Objectives: Long-term studies of oil spill responders are urgently needed as oil spills continue to occur. To this end, we established the prospective Deepwater Horizon (DWH) Oil Spill Coast Guard Cohort study.Methods: DWH oil spill responders (n=8696) and non-responders (n=44 823) who were members of the US Coast Guard (20 April–17 December 2010) were included. This cohort uses both prospective, objective health data from military medical encounters and cross-sectional survey data. Here, we describe the cohort, present adjusted prevalence ratios (PRs) estimating cross-sectional associations between crude oil exposure (none, low/medium, high) and acute physical symptoms, and present adjusted relative risks (RRs) based on longitudinal medical encounter data (2010–2012) for responders/non-responders and responders exposed/not exposed to crude oil.Results: Responders and non-responders in this large cohort (n=53 519) have similar characteristics. Crude oil exposure was reported by >50% of responders. We found statistically significant associations for crude oil exposure with coughing (PR_high=1.78), shortness of breath (PR_high=2.30), wheezing (PR_high=2.32), headaches (PR_high=1.46), light-headedness/dizziness (PR_high=1.96), skin rash/itching (PR_high=1.87), diarrhoea (PR_high=1.76), stomach pain (PR_high=1.67), nausea/vomiting (PR_high=1.48) and painful/burning urination (PR_high=2.89) during deployment. Longitudinal analyses revealed that responders had elevated RRs for dermal conditions (RR=1.09), as did oil-exposed responders for chronic respiratory conditions (RR=1.32), asthma (RR=1.83) and dermal conditions (RR=1.21).Conclusions: We found positive associations between crude oil exposure and various acute physical symptoms among responders, as well as longer term health effects. This cohort is well positioned to evaluate both short-term and long-term effects of oil spill exposures using both self-reported and clinical health data.

The Deepwater Horizon (DWH) oil spill was the largest marine oil spill in U.S. history, involving the response of tens of thousands clean-up workers. Over 8500 United States Coast Guard personnel were deployed in response to the spill. Little is understood about the acute neurological effects of oil spill clean-up-related exposures. Given the large number of people involved in large oil spill clean-ups, study of these effects is warranted. We utilized exposure, health, and lifestyle data from a post-deployment survey administered to Coast Guard responders to the DWH oil spill. Crude oil exposure was assessed via self-reported inhalation and skin contact metrics, categorized by frequency of self-reported exposure to crude oil during deployment (never, rarely, sometimes, most/all of the time). Combined exposure to crude oil and oil dispersant was also evaluated. Adjusted log binomial regressions were used to calculate prevalence ratios (PRs) and 95% confidence intervals (CI), investigating the associations between oil spill exposures and neurological symptoms during deployment. Stratified analyses investigated potential effect modification by sex, exhaust fume exposure, personal protective equipment (PPE) use, and deployment duration and timing. Increasing frequency of crude oil exposure via inhalation was associated with increased likelihood of headaches (PRmost/all vs. never = 1.80), lightheadedness (PRmost/all vs. never = 3.36), difficulty concentrating (PRmost/all vs. never = 1.72), numbness/tingling sensation (PRmost/all vs. never = 3.32), blurred vision (PRmost/all vs. never = 2.87), and memory loss/confusion (PRmost/all vs. never = 2.03), with significant tests for trend. Similar results were found for crude oil exposure via skin contact. Exposure to both oil and oil dispersants yielded associations that were appreciably greater in magnitude than for oil alone for all neurological symptoms. Sensitivity analyses excluding responders in the highest environmental heat categories and responders with relevant pre-existing conditions indicated robustness of these results. Stratified analyses indicated possible effect modification by sex, PPE use, and heat exposure. This study provides evidence of a cross sectional association between crude oil exposures and acute neurological symptoms in a sample of U.S. Coast Guard responders. Additionally, it suggests that exposure to both crude oil and oil dispersant may result in stronger associations and that heat may interact synergistically with oil exposures resulting in more acute neurological symptoms. Future investigations are needed to confirm these findings.

A nested case-control study was carried out using data from the US Department of Defense cohort between 2000 and 2013 to investigate the associations of papillary thyroid cancer (PTC) with serum concentrations of polybrominated diphenyl ethers and polybrominated biphenyls. This study included 742 histologically confirmed PTC cases (in 341 women and 401 men) and 742 matched controls with prediagnostic serum samples from the Department of Defense Serum Repository. Lipid-corrected serum concentrations of 8 congeners were measured. Multivariate conditional logistic regression analyses were performed for classical PTC and follicular variant of PTC, respectively. We also examined effect modification by sex. BDE-28, a polybrominated diphenyl ether congener, was associated with significantly increased risk of classical PTC (for the third tertile vs. below the limit of detection, odds ratio = 2.09, 95% confidence interval: 1.05, 4.15; P for trend = 0.02), adjusting for other congeners, body mass index, and branch of military service. This association was observed mainly for larger classical PTC (tumor size > 10 mm), with a significantly stronger association among women than men (P for interaction = 0.004). No consistent associations were observed for other congeners, including those at higher concentrations. This study found a significantly increased risk of classical PTC associated with increasing levels of BDE-28. The risk varied by sex and tumor size.

Background: There is a paucity of human data on exposure to blast traumatic brain injury (bTBI) and the corresponding systemic cytokine immune response at later time points (i.e., months, years) post-injury. Methods: We conducted a repeated measures, case-control study, examining associations of serum levels of pro- and anti-inflammatory cytokines, measured both pre- and post-deployment with having mild and moderate/severe bTBI. Utilizing serum from the Department of Defense Serum Repository cytokines were measured via an ELISA-based array for 15 cytokines. We compared pre- vs. post-levels among mild cases, moderate/severe cases, and controls and carried out case-control comparisons, using paired t- tests and generalized linear models. Results: The average time between bTBI and post-deployment/bTBI serum among cases was 315.8 days. From pre- to post-deployment/bTBI, levels of interleukin 8 (IL-8) were decreased among both mild cases (μ = − 83.43 pg/ml; s.e. = 21.66) and moderate/severe cases (μ = − 107.67 pg/ml; s.e. = 28.74 pg/ml), while levels increased among controls (μ = 32.86 pg/ml; s.e. = 30.29). The same pattern occurred for matrix metallopeptidase 3 (MMP3), with levels decreasing for moderate/severe cases (μ = − 3369.24 pg/ml; s.e. = 1701.68) and increasing for controls (μ = 1859.60 pg/ml; s.e. = 1737.51) from pre- to post-deployment/bTBI. Evidence was also suggestive of case-control differences, from pre- to post-deployment/bTBI for interleukin 1 alpha (IL-1α), interleukin 4 (IL-4), and interleukin 6 (IL-6) among moderate/severe cases. Conclusion: The findings of this longitudinal study indicate that in the chronic phase of bTBI, levels of IL-8 and MMP3 may be substantially lower than pre-injury. These results need confirmation in other studies, potentially those that account for treatment differences, which was not possible in our study.