Activities and risk factors associated with fall-related injuries among US Army soldiers.

INTRODUCTION: Falls/near falls are the second leading cause of hospitalisation and outpatient visits among US Army soldiers. While numerous studies have evaluated fall-related or near fall-related injuries among elderly adults, few have evaluated this association among young adults. The objective of this study is to describe the characteristics and risk factors associated with fall-related or near fall-related injuries among male US Army soldiers. METHODS: This is a cross-sectional study of male US Army Airborne Division soldiers (n=5187). Electronic surveys captured demographic, lifestyle, physical training (PT), fitness and injury data during spring/summer of 2016. Multiple logistic regression was used to identify independent risk factors of fall-related or near fall-related injuries, adjusting for potential confounders. RESULTS: Primary findings indicated that activities and risk factors associated with fall-related or near fall-related injuries among soldiers included younger age (≤35 years), holding a job that required minimal lifting activities, slower 2-mile run times and not running during personal PT. CONCLUSIONS: The findings from this study suggest that male US Army soldiers and other physically active men may benefit from (1) obtaining and/or maintaining higher aerobic endurance and muscular strength, and (2) training focused on preventing fall-related injuries during PT, road marching and sports/recreational activities. Moreover, prevention strategies and education should further target younger soldiers (≤35 years old), as younger age is not modifiable.

Psychological distress and suicidal ideation among male construction workers in the United States.

BACKGROUND: Male workers in the US construction industry have a higher suicide rate than other workers in the nation. However, related research on this population remains sparse. This study evaluated psychological distress and suicidal ideation in these workers, and possible underlying factors. METHODS: Data from the National Survey of Drug Use and Health from 2008 to 2014 were analyzed. Stratified and multiple logistic regression analyses were conducted to examine factors associated with psychological distress and suicidal ideation among male construction workers aged ≥18 years (n = 12,034). RESULTS: Nearly one-third (29.6%) of male construction workers in the United States experienced psychological distress (23.8% graded as moderate, 5.8% as severe), and 2.5% reported suicidal ideation in the past year. Higher odds of serious psychological distress and suicidal ideation were found among workers who were younger, worked part-time, missed workdays due to injury or illness, or were in poor health. Illicit opioid use (odds ratio [OR] = 1.87, 95% confidence interval [CI]: 1.22-2.89) and alcohol dependence or abuse (OR = 2.64, 95% CI: 1.74-3.99) significantly escalated the odds of suicidal ideation. The odds of suicidal ideation among workers with serious psychological distress were 33 times higher than those having no or minor psychological distress (OR = 32.91, 95% CI: 19.82-54.65) when other factors were constant. CONCLUSIONS: Occupational and nonoccupational factors were associated with constructionworkers' psychological distress and suicidal ideation. Both illicit opioid use and alcohol dependence or abuse were risk factors, and psychological distress was a strong predictor for suicidal ideation. To improve workers' mental health, it is necessary to integrate workplace injury prevention with illicit opioid-use reduction programs and suicide prevention.

Pain and Prescription Opioid Use Among US Construction Workers: Findings From the 2011‒2018 Medical Expenditure Panel Survey.

Objectives. To examine prescription opioid and nonopioid analgesic use among US construction workers and their associations with pain conditions and sociodemographic factors. Methods. We analyzed data for about 9000 (weighted 11.5 million per year) construction workers who responded to the Medical Expenditure Panel Survey from 2011 to 2018. We applied both descriptive statistics and multiple logistic regression procedures in the analyses. Results. An estimated 1.2 million (10.0%) of construction workers used prescription opioid analgesics annually. The adjusted odds of prescription opioid use were significantly higher for workers suffering from work-related injuries (adjusted odds ratio [AOR] = 3.82; 95% confidence interval [CI] = 2.72, 5.37), non‒work-related injuries (AOR = 3.37; 95% CI = 2.54, 4.46), and musculoskeletal disorders (AOR = 2.31; 95% CI = 1.80, 2.95) after we controlled for potential confounders. Adjusted odds of prescription opioid use were also higher among workers with poorer physical health (AOR = 1.95; 95% CI = 1.42, 2.69) or mental health disorders (AOR = 1.95; 95% CI = 1.41, 2.68). Conclusions. Work- and non‒work-related injuries and musculoskeletal disorders significantly increased prescription opioid use among construction workers. To prevent opioid use disorders, multipronged strategies should be approached. (Am J Public Health. 2022;112(S1):S77-S87. https://doi.org/10.2105/AJPH.2021.306510).

