Application and demonstration of meso-activity exposure factors to advance estimates of incidental soil ingestion among agricultural workers.

BACKGROUND: Soil is an understudied and underregulated pathway of chemical exposure, particularly for agricultural workers who cultivate food in soils. Little is known about how agricultural workers spend their time and how they may contact soil while growing food. Exposure factors are behavioral and environmental variables used in exposure estimation. OBJECTIVES: Our study aimed to derive exposure factors describing how growers engage in different tasks and use those factors to advance the use of time-activity data to estimate soil ingestion exposures among agricultural workers. METHODS: We administered a meso-activity-based, season-specific soil contact activity questionnaire to 38 fruit and vegetable growers. We asked growers to estimate the frequency and duration of six meso-activities and describe how they completed them. We used questionnaire data to derive exposure factors and estimate empirical and simulated exposures to a hypothetical contaminant in soil via incidental ingestion using daily, hourly, and hourly-task-specific ingestion rates. RESULTS: We generated exposure factors characterizing the frequency and duration of six meso-activities by season, and self-reported soil contact, glove use, and handwashing practices by meso-activity and season. Seasonal average daily doses (ADDs) were similar across all three forms of ingestion rates. No consistent patterns regarding task-specific contributions to seasonal or annual ADDs were observed.

A qualitative characterization of meso-activity factors to estimate soil exposure for agricultural workers.

BACKGROUND: Agricultural workers' exposure to soil contaminants is not well characterized. Activity pattern data are a useful exposure assessment tool to estimate extent of soil contact, though existing data do not sufficiently capture the range and magnitude of soil contact in the agricultural context. OBJECTIVE: We introduce meso-activity, or specific tasks, to improve traditional activity pattern methodology. We propose a conceptual framework to organize the factors that may modify soil exposure and impact soil contact estimates within each meso-activity in agriculture. We build upon models from the US EPA to demonstrate an application of this framework to dose estimation. METHODS: We conducted in-depth interviews with sixteen fruit and vegetable growers in Maryland to characterize factors that influence soil exposure in agriculture. For illustrative purposes, we demonstrate the application of the framework to translate our qualitative data into quantitative estimates of soil contact using US EPA models for ingestion and dermal exposure. RESULTS: Growers discussed six tasks, or meso-activities, involving interaction with soil and described ten factors that may impact the frequency, duration and intensity of soil contact. We organized these factors into four categories (i.e., Environmental, Activity, Timing and Receptor; EAT-R) and developed a framework to improve agricultural exposure estimation and guide future research. Using information from the interviews, we estimated average daily doses for several agricultural exposure scenarios. We demonstrated how the integration of EAT-R qualitative factors into quantitative tools for exposure assessment produce more rigorous estimates of exposure that better capture the true variability in agricultural work. SIGNIFICANCE: Our study demonstrates how a meso-activity-centered framework can be used to refine estimates of exposure for agricultural workers. This framework will support the improvement of indirect exposure assessment tools (e.g., surveys and questionnaires) and inform more comprehensive and appropriate direct observation approaches to derive quantitative estimations of soil exposure. IMPACT STATEMENT: We propose a novel classification of activity pattern data that links macro and micro-activities through the quantification and characterization of meso-activities and demonstrate how the application of our qualitative framework improves soil exposure estimation for agricultural workers. These methodological advances may inform a more rigorous approach to the evaluation of pesticide and other chemical and biological exposures incurred by persons engaged in the cultivation of agricultural commodities in soil.

Urban Soil Safety Policies: The Next Frontier for Mitigating Lead Exposures and Promoting Sustainable Food Production.

Urban soils bear the persistent legacy of leaded gasoline and past industrial practices. Soil safety policies (SSPs) are an important public health tool with the potential to inform, identify, and mitigate potential health risks faced by urban growers, but little is known about how these policies may protect growers from exposures to lead and other soil contaminants. We reviewed and evaluated 43 urban agriculture (UA) policies in 40 US cities pertaining to soil safety. About half of these cities had a least one SSP that offered recommendations or provided services for soil testing. Eight cities had at least one SSP containing a requirement pertaining to any topic (e.g., soil testing, a specific best practice for growing). We found notable inconsistencies across SSPs for "acceptable" levels of lead in soils and the activities and behaviors recommended at each level. We specify research needed to inform revisions to US Environmental Protection Agency guidance for lead in soils specific to UA. We conclude with a series of recommendations to guide the development or revision of SSPs.

