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Research investigating gastrointestinal (GI) symptoms from oil spill-related exposures is sparse. We evaluated prevalent GI symptoms among U.S. Coast Guard responders deployed to the Deepwater Horizon oil spill cleanup. Crude oil (via skin contact, inhalation, or ingestion routes), combined crude oil/oil dispersant exposures, other deployment exposures, deployment characteristics, demographics, and acute GI symptoms during deployment (i.e., nausea/vomiting, diarrhea, stomach pain, and constipation) were ascertained cross-sectionally via a post-deployment survey (median time between deployment end and survey completion 185 days) (N = 4885). Log-binomial regression analyses were employed to calculate prevalence ratios (PRs) and 95 % confidence intervals (CI). Effect modification was evaluated. In adjusted models, responders in the highest (versus lowest) tertile of self-reported degree of skin contact to crude oil were more than twice as likely to report nausea/vomiting (PR=2.45; 95 %CI, 1.85–3.23), diarrhea (PR=2.40; 95 %CI, 2.00–2.88), stomach pain (PR=2.51; 95 %CI, 2.01–3.12), and constipation (PR=2.21; 95 %CI, 1.70–2.89). Tests for trend were statistically significant (p < 0.05). Results were similar for crude oil exposure via inhalation and ingestion. Higher PRs for all symptoms were found with combined crude oil/dispersant exposure than with crude oil exposure alone. These results indicate positive associations between self-reported crude oil and combined crude oil/oil dispersant exposures and acute GI symptoms. [ABSTRACT FROM AUTHOR]

Objective: The objectives of this study were to compare population dynamics of Tilefish Lopholatilus chamaeleonticeps before and after the 2010 Deepwater Horizon (DWH) oil spill in the north‐central Gulf of Mexico (GoM) as well as inside and outside the spill area in the western and southwestern GoM (off Mexico). Methods: Due to the availability of prespill samples of Tilefish, we were able to evaluate growth, mortality, and condition factors during two time periods (2000–2009 versus 2011–2017). Samples were derived from commercial landings and research vessel surveys using demersal longline fishing gear. Result: Although some von Bertalanffy growth parameters differed for fish caught before and after the spill within the spill area, confidence limits for predicted growth curves overlapped for ages >10, while predicted growth for ages <10 declined somewhat after the spill. Tilefish grew faster off Mexico than in the northern GoM. Total instantaneous mortality rates (Z), estimated from aggregate multi‐year catch curves, were highest off Mexico (0.39 ± 0.05 SE), lowest in the western GoM outside the spill area (0.21 ± 0.03), and similar before and after the DWH spill within the spill zone (0.32 ± 0.02). Conclusion: Although Z on the stock within the spill area apparently did not change, differences in fishing mortality may have compensated for changes in natural mortality. Because 90% of the fish that were aged after the spill were alive prior to the spill, their accumulated growth history may have masked postspill growth changes. As we are now 14+ years past the 2010 spill, comparisons of population dynamics from samples collected now and in the future may provide a clearer picture of the strength of incoming year‐classes and the long‐term implications of the spill on Tilefish populations. Impact statementAdult Gulf of Mexico Tilefish did not differ in growth or total mortality before versus after the 2010 Deepwater Horizon oil spill. Condition of postspill fish was lower than prespill. Mexican fish grew faster but had lower condition and higher mortality than U.S. fish. Postspill fish analyzed were predominantly born before the spill. [ABSTRACT FROM AUTHOR]

Introduction: Approximately three-fourths of all pelagic marine prokaryotes live in the deep sea, an environment characterized by high hydrostatic pressure and, in most cases, low temperature. Labile organic matter is often scarce within these settings, providing a competitive advantage to motile cells that can access the nutrients within a greater seawater volume. Because many cells present at depth are shallow water-adapted microbes descending from more productive surface waters, deep-sea conditions could significantly reduce their motility and, consequently, their biogeochemical activities. Methods: In this study, we address this possibility by examining the impact of deep-sea physical conditions on the motility of three representative marine microbes belonging to the cosmopolitan genera Halomonas, Alcanivorax, and Shewanella. Growth-dependent motility agar assays and growth-independent microscopy assays were employed at four pressures and two temperatures. Results: At pressures equivalent to bathyal and abyssal depths (10 – 50 Megapascals), decreases in temperature (30°C – 4°C or 23°C – 7°C depending on the assay) had a greater negative impact on motility than pressure. In addition, the high-pressure and low-temperature impacts were additive. Exposure to high pressure and/or low temperature had varying degrees of effect on flagellar function, depending on the strain and the magnitude of the applied stress. These ranged from short-term impacts that were quickly reversible to long-term impacts that were detrimental to the function of the flagellum, leading to complete loss of motility. Discussion: These findings highlight the sensitivity of motility systems of piezosensitive mesophilic marine bacteria to the combined pressure/temperature conditions present in the deep sea, phenotypes that in situ are likely to manifest themselves in the modulation of diverse microbial activities.

