# Association of oil spill cleanup-related hydrocarbon exposure with incident hypertension up to 11 years after exposure in the Gulf Long-term Follow-up Study

## TL;DR

This study found that exposure to oil spill cleanup chemicals like benzene and toluene is linked to a higher risk of developing hypertension up to 11 years later.

## Contribution

This is the first longitudinal study to show a long-term association between oil spill-related hydrocarbon exposure and hypertension.

## Key findings

- Approximately 20% of oil spill cleanup workers developed hypertension after exposure.
- Higher exposure to BTEX-H chemicals was associated with a 27-35% increased risk of hypertension.
- Each quartile increase in the BTEX-H mixture was linked to a 10% higher risk of hypertension.

## Abstract

While several studies have found positive associations between exposure to oil spill cleanup-related chemicals and hypertension, no study has examined these associations longitudinally.

This study examined associations of oil spill-related benzene, toluene, ethylbenzene, xylene, and n-hexane (BTEX-H) exposures, individually and as both the aggregate sum (total) of BTEX-H and the BTEX-H mixture with incident hypertension among Gulf Long-term Follow-up (GuLF) Study participants.

Participants were 18,619 Deepwater Horizon (DWH) oil spill cleanup and response workers who enrolled in the GuLF Study (2011–2013). Cumulative exposures to each BTEX-H chemical were estimated with a job-exposure matrix linking detailed self-reported DWH participant work histories to exposure group estimates developed from air monitoring data. We defined incident hypertension as the first self-reported physician diagnosis of hypertension or high blood pressure after each worker’s last date of cleanup work, as reported at enrollment or a follow-up interview (2013–2016 or 2017–2021). We used Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI). We used quantile g-computation to estimate the joint effect of the BTEX-H mixture.

Approximately 20% (n = 3,779) of workers reported an incident hypertension diagnosis. Exposures to the individual BTEX-H chemicals were highly correlated (r = 0.87–0.95). The HRs comparing the highest to lowest quartiles of individual BTEX-H and total BTEX-H exposures ranged from 1.27 to 1.35. We found evidence of exposure-response trends across increasing quartiles of exposure. Each one quartile increase in the BTEX-H mixture was positively associated with incident hypertension (HR: 1.10, 95% CI: 1.07, 1.14).

Oil spill cleanup work-related BTEX-H exposures were associated with the risk of incident hypertension, extending prior findings of cross-sectional associations. Since BTEX-H exposures are common in occupational and population settings, these findings may have broader public health implications.

The online version contains supplementary material available at 10.1186/s12940-025-01253-9.