A science-based agenda for health-protective chemical assessments and decisions: overview and consensus statement

The source-specific health risk and biological effect assessment of PAHs in Mactra veneriformis from the Bohai Sea and Yellow Sea

Source-specific risk assessment has been widely used to analyze the source of pollution risk instead of pollutant content for more accurate control of pollution. However, due to limitations in data type, assessment of source-specific biological effect has not been reported, which is highly significant for organism protection. This study conducted a comprehensive assessment of the health risk and biological effect of polycyclic aromatic hydrocarbons (PAHs) bioaccumulated in the clam Mactra veneriformis from two typical bays in China. PAH levels ranged from 122.68 to 367.21 ng/g d.w. (dry weight), indicating a moderate level of pollution. Incremental lifetime cancer risk (ILCR) assessment revealed low cancer risks associated with clam consumption. However, the integrated biomarker response (IBR) analysis indicated higher biological stress in Laizhou Bay compared to Haizhou Bay. Positive matrix factorization (PMF) identified traffic emissions (post combustion products), coal combustion, petroleum products released without combustion, and biomass combustion as sources of PAHs. A novel approach that integrates partial least squares regression (PLSR) with IBR and PMF enable source-specific biological effect assessment possible, along with PMF-ILCR, the results showed traffic emissions as the primary source of health risks, while petroleum was the primary source of biological effects. This study emphasizes the importance of source-specific risk assessment for developing targeted pollution control strategies especially source-specific biological effect, highlighting that the priority of PAHs pollution source control for typical bays in the Bohai Sea and the Yellow Sea should be: Petroleum > Traffic > Coal > Biomass.

Development of the Navigation Guide Evidence-to-Decision Framework for Environmental Health: Version 1.0

Environmental exposures, including widespread industrial pollution, impact human health and are amplified in more highly exposed communities. Policy and regulatory frameworks for making decisions and recommendations on interventions to mitigate or prevent exposures tend to narrowly focus on exposure and some health-related data related to risks. Typically, such frameworks do not consider other factors, including essentiality, health equity, and distribution of benefits and costs. Further, decisions and recommendations lack transparency regarding how they were developed. We developed the Navigation Guide Evidence-to-Decision Framework for Environmental Health (E2DFEH) to provide a structured and transparent framework incorporating a range of scientific information and factors for decision-making. We reviewed current evidence-to-decision frameworks and engaged in an iterative consensus-based process involving 30 experts from 25 organizations in the academic, government, and nonprofit sectors. The E2DFEH framework includes three Foundations that are structural factors considered as part of recommendation development: 1) Essentiality, 2) Human Rights, and 3) Quality of the Evidence. It also includes three core Criteria that guide the development of a specific recommendation, informed by an evaluation of relevant evidence: 1) Environmental Justice, 2) Maximizing Benefits and Reducing Harm, and 3) Sociocultural Acceptability and Feasibility. The framework's goal is to make the decision process transparent and comprehensive through explicit consideration of core factors important for decisions, leading to more equitable and health-protective interventions.

Identifying studies evaluating susceptibility factors for chemical health assessments: A case study focused on methylmercury developmental neurotoxicity

Identifying susceptibility factors for adverse health effects from chemical exposures is an important aspect of characterizing human health impacts. However, to date, an efficient approach for identifying these factors has not been established. To address this limitation, two approaches were utilized to find studies that contained susceptibility information using methylmercury (MeHg) developmental neurotoxicity (DNT) as a case study. Both approaches start with a comprehensive literature search of 5 databases on MeHg followed by keyword filtering for potential epidemiology studies; however, the approaches diverged for the subsequent steps. Approach 1 initially included screening of all 7,531 studies captured by the human filter, but was modified when it was determined that 96% of studies found to include susceptibility information were captured by a dose-response filter. Approach 2 developed a susceptibility filter to limit the screening needed. Approach 1 resulted in the identification of 172 studies with information on MeHg DNT susceptibility. Approach 2 reduced screening by 52%, but only captured 74% of PECO-relevant studies when applied to the final study set. Although Approach 2 reduced screening by 12% compared with the use of the dose-response filter in Approach 1, the decreased detection of relevant studies precludes its use in most cases. Expected technological advances that allow refinement of a susceptibility filter to improve performance would be advantageous because of the potential further reduction in screening burden. However, at this time, Approach 1, involving the application of a dose-response filter, is currently recommended for identifying epidemiology papers with information on susceptibility factors.

