A community-based evaluation of proximity to unconventional oil and gas wells, drinking water contaminants, and health symptoms in Ohio.

Over 4 million Americans live within 1.6 km of an unconventional oil and gas (UO&G) well, potentially placing them in the path of toxic releases. We evaluated relationships between residential proximity to UO&G wells and (1) water contamination and (2) health symptoms in an exploratory study. We analyzed drinking water samples from 66 Ohio households for 13 UO&G-related volatile organic compounds (VOCs) (e.g., benzene, disinfection byproducts [DBPs]), gasoline-range organics (GRO), and diesel-range organics. We interviewed participants about health symptoms and calculated metrics capturing proximity to UO&G wells. Based on multivariable logistic regression, odds of detection of bromoform and dibromochloromethane in surface water decreased significantly as distance to nearest UO&G well increased (odds ratios [OR]: 0.28-0.29 per km). Similarly, distance to nearest well was significantly negatively correlated with concentrations of GRO and toluene in ground water (rSpearman: -0.40 to -0.44) and with concentrations of bromoform and dibromochloromethane in surface water (rSpearman: -0.48 to -0.50). In our study population, those with higher inverse-distance-squared-weighted UO&G well counts within 5 km around the home were more likely to report experiencing general health symptoms (e.g. stress, fatigue) (OR: 1.52, 95%CI: 1.02-2.26). This exploratory study, though limited by small sample size and self-reported health symptoms, suggests that those in closer proximity to multiple UO&G wells may be more likely to experience environmental health impacts. Further, presence of brominated DBPs (linked to UO&G wastewater) raises the question of whether UO&G activities are impacting drinking water sources in the region. The findings from this study support expanded studies to advance knowledge of the potential for water quality and human health impacts; such studies could include a greater number of sampling sites, more detailed chemical analyses to examine source attribution, and objective health assessments.

Long-term outcome of skull base surgery with microvascular reconstruction for malignant disease.

BACKGROUND: Successful resection of malignant skull base disease depends implicitly on the ability to reconstruct the resulting defects in the craniovisceral diaphragm, to support neural structures, and to prevent ascending intracranial infections. Microsurgery reliably achieves these objectives and has increased the scope of curative oncologic surgery. The authors assessed the reconstructive results and the long-term oncologic outcome of patients having skull base surgery with free tissue transfer. METHODS: A retrospective review of cases between 1989 and 2001 was undertaken. Demographics, histology, surgical management, complications, locoregional control, and survival were analyzed. RESULTS: Predominantly male patients (n = 53; 62 percent) with an average age of 60 years had microvascular reconstruction following oncologic surgery. There was a preponderance of cutaneous malignancies (56 percent), and most lesions involved the anterior skull base (53 percent). Tumors were mostly resected with a combined intracranial or extracranial approach, and reconstruction was undertaken with radial forearm, rectus abdominis, or latissimus dorsi flaps with 94 percent success. Complications occurred in 23 percent of patients, and no specific risk factors for developing intracranial complications were identified. Specifically, extensive reconstructions did not increase the complication rate. The 5-year locoregional control and survival rates were 74 percent and 60 percent, respectively. A positive resection margin significantly increased the risk of locoregional recurrence and worsened disease-specific survival on Cox regression. Survival was also influenced by grade of malignancy. CONCLUSIONS: Microsurgery is highly reliable for reconstructing defects resulting from oncologic resections of the cranial base. It can and should be undertaken using a small number of highly dependable flaps.