Crude Oil Combustion Research Articles

Methods to assess dermal exposures in occupational settings: a scoping review.

The dermal exposure route is expected to become increasingly significant relative to total worker exposure as inhalational exposure limits continue to decrease. However, standardization of occupational exposure assessment methods and scientific consensus are needed. This is the first scoping review mapping the literature across all dermal exposure assessment methods and their targeted substances/chemicals in occupational settings. Eligibility criteria broadly included studies reporting any noninvasive dermal exposure assessment method in an occupational setting. The literature search (Web of Science and MEDLINE) was restricted to peer-reviewed, primary literature published in the last 20 years (2002-2022). Titles/abstracts were dual independently screened. Data charting was performed by a single reviewer using standard template. All stages were pilot tested. The JBI (formerly, the Joanna Briggs Institute) scoping review methods and PRISMA-ScR checklist (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) were used. In total, 493 articles were data charted and categorized by 4 study types: methods development (22%), exposure assessment (51%), health outcomes (21%), and controls assessment (6%). Fourteen types of dermal exposure assessment methods were charted with biomarkers (51%), dosimeters (21%), and qualitative assessments such as questionnaires or surveys (17%) most common. Seventeen different chemicals/substances were charted; pesticides (28%) and polycyclic aromatic hydrocarbons (PAHs) (22%) associated with crude oil products and combustion were most common. Mapping between substances and exposure assessment method categories, pesticide dosimeters (11%), and PAH biomarker studies (14%) were most reported. Literature gaps were identified for cleaning agents, hair dyes, glycol ether, N,N-dimethylformamide/N-methyl-2-pyrrolidone, dioxins, and bisphenol A. To foster scientific consensus, standardization across study reporting is needed for describing: (i) exposure assessment methods used, (ii) worker tasking/conditions, (iii) targeted substances and substance state, and (iv) targeted exposure routes. Overall, this review categorizes, maps, and defines the scope of literature for occupational dermal exposure assessment methods.

SARA-based kinetics model for simulating heat release during crude oil combustion

SARA-based kinetics model for simulating heat release during crude oil combustion

Source apportionment of ambient PM2.5 in Ho Chi Minh City, Vietnam

The emission sources of fine particulate matter (PM2.5) have not yet been fully identified in Ho Chi Minh City (HCMC), Vietnam, presenting difficulties to authorities in controlling air pollution efficiently. To address this issue, this study explores the source apportionment of PM2.5 by the positive matrix factorization (PMF) model and identifies potential regional sources through the weighted concentration-weighted trajectory (WCWT) model based on the field observation data of PM2.5 in HCMC. 24-h PM2.5 samples were collected in central HCMC for a year (September 2019–August 2020). Herein, inductively coupled plasma mass spectroscopy was used to analyze trace elements, in addition to identifying PM2.5 mass and other chemical species, such as water-soluble ions and carbonaceous species, reported in our former study. The PMF results showed that PM2.5 in HCMC was dominated by anthropogenic-rich sources comprising biomass burning, coal combustion, transportation, and crustal origins (36.4% of PM2.5 mass), followed by secondary ammonium sulfate (18.4%), sea salt (13.7%), road dust (9.6%), and coal and crude oil combustion (9.4%). WCWT results suggested that the geological sources of PM2.5 were mainly from local areas and scattered to the northeast/southwest of HCMC. In addition, the long-range transport of PM2.5 from surrounding countries was revealed during the assembly restriction and lockdown period in 2020.Graphical

Experimental Tests on In Situ Combustion Using Dynamic Ignition Simulation System in High-Temperature and High-Pressure Conditions

