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

Impact of genetic polymorphisms on associations between crude oil exposure and health effects among Coast Guard Deepwater Horizon responders

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 (RRHigh vs never/low, 95 % CI = 1.18, 0.99-1.42); variant (RRHigh vs never/low, 95 % CI = 2.27, 1.26-4.10); pinteraction = 0.04] and headache by NQO1 [wildtype (PRHigh vs never/low, 95 % CI = 2.1, 1.88-2.34); variant (PRHigh vs never/low, 95 % CI = 1.44, 1.07-1.94); pinteraction = 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.

Acute gastrointestinal symptoms associated with oil spill exposures among U.S. coast guard responders to the Deepwater Horizon oil spill

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

These results indicate positive associations between self-reported crude oil and combined crude oil/oil dispersant exposures and acute GI symptoms.

Long-term effects of the Hebei Spirit oil spill on the prevalence and incidence of allergic disorders

The Hebei Spirit oil spill accident occurred in December 2007, approximately 10 km off the coast of Taean, South Korea, a location notably close to residential areas. Crude oil substances have been detected in various environmental mediums since the accident, yet previous studies have primarily focused on the acute effects of oil exposure due to the short latency period of allergic diseases. Therefore, this study evaluated the long-term effects of oil spill exposure on allergic disorders. Our study included adult residents who had participated in the Health Effects Research on Hebei Spirit Oil Spill (HEROS) study up to five years post-incident, which was a prospective cohort to monitor the health status of Taean residents. We used two indicators to assess oil spill exposure, namely the distance from the initial contaminated coastline to each participant's residence and the number of days participants had engaged in oil clean-up work. Current symptoms such as asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and multimorbidity were considered allergic disorders. In the baseline survey, the prevalence of asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and allergic multimorbidity symptoms was associated with both exposure indicators; however, these associations were not observed in the two consecutive surveys. Significant longitudinal associations between oil spill exposure indicators and the four allergic disorders, as well as multimorbidity incidences, were observed during a five-year follow-up period. Our results suggest that oil spill exposure can affect acute and long-term allergic symptoms in residents near the accident site.

Association between oil spill clean-up work and thyroid cancer: Nine years of follow-up after the Hebei Spirit oil spill accident

In 2007, an unprecedented oil spill occurred in Taean, Korea. Although crude oil contains chemicals that could increase thyroid cancer risk, few studies have examined the long-term effects of oil exposure during clean-up and thyroid cancer incidence. We investigated the long-term thyroid cancer incidence among participants involved in clean-up work. 1798 participants engaged in at least two surveys since the baseline was tracked from 2008 to 2018. Participants reported the days they participated in oil clean-up works and cancer diagnoses. Cox proportional hazard models were used to estimate the hazard ratios between clean-up work duration and thyroid cancer. Over the 9-year follow-up, 30 thyroid cancer cases were diagnosed. A positive association was observed between clean-up duration and thyroid cancer risk. This effect was more pronounced among residents living <50 m from traffic roads. Our results indicate that crude oil clean-up work participation may increase the thyroid cancer risk.

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

PURPOSE OF REVIEW

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.

RECENT FINDINGS

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.

Health outcomes among offspring of US Coast Guard responders to the Deepwater Horizon oil spill, 2010-2011

OBJECTIVE

To evaluate the potential for adverse health outcomes among infants born to US Coast Guard (USCG) responders to the Deepwater Horizon (DWH) oil spill disaster.

METHODS

Department of Defense Birth and Infant Health Research programme data identified a cohort of singleton infants born 2010-2011 to USCG personnel in the DWH Oil Spill Coast Guard Cohort study. Infants were included if their military parent ('sponsor') responded to the oil spill during a selected reproductive exposure window (ie, 3 months preconception for male sponsors and periconception through pregnancy for female sponsors), or if their sponsor was a non-responder. χ2 tests and multivariable log-binomial regression were used to compare the demographic and health characteristics of infants born to spill responders and non-responders.

RESULTS

Overall, 1974 infants with a male sponsor (n=182 responder, n=1792 non-responder) and 628 infants with a female sponsor (n=35 responder, n=593 non-responder) in the DWH Oil Spill Coast Guard Cohort were identified. Health outcomes were similar among the offspring of male responders and non-responders. The frequency of any poor live birth outcome (ie, low birth weight, preterm birth or birth defect) was higher among infants born to female responders (17.1%, n=6) than non-responders (8.9%, n=53); the maternal age-adjusted association was suggestively elevated (risk ratio 1.93, 95% CI 0.89 to 4.16).

CONCLUSION

Infant health outcomes were comparable between the offspring of male USCG oil spill responders and non-responders. Findings were limited by the small number of infants identified, particularly among female responders, and should be interpreted with caution.