Target lipid model (TLM) and toxic unit (TU) approaches were applied to ecotoxicity and chemistry data from low-energy WAFs (LE-WAFs) of source and weathered crude oils originating from the Deepwater Horizon oil spill. The weathered oils included artificially weathered oils and naturally weathered samples collected in the Gulf of Mexico after the spill. Oil weathering greatly reduced the concentrations of identified LE-WAF components, however, the mass of uncharacterized polar material (UPC) in the LE-WAFs remained largely unchanged during the weathering process. While the TLM-derived calculations displayed a significant decrease in toxicity (TUs) for the heavily weathered oils, copepod toxicity, expressed as LC10-based TUs, were comparable between LE-WAFs of fresh and weathered oils. The discrepancy between observed and predicted toxicity for the LE-WAFs of artificially weathered oils may be related to limitations by the chemical analyses or increased toxicity due to generation of new unknown compounds during the weathering process. [ABSTRACT FROM AUTHOR]

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The 2010 Deepwater Horizon (DWH) oil spill caused catastrophic damage to marine and terrestrial environments in and along the Gulf of Mexico. The DWH Natural Resource Damage Assessment (NRDA) estimated that 56,141-102,399 birds across 93 species were directly or indirectly injured, and breeding and foraging habitats suffered substantial damage. The 2016 DWH civil settlement allocated NRDA funds to Florida to replenish and protect DWH-injured bird species. Additional NRDA restoration funds were allocated Regionwide (i.e., all Gulf states) and to Open Ocean Restoration Areas. In addition, Florida was allocated funds through the National Fish and Wildlife Foundation's Gulf Environmental Benefit Fund (GEBF) to address DWH-injured living resources and habitats. NRDA and GEBF funds for bird restoration must be used in areas impacted by the DWH oil spill or in locations with clear connections to DWH-injured bird populations. We compiled and summarized literature and unpublished data to illustrate the coastal connectivity of 17 focal waterbird species between the Gulf of Mexico and the Atlantic Coast. We documented coastal connectivity for 13 of the 17 (76%) focal species. Rates of coastal connectivity derived from United States Geological Survey Bird Banding Lab data for populations anywhere on the United States Atlantic or Gulf coasts ranged by species from 0-22% of resighted individuals being observed on both coasts and ranged from 0-30% when restricted to coasts within Florida. The connectivity between the majority of Atlantic and Gulf coast focal populations is substantial, and the consideration of restoration projects on the Atlantic Coast should be determined on a case-by-case basis. Restoring living resources and breeding and foraging habitats along Florida's coastlines for the benefit of avian species that exhibit coastal connectivity will help create more resilient habitats for the benefit of at-risk species in the face of future catastrophes. [ABSTRACT FROM AUTHOR]

The 2010 Gulf of Mexico Deepwater Horizon was the largest oil spill in human history that occurred during a 12-week period in a region less than 100 km from the coast of Louisiana; however, after more than a decade of post-spill research, few definitives can be said to be known about the long-term impacts on the development and distribution of fishes in and around the region of the disaster. Here, we examine endemic Gulf of Mexico fish species that may have been most impacted by noting their past distributions in the region of the spill and examining data of known collecting events and observations over the last twenty years (ten years prior to the spill, ten years post-spill). Five years post-spill, it was reported that 48 of the Gulf’s endemic fish species had not been collected and, with expanded methods, we now report that 29 (of the 78 endemic species) have not been reported in collections since 2010 (five of these are only known from observations post-spill). Although the good news that some previously ‘missing’ species have been found may be cause to celebrate, the lack of information for many species remains a cause for concern given focused sampling efforts post-spill.