Injury Risk Factors Associated With Weight Training.

ABSTRACT: Grier, T, Brooks, RD, Solomon, Z, and Jones, BH. Injury risk factors associated with weight training. J Strength Cond Res 36(2): e24-e30, 2022-The purpose of this evaluation was to identify injury risk factors associated with weight training (WT). Subjects were 4,785 men and 542 women in a U.S. Army Division. Personal characteristics, unit training, personal training, fitness, and 12-month injury history were obtained by an electronic survey. Risk factors for WT injuries were explored using backward stepping multivariable logistic regression. Risk ratios, odds ratios (ORs), and 95% confidence intervals (95% CIs) were calculated for each risk factor. Over a one-year period, 4.5% of men and 0.6% of women experienced a WT injury. Weight-training injury incidence was 0.31 and 0.05 per 1,000 hours of WT for men and women, respectively. Overall, men were 7.4 times more likely to experience a WT injury compared with women. For men who participated in WT, independent risk factors for a WT injury included older age (OR [23-27/≤ 22 years] = 1.99, 95% CI 1.22-3.27; OR [>28/≤ 22 years] = 2.48, 95% CI 1.52-4.03) and higher amounts of personal WT per week (OR [60-165/≥ 166 minutes] = 0.58, 95% CI 0.39-0.88; and OR [15-59/≥ 166 minutes] = 0.40, 95% CI 0.24-0.66). A linear trend was revealed indicating an increasing risk of a WT injury with greater amounts of time spent WT per week (p < 0.01). Performing moderate amounts of WT may reduce the risk of experiencing a WT injury. However, because muscle strength is an important component of fitness for Soldiers, specialized WT programs that improve strength while minimizing injury risks are needed.

Injury inequalities among U.S. construction workers.

This study explores racial/ethnic inequalities in work-related injuries among U.S. construction workers. Data from the 2004-2017 National Health Interview Survey were used to estimate work-related injuries by race/ethnicity in construction. Disparities in demographic, socioeconomic, and injury status among construction workers were examined by race/ethnicity. Injury differences were also evaluated in multiple logistic regression analyses controlling for potential confounders. Compared to white, non-Hispanic workers, minority workers were more likely to have lower socioeconomic statuses (e.g., lower educational attainment, lack of health insurance coverage, and family income below the poverty level), which considerably increased the likelihood of work-related injuries. The odds of work-related injuries were 70% higher among racial/ethnic minorities than white, non-Hispanics in construction. Injuries were also more severe among minorities than white, non-Hispanic workers. Among workers with a work-related injury, nearly 85% of Hispanics reported missing at least one workday due to injury, 45.6% higher than the proportion of 57.9% for their white, non-Hispanic counterparts. After adjusting for major demographic and socioeconomic factors, the work-related injury difference between race/ethnicity was no longer statistically significant. However, the odds of work-related injury remained significantly higher among workers who were younger (35-54 years vs. ≥ 55 years: aOR = 2.2, 95% CI: 1.3-3.6); male (aOR = 5.3, 95% CI: 2.9-9.8); not college-educated (aOR = 1.5, 95% CI: 1.0-2.2); had a family income below the poverty threshold (aOR = 1.8, 95% CI: 1.2-2.8); or held a blue-collar occupation (aOR = 2.0, 95% CI: 1.2-3.4). These findings suggest that the injury differences between race/ethnicity were strongly associated with demographics and socioeconomic inequalities in these worker groups. The identified injury disparities should be reduced or eliminated, following the hierarchy of controls paradigm.

Musculoskeletal Disorders and Prescription Opioid Use Among U.S. Construction Workers.