A structural equation model for assessing toxic effects of polycyclic aromatic hydrocarbons on scallop Chlamys farreri and the establishment of a novel integrated biomarker index

Persistent organic pollutants (POP) occur in coastal areas worldwide and seriously affect marine ecosystems, especially aquatic organisms. Here, we assessed the bioaccumulation, biological effects, and health risks of polycyclic aromatic hydrocarbons (PAHs), one typical kind of global POPs, in the scallop Chlamys farreri from typical bays of the Yellow Sea and the Bohai Sea, China. Results revealed higher PAH bioaccumulation in scallops from Laizhou Bay and Jiaozhou Bay compared to Rushan Bay and Haizhou Bay. Structural equation modeling (SEM) was used to screen sensitive biomarkers, including aryl hydrocarbon receptor (AhR), ethoxyresorufin-O-deethylase (EROD), glutathione (GSH), DNA damage (DNAD), and acetylcholinesterase (AChE) in the digestive gland. Incremental lifetime cancer risk (ILCR) and margin of exposure (MOE) were calculated to assess dietary exposure risks, with ILCR suggesting a relatively low risk, while MOE indicated potential risks at two sites. A novel integrated biomarker index, i.e., integrated pollution index (IPI), was developed by merging integrated biomarker response (IBR) and multi-biomarker pollution index (MPI), providing a comprehensive assessment of the biological effects of PAHs on scallops. Spearman correlation analysis between IPI and PAHs content, ILCR, and MOE further verified its effectively. Collectively, this study will provide scientific foundation for monitoring marine POPs pollution risks and assessing the safety of seafood products.

Mapping commercial practices of the pesticide industry to shape science and policymaking: a scoping review

There is a growing body of evidence for how health harming industries (HHIs) engage in similar practices to influence science and policymaking. However, limited attention has been paid to the pesticide industry within the commercial determinants of health (CDOH) field. We conducted a scoping review to map practices adopted by the pesticide industry to influence science and policymaking and to assess the breadth and focus of the associated literature. We included 31 documents and categorized the extracted data using a typology of commercial practices. The documents described how major pesticide companies, and their trade bodies, have acted to influence science and maintain favourable regulatory environments while undermining the credibility of researchers and agencies that publish findings threatening to their commercial interests. A large proportion of the literature consists of historical analyses, narrative reviews, commentaries/perspective pieces, and investigative reports published in the grey literature, predominantly informed by analysis of internal industry documents and freedom of information requests. Most studies focus on high-income settings. There were a limited number of primary peer-reviewed empirical studies that explicitly aimed to study the practices of the pesticide industry from a CDOH perspective. However, our findings show that major pesticide companies adopt political and scientific practices highly similar to other HHIs. The review shows a critical need for research on the pesticide industry's current practices in low- and middle-income countries where the negative impacts of its activities on health and the environment are likely to be more marked.

