially leading to further unchecked contagion should these cases not self-isolate. CONCLUSION: The best way to better understand bias in the epidemic curves of COVID-19 due to errors in testing is to empirically evaluate misclassification of diagnosis in clinical settings and apply this knowledge to adjustment of epidemic curves.

Women's occupational exposure to polycyclic aromatic hydrocarbons and risk of breast cancer.

OBJECTIVE: To estimate the association between occupational polycyclic aromatic hydrocarbon (PAH) exposure and female breast cancer. METHODS: Lifetime work histories for 1130 cases and 1169 controls from British Columbia and Ontario (Canada) were assessed for PAH exposure using a job-exposure matrix based on compliance measurements obtained during US Occupational Safety and Health Administration workplace safety inspections. RESULTS: Exposure to any level of PAHs was associated with an increased risk of breast cancer (OR=1.32, 95% CI: 1.10 to 1.59), as was duration at high PAH exposure (for >7.4 years: OR=1.45, 95% CI: 1.10 to 1.91; ptrend=0.01), compared with women who were never exposed. Increased risk of breast cancer was most strongly associated with prolonged duration at high occupational PAH exposure among women with a family history of breast cancer (for >7.4 years: OR=2.79, 95% CI: 1.25 to 6.24; ptrend<0.01). CONCLUSIONS: Our study suggests that prolonged occupational exposure to PAH may increase breast cancer risk, especially among women with a family history of breast cancer.

Occupation and Parkinson disease in the Women's Health Initiative Observational Study.

INTRODUCTION: There is a lack of consistent study findings on associations between workplace exposures and the risk of Parkinson disease (PD) and a paucity of such data on women. We assessed PD risk among occupational groups to derive insights about potential occupation-specific exposures in a large cohort of women. METHODS: The Women's Health Initiative Observational Study (WHI-OS) is a prospective cohort that enrolled 91 627 postmenopausal women, 50 to 79 years of age, from 01 October 1993 through 31 December 1998, at 40 clinical centers across the United States, with average follow-up interval of 11 years. These women reported up to three paid jobs, held the longest since age 18; these jobs were coded and duration of employment calculated. We defined a case by self-report of doctor-diagnosed PD (at baseline or follow-up), death attributed to PD, or taking medication consistent with PD. RESULTS: Among 2590 PD cases, we found evidence of excess risk among "counselors, social workers, and other community and social service specialists," and there was a suggestion of increased in risk among postsecondary teachers, and "building and grounds cleaning and maintenance" workers. There was also evidence of a deficit in risk among women who worked in sales. Results according to ever-employed and job duration were similar, except for evidence of excess risk among "health technologists and technicians" with more than 20 years of employment. Longer duration of life on a farm was associated with higher risk. CONCLUSION: Our findings paint a largely reassuring picture of occupational risks for PD among US women.

Correction of odds ratios in case-control studies for exposure misclassification with partial knowledge of the degree of agreement among experts who assessed exposures.

OBJECTIVES: Estimates of association between exposures and diseases are often distorted by error in exposure classification. When the validity of exposure assessment is known, this can be used to adjust these estimates. When exposure is assessed by experts, even if validity is not known, we sometimes have information about interrater reliability. We present a Bayesian method for translating the knowledge of interrater reliability, which is often available, into knowledge about validity, which is often needed but not directly available, and applying this to correct odds ratios (OR). METHODS: The method allows for inclusion of observed potential confounders in the analysis, as is common in regression-based control for confounding. Our method uses a novel type of prior on sensitivity and specificity. The approach is illustrated with data from a case-control study of lung cancer risk and occupational exposure to diesel engine emissions, in which exposure assessment was made by detailed job history interviews with study subjects followed by expert judgement. RESULTS: Using interrater agreement measured by kappas (κ), we estimate sensitivity and specificity of exposure assessment and derive misclassification-corrected confounder-adjusted OR. Misclassification-corrected and confounder-adjusted OR obtained with the most defensible prior had a posterior distribution centre of 1.6 with 95% credible interval (Crl) 1.1 to 2.6. This was on average greater in magnitude than frequentist point estimate of 1.3 (95% Crl 1.0 to 1.7). CONCLUSIONS: The method yields insights into the degree of exposure misclassification and appears to reduce attenuation bias due to misclassification of exposure while the estimated uncertainty increased.