Crude oil spilled at sea is chemically altered through environmental processes such as dissolution, biodegradation, and photodegradation. Transformation of hydrocarbons to oxygenated species increases water-solubility. Metabolites and oxidation products largely remain uncharacterized by common analytical methods but may be more bioavailable to aquatic organisms. Studies have shown that unresolved (i.e. unidentified) polar compounds ('UPCs') may constitute > 90% of the water-accommodated fraction (WAF) of heavily weathered crude oils, but still there is a paucity of information characterizing their toxicological significance in relation to other oil-derived toxicants. In this study, low-energy WAFs (no droplets) were generated from two field-weathered oils (collected during the 2010 Deepwater Horizon incident) and their polar fractions were isolated through fractionation. To allow establishment of thresholds for acute toxicity (LC50) of the dissolved and polar fraction of field collected oils, we concentrated both WAFs and polar fractions to beyond field-documented concentrations, and the acute toxicity of both to the marine copepod Acartia tonsa was measured and compared to the toxicity of the native WAF (non-concentrated). The difference in toxic units (TUs) between the total of the mixture and of identified compounds of known toxicity (polycyclic aromatic hydrocarbons [PAHs] and alkyl phenols) in both WAF and polar fractions was used to estimate the contribution of the UPC to overall toxicity. This approach identified that UPC had a similar contribution to toxicity as identified compounds within the WAFs of the field-weathered oils. This signifies the relative importance of polar compounds when assessing environmental impacts of spilled and weathered oil. [ABSTRACT FROM AUTHOR]

The 2010 Gulf of Mexico Deepwater Horizon was the largest oil spill in human history that occurred during a 12-week period in a region less than 100 km from the coast of Louisiana; however, after more than a decade of post-spill research, few definitives can be said to be known about the long-term impacts on the development and distribution of fishes in and around the region of the disaster. Here, we examine endemic Gulf of Mexico fish species that may have been most impacted by noting their past distributions in the region of the spill and examining data of known collecting events and observations over the last twenty years (ten years prior to the spill, ten years post-spill). Five years post-spill, it was reported that 48 of the Gulf's endemic fish species had not been collected and, with expanded methods, we now report that 29 (of the 78 endemic species) have not been reported in collections since 2010 (five of these are only known from observations post-spill). Although the good news that some previously 'missing' species have been found may be cause to celebrate, the lack of information for many species remains a cause for concern given focused sampling efforts post-spill. [ABSTRACT FROM AUTHOR]

This article presents a content analysis of news coverage of three environmental disasters: the 2014 Mount Polley mine leak, the 2010 Deepwater Horizon oil spill, and the 2011 Fukushima nuclear disaster. The aim is to better understand how political actors talk about industrial environmental disasters in their aftermath. Since most people understand dramatic events through news media, an examination of post-disaster media framing may begin to shed light on the variation of public response after disasters. Specifically, the findings challenge some prevailing assumptions about nonviolent protest mobilization and prompt a further investigation of the role of uncertainty in political participation. [ABSTRACT FROM AUTHOR]

The northern Gulf of Mexico has been the focus of many coastal habitat restoration projects in the wake of new funding streams stemming from the settlement of the 2010 Deepwater Horizon oil spill litigation. One such project was the creation of New Round Island (RNDI) in Mississippi, a 86 ha island created using dredge material in 2017. The island design incorporated a novel U‐shaped sand berm with multiple interconnected containment sells. In this study we sought to document changes in relative abundance of various coastal bird species. We conducted surveys for breeding and nonbreeding birds from June 2017 to May 2021, and we conducted nonbreeding surveys at two reference sites for comparison. Breeding bird numbers were dominated by colonial nesting species in years 1 and 2, which subsequently declined as vegetation cover increased. Solitary nesting species increased over time, with Wilson's Plover (Charadrius wilsonia) nest count increasing from zero in year 1 to 29 in year 5. Nonbreeding shorebird counts peaked in years 1–2 and subsequently declined, although shorebird counts also decreased at the reference sites. Relative abundance of waders (Ardeidae), rallids (Rallidae), and passerines (Passeriformes and allies) increased in comparison to reference sites. This study demonstrates the short‐term benefits of this U‐shaped island design to early‐succession breeding species and nonbreeding shorebirds shortly after construction, with longer‐term benefits to breeding Wilson's Plover and to marsh birds as vegetation fills in. [ABSTRACT FROM AUTHOR]