BACKGROUND: Musculoskeletal disorders (MSDs) and opioid use are a combined burden for construction safety and health. This study examines both issues among construction workers using a large population-based survey. METHODS: The prevalence of MSDs in construction was estimated using multi-year data from the Medical Expenditure Panel Survey. Prescription opioid use among workers with MSDs was compared to those without MSDs. RESULTS: About 34% of construction workers had at least one MSD symptom. Compared to those without MSDs, prescription opioid use tripled (aOR = 3.28, 95% CI: 2.44 to 4.41) among construction workers with MSDs. CONCLUSIONS: MSDs are prevalent among construction workers, and prescription opioid use significantly increased among workers with MSDs. It is critical to adopt ergonomic solutions in construction to reduce MSDs, and support workers in injury recovery with effective pain management.

The association between nutrition and behavioural health in a US Army population.

OBJECTIVE: The relationship between nutrition and behavioural health (BH) outcomes has been established in the literature. However, the relationship between nutrition and anxiety is unclear. Furthermore, the relationship between nutrition and BH outcomes has not been examined in a US Army Soldier population. This study sought to understand the relationship between Soldiers' nutritional intake and anxiety as well as depression. DESIGN: This cross-sectional study utilised multivariable logistic regression analyses to examine the relationship between nutritional intake and BH outcomes. SETTING: The study utilised data collected in 2018 during a BH epidemiological consultation conducted at one Army installation. PARTICIPANTS: Participants were 7043 US Army Soldiers at one Army installation. RESULTS: Of the Soldiers completing the survey, 12 % (n 812) screened positive for anxiety and 11 % (n 774) for depression. The adjusted odds of anxiety were significantly higher among Soldiers who reported low fruit intake compared with Soldiers who reported high fruit intake (adjusted OR (AOR) 1·36; 95 % CI 1·04, 1·79). The adjusted odds of depression were higher for Soldiers who reported low fruit intake (AOR 1·35; 95 % CI 1·01, 1·79) and/or low green vegetable intake (AOR 1·37; 95 % CI 1·02, 1·83). Lastly, the adjusted odds of depression were lower for Soldiers who reported low sugary drink intake (AOR 0·62; 95 % CI 0·48, 0·81). CONCLUSIONS: This study is the first to examine the important connection between nutritional intake and anxiety and depression at a US military installation. The information learned from this study has implications for enhancing Soldiers' nutritional knowledge and BH, ultimately improving Soldiers' health and medical readiness.

Prescription opioid use and associated factors among US construction workers.

BACKGROUND: Construction workers are among the segments of the US population that were hit hardest by the opioid prescription and overdose deaths in the past decades. Factors that underlie opioid use in construction workers have been compartmentalized and isolated in existing studies of opioid use and opioid overdose, but they ignore the overall context of their use. This study examines prescription opioid use and its association with a variety of occupational and nonoccupational factors in construction workers in the United States. METHODS: Data from the 2011-2017 Medical Expenditure Panel Survey (n = 7994) were analyzed. The prevalence of prescribed opioid use and the association with occupational and nonoccupational characteristics among construction workers were examined in four multiple logistic regression models. RESULTS: The odds of prescription opioid use for workers with occupational injuries was more than triple that of their noninjured counterparts when demographics and occupational factors were controlled (odds ratio = 3.38, 95% confidence interval: 2.38-4.81). Odds of prescription opioid use were higher in older construction workers, workers who were white, non-Hispanic, working part-time, and in poorer health, while Hispanic workers and those without health insurance were much less likely to report prescription opioid use. CONCLUSIONS: Prescription opioid use among construction workers encompasses both occupational and nonoccupational factors. As an insight into opioid use among construction workers becomes clearer, effectively responding to the opioid crisis remains a challenge.

Vaping, Smoking, and the Physical Fitness of Active Young Men.