Charting a Path Forward: Assessing the Science of Chemical Risk Evaluations under the Toxic Substances Control Act in the Context of Recent National Academies Recommendations.

BACKGROUND: In 2016, Congress enacted the Frank R. Lautenberg Chemical Safety for the 21st Century Act ("the Lautenberg Act"), which made major revisions to the main U.S. chemical safety law, the 1976 Toxic Substances Control Act (TSCA). Among other reforms, the Lautenberg Act mandates that the U.S. Environmental Protection Agency (U.S. EPA) conduct comprehensive risk evaluations of chemicals in commerce. The U.S. EPA recently finalized the first set of such chemical risk evaluations. OBJECTIVES: We examine the first 10 TSCA risk evaluations in relation to risk science recommendations from the National Academies to determine consistency with these recommendations and to identify opportunities to improve future TSCA risk evaluations by further implementing these key approaches and methods. DISCUSSION: Our review of the first set of TSCA risk evaluations identified substantial deviations from best practices in risk assessment, including overly narrow problem formulations and scopes; insufficient characterization of uncertainty in the evidence; inadequate consideration of population variability; lack of consideration of background exposures, combined exposures, and cumulative risk; divergent approaches to dose-response assessment for carcinogens and noncarcinogens; and a flawed approach to systematic review. We believe these deviations result in underestimation of population exposures and health risks. We are hopeful that the agency can use these insights and have provided suggestions to produce chemical risk evaluations aligned with the intent and requirements of the Lautenberg Act and the best available science to better protect health and the environment-including the health of those most vulnerable to chemical exposures. https://doi.org/10.1289/EHP9649.

Key considerations for assessing soil ingestion exposures among agricultural workers.

BACKGROUND: Soil ingestion is a critical, yet poorly characterized route of exposure to contaminants, particularly for agricultural workers who have frequent, direct contact with soil. OBJECTIVE: This qualitative investigation aims to identify and characterize key considerations for translating agricultural workers' soil ingestion experiences into recommendations to improve traditional exposure science tools for estimating soil ingestion. METHODS: We conducted qualitative in-depth interviews with 16 fruit and vegetable growers in Maryland to characterize their behaviors and concerns regarding soil contact in order to characterize the nature of soil ingestion in the agricultural context. RESULTS: We identified and discussed four emergent themes: (1) variability in growers' descriptions of soil and dust, (2) variability in growers' soil contact, (3) growers' concerns regarding soil contact, (4) growers' practices to modify soil contact. We also identified environmental and behavioral factors and six specific agricultural tasks that may impact soil ingestion rates. SIGNIFICANCE: Our investigation fills an important gap in occupational exposure science methodology by providing four key considerations that should be integrated into indirect measurement tools for estimating soil ingestion rates in the agricultural context. Specifically, a task-based framework may provide a structure for future investigations of soil contact that may be useful in other populations.

Reimagining Public Health in the Aftermath of a Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic is an unprecedented challenge for society, affecting those already subject to unacceptable health inequalities and resulting in vast economic impacts. The pandemic reminds everyone of the value and necessity of public health.In the context of an era that will be shaped by COVID-19, we outline the coming series of challenges and transitions in public health and the needed actions over the next 5 years to reinvent our public health systems. Multiple limitations in current US and global public health systems have been uncovered by the pandemic, including insufficient preparedness and surveillance capabilities complicated by long-standing and worsening health inequalities and the rapid spread of misinformation that needs to be countered. We foresee 3 phases for public health over the next 5 years: (1) reactive crisis management, (2) efforts to maintain initial gains, and (3) efforts to sustain and enhance progress.A reinvented public health system will depend highly on leadership and political will, rethinking how we categorize and address population-level risk, employing 21st-century data sciences, and applying new communication skills.

Deregulation and the Assault on Science and the Environment.