The goal of this paper was to review the evidence of population-level impacts of the Deepwater Horizon Oil Spill (DWH) on Gulf of Mexico (GOM) continental shelf taxa, as well as evidence of resiliency following the DWH. There is considerable environmental and biological evidence that GOM shelf taxa were exposed to and suffered direct and indirect impacts of the DWH. Numerous assessments, from mesocosm studies to analysis of biopsied tissue or tissue samples from necropsied animals, revealed a constellation of physiological effects related to DWH impacts on GOM biota, some of which clearly or likely resulted in mortality. While the estimated concentrations of hydrocarbons in shelf waters and sediments were orders of magnitude lower than measured in inshore or deep GOM environments, the level of mortality observed or predicted was substantial for many shelf taxa. In some cases, such as for zooplankton, community shifts following the spill were ephemeral, likely reflecting high rates of population turnover and productivity. In other taxa, such as GOM reef fishes, impacts of the spill are confounded with other stressors, such as fishing mortality or the appearance and rapid population growth of invasive lionfish (Pterois spp.). In yet others, such as cetaceans, modeling efforts to predict population-level effects of the DWH made conservative assumptions given the species’ protected status, which post-DWH population assessments either failed to detect or population increases were estimated. A persistent theme that emerged was the lack of precise population-level data or assessments prior to the DWH for many taxa, but even when data or assessments did exist, examining evidence of population resiliency was confounded by other stressors impacting GOM biota. Unless efforts are made to increase the resolution of the data or precision of population assessments, difficulties will likely remain in estimating the scale of population-level effects or resiliency in the case of future large-scale environmental catastrophes.

The 2010 Deepwater Horizon (DWH) oil well blowout in the Gulf of Mexico (GoM) was the largest and perhaps most consequential accidental marine oil spill in global history. This paper provides an overview of a Research Topic consisting of four additional papers that: (1) assemble time series data for ecosystem components in regions impacted by the spill, and (2) interpret temporal changes related to the vulnerability of species and ecosystems to DWH and the ensuing resilience to perturbation. Time series abundance data for many taxa pre-date DWH, often by decades, thus allowing an assessment of population- and community-level impacts. We divided the north central GoM into four interconnected “eco-types”: the coastal/nearshore, continental shelf, open-ocean pelagic and deep benthic. Key taxa in each eco-type were evaluated for their vulnerability to the circumstances of the DWH spill based on population overlap with oil, susceptibility to oil contamination, and other factors, as well their imputed resilience to population-level impacts, based on life history metrics, ecology and post-spill trajectories. Each taxon was scored as low, medium, or high for 13 vulnerability attributes and 11 resilience attributes to produce overall vulnerability and resilience scores, which themselves were also categorical (i.e., low, medium, or high). The resulting taxon-specific V-R scores provide important guidance on key species to consider and monitor in the event of future spills similar to DWH. Similar analyses may also guide resource allocation to collect baseline data on highly vulnerable taxa or those with low resilience potential in other ecosystems. For some species, even a decade of observation has been insufficient to document recovery given chronic, long-term exposure to DWH oil remaining in all eco-types and because of impacts to the reproductive output of long-lived species. Due to the ongoing threats of deep-water blowouts, continued surveillance of populations affected by DWH is warranted to document long-term recovery or change in system state. The level of population monitoring in the open-ocean and deep benthic eco-types has historically been low and is inconsistent with the continued migration of the oil industry to the ultra-deep (≥1,500 m) where the majority of leasing, exploration, and production now occurs.