INTRODUCTION: Adverse effects of cigarette smoking on physical performance are well studied. Because of the recent rise in popularity of vaping, it is important to evaluate its effect on fitness both independently and in conjunction with traditional cigarette use. METHODS: This was a secondary analysis performed in 2018 on data collected from U.S. Army Soldiers during 2016. All metrics were self-reported via an electronic questionnaire. Personal characteristics of current ENDS users, smokers, and dual users were compared with a reference group that reported no history of use. Adjusting for age and physical training habits, an ANCOVA was used to compare Army physical fitness test results. A Fisher's exact test determined specific mean differences between groups. RESULTS: This study population consisted of 2,854 men aged 24.6 years on average. Differences in physical training and fitness were shown between the groups. Never users averaged the most total physical training, followed by ENDS users, smokers, and then dual users. Compared with never users on the fitness tests, ENDS users had an adjusted mean difference of +27 seconds on the 2-mile run, -4.56 push-ups, and -2.01 sit-ups; smokers averaged +8 seconds, -2.15 push-ups, and -1.44 sit-ups; and dual users averaged +32 seconds, -5.17 push-ups, and -3.88 sit-ups. Dual users had significantly (p<0.05) lower scores than current smokers and never users on all 3 fitness events. CONCLUSIONS: This study suggests that individuals who use e-cigarettes and tobacco cigarettes average a lower level of fitness than individuals who abstain.

The Combined Effect of Cigarette Smoking and Fitness on Injury Risk in Men and Women.

BACKGROUND: Prior studies have identified cigarette smoking and low fitness as independent risk factors for injury; however, no studies have evaluated the combined effect of cigarette smoking and fitness on injury risk. OBJECTIVE: To evaluate the combined effect of cigarette smoking and fitness on injury risk in men and women. DESIGN: This is a secondary analysis of data collected from US Army recruits (n = 2000) during basic combat training within the United States in 2007. Physical training and fitness, cigarette smoking, and prior injury data were obtained from questionnaires, whereas demographic and injury data were obtained from medical and basic combat training unit records. Chi-squared tests were used to assess differences in injury risk by fitness level and cigarette smoking. Relative risk values were calculated with 95% confidence intervals. RESULTS: The primary findings showed that smokers experienced 20%-30% higher risk of injury than nonsmokers. In addition, higher aerobic and muscular fitness was generally not protective against injury between least fit and more fit smokers. However, higher fitness was protective against injury between least and more fit nonsmokers, with least fit nonsmokers being 30%-50% more likely to experience an injury than fit nonsmokers. CONCLUSION: This study revealed that higher aerobic and muscular fitness was not protective against injury among smokers; however, it was protective against injury among nonsmokers. Further implementation of smoking cessation programs may be beneficial for military and civilian personnel who are required to be physically fit in order to carry out their job responsibilities. IMPLICATIONS: Male and female smokers experienced significantly higher risk of injury than nonsmokers. Although higher fitness is protective against injury in nonsmokers, the protective effect of fitness is lost among smokers. In an attempt to reduce injury risk among military and emergency personnel, smoking cessation programs should be further implemented among both more fit and less fit smokers.

Barriers to antiretroviral therapy initiation for HIV-positive children aged 2-18 months in Swaziland.

Although early antiretroviral therapy (ART) reduces HIV-related mortality in children by up to 75%, almost half of HIV-positive children younger than 1 year old in Swaziland do not initiate ART. This study was conducted to identify barriers to early ART initiation among HIV-positive infants. This was a case-control study among HIV-positive infants, aged 2 to 18 months, who either did not initiate ART (cases), or initiated ART (controls), during 18 months after testing. Multivariable logistic regression showed that infants who visited the clinic every month, or every 2 months, were 5.78 and 6.20 times more likely to initiate ART than those who visited less often (OR 5.78, 95% CI 1.82-18.33 and OR 6.20, 95% CI 1.30-29.60 respectively). Children who lived ≤30 and 31-60 minutes from the nearest clinic were 84% and 79% less likely respectively to initiate ART (OR 0.16, 95% CI 0.03-0.78 and OR 0.21, 95% CI 0.04-0.98) compared with those who lived more than 60 minutes away. Children who received immunisation after 6 months were 22.59 times more likely to initiate ART (OR 22.59, 95% CI 7.00-21.72) than those who did not. Infants of caregivers who had excellent or good relationships with their healthcare provider were 4.32 times more likely to initiate ART (OR 4.32, 95% CI 1.01-18.59) than those of caregivers who had average or poor relationships with healthcare providers. The significant predictors of ART initiation identified in this study should be regarded as priority areas for intervention among HIV-positive women in Swaziland.

