Deepwater Horizon Oil Spill Response Research Articles

Association between spill-related exposure to fine particulate matter and peripheral motor and sensory nerve function among oil spill response and cleanup workers following the Deepwater Horizon oil spill.

Burning/flaring of oil/gas during the Deepwater Horizon oil spill response and cleanup (OSRC) generated high concentrations of fine particulate matter (PM2.5). Personnel working on the water during these activities may have inhaled combustion products. Neurologic effects of PM2.5 have been reported previously but few studies have examined lasting effects following disaster exposures. The association of brief, high exposures and adverse effects on sensory and motor nerve function in the years following exposure have not been examined for OSRC workers. We assessed the relationship between exposure to burning/flaring-related PM2.5 and measures of sensory and motor nerve function among OSRC workers. PM2.5 concentrations were estimated from Gaussian plume dispersion models and linked to self-reported work histories. Quantitative measures of sensory and motor nerve function were obtained 4-6 years after the disaster during a clinical exam restricted to those living close to two clinics in Mobile, AL or New Orleans, LA (n = 3401). We obtained covariate data from a baseline enrollment survey and a home visit, both in 2011-2013. The analytic sample included 1186 participants. We did not find strong evidence of associations between exposure to PM2.5 and sensory or motor nerve function, although there was a suggestion of impairment based on single leg stance among individuals with high exposure to PM2.5. Results were generally consistent whether we examined average or cumulative maximum exposures or removed individuals with the highest crude oil exposures to account for co-pollutant confounding. There was no evidence of exposure-response trends. Remediating environmental disasters is essential for long-term human and environmental health. During the Deepwater Horizon oil spill disaster, burning and flaring of oil and gas were used to remove these pollutants from the environment, but led to potentially high fine particulate matter exposures for spill response workers working on the water. We investigate the potential adverse effects of these exposures on peripheral nerve function; understanding the potential health harm of remediation tactics is necessary to inform future clean up approaches and protect human health.

Counter-historical study of alternative dispersant use in the Deepwater Horizon oil spill response

Recent completion of oil fate modeling and a mass budget of the Deepwater Horizon (DWH) oil spill allows for a counter-historical study using quantitative Comparative Risk Assessment (CRA) methodology. Novel application of subsea dispersant injection (SSDI) during the response reduced surfacing oil, volatile organic carbon emissions, and oil on shorelines. The effectiveness of that application, and potential alternatives had dispersant not been used or been used more aggressively, were evaluated by modifying and comparing the validated oil fate model under different SSDI strategies. A comparison of mass balance results, exposure metrics, and CRA scoring for Valued Ecological Components (VECs) shows the value of SSDI in achieving risk reduction and tradeoffs that were made. Actual SSDI applied during the DWH oil spill reduced exposures to varying degrees for different VECs. Exposures and relative risks across the ecosystem would have been substantially reduced with more effective SSDI.

Estimation of Aerosol Concentrations of Oil Dispersants COREXIT™ EC9527A and EC9500A during the Deepwater Horizon Oil Spill Response and Clean-up Operations.

The April 2010 Deepwater Horizon drilling unit explosion at the Macondo oil well resulted in the release of approximately 779 million l of oil into the Gulf of Mexico. As part of the response effort to break up oil slicks on the water's surface, 6.81 million l of chemical dispersants COREXIT™ EC9500A and COREXIT™ EC9527A were applied by plane or vessel or injected near the seabed. The GuLF Long-term Follow-up Study is investigating possible adverse health effects of workers involved in the oil spill response and clean-up (OSRC). In this paper, we describe potential dispersant-related air concentrations generated from aerial spraying of dispersants to provide insight as to what concentrations OSRC workers may have been exposed under worst-case conditions. Personal exposure measurement data were not collected. Modeling, therefore, was conducted to estimate airborne concentrations of total aerosol to COREXIT™ EC9527A and EC9500A. Using the AgDISP model, we estimated air concentrations to dispersant total aerosols, defined as all components of the dispersant including active ingredients, surfactants, and water, resulting from aerial and vessel applications, as average 1-h and 2-min concentrations. For comparison, 1-h air concentrations associated with aerial spraying were estimated using another model, AERMOD. At 152 m horizontal to the flight path, average 1-h total aerosol concentrations associated with aerial applications were estimated to be as high as 49.3 µg m-3 (9527A) and 45.4 µg m-3 (9500A), and both decreased with increased distance from the flight line. The estimates for spraying 9500A from vessels indicated that total aerosol concentrations were potentially as high as 0.33 µg m-3 at 10 m from the nozzles. These results suggest that personal exposures to dispersant aerosols were negligible.