Law – through regulation, criminalization and litigation – provides key mechanisms for mitigating the harmful effects of oil disasters. At the same time, these mechanisms also enable the perpetuation of oil disasters under an extractivist imperative. This disaster tolerance is the point of departure for this article's examination of the legal response to the 2010 Deepwater Horizon disaster over the last decade. Based on a methodology that combines a social harm approach with the political ecology of Felix Guattari, we firstly present a reconceptualization of harm inflicted by oil corporations across three registers: environment, society, and subjectivity. We subsequently introduce the concept of transversal harm, which allows us to move beyond the criminal and civil damage of corporate crime and negligence and to capture the collective and continuous impact of oil extractivism, as opposed to the exceptional impact of oil disasters. Transversal harm opens new avenues for assigning corporate responsibility and reducing disaster tolerance as the by-product of environmental law. [ABSTRACT FROM AUTHOR]

The pronephros (early-stage kidney) is an important osmoregulatory organ, and the onset of its function occurs relatively early in some teleost fishes. As such, any defects in kidney development and function are likely associated with a decreased ability to osmoregulate. Previous work has shown that early-life stage (ELS) zebrafish (Danio rerio) acutely exposed to Deepwater Horizon (DWH) crude oil exhibit transcriptional changes in key genes involved in pronephros development and function, as well as pronephric morphological defects and whole-animal osmoregulatory impairment. The objective of this study was to examine the acute effects of crude oil exposure during zebrafish ELS on pronephros function by assessing its fluid clearance capacity and glomerular filtration integrity. Following a 72-h exposure to control conditions, 20% or 40% dilutions of high-energy water-accommodated fractions (HEWAF) of DWH crude oil, zebrafish were injected into the common cardinal vein either with fluorescein-labeled (FITC) 70-kDa dextran to assess glomerular filtration integrity or with FITC-inulin to assess pronephric clearance capacity. Fluorescence was quantified after the injections at predetermined time intervals by fluorescence microscopy. The results demonstrated a diminished pronephric fluid clearance capacity and failed glomerular perfusion when larvae were exposed to 40% HEWAF dilutions, whereas only a reduced glomerular filtration selectivity was observed in zebrafish previously exposed to the 20% HEWAF dilution. [ABSTRACT FROM AUTHOR]

The Deepwater Horizon oil spill was one of the largest and deepest oil spills recorded. The wellhead was located at approximately 1500 m below the sea where low temperature and high pressure are key environmental characteristics. Using cells collected 4 months following the Deepwater Horizon oil spill at the Gulf of Mexico, we set up Macondo crude oil enrichments at wellhead temperature and different pressures to determine the effect of increasing depth/pressure to the in situ microbial community and their ability to degrade oil. We observed oil degradation under all pressure conditions tested [0.1, 15, and 30 megapascals (MPa)], although oil degradation profiles, cell numbers, and hydrocarbon degradation gene abundances indicated greatest activity at atmospheric pressure. Under all incubations the growth of psychrophilic bacteria was promoted. Bacteria closely related to Oleispira antarctica RB-8 dominated the communities at all pressures. At 30 MPa we observed a shift toward Photobacterium, a genus that includes piezophiles. Alphaproteobacterial members of the Sulfitobacter, previously associated with oil-degradation, were also highly abundant at 0.1 MPa. Our results suggest that pressure acts synergistically with low temperature to slow microbial growth and thus oil degradation in deep-sea environments.

[This corrects the article DOI: 10.3389/fmicb.2018.00808.].

Recent work has suggested that the phytoremediation potential of S. alterniflora may be linked to a selection by the plant for oil-degrading microbial communities in the soil, in combination with enhanced delivery of oxygen and plant enzymes to the soil. In salt marshes, where the soil is saline and hypoxic, this relationship may be enhanced as plants in extreme environments have been found to be especially dependent on their microbiome for resilience to stress and to respond to toxins in the soil. Optimizing methods for restoration of oiled salt marshes would be especially meaningful in the Gulf of Mexico, where there is a persistently high threat of petroleum contamination. One favorable strategy for restoration of oiled sites might include planting S. alterniflora with a microbiome that has been preselected for an oiled environment. We examined this strategy with a two-year greenhouse experiment and found that planting S. alterniflora in an oiled environment enhances decomposition of oil residues without a clear negative impact on plant growth. Manipulation of the S. alterniflora microbiome through soil inoculation and through exposure to oil residues, elicited a detectable response of soil prokaryote communities to the presence of oil, while only demonstrating an analogous response in fungal communities in the plant roots and leaves. Yet, manipulation of the plant microbiome did not change plant morphology or relative decomposition of polycyclic aromatic hydrocarbons (PAHs) in the soil. Therefore, despite evident relationships between the plant, microbes, and oil, manipulation of the microbiome may not be a worthwhile addition to S. alterniflora phytoremediation strategies. Nevertheless, our work adds support for replanting S. alterniflora in oiled salt marshes as an effective strategy for reducing oil residues in salt marshes, in addition to the re-vegetation and erosion reduction benefits demonstrated by others. [ABSTRACT FROM AUTHOR]