The quality of the environment is a major determinant of the health and well-being of a population. The role of scientific evidence is central in the network of laws addressing environmental pollution in the United States and has been critical in addressing the myriad sources of environmental pollution and the burden of disease attributable to environmental factors. We address the shift away from reasoned action and science to a reliance on belief and document the efforts to separate regulation from science and to remove science-based regulations and policies intended to protect public health. We outline the general steps for moving from research to policy, show how each has been undermined, offer specific examples, and point to resources that document the enormity of the current efforts to set aside scientific evidence.

Pembrolizumab plus chemotherapy for first-line treatment of metastatic nonsquamous non-small-cell lung cancer: a network meta-analysis.

AIM: A systematic review and network meta-analysis were conducted to evaluate the efficacy of pembrolizumab + pemetrexed + platinum relative to other regimens in metastatic nonsquamous non-small-cell lung cancer (NSq-NSCLC). PATIENTS & METHODS: Eligible studies evaluated first-line regimens in NSq-NSCLC patients without known targetable mutations. Relative treatment effects were synthesized with random effects proportional hazards Bayesian network meta-analyses. RESULTS: The hazard ratio (HR) for overall survival (OS) for pembrolizumab + pemetrexed + platinum was statistically significant over all platinum-doublet (HR range: 0.42-0.61), platinum-doublet + bevacizumab (HR range: 0.44-0.53) and platinum-doublet + atezolizumab regimens (HR range: 0.56-0.62). Additionally, pembrolizumab + pemetrexed + platinum numerically improved OS over atezolizumab + paclitaxel + carboplatin + bevacizumab (HR: 0.65; 95% credible interval: 0.43, 1.01). Pembrolizumab + pemetrexed + platinum had 95.6% probability of being the best treatment regimen for OS. CONCLUSION: Pembrolizumab + pemetrexed + platinum is likely the most efficacious first-line regimen for metastatic NSq-NSCLC.

Building Healthy Community Environments: A Public Health Approach.

Environmental quality has a profound effect on health and the burden of disease. In the United States, the environment-related burden of disease is increasingly dominated by chronic diseases. At the local level, public health practitioners realize that many policy decisions affecting environmental quality and health transcend the authorities of traditional health department programs. Healthy decisions about the built environment, including housing, transportation, and energy, require broad collaborative efforts. Environmental health professionals have an opportunity to address the shift in public health burden toward chronic diseases and play an important role in the design of healthy communities by bringing data and tools to decision makers. This article provides a guide for community leaders to consider the public health effects of decisions about the built environment. We present a conceptual framework that represents a shift from compartmentalized solutions toward an inclusive systems approach that encourages partnership across disciplines and sectors. We discuss practical tools to assist with environmental decision making, such as Health Impact Assessments, environmental public health tracking, and cumulative risk assessment. We also identify priorities in research, practice, and education to advance the role of public health in decision making to improve health, such as the Health Impact Assessment, as a core competency for environmental health practitioners. We encourage cross-disciplinary communication, research, and education that bring the fields of planning, transportation, and energy in closer collaboration with public health to jointly advance the systems approach to today's environmental challenges.

Opportunities and Challenges for Dietary Arsenic Intervention.

The diet is emerging as the dominant source of arsenic exposure for most of the U.S. population. Despite this, limited regulatory efforts have been aimed at mitigating exposure, and the role of diet in arsenic exposure and disease processes remains understudied. In this brief, we discuss the evidence linking dietary arsenic intake to human disease and discuss challenges associated with exposure characterization and efforts to quantify risks. In light of these challenges, and in recognition of the potential longer-term process of establishing regulation, we introduce a framework for shorter-term interventions that employs a field-to-plate food supply chain model to identify monitoring, intervention, and communication opportunities as part of a multisector, multiagency, science-informed, public health systems approach to mitigation of dietary arsenic exposure. Such an approach is dependent on coordination across commodity producers, the food industry, nongovernmental organizations, health professionals, researchers, and the regulatory community. https://doi.org/10.1289/EHP3997.

Epidemiology: a foundation of environmental decision making.

Many epidemiologic studies are designed so they can be drawn upon to provide scientific evidence for evaluating hazards of environmental exposures, conducting quantitative assessments of risk, and informing decisions designed to reduce or eliminate harmful exposures. However, experimental animal studies are often relied upon for environmental and public health policy making despite the expanding body of observational epidemiologic studies that could inform the relationship between actual, as opposed to controlled, exposures and health effects. This paper provides historical examples of how epidemiology has informed decisions at the U.S. Environmental Protection Agency, discusses some challenges with using epidemiology to inform decision making, and highlights advances in the field that may help address these challenges and further the use of epidemiologic studies moving forward.

