Department of Pediatrics, Uniformed Services University, Bethesda, MD, United States of America.
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, United States of America.
Environ Int. 2019 Oct;131:104963. doi: 10.1016/j.envint.2019.104963. Epub 2019 Aug 2.
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 (PR = 1.80), lightheadedness (PR = 3.36), difficulty concentrating (PR = 1.72), numbness/tingling sensation (PR = 3.32), blurred vision (PR = 2.87), and memory loss/confusion (PR = 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.
深水地平线（DWH）溢油事故是美国历史上最大的海洋溢油事故，涉及数万名清理人员的应对工作。超过 8500 名美国海岸警卫队人员被部署来应对此次溢油事故。对于清理溢油相关暴露引起的急性神经影响，人们知之甚少。鉴于参与大型溢油清理的人数众多，有必要对这些影响进行研究。
我们利用了在德克萨斯州加尔维斯顿对参与深水地平线溢油事故清理的海岸警卫队人员进行的部署后调查中的暴露、健康和生活方式数据。通过自我报告的吸入和皮肤接触指标评估原油暴露情况，并根据部署期间自我报告的接触原油频率进行分类（从未、很少、有时、大部分/全部时间）。还评估了原油和油分散剂的综合暴露情况。采用调整后的对数二项式回归计算患病率比（PR）和 95%置信区间（CI），调查溢油暴露与部署期间神经症状之间的关联。分层分析调查了性别、废气暴露、个人防护设备（PPE）使用以及部署持续时间和时间的潜在效应修饰作用。
吸入原油的频率增加与头痛（PR=1.80）、头晕（PR=3.36）、注意力集中困难（PR=1.72）、麻木/刺痛感（PR=3.32）、视力模糊（PR=2.87）和记忆丧失/意识模糊（PR=2.03）的可能性增加相关，趋势检验具有统计学意义。通过皮肤接触接触原油也得到了类似的结果。对于所有神经症状，暴露于油和油分散剂产生的关联的幅度明显大于单独暴露于油的关联。排除环境热类别最高和存在相关既往疾病的 responder 进行敏感性分析表明了这些结果的稳健性。分层分析表明，性别、PPE 使用和热暴露可能存在潜在的修饰作用。
本研究提供了美国海岸警卫队人员样本中原油暴露与急性神经症状之间存在横断面关联的证据。此外，它表明暴露于原油和油分散剂可能会产生更强的关联，并且热可能与油暴露协同作用，导致更严重的急性神经症状。需要进一步的调查来证实这些发现。