The U.S. Coast Guard led a clean-up response to the Deepwater Horizon (DWH) oil spill, the largest marine oil spill in history. Studies from the Deepwater Horizon Coast Guard Cohort (DWH-CG) have shown associations between crude oil exposure and various acute symptoms and longer-term health outcomes. Evidence has suggested genetic polymorphisms in metabolizing genes could modify the toxicity of crude oil and its components, which could impact health effects in responders exposed to crude oil. We applied log-binomial regression to calculate prevalence ratios (PRs) and 95 % confidence intervals (CIs) in the relationship between crude oil exposure (categorized to never, low, and high) and four acute symptoms (cough, shortness of breath/wheeze, skin rash/itching, headache) and to calculate risk ratios (RR) and 95 % CIs in the relationship between crude oil exposure and incidence of hypertension and asthma in the DWH-CG cohort. Effect modification by polymorphisms in 6 metabolizing genes [Cytochrome P450 family 2 subfamily E member 1 (CYP2E1), Glutathione S-Transferase Mu 1 (GSTM1), Glutathione S-Transferase Theta 1 (GSTT1), Epoxide Hydrolase 1 (EPHX1), NADPH quinone oxidoreductase-1 (NQO1), and Myeloperoxidase (MPO)] was evaluated. Results were stratified into wildtype and variant [i.e., those with at least one variant allele] for each gene. There was evidence of effect modification in the relationship between crude oil exposure and asthma by CYP2E1 [wildtype (RR High vs never/low , 95 % CI = 1.18, 0.99-1.42); variant (RR High vs never/low, 95 % CI = 2.27, 1.26-4.10); p interaction  = 0.04] and headache by NQO1 [wildtype (PR High vs never/low , 95 % CI = 2.1, 1.88-2.34); variant (PR High vs never/low , 95 % CI = 1.44, 1.07-1.94); p interaction  = 0.04]. Our study indicated the potential effect modification by metabolizing genotype in the relationship between crude oil exposure and headaches or asthma. These findings underscore the importance of considering potential genetic susceptibility among oil spill responders. Genotype variations, which are revealed only via specialized testing and thus not readily apparent, may contribute to differential vulnerability to the health effects associated with oil spill exposures., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jennifer A. Rusiecki reports financial support was provided by National Institutes of Health. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier B.V.)

Recent work has suggested that the phytoremediation potential of S. alterniflora may be linked to a selection by the plant for oil-degrading microbial communities in the soil, in combination with enhanced delivery of oxygen and plant enzymes to the soil. In salt marshes, where the soil is saline and hypoxic, this relationship may be enhanced as plants in extreme environments have been found to be especially dependent on their microbiome for resilience to stress and to respond to toxins in the soil. Optimizing methods for restoration of oiled salt marshes would be especially meaningful in the Gulf of Mexico, where there is a persistently high threat of petroleum contamination. One favorable strategy for restoration of oiled sites might include planting S. alterniflora with a microbiome that has been pre-selected for an oiled environment. We examined this strategy with a two-year greenhouse experiment and found that planting S. alterniflora in an oiled environment enhances decomposition of oil residues without a clear negative impact on plant growth. Manipulation of the S. alterniflora microbiome through soil inoculation and through exposure to oil residues, elicited a detectable response of soil prokaryote communities to the presence of oil, while only demonstrating an analogous response in fungal communities in the plant roots and leaves. Yet, manipulation of the plant microbiome did not change plant morphology or relative decomposition of polycyclic aromatic hydrocarbons (PAHs) in the soil. Therefore, despite evident relationships between the plant, microbes, and oil, manipulation of the microbiome may not be a worthwhile addition to S. alterniflora phytoremediation strategies. Nevertheless, our work adds support for replanting S. alterniflora in oiled salt marshes as an effective strategy for reducing oil residues in salt marshes, in addition to the re-vegetation and erosion reduction benefits demonstrated by others.