The study of crude oil oxidation characteristics is fundamental to the design of ignition in situ combustion. Experimentation is the most crucial method for studying the oxidation characteristics of crude oil. Aiming to address the challenges posed by high temperature, high pressure, and rapid temperature changes during the combustion of crude oil, a dynamic simulation system for high-temperature and high-pressure ignition is designed. In order to study the oxidation characteristics of the crude oil ignition process, we conducted experiments using a high-temperature and high-pressure dynamic ignition simulation device. The experiments focused on determining the ignition point of crude oil under different pressure conditions, oil–water ratios, heating rates, gas injection rates, and other relevant characteristics. The kinetic model for the oxidation process of crude oil ignition was established. The kinetic parameters were calculated for different ignition conditions and the apparent activation energy for each oxidation stage was determined. Additionally, the stability of in situ combustion was evaluated under various ignition parameters. The results show that the Arrhenius curves for crude oil exhibit noticeable differences in the HTO (high-temperature oxidation) and LTO (low-temperature oxidation) regions. The curves demonstrate good linearity in the HTO region, with correlation coefficients exceeding 0.9. Moreover, the apparent activation energies in the HTO region range from 8.01 to 26.7 kJ/mol. The apparent activation energies and finger front factors were calculated for the HTO stage under different pressure conditions. The results showed that, as the pressure increased, the autoignition point, inflection point temperature, and apparent activation energy of the crude oil decreased. This suggests that increasing the pressure can enhance the HTO of the crude oil. The spontaneous ignition point of the crude oil exhibited an upward trend as the heating rate increased. Additionally, the maximum temperature during the combustion process generally increased with the heating rate, reaching a maximum temperature of 453.1 °C. The tests demonstrated that the simulation system is capable of real-time monitoring and recording of oxidation parameters during the combustion process of crude oil. This system can provide essential data for project implementation and numerical simulation.

Compositional numerical analysis of multiphase flow of crude oil in porous media under non-isothermal conditions

Abstract The present work details the development of a compositional model to replicate the heavy hydrocarbon flow in porous reservoir systems under non-isothermal conditions. The mathematical model considers mass and energy conservation equations describing the reactive of natural variables distributed in a multiphase hydrocarbon system. Such natural variable based compositional models better suit fully implicit numerical schemes with inexpensive Jacobian matrix computations. Further, the model accommodates a switch of primary variables for the disappearance and reappearance of a phase. The resulting nonlinear conservation equations are numerically discretized using a block-centered finite-difference scheme and solved with a quasi-Newton based implicit iterative solver. The present model is validated with the thermal profiles presented in the literature for the multiphase flow during the combustion of heavy crude oil in petroleum reservoir system with performance coefficient (R 2), mean absolute error (MBE), and maximum absolute percentage error (MAPE) of about 0.954, 0.37, and 0.01 respectively. The developed compositional model projected 26 and 72 % of light and heavy oil recoveries respectively in about 160 days with a maximum or peak temperature of about 798 K. Further, the thermal and production profiles projected by the sensitivity analysis on various operating parameters are presented. It is noteworthy that the present works aid in providing an economical numerical based tool in evaluating the flow and transport during underground or in-situ combustion process for efficient energy exploration.

Nontraditional Occupational Exposures to Crude Oil Combustion Disasters and Respiratory Disease Risk: A Narrative Review of Literature.

Burning of petroleum products has been consistently associated with adverse respiratory health effects. Combustion of crude oil, specifically, produces toxic byproducts, but there have been relatively few studies of health effects. Burning of crude oil is increasingly employed as a means of mitigating environmental disasters despite the potential health risks to workers involved in clean-up efforts. Here, we review epidemiological studies of respiratory effects following unique crude oil burning events to (1) characterize respiratory health effects from this nontraditional occupational exposure and (2) identify approaches used to characterize exposures that could be applied to future disaster-related studies. We searched PubMed and EMBASE for references from inception to January 30, 2023. We also manually screened references cited in eligible articles. We identified 14 eligible publications. Our review suggests that exposure to crude oil combustion has adverse respiratory effects, including reduced lung function and increased occurrence of respiratory symptoms and disease. However, the evidence is inconsistent, and quality of data varied across studies.While some studies used quantitative, modeled exposure estimates, most used self-reported proxies of exposure. Although disasters involving crude oil combustion are relatively rare, limited evidence suggests that some worker populations may be at risk for respiratory effects from burning exposures in disaster settings. Future studies that use improved exposure assessment methods (e.g., personal monitors, remote sensing data) may help further quantify the respiratory risk from crude oil burning exposures.