A qualitative analysis of the barriers to antiretroviral therapy initiation among children 2 to 18 months of age in Swaziland.

HIV/AIDS remains one of the leading causes of death among children under 5 years old in Swaziland. Although studies have shown that early initiation of infants and children diagnosed with HIV on antiretroviral therapy (ART) significantly reduces mortality, many children do not initiate ART until the later stages of disease. This study was designed to collect qualitative data from mothers and caregivers of HIV-positive children to identify the barriers to ART initiation. Focus group discussion (FGD) sessions were conducted in siSwati between July and September 2014 among caregivers of aged children 2-18 months in Swaziland who did or did not initiate ART between January 2011 and December 2012 after HIV DNA PCR-positive diagnosis of the infants. Denial, guilt, lack of knowledge, tuberculosis (TB)/HIV co-infection, HIV-related stigma, lack of money, and distance to clinics were reported by the participants as barriers to ART initiation. The findings further revealed that non-initiation on ART was not linked to a negative perception of the treatment. Findings suggest a need to improve sensitivity among healthcare workers as well as education and counselling services that will facilitate the ART initiation process.

Screening, prevalence, and risk factors for cervical lesions among HIV positive and HIV negative women in Swaziland.

BACKGROUND: Cervical Cancer (CC) is the number one cancer among women in sub-Saharan Africa. Although CC is preventable, most women in developing countries do not have access to screening. METHODS: This cross-sectional study was conducted to determine the prevalence and risk factors for cervical lesions using visual inspection with acetic acid (VIA) among 112 HIV positive and 161 negative women aged 18-69 years. RESULTS: The presence of cervical lesions was greater among HIV positive (22.9%) than HIV negative women (5.7%; p < 0.0001). In logistic models, the risk of cervical lesions among HIV positive women was 5.24 times higher when adjusted by age (OR 5.24, CI 2.31-11.88), and 4.06 times higher in a full model (OR 4.06, CI 1.61-10.25), than among HIV negative women. In the age-adjusted model women who had ≥2 lifetime sexual partners were 3 times more likely (OR 3.00, CI 1.02-8.85) to have cervical lesions compared to women with one lifetime partner and the odds of cervical lesions among women with a history of STIs were 2.16 greater (OR 2.16, CI 1.04-4.50) than among women with no previous STI. In the fully adjusted model women who had a previous cervical exam were 2.5 times more likely (OR 2.53, CI 1.06-6.05) to have cervical lesions than women who had not. CONCLUSIONS: The high prevalence of HIV infection and the strong association between HIV and cervical lesions highlight the need for substantial scale-up of cervical screening to decrease the rate of CC in Swaziland.

The Epidemiology of Emergency Department-Treated Burn Injuries Associated with Portable Heaters in the United States, 2003-2013.

The purpose of this study is to examine the epidemiology of portable space heater-related burn injuries among an emergency department nationally representative population of the United States. The data analyzed in this study were collected from the Consumer Products Safety Commission's 2003-2013 National Electronic Injury Surveillance System. There were approximately 53,636 space heater-related thermal burn injuries attributed to portable space heaters from 2003 to 2013. The rate of injuries was relatively constant during the 10-year span. The number of burn injuries was highest during winter months. Young children, older adults, males, and Blacks had the highest rates of injury. The body part most commonly injured was the hand, which accounted for 33.3% of all burn injuries. It is important to understand the characteristics of persons who have an increased risk of portable space heater burn and trip/fall injuries, so that preventative methods and awareness strategies can be used to help reduce the number of annual portable space heater injuries.