Risk-based prioritization of PFAS using phenotypic and transcriptomic data from human induced pluripotent stem cell-derived hepatocytes and cardiomyocytes

Per- and polyfluoroalkyl substances (PFAS) are chemicals with important applications; they are persistent in the environment and may pose human health hazards. Regulatory agencies are con­sidering restrictions and bans of PFAS; however, little data exists for informed decisions. Several prioritization strategies were proposed for evaluation of potential hazards of PFAS. Structure-based grouping could expedite the selection of PFAS for testing; still, the hypothesis that structure-effect relationships exist for PFAS requires confirmation. We tested 26 structurally diverse PFAS from 8 groups using human induced pluripotent stem cell-derived hepatocytes and cardiomyocytes, and tested concentration-response effects on cell function and gene expression. Few phenotypic effects were observed in hepatocytes, but negative chronotropy was observed in cardiomyocytes for 8 PFAS. Substance- and cell type-dependent transcriptomic changes were more prominent but lacked substantial group-specific effects. In hepatocytes, we found upregulation of stress-related and extracellular matrix organization pathways, and down-regulation of fat metabolism. In car­diomyocytes, contractility-related pathways were most affected. We derived phenotypic and transcriptomic points of departure and compared them to predicted PFAS exposures. Conservative estimates for bioactivity and exposure were used to derive a bioactivity-to-exposure ratio (BER) for each PFAS; 23 of 26 PFAS had BER > 1. Overall, these data suggest that structure-based PFAS grouping may not be sufficient to predict their biological effects. Testing of individual PFAS may be needed for scientifically-supported decision-making. Our proposed strategy of using two human cell types and considering phenotypic and transcriptomic effects, combined with dose-response analysis and calculation of BER, may be used for PFAS prioritization.

The assessment of bioavailability and environmental risk of dissolved and particulate polycyclic aromatic hydrocarbons in the seawater of typical bays

The pollution of dissolved and particulate polycyclic aromatic hydrocarbons (PAHs) in coastal waters has been increasing in recent decades. However, limited research has been conducted on the characteristics of dissolved and particulate PAHs in seawater and their associated risk assessment. Here, we focused on the bioavailability and environmental risk of PAHs in four typical bays of Shandong Province, China, and used scallop Chlamys farreri and clam Mactra veneriformis as sentinel species. The results revealed that dissolved PAHs tended to bioaccumulate in scallop C. farreri, and their ecological risk exhibited a significant correlation with the health risk of bioaccumulated PAHs and the bioeffect of screened biomarkers in scallop. Conversely, particulate PAHs demonstrated a higher bioaccumulation potential in the clam M. veneriformis, showing a stronger correlation between their ecological risk, health risk, and bioeffect in clams. This study provides the first elucidation of the connection between the ecological risk, health risk, and bioeffect of PAHs. Furthermore, based on the better correlation of health risk and bioeffect caused by PAHs with total PAHs in seawater, we propose that the clam M. veneriformis is a more suitable sentinel species for assessing environmental risk in typical bays of Shandong Province.

Investigating open access new approach methods (NAM) to assess biological points of departure: A case study with 4 neurotoxic pesticides

Open access new approach methods (NAM) in the US EPA ToxCast program and NTP Integrated Chemical Environment (ICE) were used to investigate activities of four neurotoxic pesticides: endosulfan, fipronil, propyzamide and carbaryl. Concordance of in vivo regulatory points of departure (POD) adjusted for interspecies extrapolation (AdjPOD) to modelled human Administered Equivalent Dose (AEDHuman) was assessed using 3-compartment or Adult/Fetal PBTK in vitro to in vivo extrapolation. Model inputs were from Tier 1 (High throughput transcriptomics: HTTr, high throughput phenotypic profiling: HTPP) and Tier 2 (single target: ToxCast) assays. HTTr identified gene expression signatures associated with potential neurotoxicity for endosulfan, propyzamide and carbaryl in non-neuronal MCF-7 and HepaRG cells. The HTPP assay in U-2 OS cells detected potent effects on DNA endpoints for endosulfan and carbaryl, and mitochondria with fipronil (propyzamide was inactive). The most potent ToxCast assays were concordant with specific components of each chemical mode of action (MOA). Predictive adult IVIVE models produced fold differences (FD) < 10 between the AEDHuman and the measured in vivo AdjPOD. The 3-compartment model was concordant (i.e., smallest FD) for endosulfan, fipronil and carbaryl, and PBTK was concordant for propyzamide. The most potent AEDHuman predictions for each chemical showed HTTr, HTPP and ToxCast were mainly concordant with in vivo AdjPODs but assays were less concordant with MOAs. This was likely due to the cell types used for testing and/or lack of metabolic capabilities and pathways available in vivo. The Fetal PBTK model had larger FDs than adult models and was less predictive overall.