Biomimetic, fire-resistant, ultralight and porous carbon fiber sponges enabling safe and efficient remediation of crude oil spills in harsh environments

Advanced absorbents must meet the requirements of superior hydrophobic/oleophilic behavior, favorable adsorption efficiency, and high photothermal and Joule heating performance to handle frequent crude oil spills. However, current carbon-based absorbents suffer from poor fire resistance, thus severely limiting their application in harsh environments. Herein, inspired by a bird's nest, a polymer “welding” strategy is proposed to design a versatile absorbent in which the polymer serves as a “binder” to interconnect discontinuous fibers together to form a 3D welded structure. The continuous conductive networks endow the absorbent with high photothermal and Joule heating effect, thus achieving all-weather adsorption, and improving the adsorption efficiency of crude oil via the self-heating function. Compared with other absorbents, the absorbent prepared via polymer welding technology exhibited preferable comprehensive performance, such as superhydrophobicity, high fire resistance, and high absorption efficiency. Specially, the noninflammable absorbent can restrain the combustion of crude oil, thereby reducing its combustion in case of fire. The versatile absorbent is expected to provide a promising solution for the safe and efficient cleanup of crude oil spills in harsh environments. Overall, the unique polymer welding strategy can be developed into a universal strategy for other material systems to expand their applications.

Epoxy Flooring/Oil Fly Ash as a Multifunctional Composite with Enhanced Mechanical Performance for Neutron Shielding and Chemical-Resistance Applications.

Heavy-oil fly ash (HOFA) is a graphitic carbon powder extracted in vast amounts as a waste material from burning crude oil in power plants. This HOFA has attractive structural properties besides its high amount of pure carbon (∼90 wt %). This powder exists in spherical, highly porous micron-sized particles, which implies its great potential as a mechanical reinforcement for different polymers. In this work, HOFA has been utilized to enhance the mechanical properties of epoxy flooring at HOFA weight fractions of 0, 1, 1.6, and 3.2 wt %. The obtained results revealed that the prepared epoxy-flooring/HOFA composites at a HOFA content of 1.6 wt % showed significant mechanical improvements compared with the pristine polymer. The tensile strength and Young's module values were enhanced by ∼17 and 11%, respectively. Furthermore, the neutron-shielding performance was investigated. The composite with 1.6 wt % showed better neutron attenuation and lower transmittance than the pristine epoxy. The chemical resistance was also extensively studied against sodium hydroxide, nitric acid, and sulfuric acid. The changes in morphology, chemical elements, mass, volume, and molecular structures were investigated rigorously for pristine epoxy and its composite with HOFA at 1.6 wt %. After exposure to these chemicals for 21 days, the tested properties of the epoxy-flooring/HOFA composite showed better chemical resistance than that of the pristine epoxy. Where the epoxy-flooring/HOFA composite showed a surface with low cracks and blistering, it showed lesser changes in mass and volume and fewer molecular structure changes. These results indicated that it is possible to use this multifunctional composite for several applications, including the petrochemical industry, radiation shielding, construction, and automobiles.

Combustion of crude oil during in-situ burning can introduce polycyclic aromatic compounds (PACs) into small-scale freshwater systems

In-situ burning (ISB) is the controlled combustion of an oil slick to remove large quantities of spilled oil from the aquatic environment. Prior to employing ISB as a remediation technique, an oil slick must often be corralled by physical or chemical means to achieve a sufficient thickness (typically >1 mm) for ignition. While ISB is an effective means to remove oil mass, less is known about the potential for ISB to mobilize polycyclic aromatic compounds (PACs) into the aquatic environment. The PACs are primary contaminants of concern in crude oil due to their environmental persistence and toxicity. We examined the potential for ISB to mobilize PACs into underlying waters in a series of small-scale burns conducted across a gradient of oil slick thicknesses (0–7 mm). Concentrations of PACs in underlying waters were evaluated and compared to reference conditions using an equivalent gradient of oil slick thicknesses that were not ignited. At thinner slick thicknesses (i.e. 0 – 4 mm) ISB enhanced the mobilization of total PACs, likely a result of heat transfer to underlying waters; this effect increased as slick thickness increased. Among thicker slicks (i.e. 4 – 7 mm), pyrogenic PACs became more prevalent and greater concentrations of 4-ring PACs were detected in underlying waters. The potential for PAC mobilization needs to be considered in scenarios where ISB may be the only viable oil spill remediation option (e.g. wetlands, marshes, or where oil is entrained) and in shallow systems susceptible to temperature changes.