Chemical Risk Assessment: Traditional vs Public Health Perspectives.

Preventing adverse health effects of environmental chemical exposure is fundamental to protecting individual and public health. When done efficiently and properly, chemical risk assessment enables risk management actions that minimize the incidence and effects of environmentally induced diseases related to chemical exposure. However, traditional chemical risk assessment is faced with multiple challenges with respect to predicting and preventing disease in human populations, and epidemiological studies increasingly report observations of adverse health effects at exposure levels predicted from animal studies to be safe for humans. This discordance reinforces concerns about the adequacy of contemporary risk assessment practices for protecting public health. It is becoming clear that to protect public health more effectively, future risk assessments will need to use the full range of available data, draw on innovative methods to integrate diverse data streams, and consider health endpoints that also reflect the range of subtle effects and morbidities observed in human populations. Considering these factors, there is a need to reframe chemical risk assessment to be more clearly aligned with the public health goal of minimizing environmental exposures associated with disease.

The bacterial virulence factors VopL and VopF nucleate actin from the pointed end.

VopL and VopF (VopL/F) are tandem WH2-domain actin assembly factors used by infectious Vibrio species to induce actin assembly in host cells. There is disagreement about the filament assembly mechanism of VopL/F, including whether they associate with the filament barbed or pointed end. Here, we used multicolor total internal reflection fluorescence microscopy to directly observe actin assembly with fluorescently labeled VopL/F. In actin monomer assembly reactions, VopL/F exclusively nucleate actin filament assemblies, remaining only briefly associated with the pointed end. VopL/F do not associate with the ends of preassembled filaments. In assembly reactions with saturating profilin, ∼85% of VopL/F molecules also promote nucleation from the pointed end, whereas a smaller fraction (<15%) associate for ∼25 s with the barbed end of preassembled filaments, inhibiting their elongation. We conclude that VopL/F function primarily as actin nucleation factors that remain briefly (∼100 s) associated with the pointed end.

Rethinking Environmental Protection: Meeting the Challenges of a Changing World.

SUMMARY: From climate change to hydraulic fracturing, and from drinking water safety to wildfires, environmental challenges are changing. The United States has made substantial environmental protection progress based on media-specific and single pollutant risk-based frameworks. However, today's environmental problems are increasingly complex and new scientific approaches and tools are needed to achieve sustainable solutions to protect the environment and public health. In this article, we present examples of today's environmental challenges and offer an integrated systems approach to address them. We provide a strategic framework and recommendations for advancing the application of science for protecting the environment and public health. We posit that addressing 21st century challenges requires transdisciplinary and systems approaches, new data sources, and stakeholder partnerships. To address these challenges, we outline a process driven by problem formulation with the following steps: a) formulate the problem holistically, b) gather and synthesize diverse information, c) develop and assess options, and d) implement sustainable solutions. This process will require new skills and education in systems science, with an emphasis on science translation. A systems-based approach can transcend media- and receptor-specific bounds, integrate diverse information, and recognize the inextricable link between ecology and human health.

US State-Level Policy Responses to the Ebola Outbreak, 2014-2015.

CONTEXT: The 2014-2015 Ebola epidemic in West Africa raised concerns about the potential occurrence of an Ebola outbreak in the United States. The federal government and individual states developed guidance and policies to determine how to manage individuals within the United States who may have been exposed to Ebola. DESIGN: A total of 139 documents describing state policies for individuals considered at risk for Ebola and the requirements, as well as restrictions these individuals may be subject to, were systematically identified and analyzed. RESULTS: A wide range of policy responses and variations on quarantine, movement restrictions, exposure categories, and monitoring were found. While the majority of states reflected US Centers for Disease Control and Prevention guidance, some states enacted aggressive quarantine policies and movement restrictions, developed unique categorization strategies, and established more frequent monitoring procedures. CONCLUSIONS: Findings may help public health practitioners and policymakers anticipate what policies could be implemented in response to future infectious disease threats. Furthermore, practitioners and policymakers should assume that some variation in response policies will occur at the state level.