The science of uncertainty guides fetal-neonatal neurology principles and practice: diagnostic-prognostic opportunities and challenges

Fetal-neonatal neurologists (FNNs) consider diagnostic, therapeutic, and prognostic decisions strengthened by interdisciplinary collaborations. Bio-social perspectives of the woman's health influence evaluations of maternal-placental-fetal (MPF) triad, neonate, and child. A dual cognitive process integrates "fast thinking-slow thinking" to reach shared decisions that minimize bias and maintain trust. Assessing the science of uncertainty with uncertainties in science improves diagnostic choices across the developmental-aging continuum. Three case vignettes highlight challenges that illustrate this approach. The first maternal-fetal dyad involved a woman who had been recommended to terminate her pregnancy based on an incorrect diagnosis of an encephalocele. A meningocele was subsequently identified when she sought a second opinion with normal outcome for her child. The second vignette involved two pregnancies during which fetal cardiac rhabdomyoma was identified, suggesting tuberous sclerosis complex (TSC). One woman sought an out-of-state termination without confirmation using fetal brain MRI or postmortem examination. The second woman requested pregnancy care with postnatal evaluations. Her adult child experiences challenges associated with TSC sequelae. The third vignette involved a prenatal diagnosis of an open neural tube defect with arthrogryposis multiplex congenita. The family requested prenatal surgical closure of the defect at another institution at their personal expense despite receiving a grave prognosis. The subsequent Management of Myelomeningocele Study (MOMS) would not have recommended this procedure. Their adult child requires medical care for global developmental delay, intractable epilepsy, and autism. These three evaluations involved uncertainties requiring shared clinical decisions among all stakeholders. Falsely negative or misleading positive interpretation of results reduced chances for optimal outcomes. FNN diagnostic skills require an understanding of dynamic gene-environment interactions affecting reproductive followed by pregnancy exposomes that influence the MPF triad health with fetal neuroplasticity consequences. Toxic stressor interplay can impair the neural exposome, expressed as anomalous and/or destructive fetal brain lesions. Functional improvements or permanent sequelae may be expressed across the lifespan. Equitable and compassionate healthcare for women and families require shared decisions that preserve pregnancy health, guided by person-specific racial-ethnic, religious, and bio-social perspectives. Applying developmental origins theory to neurologic principles and practice supports a brain health capital strategy for all persons across each generation.

Interdisciplinary fetal-neonatal neurology training applies neural exposome perspectives to neurology principles and practice