In Situ Combustion of Heavy, Medium, and Light Crude Oils: Low-Temperature Oxidation in Terms of a Chain Reaction Approach

In Situ Combustion of Heavy, Medium, and Light Crude Oils: Low-Temperature Oxidation in Terms of a Chain Reaction Approach

Environmental Effect of KPO-Fire in Niger Delta and Future Health Implication

Crude oil discovery and exploration in the Niger Delta of Nigeria which includes Delta, Bayelsa, Abia, Rivers, Cross River, Akwa-Ibom, Imo, Edo and Ondo States of Nigeria, has led to significant economic growth of the nation especially in the creation of job opportunities also the generation of revenue. Unfortunately, Oil thefts have become the idea that replaced the most crisis and agitations in the Niger Delta communities against the perceived neglect of the areas. This had resulted to widespread operation of illegal oil bunkering activities called Kpofire. Kpofire, as described by the Niger deltans, is a process of burning crude oil by illegal oil operatives or thieves at isolated locations called bunkering sites or dumpsites in order to extract refined petroleum products. The design for the extraction of the petroleum products involves the sections of steaming and collection. These sections are connected by a very long pipe. Heat is applied to the steaming section using wood from the mangroves that is called ‘Ngala’ or ‘Agala’, thereafter, crude oil is used. The products extracted are fuel, kerosene and diesel. One of the major problems of Kpofire is the introduction of soot into the environment. Soot is a product is uncontrolled and incomplete combustion or pyrolisis of materials that contain carbon. The highest constituent of soot is the Polynuclear aromatic hydrocarbon (PAH). The Niger Delta people are faced with daily environmental challenges such as inadequate housing facilities, contaminated drinking water sources, barren lands for agriculture, dead rivers for fishing activities and poor health conditions, soot, which has become a gradual but huge challenge in many Niger Delta communities, has been shown to play a huge role in respiratory, skin, and reproductive health conditions. However, vulnerability is seen more in babies and children (particularly because their respiratory organs are not matured enough), the elderly, and people with preexisting health conditions, also heart or lung diseases (such as asthma). High exposure to PAH at prenatal stages is linked to a low IQ and lead to increased behavioral problems in the early-age child and childhood asthma. A collective effort is needed to put a stop this menace called kpofire in order to avoid environmental pollution thereby endangering the health of the people of Niger Delta.

UJI KARAKTERISTIK PEMBAKARAN CRUDE PALM OIL - MINYAK DIESEL DENGAN MENGGUNAKAN DROPLET

This study aims to find out and see the characteristics of combustion of crude palm oil and diesel oil using droplets, the characteristics observed are the flashpoint of a fuel at the lowest temperature (Flash Point), the time from the heater under the droplet until the fire ignites (Ignition delay time), burning time of each droplet (Burning rate) and measure the height of fire on the results of combustion. Variation of the mixture of fuel Crude Palm Oil and diesel oil namely 10% Crude Palm Oil and 90% Diesel Oil, 20% Crude Palm Oil and 80% Miyak Diesel, 30% Crude palm Oil and 70% Diesel Oil, 40% Crude Palm oil and 60% Diesel Oil, and 50% Crude Palm Oil and 50% Diesel Oil. The tool used is a combustion chamber designed by researchers, Crude Palm Oil, Diesel Oil, Thermocouple and others. The results of this study are the lowest flashpoint results obtained in the mixture of 10% crude palm oil has a lower flash point value of 97⁰C and the highest value in the 50% crude palm oil fuel mixture is 152⁰C, the result of Ignition Delay Time is the value the lowest in the crude palm oil mixture of 10% has an average value of 0.52 seconds while the highest value in the crude palm oil fuel mixture is 50%, the average value is 2.72 seconds, then the results of the Burning Rate are the lowest value in the mixture of ingredients crude palm oil fuel 10% the average burning rate is 3.36 seconds while the highest value in the crude palm oil mixture is 40%, the average burning rate is 4.4 seconds and the result of visualization of fire or flame height is the highest value from a mixture of 10% crude palm oil with a fire height of 71.18 mm while those with the lowest fire height in a mixture of crude palm oil 50% have a high flame 66.45 mm.