Association of Deepwater Horizon Oil Spill Response and Cleanup Work With Risk of Developing Hypertension

Exposure to hydrocarbons, fine particulate matter (PM2.5), and other chemicals from the April 20, 2010, Deepwater Horizon disaster may be associated with increased blood pressure and newly detected hypertension among oil spill response and cleanup workers. To determine whether participation in cleanup activities following the disaster was associated with increased risk of developing hypertension. This cohort study was conducted via telephone interviews and in-person home exams. Participants were 6846 adults who had worked on the oil spill cleanup (workers) and 1505 others who had completed required safety training but did not do cleanup work (nonworkers). Eligible participants did not have diagnosed hypertension at the time of the oil spill. Statistical analyses were performed from June 2018 to December 2021. Engagement in cleanup activities following the Deepwater Horizon oil spill disaster, job classes, quintiles of cumulative total hydrocarbons exposure level, potential exposure to burning or flaring oil, and estimated PM2.5 were examined. Systolic and diastolic blood pressure measurements were collected during home exams from 2011 to 2013 using automated oscillometric monitors. Newly detected hypertension was defined as antihypertensive medication use or elevated blood pressure since the spill. Log binomial regression was used to calculate prevalence ratios (PR) and 95% CIs for associations between cleanup exposures and hypertension. Multivariable linear regression was used to estimate exposure effects on continuous blood pressure levels. Of 8351 participants included in this study, 6484 (77.6%) were male, 517 (6.2%) were Hispanic, 2859 (34.2%) were non-Hispanic Black, and 4418 (52.9%) were non-Hispanic White; the mean (SD) age was 41.9 (12.5) years at enrollment. Among workers, the prevalence of newly detected hypertension was elevated in all quintiles (Q) of cumulative total hydrocarbons above the first quintile (PR for Q3, 1.29 [95% CI, 1.13-1.46], PR for Q4, 1.25 [95% CI, 1.10-1.43], and PR for Q5, 1.31 [95% CI, 1.15-1.50]). Both exposure to burning and/or flaring oil and gas (PR, 1.16 [95% CI, 1.02-1.33]) and PM2.5 from burning (PR, 1.26 [95% CI, 0.89-1.71]) for the highest exposure category were associated with increased risk of newly detected hypertension, as were several types of oil spill work including cleanup on water (PR, 1.34 [95% CI, 1.08-1.66]) and response work (PR, 1.51 [95% CI, 1.20-1.90]). Oil spill exposures were associated with newly detected hypertension after the Deepwater Horizon disaster. These findings suggest that blood pressure screening should be considered for workers with occupational hydrocarbon exposures.

Using Real-Time Area VOC Measurements to Estimate Total Hydrocarbons Exposures to Workers Involved in the Deepwater Horizon Oil Spill.