An interdisciplinary fetal-neonatal neurology (FNN) program over the first 1,000 days teaches perspectives of the neural exposome that are applicable across the life span. This curriculum strengthens neonatal neurocritical care, pediatric, and adult neurology training objectives. Teaching at maternal-pediatric hospital centers optimally merges reproductive, pregnancy, and pediatric approaches to healthcare. Phenotype-genotype expressions of health or disease pathways represent a dynamic neural exposome over developmental time. The science of uncertainty applied to FNN training re-enforces the importance of shared clinical decisions that minimize bias and reduce cognitive errors. Trainees select mentoring committee participants that will maximize their learning experiences. Standardized questions and oral presentations monitor educational progress. Master or doctoral defense preparation and competitive research funding can be goals for specific individuals. FNN principles applied to practice offer an understanding of gene-environment interactions that recognizes the effects of reproductive health on the maternal-placental-fetal triad, neonate, child, and adult. Pre-conception and prenatal adversities potentially diminish life-course brain health. Endogenous and exogenous toxic stressor interplay (TSI) alters the neural exposome through maladaptive developmental neuroplasticity. Developmental disorders and epilepsy are primarily expressed during the first 1,000 days. Communicable and noncommunicable illnesses continue to interact with the neural exposome to express diverse neurologic disorders across the lifespan, particularly during the critical/sensitive time periods of adolescence and reproductive senescence. Anomalous or destructive fetal neuropathologic lesions change clinical expressions across this developmental-aging continuum. An integrated understanding of reproductive, pregnancy, placental, neonatal, childhood, and adult exposome effects offers a life-course perspective of the neural exposome. Exosome research promises improved disease monitoring and drug delivery starting during pregnancy. Developmental origins of health and disease principles applied to FNN practice anticipate neurologic diagnoses with interventions that can benefit successive generations. Addressing health care disparities in the Global South and high-income country medical deserts require constructive dialogue among stakeholders to achieve medical equity. Population health policies require a brain capital strategy that reduces the global burden of neurologic diseases by applying FNN principles and practice. This integrative neurologic care approach will prolong survival with an improved quality of life for persons across the lifespan confronted with neurological disorders.

Varying Diet Composition Causes Striking Differences in Legacy and Emerging Contaminant Concentrations in Killer Whales across the North Atlantic

Lipophilic persistent organic pollutants (POPs) tend to biomagnify in food chains, resulting in higher concentrations in species such as killer whales (Orcinus orca) feeding on marine mammals compared to those consuming fish. Advancements in dietary studies include the use of quantitative fatty acid signature analysis (QFASA) and differentiation of feeding habits within and between populations of North Atlantic (NA) killer whales. This comprehensive study assessed the concentrations of legacy and emerging POPs in 162 killer whales from across the NA. We report significantly higher mean levels of polychlorinated biphenyls (PCBs), organochlorine pesticides, and flame retardants in Western NA killer whales compared to those of Eastern NA conspecifics. Mean ∑PCBs ranged from ∼100 mg/kg lipid weight (lw) in the Western NA (Canadian Arctic, Eastern Canada) to ∼50 mg/kg lw in the mid-NA (Greenland, Iceland) to ∼10 mg/kg lw in the Eastern NA (Norway, Faroe Islands). The observed variations in contaminant levels were strongly correlated with diet composition across locations (inferred from QFASA), emphasizing that diet and not environmental variation in contaminant concentrations among locations is crucial in assessing contaminant-associated health risks in killer whales. These findings highlight the urgency for implementing enhanced measures to safely dispose of POP-contaminated waste, prevent further environmental contamination, and mitigate the release of newer and potentially harmful contaminants.

A New Interpretation of Relative Importance on an Analysis of Per and Polyfluorinated Alkyl Substances (PFAS) Exposures on Bone Mineral Density

BACKGROUND

The relative contribution of environmental contaminants is an important, and frequently unanswered, question in human or ecological risk assessments. This interpretation of relative importance allows determination of the overall effect of a set of variables relative to other variables on an adverse health outcome. There are no underlying assumptions of independence of variables. The tool developed and used here is specifically designed for studying the effects of mixtures of chemicals on a particular function of the human body.

METHODS

We apply the approach to estimate the contributions of total exposure to six PFAS (perfluorodecanoic acid, perfluorohexane sulfonic acid, 2-(N-methyl-PFOSA) acetate, perfluorononanoic acid, perfluoroundecanoic acid and perfluoroundecanoic acid) to loss of bone mineral density relative to other factors related to risk of osteoporosis and bone fracture, using data from subjects who participated in the US National Health Examination and Nutrition Surveys (NHANES) of 2013-2014.

RESULTS

PFAS exposures contribute to bone mineral density changes relative to the following variables: age, weight, height, vitamin D2 and D3, gender, race, sex hormone binding globulin, testosterone, and estradiol.

CONCLUSION

We note significant alterations to bone mineral density among more highly exposed adults and significant differences in effects between men and women.