Identification of New Dioxygenases Able to Recognize Polycyclic Aromatic Hydrocarbons with High Aromaticity

Polycyclic aromatic hydrocarbons (PAHs), products from the incomplete combustion of crude oil, are pollutants present in nature. Ring hydroxylating dioxygenase enzymes are able to catalyze polycyclic aromatic hydrocarbons in the biodegradation process with a high degree of stereo-, regio-, and enantiospecificity. In this work, we present the first approximation of the binding modes of 9 PAHs with high aromaticity in the catalytic sites of biphenyl or naphthalene dioxygenases from four microorganisms usually used in bio-remediation processes: Sphingobium yanoikuyae, Rhodococcus jostii RHA1, Pseudomonas sp. C18, and Paraburkholderia xenovorans. Molecular modeling studies of two biphenyl dioxygenases from Sphingobium yanoikuyae and Paraburkholderia xenovorans showed good binding affinity for PAHs with 2–4 benzene rings (fluoranthene, pyrene, and chrysene), and both enzymes had a similar amount of substrate binding. Molecular docking studies using naphthalene dioxygenase from Pseudomonas sp. C18 showed that the enzyme is able to accommodate PAHs with high aromaticity (benzo(a)pyrene, indeno(1,2,3-cd)pyrene), with good docking scores. This study provides important insight into the utility of naphthalene dioxygenases in the degradation of HAPs with high aromaticity.

Catalytic combustion of heavy crude oil by oil-dispersed copper-based catalysts: Effect of different organic ligands

Oil-dispersed copper stearate has been reported to be a promising catalyst for improving in-situ oil combustion due to its good dispersibility in crude oils and the high catalytic activity of copper. This work focuses on investigating the influence of different organic ligands (stearate, oleate and decanoate) on the catalytic activity of copper-based organic salts as catalysts using porous medium thermo-effect cell (PMTEC). The kinetics of oil oxidation processes in the absence and presence of catalysts were estimated using isoconversional methods. All copper-based organic salts exhibited some catalytic activities in oil oxidation reactions, which is reflected in shifting oil oxidation process to lower temperatures and decreasing apparent activation energy. Nevertheless, the organic ligands have a significant impact on the catalytic performance of copper-based organic salts. Copper stearate and copper decanoate displayed a much higher catalytic activity than copper oleate. Copper decanoate with a shorter organic chain showed the lowest activation energy during all oxidation processes. In addition, stearic, oleic and decanoic acids were also added to oil for oxidation experiments to understand if the organic ligands themselves contribute to the promotion of oxidation reactions or not. It turned out that pure organic acids showed small effects on oil oxidation behavior in terms of temperature increase, which proves that the high catalytic activity arises from these copper-based organic salts, rather than the organic acids themselves.