The objective was to present a method that used real-time volatile organic compounds (VOCs) area measurements transformed to daily total hydrocarbons (THC) time-weighted averages (TWAs) to supplement THC personal full-shift measurements collected using passive charcoal badges. A second objective was to develop exposure statistics using these data for workers on vessels piloting remotely operated vehicle (ROV) vessels and other marine vessels (MVs) not at the job title level, but at the vessel level. From hourly vessel averages derived from ~26 million real-time VOC measurements, we estimated full-shift VOC TWAs. Then, we determined the relationship between these TWAs and corresponding full-shift THC personal measurements taken on the same vessel-day. We used this relationship to convert the full-shift VOC measurements to full-shift 'THC' TWA estimates when no personal THC measurements existed on a vessel-day. We then calculated arithmetic means (AMs) and other statistics of THC exposures for each vessel. The VOC-derived estimates substantially supplemented the THC personal measurements, with the number of vessel-days for which we have exposure estimates increasing by ~60%. The estimates of the AMs are some of the highest observed in the GuLF STUDY. As expected, the AMs decreased over time, consistent with our findings on other vessels. Despite the inherent limitations of using real-time area measurements, we were able to develop additional daily observations of personal THC exposures for workers on the ROV vessels and other MVs over time. The estimates likely resulted in more representative estimates of the AMs in the GuLF STUDY. The method used here can be applied in other occupational settings and industries for personal exposure estimation where large amounts of area measurements and more limited numbers of personal measurements are available.

Methods for the Analysis of 26 Million VOC Area Measurements during the Deepwater Horizon Oil Spill Clean-up.

The NIEHS GuLF STUDY is an epidemiologic study of the health of workers who participated in the 2010 Deepwater Horizon oil spill response and clean-up effort. Even with a large database of approximately 28 000 personal samples that were analyzed for total hydrocarbons (THCs) and other oil-related chemicals, resulting in nearly 160 000 full-shift personal measurements, there were still exposure scenarios where the number of measurements was too limited to rigorously assess exposures. Also available were over 26 million volatile organic compounds (VOCs) area air measurements of approximately 1-min duration, collected from direct-reading instruments on 38 large vessels generally located near the leaking well. This paper presents a strategy for converting the VOC database into hourly average air concentrations by vessel as the first step of a larger process designed to use these data to supplement full-shift THC personal exposure measurements. We applied a Bayesian method to account for measurements with values below the analytic instrument's limit of detection while processing the large database into average instrument-hour concentrations and then hourly concentrations across instruments on each day of measurement on each of the vessels. To illustrate this process, we present results on the drilling rig ship, the Discoverer Enterprise. The methods reduced the 26 million measurements to 21 900 hourly averages, which later contributed to the development of additional full-shift THC observations. The approach used here can be applied by occupational health professionals with large datasets of direct-reading instruments to better understand workplace exposures.

Estimates of Inhalation Exposures to Oil-Related Components on the Supporting Vessels During the Deepwater Horizon Oil Spill.

The Deepwater Horizon oil spill response and clean-up (OSRC) involved over 9000 large and small vessels deployed in waters of the Gulf of Mexico across four states (Alabama, Florida, Louisiana, and Mississippi). For the GuLF STUDY, we developed exposure estimates of oil-related components for many work groups to capture a wide range of OSRC operations on these vessels, such as supporting the four rig vessels charged with stopping the spill at the wellhead; skimming oil; in situ burning of oil; absorbing and containing oil by boom; and environmental monitoring. Work groups were developed by: (i) vessel activity; (ii) location (area of the Gulf or state); and (iii) time period. Using Bayesian methods, we computed exposure estimates for these groups for: total hydrocarbons measured as total petroleum hydrocarbons (THC), benzene, toluene, ethylbenzene, xylene, and n-hexane (BTEX-H). Estimates of the arithmetic means for THC ranged from 0.10 ppm [95% credible interval (CI) 0.04, 0.38 ppm] in time periods 2 and 3 (16 July-30 September 2010) to 15.06 ppm (95% CI 10.74, 22.41 ppm) in time period 1a (22 April-15 May 2010). BTEX-H estimates were substantially lower (in the parts per billion range). Exposure levels generally fell over time and differed statistically by activity, location, and time for some groups. These exposure estimates have been used to develop job-exposure matrices for the GuLF STUDY.