A conceptual model for take-home workplace exposures.

The boundary between occupational and environmental exposures is often artificial, as occupational hazards can readily escape the workplace. One way that this occurs is when workers "take-home" occupational hazards, exposing family members. While take-home exposures have long been recognized, there is no comprehensive framework describing the pathways by which workers bring home workplace hazards. In this article, we provide such a conceptual model that includes three pathways for take-home exposures: external contamination, internal dose, and behavior change of workers. This conceptual model should help to describe the problems of take-home exposures more comprehensively in future research.

Social, obstetric and environmental determinants of low Apgar score among infants born in four selected hospitals in Ibadan, Nigeria.

Little information exists about socio-economic, environmental or occupational determinants of low Apgar scores among Nigerian neonates. Mothers in lying-in wards of four hospitals in Ibadan were interviewed on socio-demographic characteristics, obstetric history and work activities during index pregnancy. Apgar scores and clinical data were extracted from case notes. Of the 1349 respondents, 20% had Apgar score <7 at one minute, 4% at five minutes. Lower education, cooking with kerosene, physical exertion at work, nulliparity, hypertension in pregnancy, prolonged rupture of membranes, breech presentation and caesarean section were predictors for low Apgar scores at one minute; nulliparity, male infant and breech presentation at five minutes. Occupations with lower socio-economic status or those requiring physical exertion; tailoring, catering and hairdressing recorded higher rates of low Apgar scores at one minute (p = .08). Physical exertion at work and cooking with kerosene may be predictive of low Apgar scores and require further study.

Bayesian Approaches to Racial Disparities in HIV Risk Estimation Among Men Who Have Sex with Men.

BACKGROUND: Men who have sex with men (MSM) continue to be overrepresented for new HIV infections compared with non-MSM. This disparity becomes even more alarming when considering racial groups. We describe the race-specific effects in HIV prevalence among MSM relative to non-MSM and explore the causes of disagreement among estimates. METHODS: We used data from the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative longitudinal survey conducted in the US Bayesian learning corrected for potential misclassification of MSM status and adjusted for residual confounding, hypothesized to explain the MSM racial disparity in HIV. We articulated the structure and strength of the latent confounders that would make race-specific risk gradients equivalent. RESULTS: Compared with non-MSM, the adjusted prevalence odds ratio (POR) and 95% credible interval for black MSM having self-reported HIV infection was 5.8 (2.0, 16), while the POR for white MSM was 12 (4.2, 31). For all MSM, the POR for HIV infection was 9.3 (3.6, 23) with black men having 2.6 times the odds of prevalent infection compared with white men. CONCLUSIONS: The observed race-specific associations in MSM are likely not due to misclassification alone, but represent a constellation of factors that differ between racial groups. We recommend specific risk factors in surveys needed to further identify the behavioral characteristics that lead to the observed differences when the estimates are stratified by race.

Parental exposures to occupational asthmagens and risk of autism spectrum disorder in a Danish population-based case-control study.

BACKGROUND: Environmental exposures and immune conditions during pregnancy could influence development of autism spectrum disorder (ASD) in offspring. However, few studies have examined immune-triggering exposures in relation to ASD. We evaluated the association between parental workplace exposures to risk factors for asthma ("asthmagens") and ASD. METHODS: We conducted a population-based case-control study in the Danish population using register linkage. Our study population consisted of 11,869 ASD cases and 48,046 controls born from 1993 through 2007. Cases were identified by ICD-10 codes in the Danish Psychiatric Central Register. ASD cases and controls were linked to parental Danish International Standard Classification of Occupations (DISCO-88) job codes. Parental occupational asthmagen exposure was estimated by linking DISCO-88 codes to an asthma-specific job-exposure matrix. RESULTS: Our maternal analyses included 6706 case mothers and 29,359 control mothers employed during the pregnancy period. We found a weak inverse association between ASD and any maternal occupational asthmagen exposure, adjusting for sociodemographic covariates (adjusted OR: 0.92, 95% CI: 0.86-0.99). In adjusted analyses, including 7647 cases and 31,947 controls with employed fathers, paternal occupational asthmagen exposure was not associated with ASD (adjusted OR: 0.98, 95% CI: 0.92-1.05). CONCLUSIONS: We found a weak inverse association between maternal occupational asthmagen exposure and ASD, and a null association between paternal occupational exposure and ASD. We suggest that unmeasured confounding negatively biased the estimate, but that this unmeasured confounding is likely not strong enough to bring the effect above the null. Overall, our results were consistent with no positive association between parental asthmagen exposure and ASD in the children.