This study (1) assessed whether parent health mediated associations between exposures to the 2010 BP Deepwater Horizon oil spill (BP-DHOS) and child health, and whether child health mediated associations between BP-DHOS exposures and parent health; and (2) assessed bidirectional longitudinal associations between parent health and child health following the BP-DHOS. The study used three waves of panel data (2014, 2016, and 2018) from South Louisiana communities highly impacted by the BP-DHOS. Parents with children (aged 4–18 at the time of the interview) were interviewed based on a probability sample of households. Focal measures included economic and physical BP-DHOS exposures, self-reported parent health, and parent-reported child health. Health measures were gathered at three time points. The analyses included mediation analysis and estimating and comparing effect sizes of longitudinal cross-lagged effects between parent health and child health. Results showed that parent health partly mediated associations between BP-DHOS exposures and child health, and that child health partly mediated associations between BP-DHOS exposures and parent health. Paths from prior waves of parent health to subsequent waves of child health were positive and statistically significant as were paths from prior waves of child health to subsequent waves of parent health. The differences in size of the child-to-parent health effects and the parent-to-child health effects were not statistically significant. This study's results extend evidence for the post-disaster effect of parent health on child health and the effects of child health on parent health. These findings support the contention that harm to the health of one's family member following disasters operates as a form of resource loss deleterious to one's health. [ABSTRACT FROM AUTHOR]

Objective: Inhalation exposure systems are tools for delivering compounds (particles, vapors, and gases) under well-controlled conditions for toxicological testing. The objective of this project was to develop an automated computer-controlled system to expose small laboratory animals to precise concentrations of crude oil vapor (COV). Materials and Methods: Vapor from heated Deepwater Horizon surrogate oil was atomized into a fine mist then diluted with filtered air, then the air/droplet mixture was routed into an evaporation column with an high efficiency particulate air (HEPA) filter on its exit port. The HEPA filter was used to remove oil particles, thus ensuring only vapor would pass. The vapor was then introduced into a custom-built exposure chamber housing rats. A calibrated flame ionization detector was used to read the total volatile organic compounds (TVOC) in real time, and custom software was developed to automatically adjust the amount of oil entering the atomizer with a syringe pump. The software also controlled relative humidity and pressure inside the exposure chamber. Other exposure chamber environmental parameters, e.g. temperature and CO2 levels, were monitored. Four specific components within the COV were monitored during each exposure: benzene, toluene, ethylbenzene, and xylenes. Results: The TVOC vapor concentration control algorithm maintained median concentrations to within ±2 ppm of the target concentration (300 ppm) of TVOC during exposures lasting 6 h. The system could reach 90% of the desired target in less than 15 min, and repeat exposures were consistent and reproducible. Conclusion: This exposure system provided a highly automated tool for conducting COV inhalation toxicology studies. [ABSTRACT FROM AUTHOR]

The 2010 Deepwater Horizon disaster introduced an unprecedented discharge of oil into the deep Gulf of Mexico. Considerable uncertainty has persisted regarding the oil's fate and effects in the deep ocean. In this work we assess the compound-specific rates of biodegradation for 125 aliphatic, aromatic, and biomarker petroleum hydrocarbons that settled to the deep ocean floor following release from the damaged Macondo Well. Based on a dataset comprising measurements of up to 168 distinct hydrocarbon analytes in 2,980 sediment samples collected within 4 y of the spill, we develop a Macondo oil "fingerprint" and conservatively identify a subset of 312 surficial samples consistent with contamination by Macondo oil. Three trends emerge from analysis of the biodegradation rates of 125 individual hydrocarbons in these samples. First, molecular structure served to modulate biodegradation in a predictable fashion, with the simplest structures subject to fastest loss, indicating that biodegradation in the deep ocean progresses similarly to other environments. Second, for many alkanes and polycyclic aromatic hydrocarbons biodegradation occurred in two distinct phases, consistent with rapid loss while oil particles remained suspended followed by slow loss after deposition to the seafloor. Third, the extent of biodegradation for any given sample was influenced by the hydrocarbon content, leading to substantially greater hydrocarbon persistence among the more highly contaminated samples. In addition, under some conditions we find strong evidence for extensive degradation of numerous petroleum biomarkers, notably including the native internal standard 17α(H),21β(H)-hopane, commonly used to calculate the extent of oil weathering.