A qualitative analysis of the barriers to antiretroviral therapy initiation among children 2 to 18 months of age in Swaziland

HIV/AIDS remains one of the leading causes of death among children under 5 years old in Swaziland. Although studies have shown that early initiation of infants and children diagnosed with HIV on antiretroviral therapy (ART) significantly reduces mortality, many children do not initiate ART until the later stages of disease. This study was designed to collect qualitative data from mothers and caregivers of HIV-positive children to identify the barriers to ART initiation. Focus group discussion (FGD) sessions were conducted in siSwati between July and September 2014 among caregivers of aged children 2­18 months in Swaziland who did or did not initiate ART between January 2011 and December 2012 after HIV DNA PCR-positive diagnosis of the infants. Denial, guilt, lack of knowledge, tuberculosis (TB)/HIV co-infection, HIV-related stigma, lack of money, and distance to clinics were reported by the participants as barriers to ART initiation. The findings further revealed that non-initiation on ART was not linked to a negative perception of the treatment. Findings suggest a need to improve sensitivity among healthcare workers as well as education and counselling services that will facilitate the ART initiation process

Developing a Physiologically-Based Pharmacokinetic Model Knowledgebase in Support of Provisional Model Construction.

Developing physiologically-based pharmacokinetic (PBPK) models for chemicals can be resource-intensive, as neither chemical-specific parameters nor in vivo pharmacokinetic data are easily available for model construction. Previously developed, well-parameterized, and thoroughly-vetted models can be a great resource for the construction of models pertaining to new chemicals. A PBPK knowledgebase was compiled and developed from existing PBPK-related articles and used to develop new models. From 2,039 PBPK-related articles published between 1977 and 2013, 307 unique chemicals were identified for use as the basis of our knowledgebase. Keywords related to species, gender, developmental stages, and organs were analyzed from the articles within the PBPK knowledgebase. A correlation matrix of the 307 chemicals in the PBPK knowledgebase was calculated based on pharmacokinetic-relevant molecular descriptors. Chemicals in the PBPK knowledgebase were ranked based on their correlation toward ethylbenzene and gefitinib. Next, multiple chemicals were selected to represent exact matches, close analogues, or non-analogues of the target case study chemicals. Parameters, equations, or experimental data relevant to existing models for these chemicals and their analogues were used to construct new models, and model predictions were compared to observed values. This compiled knowledgebase provides a chemical structure-based approach for identifying PBPK models relevant to other chemical entities. Using suitable correlation metrics, we demonstrated that models of chemical analogues in the PBPK knowledgebase can guide the construction of PBPK models for other chemicals.

A Workflow to Investigate Exposure and Pharmacokinetic Influences on High-Throughput in Vitro Chemical Screening Based on Adverse Outcome Pathways.

BACKGROUND: Adverse outcome pathways (AOPs) link adverse effects in individuals or populations to a molecular initiating event (MIE) that can be quantified using in vitro methods. Practical application of AOPs in chemical-specific risk assessment requires incorporation of knowledge on exposure, along with absorption, distribution, metabolism, and excretion (ADME) properties of chemicals. OBJECTIVES: We developed a conceptual workflow to examine exposure and ADME properties in relation to an MIE. The utility of this workflow was evaluated using a previously established AOP, acetylcholinesterase (AChE) inhibition. METHODS: Thirty chemicals found to inhibit human AChE in the ToxCast™ assay were examined with respect to their exposure, absorption potential, and ability to cross the blood-brain barrier (BBB). Structures of active chemicals were compared against structures of 1,029 inactive chemicals to detect possible parent compounds that might have active metabolites. RESULTS: Application of the workflow screened 10 "low-priority" chemicals of 30 active chemicals. Fifty-two of the 1,029 inactive chemicals exhibited a similarity threshold of ≥ 75% with their nearest active neighbors. Of these 52 compounds, 30 were excluded due to poor absorption or distribution. The remaining 22 compounds may inhibit AChE in vivo either directly or as a result of metabolic activation. CONCLUSIONS: The incorporation of exposure and ADME properties into the conceptual workflow eliminated 10 "low-priority" chemicals that may otherwise have undergone additional, resource-consuming analyses. Our workflow also increased confidence in interpretation of in vitro results by identifying possible "false negatives." CITATION: Phillips MB, Leonard JA, Grulke CM, Chang DT, Edwards SW, Brooks R, Goldsmith MR, El-Masri H, Tan YM. 2016. A workflow to investigate exposure and pharmacokinetic influences on high-throughput in vitro chemical screening based on adverse outcome pathways. Environ Health Perspect 124:53-60; http://dx.doi.org/10.1289/ehp.1409450.