Risk of longer-term neurological conditions in the Deepwater Horizon Oil Spill Coast Guard Cohort Study - Five years of follow-up

BACKGROUND

Long-term neurological health risks associated with oil spill cleanup exposures are largely unknown. We aimed to investigate risks of longer-term neurological conditions among U.S. Coast Guard (USCG) responders to the 2010 Deepwater Horizon (DWH) oil spill.

METHODS

We used data from active duty members of the DWH Oil Spill Coast Guard Cohort Study (N=45224). Self-reported oil spill exposures were ascertained from post-deployment surveys. Incident neurological outcomes were classified using International Classification of Diseases, 9th Revision, codes from military health encounter records up to 5.5 years post-DWH. We used Cox Proportional Hazards regression to calculate adjusted hazard ratios (aHR) and 95% confidence intervals (CI) for various incident neurological diagnoses (2010-2015). Oil spill responder (n=5964) vs. non-responder (n= 39260) comparisons were adjusted for age, sex, and race, while within-responder comparisons were additionally adjusted for smoking.

RESULTS

Compared to those not responding to the spill, spill responders had reduced risks for headache (aHR=0.84, 95% CI: 0.74-0.96), syncope and collapse (aHR=0.74, 95% CI: 0.56-0.97), and disturbance of skin sensation (aHR=0.81, 95% CI: 0.68-0.96). Responders reporting ever (n=1068) vs. never (n=2424) crude oil inhalation exposure were at increased risk for several individual and grouped outcomes related to headaches and migraines (aHR range: 1.39-1.83). Crude oil inhalation exposure was also associated with elevated risks for an inflammatory nerve condition, mononeuritis of upper limb and mononeuritis multiplex (aHR=1.71, 95% CI: 1.04-2.83), and tinnitus (aHR=1.91, 95% CI: 1.23-2.96), a condition defined by ringing in one or both ears. Risk estimates for those neurological conditions were higher in magnitude among responders reporting exposure to both crude oil and oil dispersants than among those reporting crude oil only.

CONCLUSION

In this large study of active duty USCG responders to the DWH disaster, self-reported spill cleanup exposures were associated with elevated risks for longer-term neurological conditions.

Evolution of polycyclic aromatic hydrocarbons in the surface sediment of southern Jiaozhou Bay in northern China after an accident of oil pipeline explosion

The 2013 "Qingdao oil pipeline explosion" contaminated about 2.5 km of shoreline in the Jiaozhou Bay area and aroused widespread concern because of the serious casualties even though it was not the most severe oil-spill contamination in China. To evaluate the long-term impact, we collected thirty-three surface sediment samples after 3 years of the accident, with sixteen polycyclic aromatic hydrocarbons (PAHs) detected. Spatial-temporal variation in PAHs revealed that a minimal impact might still be present after 3 years. Source analysis combined with a one-way ANOVA showed that pyrolytic sources were consistently predominant. The environmental impact was already minimal 3 years later and negligible thereafter. Although the cancer risk has decreased over the years, there has always been a potential hazard to human for specific occupation, with all of the risk values exceeded 10^-6. This study offers a reference for assessing the long-term impact of oil spills in similar bay areas.

Hair Toxic Trace Elements of Residents across the Caspian Oil and Gas Region of Kazakhstan: Cross-Sectional Study

This study aimed to assess the relationship between the content of toxic trace elements, such as aluminum (Al), arsenic (As), beryllium (Be), cadmium (Cd), mercury (Hg), and lead (Pb), in the hair of the adult population of western Kazakhstan and the distance of their residence from oil and gas fields. The cross-sectional study included 850 adults aged 18-60 years. Inductively coupled plasma mass spectrometry was used to measure the level of Al, As, Be, Cd, Hg, and Pb in hair. The relationship between the concentration of toxic trace elements in the hair and the distance from oil and gas fields was assessed in three groups (<16 km, 16-110 km, and >110 km), using multiple linear regression analysis. The highest concentration of Hg = 0.338 μg/g was determined in the group living near oil and gas fields (0-16 km), whereas the lowest concentration of Al = 3.127 μg/g and As = 0.028 μg/g was determined in participants living at a long distance (more than 110 km) (p < 0.001). The concentration of Al (-0.126 (CI: -0.174; -0.077)), Hg (-0.065 (CI: -0.129; -0.001)), and Pb (0.111 (CI: 0.045; 0.177)) is associated with the distance to oil and gas fields. The obtained data indicate a change in the toxic trace element content in the hair of residents in the Caspian region of western Kazakhstan, a change that is most pronounced in residents living in the zone of oil and gas pollution. The distance to the oil and gas fields affects the content of toxic elements in scalp hair. In particular, the concentration of Al and Hg is associated with a decrease in the distance to oil and gas fields, while the concentration of Pb is associated with an increase in the distance to these fields. The lowest content of Al and As was determined in the hair of study participants living in the most remote areas (more than 110 km from oil and gas fields). Our results demonstrate the need for the biomonitoring of toxic elements to determine long-term temporal trends in the impact of chemicals on public health in western Kazakhstan.