Scope of Hydrogen-Based Vehicles in India: A Review

India is dealing with the problem of high automotive emissions as the number of vehicles on the road is rising. The primary cause of these emissions is the burning of crude oil. India imports crude oil from nations with abundant oil supplies because it lacks the resources to meet all of the country's energy needs for cars. There is a need to look for a carbon-free alternative fuel that is locally accessible in sufficient quantity to suit India's energy needs in order to address the problems related to oil imports and vehicle emissions. Hydrogen is a clean fuel choice among the potential energy sources because its combustion only yields water as a byproduct, and also due to its purity and high energy content, hydrogen energy offers a sustainable alternative to fossil fuels. India has the benefit of producing hydrogen from renewable sources like solar and wind during periods of lower demand because of its continuously expanding renewable energy generation capacity, and Asia is one of the continents with a wealth of these resources. Also, the exponential increase in food waste generation has prompted the scientific community to convert it into value-added resources. The main elements influencing the adoption of hydrogen as a cost-effective energy source in Asian nations are the availability of resources, safety requirements, public acceptance, and appropriate government incentives. The current analysis discusses the need to use hydrogen as an alternative fuel, its production processes, storage concerns, transportation, and the sources that are available. In various Asian nations like Japan, Korea, China, India, and Malaysia, particular focus has been placed on the notion of a renewable hydrogen economy. Perspectives on fuel supply, environmental effects, and social acceptance could help the biohydrogen energy sector evolve in a favorable way.

Image-based modelling of coke combustion in a multiscale porous medium using a micro-continuum framework

Non-isothermal reactive transport in complicated porous media is diverse in nature and industrial applications. There are challenges in the modelling of multiple physicochemical processes in multiscale pore structures with various length scales ranging from nanometres to micrometres. This study focuses on coke combustion during in situ crude oil combustion techniques. A micro-continuum model was developed to perform an image-based simulation of coke combustion through a multiscale porous medium. The simulation coupled weakly compressible gas flow, species transport, conjugate heat transfer, heterogeneous coke oxidation kinetics and structural evolution. The unresolved nanoporous coke region was treated as a continuum, for which the random pore model, permeability model and species diffusivity model were integrated as sub-grid models to account for the sub-resolution reactive surface area, Darcy flow and Knudsen diffusion, respectively. A Pe–Da diagram was provided to present five characteristic combustion regimes covering the ignition temperature and air flux in realistic field operations and laboratory measurements. The present model proved to achieve more accurate predictions of the feasible ignition temperature than previous models. Compared with the air flux of $\phi \sim O\textrm{(1) s}{\textrm{m}^\textrm{3}}(\textrm{air})\;{({\textrm{m}^\textrm{2}}\ \textrm{h})^{ - 1}}$ in the field, the increasing air flux in the laboratory transformed the combustion regime from diffusion-limited to convection-limited, which led to an overpredicted burning temperature. Reactive fingering combustion was analysed to understand the potential risks in some experimental measurements. The findings provide a better understanding of coke combustion and can help engineers design sustainable combustion methods. The developed image-based model allows other types of multiscale and nonlinear reactive transport to be simulated.

Autonomous Energy-Efficient Complexes Based on Crude Oil for Working in Arctic Conditions

The work is devoted to solving scientific and technical problems on the development of new generation Russian power equipment. Comprehensive theoretical and experimental studies of the effect of aerodynamic and heat-mass exchange processes on the ignition and combustion of crude oil in the straitened conditions of fire-tube boilers are reviewed and described. Based on the results of the research, design developments were carried out, prototypes of a fire-tube hot-water boiler with a remoted economizer and an automated low-emission burner device were manufactured and successfully tested. The efficiency of the boiler more than 94% and the reduced level of pollutants emissions in the operating load range are confirmed.

Green hydrogen economy and opportunities for India

With increasing numbers of vehicles on roads, India is facing the issue of large vehicular emissions. The burning of crude oil is the major issue behind these emissions. India doesn’t have enough resources to fulfill all the energy demands of vehicles and hence, imports crude oil from oil-rich countries. To tackle the issues associated with oil imports and vehicular emissions, there is a need to search for carbon-free alternate fuel that is available locally in sufficient quantity to meet India’s energy demands. The green economy is a new concept evolving and gaining attention worldwide, the concept focuses on sustainable and environmentally friendly solutions. Hydrogen is such a carbon-free fuel that can help to achieve the targets of the green economy and the best means to store energy for a long time. Hydrogen is a high energy content fuel and has about zero greenhouse gas emissions when used in fuel cells. Hydrogen is not directly available in free form, but it can be produced using electrolyzers and various other techniques. India’s continuously growing renewable power generation capacity gives the advantage to produce hydrogen from green sources like solar, and wind at the time of lower demand. The present review work focuses on the opportunities for India in green hydrogen production as the adaption of green hydrogen offers many benefits to India including energy security, and decarbonizing the transport sector.