Bayesian Correction of Misclassification of Pertussis in Vaccine Effectiveness Studies: How Much Does Underreporting Matter?

Diagnosis of pertussis remains a challenge, and consequently research on the risk of disease might be biased because of misclassification. We quantified this misclassification and corrected for it in a case-control study of children in Philadelphia, Pennsylvania, who were 3 months to 6 years of age and diagnosed with pertussis between 2011 and 2013. Vaccine effectiveness (VE; calculated as (1 - odds ratio) × 100) was used to describe the average reduction in reported pertussis incidence resulting from persons being up to date on pertussis-antigen containing vaccines. Bayesian techniques were used to correct for purported nondifferential misclassification by reclassifying the cases per the 2014 Council of State and Territorial Epidemiologists pertussis case definition. Naïve VE was 50% (95% confidence interval: 16%, 69%). After correcting for misclassification, VE ranged from 57% (95% credible interval: 30, 73) to 82% (95% credible interval: 43, 95), depending on the amount of underreporting of pertussis that was assumed to have occurred in the study period. Meaningful misclassification was observed in terms of false negatives detected after the incorporation of infant apnea to the 2014 case definition. Although specificity was nearly perfect, sensitivity of the case definition varied from 90% to 20%, depending on the assumption about missed cases. Knowing the degree of the underreporting is essential to the accurate evaluation of VE.

Genetic variation in vitamin D-related genes and risk of breast cancer among women of European and East Asian descent.

Studies of vitamin D-related genetic variants and breast cancer have been inconsistent. This study aimed to investigate associations of vitamin D-related polymorphisms and breast cancer risk among European and East Asian women and potential interactions with menopausal status and breast tumour subtypes. Data from a case-control study of breast cancer (1037 cases and 1050 controls) were used to assess relationships between 21 polymorphisms in two vitamin D-related genes (GC and VDR) and breast cancer risk. Odds ratios were calculated in stratified analyses of European and East Asian women, using logistic regression in an additive genetic model. An interaction term was used to explore modification by menopausal status. Polytomous regression was used to assess heterogeneity by breast tumour subtype. False discovery rate adjustments were conducted to account for multiple testing. No association was observed between GC or VDR polymorphisms and breast cancer risk. Modification of these relationships by menopausal status was observed for select polymorphisms in both Europeans (VDR rs4328262 and rs11168292) and East Asians (GC rs7041 and VDR rs11168287). Heterogeneity by tumour subtype was seen for three VDR polymorphisms (rs1544410, rs7967152 and rs2239186) among Europeans, in which associations with ER-/PR-/HER2+ tumours, but not with other subtypes, were observed. In conclusion, associations between vitamin D-related genetic variants and breast cancer were not observed overall, although the relationships between vitamin D pathway polymorphisms and breast cancer may be modified by menopausal status and breast tumour subtype.

Identification of confounder in epidemiologic data contaminated by measurement error in covariates.

BACKGROUND: Common methods for confounder identification such as directed acyclic graphs (DAGs), hypothesis testing, or a 10 % change-in-estimate (CIE) criterion for estimated associations may not be applicable due to (a) insufficient knowledge to draw a DAG and (b) when adjustment for a true confounder produces less than 10 % change in observed estimate (e.g. in presence of measurement error). METHODS: We compare previously proposed simulation-based approach for confounder identification that can be tailored to each specific study and contrast it with commonly applied methods (significance criteria with cutoff levels of p-values of 0.05 or 0.20, and CIE criterion with a cutoff of 10 %), as well as newly proposed two-stage procedure aimed at reduction of false positives (specifically, risk factors that are not confounders). The new procedure first evaluates potential for confounding by examination of correlation of covariates and applies simulated CIE criteria only if there is evidence of correlation, while rejecting a covariate as confounder otherwise. These approaches are compared in simulations studies with binary, continuous, and survival outcomes. We illustrate the application of our proposed confounder identification strategy in examining the association of exposure to mercury in relation to depression in the presence of suspected confounding by fish intake using the National Health and Nutrition Examination Survey (NHANES) 2009-2010 data. RESULTS: Our simulations showed that the simulation-determined cutoff was very sensitive to measurement error in exposure and potential confounder. The analysis of NHANES data demonstrated that if the noise-to-signal ratio (error variance in confounder/variance of confounder) is at or below 0.5, roughly 80 % of the simulated analyses adjusting for fish consumption would correctly result in a null association of mercury and depression, and only an extremely poorly measured confounder is not useful to adjust for in this setting. CONCLUSIONS: No a prior criterion developed for a specific application is guaranteed to be suitable for confounder identification in general. The customization of model-building strategies and study designs through simulations that consider the likely imperfections in the data, as well as finite-sample behavior, would constitute an important improvement on some of the currently prevailing practices in confounder identification and evaluation.

