Assessing Unconventional Oil and Gas Exposure in the Appalachian Basin: Comparison of Exposure Surrogates and Residential Drinking Water Measurements.

Health studies report associations between metrics of residential proximity to unconventional oil and gas (UOG) development and adverse health endpoints. We investigated whether exposure through household groundwater is captured by existing metrics and a newly developed metric incorporating groundwater flow paths. We compared metrics with detection frequencies/concentrations of 64 organic and inorganic UOG-related chemicals/groups in residential groundwater from 255 homes (Pennsylvania n = 94 and Ohio n = 161). Twenty-seven chemicals were detected in ≥20% of water samples at concentrations generally below U.S. Environmental Protection Agency standards. In Pennsylvania, two organic chemicals/groups had reduced odds of detection with increasing distance to the nearest well: 1,2-dichloroethene and benzene (Odds Ratio [OR]: 0.46, 95% confidence interval [CI]: 0.23-0.93) and m- and p-xylene (OR: 0.28, 95% CI: 0.10-0.80); results were consistent across metrics. In Ohio, the odds of detecting toluene increased with increasing distance to the nearest well (OR: 1.48, 95% CI: 1.12-1.95), also consistent across metrics. Correlations between inorganic chemicals and metrics were limited (all |ρ| ≤ 0.28). Limited associations between metrics and chemicals may indicate that UOG-related water contamination occurs rarely/episodically, more complex metrics may be needed to capture drinking water exposure, and/or spatial metrics in health studies may better reflect exposure to other stressors.

Groundwaters in Northeastern Pennsylvania near intense hydraulic fracturing activities exhibit few organic chemical impacts.

Horizontal drilling with hydraulic fracturing (HDHF) relies on the use of anthropogenic organic chemicals in proximity to residential areas, raising concern for groundwater contamination. Here, we extensively characterized organic contaminants in 94 domestic groundwater sites in Northeastern Pennsylvania after ten years of activity in the region. All analyzed volatile and semi-volatile compounds were below recommended United States Environmental Protection Agency maximum contaminant levels, and integrated concentrations across two volatility ranges, gasoline range organic compounds (GRO) and diesel range organic compounds (DRO), were low (0.13 ± 0.06 to 2.2 ± 0.7 ppb and 5.2-101.6 ppb, respectively). Following dozens of correlation analyses with distance-to-well metrics and inter-chemical indicator correlations, no statistically significant correlations were found except: (1) GRO levels were higher within 2 km of violations and (2) correlation between DRO and a few inorganic species (e.g., Ba and Sr) and methane. The correlation of DRO with inorganic species suggests a potential high salinity source, whereas elevated GRO may result from nearby safety violations. Highest-concentration DRO samples contained bis-2-ethylhexyl phthalate and N,N-dimethyltetradecylamine. Nevertheless, the overall low rate of contamination for the analytes could be explained by a spatially-resolved hydrogeologic model, where estimated transport distances from gas wells over the relevant timeframes were short relative to the distance to the nearest groundwater wells. Together, the observations and modeled results suggest a low probability of systematic groundwater organic contamination in the region.

Neonatal resuscitation: an update.

Appropriate resuscitation must be available for each of the more than 4 million infants born annually in the United States. Ninety percent of infants transition safely, and it is up to the physician to assess risk factors, identify the nearly 10 percent of infants who need resuscitation, and respond appropriately. A team or persons trained in neonatal resuscitation should be promptly available to provide resuscitation. The Neonatal Resuscitation Program, which was initiated in 1987 to identify infants at risk of needing resuscitation and provide high-quality resuscitation, underwent major updates in 2006 and 2010. Among the most important changes are to not intervene with endotracheal suctioning in vigorous infants born through meconium-stained amniotic fluid (although endotracheal suctioning may be appropriate in nonvigorous infants); to provide positive pressure ventilation with one of three devices when necessary; to begin resuscitation of term infants using room air or blended oxygen; and to have a pulse oximeter readily available in the delivery room. The updated guidelines also provide indications for chest compressions and for the use of intravenous epinephrine, which is the preferred route of administration, and recommend not to use sodium bicarbonate or naloxone during resuscitation. Other recommendations include confirming endotracheal tube placement using an exhaled carbon dioxide detector; using less than 100 percent oxygen and adequate thermal support to resuscitate preterm infants; and using therapeutic hypothermia for infants born at 36 weeks' gestation or later with moderate to severe hypoxic-ischemic encephalopathy.