Finding renewal in the midst of disaster: The case of the deepwater horizon oil spill

In 2010, the United States experienced the worst environmental disaster in its history. An explosion on a BP oilrig located in the Gulf of Mexico triggered the crisis. As a result, the United States coast guard and BP were charged with crisis communication in its response to the crisis. This essay provides an unprecedented examination and analysis of the communication experiences of public information officers who worked in the unified command center in Houma, Louisiana during the Deepwater Horizon oil spill response. The authors use the discourse of renewal theory to understand the communication practices and choices of the public information officers. Then, using the renewal framework, the authors present three implications for improving crisis communication research and practice.

Association between Deepwater Horizon oil spill response and cleanup work experiences and lung function

IntroductionOil spill response and cleanup (OSRC) workers had potentially stressful experiences during mitigation efforts following the 2010 Deepwater Horizon disaster. Smelling chemicals; skin or clothing contact with oil; heat stress; handling oily plants/wildlife or dead animal recovery; and/or being out of regular work may have posed a risk to worker respiratory health through psychological stress mechanisms. ObjectiveTo evaluate the association between six potentially stressful oil spill experiences and lung function among OSRC workers 1–3 years following the Deepwater Horizon disaster, while controlling for primary oil spill inhalation hazards and other potential confounders. MethodsOf 6811 GuLF STUDY participants who performed OSRC work and completed a quality spirometry test, 4806 provided information on all exposures and confounders. We carried out complete case analysis and used multiple imputation to assess risk among the larger sample. Potentially stressful work experiences were identified from an earlier study of these workers. The lung function parameters of interest include the forced expiratory volume in 1 s (FEV1, mL), the forced vital capacity (FVC, mL) and the ratio (FEV1/FVC, %). ResultsOn average, participants in the analytic sample completed spirometry tests 1.7 years after the spill. Among workers with at least 2 acceptable FEV1 and FVC curves, workers with jobs that involved oily plants/wildlife or dead animal recovery had lower values for FEV1 (Mean difference: −53 mL, 95% CI: −84, −22), FVC (Mean difference: −45 mL, 95% CI: −81, −9) and FEV1/FVC (Mean difference: −0.44%, 95% CI: −0.80, −0.07) compared to unexposed workers in analyses using multiple imputation. ConclusionsWorkers involved in handling oily plants/wildlife or dead animal recovery had lower lung function than unexposed workers after accounting for other OSRC inhalation hazards.

Gauging the influence of increased search effort on reporting rates of bottlenose dolphin (Tursiops truncatus) strandings following the deepwater horizon oil spill.

The co-occurrence of the Deepwater Horizon oil spill and the northern Gulf of Mexico cetacean Unusual Mortality Event have raised questions about the stability of inshore bottlenose dolphin (Tursiops truncatus) populations throughout the region. Several factors could have contributed to the ongoing event, but little attention has been paid to the potential effects of increased search effort and reporting of strandings associated with oil spill response activities, which were widespread for an extended period. This study quantified the influence of increased search effort by estimating the number of bottlenose dolphin strandings reported by oil spill responders and comparing monthly stranding rates with and without response-related records. Results showed that response teams reported an estimated 58% of strandings during the Active Response period within the study area. Comparison of Poisson rates tests showed that when responder-influenced stranding records were removed, the monthly stranding rates from the Active Response period (May 2010 –April 2014) were similar to the Post-Removal Actions Deemed Complete period (May 2013 –March 2015) (e.g., p = 0.83 for remote areas in Louisiana). Further, analyses using the Getis-Ord Gi* spatial statistic showed that when response-related stranding reports were removed from the Active Response period, significant spatial clustering of strandings (p < 0.05) was reduced by 48% in coastal Louisiana. Collectively, these results suggest that increased search effort resulting from the Deepwater Horizon oil spill response throughout remote portions of the Unusual Mortality Event geographic region had the capacity to increase reporting and recovery of marine mammal strandings to unusually high levels. To better understand how stranding data relates to actual mortality, more work is needed to quantify dolphin population size, population trends, and carcass detection rates including the role of search effort. This is vital for understanding the status of a protected species within the northern Gulf of Mexico.