Dissolved organic matter production from herder application and in-situ burning of crude oil at high latitudes: Bioavailable molecular composition patterns and microbial community diversity effects

Chemical herders and in-situ burning (ISB) are designed to mitigate the effects that oil spills may have on the high latitude marine environment. Little information exists on the water solubilization of petroleum residues stemming from chemically herded ISB and whether these bioavailable compounds have measurable impacts on marine biota. In this experiment, we investigated the effects of Siltech OP40 and crude oil ISB on a) petroleum-derived dissolved organic matter (DOMHC) composition and b) seawater microbial community diversity over 28 days at 4 °C in aquarium-scale mesocosms. Ultra-high resolution mass spectrometry and fluorescence spectroscopy revealed increases in aromaticity over time, with ISB and ISB+OP40 samples having higher % aromatic classes in the initial incubation periods. ISB+OP40 contained a nearly 12-fold increase in the number of DOMHC formulae relative to those before ISB. 16S rRNA gene sequencing identified differences in microbial alpha diversity between seawater, ISB, OP40, and ISB+OP40. Microbial betadiversity shifts were observed that correlated strongly with aromatic/condensed relative abundance and incubation time. Proteobacteria, specifically from the genera Marinomonas and Perlucidibaca experienced −22 and +24 log2-fold changes in ISB+OP40 vs. seawater, respectively. These findings provide an important opportunity to advance our understanding of chemical herders and ISB in the high latitude marine environment.

Incidence of chronic respiratory conditions among oil spill responders: Five years of follow-up in the Deepwater Horizon Oil Spill Coast Guard Cohort study

BackgroundOver ten years after the Deepwater Horizon (DWH) oil spill, our understanding of long term respiratory health risks associated with oil spill response exposures is limited. We conducted a prospective analysis in a cohort of U.S. Coast Guard personnel with universal military healthcare. MethodsFor all active duty cohort members (N = 45,193) in the DWH Oil Spill Coast Guard Cohort Study we obtained medical encounter data from October 01, 2007 to September 30, 2015 (i.e., ~2.5 years pre-spill; ~5.5 years post-spill). We used Cox Proportional Hazards regressions to calculate adjusted hazard ratios (aHR), comparing risks for incident respiratory conditions/symptoms (2010–2015) for: responders vs. non-responders; responders reporting crude oil exposure, any inhalation of crude oil vapors, and being in the vicinity of burning crude oil versus responders without those exposures. We also evaluated self-reported crude oil and oil dispersant exposures, combined. Within-responder comparisons were adjusted for age, sex, and smoking. ResultsWhile elevated aHRs for responder/non-responder comparisons were generally weak, within-responder comparisons showed stronger risks with exposure to crude oil. Notably, for responders reporting exposure to crude oil via inhalation, there were elevated risks for allsinusitis (aHR = 1.48; 95%CI, 1.06–2.06), unspecified chronic sinusitis (aHR = 1.55; 95%CI, 1.08–2.22), chronic obstructive pulmonary disease (COPD) and other allied conditions (aHR = 1.43; 95%CI, 1.00–2.06), and dyspnea and respiratory abnormalities (aHR = 1.29; 95%CI, 1.00–1.67); there was a suggestion of elevated risk for diseases classified as asthma and reactive airway diseases (aHR = 1.18; 95%CI, 0.98–1.41), including the specific condition, asthma (aHR = 1.35; 95%CI, 0.80–2.27), the symptom, shortness of breath (aHR = 1.50; 95%CI, 0.89–2.54), and the overall classification of chronic respiratory conditions (aHR = 1.18; 95%CI, 0.98–1.43). Exposure to both crude oil and dispersant was positively associated with elevated risk for shortness of breath (HR = 2.24; 95%CI, 1.09–4.64). ConclusionsAmong active duty Coast Guard personnel, oil spill clean-up exposures were associated with moderately increased risk for longer term respiratory conditions.