Trends in OSHA Compliance Monitoring Data 1979-2011: Statistical Modeling of Ancillary Information across 77 Chemicals.

OBJECTIVES: The Integrated Management Information System (IMIS) is the largest multi-industry source of exposure measurements available in North America. However, many have suspected that the criteria through which worksites are selected for inspection are related to exposure levels. We investigated associations between exposure levels and ancillary variables in IMIS in order to understand the predictors of high exposure within an enforcement context. METHODS: We analyzed the association between nine variables (reason for inspection, establishment size, total amount of penalty, Occupational Safety and Health Administration (OSHA) plan, OSHA region, union status, inspection scope, year, and industry) and exposure levels in IMIS using multimodel inference for 77 agents. For each agent, we used two different types of models: (i) logistic models were used for the odds ratio (OR) of exposure being above the threshold limit value (TLV) and (ii) linear models were used for exposure concentrations restricted to detected results to estimate percent increase in exposure level, i.e. relative index of exposure (RIE). Meta-analytic methods were used to combine results for each variable across agents. RESULTS: A total of 511,047 exposure measurements were modeled for logistic models and 299,791 for linear models. Higher exposures were measured during follow-up inspections than planned inspections [meta-OR = 1.61, 95% confidence interval (CI): 1.44-1.81; meta-RIE = 1.06, 95% CI: 1.03-1.09]. Lower exposures were observed for measurements collected under state OSHA plans compared to measurements collected under federal OSHA (meta-OR = 0.82, 95% CI: 0.73-0.92; meta-RIE = 0.86, 95% CI: 0.81-0.91). A 'high' total historical amount of penalty relative to none was associated with higher exposures (meta-OR = 1.54, 95% CI: 1.40-1.71; meta-RIE = 1.18, 95% CI: 1.13-1.23). CONCLUSIONS: The relationships observed between exposure levels and ancillary variables across a vast majority of agents suggest that certain elements of OSHA's process of selecting worksites for inspection influence the exposure levels that OSHA inspectors encounter. Nonetheless, given the paucity of other sources of exposure data and the lack of a more demonstrably representative data source, our study considers the use of IMIS data for the estimation of exposures in the broader universe of worksites in the USA.

Elemental Concentrations in Urban Green Stormwater Infrastructure Soils.

Green stormwater infrastructure (GSI) is designed to capture stormwater for infiltration, detention, evapotranspiration, or reuse. Soils play a key role in stormwater interception at these facilities. It is important to assess whether contamination is occurring in GSI soils because urban stormwater drainage areas often accumulate elements of concern. Soil contamination could affect hydrologic and ecosystem functions. Maintenance workers and the public may also be exposed to GSI soils. We investigated soil elemental concentrations, categorized as macro- and micronutrients, heavy metals, and other elements, at 59 GSI sites in the city of Philadelphia. Non-GSI soil samples 3 to 5 m upland of GSI sites were used for comparison. We evaluated differences in elemental composition in GSI and non-GSI soils; the comparisons were corrected for the age of GSI facility, underlying soil type, street drainage, and surrounding land use. Concentrations of Ca and I were greater than background levels at GSI sites. Although GSI facilities appear to accumulate Ca and I, these elements do not pose a significant human health risk. Elements of concern to human health, including Cd, Hg, and Pb, were either no different or were lower in GSI soils compared with non-GSI soils. However, mean values found across GSI sites were up to four times greater than soil cleanup objectives for residential use.