Multivariate left-censored Bayesian model for predicting exposure using multiple chemical predictors.

Environmental health exposures to airborne chemicals often originate from chemical mixtures. Environmental health professionals may be interested in assessing exposure to one or more of the chemicals in these mixtures, but often exposure measurement data are not available, either because measurements were not collected/assessed for all exposure scenarios of interest or because some of the measurements were below the analytical methods' limits of detection (i.e. censored). In some cases, based on chemical laws, two or more components may have linear relationships with one another, whether in a single or in multiple mixtures. Although bivariate analyses can be used if the correlation is high, often correlations are low. To serve this need, this paper develops a multivariate framework for assessing exposure using relationships of the chemicals present in these mixtures. This framework accounts for censored measurements in all chemicals, allowing us to develop unbiased exposure estimates. We assessed our model's performance against simpler models at a variety of censoring levels and assessed our model's 95% coverage. We applied our model to assess vapor exposure from measurements of three chemicals in crude oil taken on the Ocean Intervention III during the Deepwater Horizon oil spill response and clean-up.

Development of API Selection and Training Guidelines for in situ Burning Personnel

ABSTRACT Guidance for in situ burning of oil spills has been developed under the auspices of the Joint Industry Oil Spill Preparedness and Response (OSPR) Task Force (JITF) and the American Petroleum Institute (API), Oil Spill, Emergency Preparedness &amp; Response Subcommittee (OSEPR). These groups convened to evaluate the procedures and lessons learned during the Deepwater Horizon oil spill response. The initial focus was to identify potential opportunities for improvement to the oil spill response system. One of the categories addressed by the JITF and OSEPR was in situ burning of spilled oil. Within this category a number of projects were identified to be worked on by individual project teams. One of those projects was to develop selection and training guidance for oil spill responders to in situ burns. Consequently, a project team was formed of volunteers representing the oil and gas industry, federal and state government, subject matter experts, oil spill response organizations and manufacturers of relevant equipment.

Clinicopathological findings in sea turtles assessed during the Deepwater Horizon oil spill response

Clinicopathological findings in sea turtles assessed during the Deepwater Horizon oil spill response

Pulmonary effects of inhaled oil dispersant (COREXIT® EC9500A) in rats

COREXIT® EC9500A (CE) was used to disperse crude oil during the 2010 Deepwater Horizon oil spill response. While the environmental impact of CE has been examined, the pulmonary effects of CE are unknown. Here we investigated whether inhaled CE elicits airway inflammation, alters pulmonary function, or affects airway reactivity to methacholine (MCh). Rats were exposed to CE (mean 27 mg/m3, 5 h) and examined 1 and 7 d post‐exposure. Under anesthesia, the lung lavage fluid was harvested. Lactate dehydrogenase (LDH) and albumin (A) were measured as indices of lung injury, recovered lung cells were differentiated (macrophages, neutrophils, lymphocytes, and eosinophils) to evaluate inflammation, and oxidant production by macrophages was measured. There were no significant differences in LDH, A, inflammatory cell levels or oxidant production between air‐ and CE‐exposed groups at either time point. Pulmonary function assessed in conscious animals indicated that neither breathing frequency nor specific airway resistance were altered at 1 and 7 d post‐exposure. Airway resistance responses to MCh aerosol in anesthetized animals were unaffected at 1 and 7 d post‐exposure, while dynamic compliance responses were decreased at 1 d but not at 7 d post‐exposure. Our findings suggest that CE inhalation does not initiate lung inflammation, but may transiently increase the difficulty of breathing.