Characterization and prediction of chemical functions and weight fractions in consumer products.

Assessing exposures from the thousands of chemicals in commerce requires quantitative information on the chemical constituents of consumer products. Unfortunately, gaps in available composition data prevent assessment of exposure to chemicals in many products. Here we propose filling these gaps via consideration of chemical functional role. We obtained function information for thousands of chemicals from public sources and used a clustering algorithm to assign chemicals into 35 harmonized function categories (e.g., plasticizers, antimicrobials, solvents). We combined these functions with weight fraction data for 4115 personal care products (PCPs) to characterize the composition of 66 different product categories (e.g., shampoos). We analyzed the combined weight fraction/function dataset using machine learning techniques to develop quantitative structure property relationship (QSPR) classifier models for 22 functions and for weight fraction, based on chemical-specific descriptors (including chemical properties). We applied these classifier models to a library of 10196 data-poor chemicals. Our predictions of chemical function and composition will inform exposure-based screening of chemicals in PCPs for combination with hazard data in risk-based evaluation frameworks. As new information becomes available, this approach can be applied to other classes of products and the chemicals they contain in order to provide essential consumer product data for use in exposure-based chemical prioritization.

SHEDS-HT: an integrated probabilistic exposure model for prioritizing exposures to chemicals with near-field and dietary sources.

United States Environmental Protection Agency (USEPA) researchers are developing a strategy for high-throughput (HT) exposure-based prioritization of chemicals under the ExpoCast program. These novel modeling approaches for evaluating chemicals based on their potential for biologically relevant human exposures will inform toxicity testing and prioritization for chemical risk assessment. Based on probabilistic methods and algorithms developed for The Stochastic Human Exposure and Dose Simulation Model for Multimedia, Multipathway Chemicals (SHEDS-MM), a new mechanistic modeling approach has been developed to accommodate high-throughput (HT) assessment of exposure potential. In this SHEDS-HT model, the residential and dietary modules of SHEDS-MM have been operationally modified to reduce the user burden, input data demands, and run times of the higher-tier model, while maintaining critical features and inputs that influence exposure. The model has been implemented in R; the modeling framework links chemicals to consumer product categories or food groups (and thus exposure scenarios) to predict HT exposures and intake doses. Initially, SHEDS-HT has been applied to 2507 organic chemicals associated with consumer products and agricultural pesticides. These evaluations employ data from recent USEPA efforts to characterize usage (prevalence, frequency, and magnitude), chemical composition, and exposure scenarios for a wide range of consumer products. In modeling indirect exposures from near-field sources, SHEDS-HT employs a fugacity-based module to estimate concentrations in indoor environmental media. The concentration estimates, along with relevant exposure factors and human activity data, are then used by the model to rapidly generate probabilistic population distributions of near-field indirect exposures via dermal, nondietary ingestion, and inhalation pathways. Pathway-specific estimates of near-field direct exposures from consumer products are also modeled. Population dietary exposures for a variety of chemicals found in foods are combined with the corresponding chemical-specific near-field exposure predictions to produce aggregate population exposure estimates. The estimated intake dose rates (mg/kg/day) for the 2507 chemical case-study spanned 13 orders of magnitude. SHEDS-HT successfully reproduced the pathway-specific exposure results of the higher-tier SHEDS-MM for a case-study pesticide and produced median intake doses significantly correlated (p<0.0001, R2=0.39) with medians inferred using biomonitoring data for 39 chemicals from the National Health and Nutrition Examination Survey (NHANES). Based on the favorable performance of SHEDS-HT with respect to these initial evaluations, we believe this new tool will be useful for HT prediction of chemical exposure potential.