Acute effects of COREXIT® EC9500A on cardiovascular function

The goal of these studies was to characterize cardiovascular responses after an acute inhalation exposure to COREXIT® EC9500A, the oil dispersant used in the Deepwater Horizon oil spill response. Male Sprague Dawley rats underwent a single 5 h exposure to COREXIT® EC9500A (N= 5 exposures, average exposure level 27.12 mg/m3) or air. On days 1 and 7 following the exposure, rats were implanted with indwelling catheters and changes in heart rate and blood pressure were assessed in response to increasing levels of adrenoreceptor agonists. Separate groups of rats were euthanized at the same time points, ventral tail arteries were dissected, and vascular tone along with dose‐dependent responses to vasoconstricting and dilating factors were assessed in vitro. Agonist‐induced dose‐dependent increases in heart rate and blood pressure where greater in COREXIT® EC9500A than air exposed rats 1 but not 7 days after the exposure. COREXIT® EC9500A exposure also induced an increase in basal tone and a reduced responsiveness of tail arteries to acetylcholine‐mediated vasodilation 1 day following the exposure. These findings demonstrate that an acute exposure to COREXIT® EC9500A had transient effects on cardiovascular and peripheral vascular function.

The Natural Resource Advisor Program: An Innovative Approach to Protect Natural and Cultural Resources during the Deepwater Horizon Oil Spill Response

Abstract The Deepwater Horizon (MC252) oil spill response required the removal of oil from the affected shorelines of Louisiana, Mississippi, Alabama, and Florida. Many of the shoreline cleanup activities had the potential to cause inadvertent but significant impacts to natural and cultural resources. As part of an emergency section 7 consultation, the USFWS developed a list of Best Management Practices (BMPs) to be implemented to minimize the impacts to federally listed species, designated critical habitat, and candidate species. Additional BMPs were developed to aid compliance with U.S. Army Corps of Engineers permits and conditions required by state natural and cultural resource agencies. The Deepwater Horizon SCAT group integrated these BMPs into their Shoreline Treatment Recommendations but, due to the size of the response area (>1000 miles), it was difficult for the SCAT teams to ensure BMP compliance throughout the entire response while fulfilling their primary duties. Thus, the Mobile Unified Comm...

International Assistance: Deepwater Horizon Oil Spill Response

ABSTRACT In The Federal Response to Hurricane Katrina: Lessons Learned, the U.S. Department of Homeland Security acknowledged that the U.S. lacks the capability to prioritize and integrate a large ...

Emergency responder health: what have we learned from past disasters?

As the Deepwater Horizon disaster unfolds in the Gulf of Mexico, public health practitioners are having a sinking deja vu feeling. Once again, environmental disaster has struck, and tens of thousands of emergency responders—some professionals, but many more volunteers—have swung into action, potentially risking their health as they work to clean up the worst oil spill in U.S. history. Veterans of similar disasters are wondering if historical lessons learned can help keep the damage to a bare minimum. But a paucity of hard data on emergency responder health makes it difficult even to ask the right questions. “Emergency responders have not been adequately studied,” says Gina Solomon, codirector of the occupational and environmental medicine residency and fellowship program at the University of California, San Francisco, and a senior scientist with the Natural Resources Defense Council. “They tend to be ignored.” Professional emergency responders such as firefighters may not put much emphasis on health effects studies. “They are going to do what they need to do regardless of their own safety,” says Don Donahue, executive director of the Center for Health Policy & Preparedness at the Potomac Institute for Policy Studies, who has firefighters in his extended family. “They have to be a little crazy by definition.” That heroic approach is manna for the people they save, but firefighters may pay a price with disorders such as cancer. Studies of cancers in firefighters have had mixed results, but there is evidence linking this occupation with brain, thyroid, esophageal, bladder, testicular, prostate, and cervical cancers, as well as melanoma and Hodgkin disease (Bates1 and Ma et al.2 are two such studies). Health risks tend to be even greater for the many nonprofessional emergency responders who rush to the scene of crises such as oil spills, terrorist attacks, hurricanes, train derailments, and chemical releases. Those workers often don’t have the training and advanced equipment that protect professional emergency responders to some degree. These and many other factors make it a daunting challenge to protect the health of emergency responders during disasters.