Associations between Unconventional Natural Gas Development and Nasal and Sinus, Migraine Headache, and Fatigue Symptoms in Pennsylvania

The human health effects of unconventional oil and gas (UOG) chemical exposures: a scoping review of the toxicological literature

Many chemicals associated with unconventional oil and natural gas (UOG) are known toxicants, leading to health concerns about the effects of UOG. Our objective was to conduct a scoping review of the toxicological literature to assess the effects of UOG chemical exposures in models relevant to human health. We searched databases for primary research studies published in English or French between January 2000 and June 2023 on UOG-related toxicology studies. Two reviewers independently screened abstracts and full texts to determine inclusion. Seventeen studies met our study inclusion criteria. Nine studies used solely in vitro models, while six conducted their investigation solely in animal models. Two studies incorporated both types of models. Most studies used real water samples impacted by UOG or lab-made mixtures of UOG chemicals to expose their models. Most in vitro models used human cells in monocultures, while all animal studies were conducted in rodents. All studies detected significant deleterious effects associated with exposure to UOG chemicals or samples, including endocrine disruption, carcinogenicity, behavioral changes and metabolic alterations. Given the plausibility of causal relationships between UOG chemicals and adverse health outcomes highlighted in this review, future risk assessment studies should focus on measuring exposure to UOG chemicals in human populations.

The human health effects of unconventional oil and gas development (UOGD): A scoping review of epidemiologic studies

OBJECTIVE

Unconventional oil and gas development (UOGD, sometimes termed "fracking" or "hydraulic fracturing") is an industrial process to extract methane gas and/or oil deposits. Many chemicals used in UOGD have known adverse human health effects. Canada is a major producer of UOGD-derived gas with wells frequently located in and around rural and Indigenous communities. Our objective was to conduct a scoping review to identify the extent of research evidence assessing UOGD exposure-related health impacts, with an additional focus on Canadian studies.

METHODS

We included English- or French-language peer-reviewed epidemiologic studies (January 2000-December 2022) which measured exposure to UOGD chemicals directly or by proxy, and where health outcomes were plausibly caused by UOGD-related chemical exposure. Results synthesis was descriptive with results ordered by outcome and hierarchy of methodological approach.

SYNTHESIS

We identified 52 studies from nine jurisdictions. Only two were set in Canada. A majority (n = 27) used retrospective cohort and case-control designs. Almost half (n = 24) focused on birth outcomes, with a majority (n = 22) reporting one or more significant adverse associations of UOGD exposure with: low birthweight; small for gestational age; preterm birth; and one or more birth defects. Other studies identified adverse impacts including asthma (n = 7), respiratory (n = 13), cardiovascular (n = 6), childhood acute lymphocytic leukemia (n = 2), and all-cause mortality (n = 4).

CONCLUSION

There is a growing body of research, across different jurisdictions, reporting associations of UOGD with adverse health outcomes. Despite the rapid growth of UOGD, which is often located in remote, rural, and Indigenous communities, Canadian research on its effects on human health is remarkably sparse. There is a pressing need for additional evidence.

The Environment and Headache: a Narrative Review

PURPOSE OF REVIEW

In this narrative review, we summarize the peer-reviewed literature published between 2017 and 2022 that evaluated ambient environmental risk factors for primary headache disorders, which affect more than half of the population globally. Primary headache disorders include migraine, tension-type headache (TTH), and trigeminal and autonomic cephalalgias (TAC).

RECENT FINDINGS

We identified 17 articles that met the inclusion criteria via PubMed or Google Scholar. Seven studies (41%) relied on data from US populations. The remaining studies were conducted in China, Taiwan, Germany, Ghana, Japan, the Netherlands, South Korea, and Turkey. Air pollution was the most frequently assessed environmental risk factor. Most studies were cross-sectional and focused on all-cause or migraine headaches; one study included TTH, and none included TAC. Short-term exposure to fine particulate matter (PM2.5) was not consistently associated with headache endpoints, but long-term exposure to PM2.5 was associated with migraine headache prevalence and severity across multiple studies. Elevated ambient temperature, changes in weather, oil and gas well exposure, and less natural greenspace, but not noise pollution, were also associated with headache. No studies considered water pollution, metal exposure, ultrafine particulate matter, or wildfire smoke exposure. There is a need for ongoing research focused on headache and the environment. Study designs with the greatest explanatory power may include longitudinal studies that capture the episodic nature of headache and case-crossover analysis, which control for time-invariant individual-level confounders by design. There is also a clear need for research that considers comorbid psychiatric illness and socioeconomic position as powerful modifiers of the effect of the environment on headache.

Volatile organic compounds: A threat to the environment and health hazards to living organisms - A review

Volatile organic compounds (VOCs) are the organic compounds having a minimum vapor pressure of 0.13 kPa at standard temperature and pressure (293 K, 101 kPa). Being used as a solvent for organic and inorganic compounds, they have a wide range of applications. Most of the VOCs are non-biodegradable and very easily become component of the environment and deplete its purity. It also deteriorates the water quality index of the water bodies, impairs the physiology of living beings, enters the food chain by bio-magnification and degrades, decomposes and manipulates the physiology of living organisms. To unveil the adverse impacts of volatile organic compounds (VOCs) and their rapid eruption and interference in the living world, a review has been designed. This review presents an insight into the currently available VOCs, their sources, applications, sampling methods, analytic procedures, imposition on the health of aquatic and terrestrial communities and their contamination of the environment. Elaboration has been done on representation of toxicological effects of VOCs on vertebrates, invertebrates, and birds. Subsequently, the role of environmental agencies in the protection of environment has also been illustrated.

Migraine and air pollution: A systematic review

OBJECTIVE

To systematically synthesize evidence from a broad range of studies on the association between air pollution and migraine.

BACKGROUND

Air pollution is a ubiquitous exposure that may trigger migraine attacks. There has been no systematic review of this possible association.

METHODS

We searched for empirical studies assessing outdoor air pollution and any quantified migraine outcomes. We included short- and long-term studies with quantified air pollution exposures. We excluded studies of indoor air pollution, perfume, or tobacco smoke. We assessed the risk of bias with the World Health Organization's bias assessment instrument for air quality guidelines.

RESULTS

The final review included 12 studies with over 4,000,000 participants. Designs included case-crossover, case-control, time series, and non-randomized pre-post intervention. Outcomes included migraine-related diagnoses, diary records, medical visits, and prescriptions. Rather than pooling the wide variety of exposures and outcomes into a meta-analysis, we tabulated the results. Point estimates above 1.00 reflected associations of increased risk. In single-pollutant models, the percent of point estimates above 1.00 were carbon monoxide 5/5 (100%), nitrogen dioxide 10/13 (78%), ozone 7/8 (88%), PM2.5 13/15 (87%), PM10 2/2 (100%), black carbon 0/1 (0%), methane 4/6 (75%), sulfur dioxide 3/5 (60%), industrial toxic waste 1/1 (100%), and proximity to oil and gas wells 6/13 (46%). In two-pollutant models, 16/17 (94%) of associations with nitrogen dioxide were above 1.00; however, more than 75% of the confidence intervals included the null value. Most studies had low to moderate risks of bias. Where differences were observed, stronger quality articles generally reported weaker associations.

CONCLUSIONS

Balancing the generally strong methodologies with the small number of studies, point estimates were mainly above 1.00 for associations of carbon monoxide, nitrogen dioxide, ozone, and particulate matter with migraine. These results were most consistent for nitrogen dioxide.

Environmental Justice: Where It Has Been, and Where It Might Be Going

Taking stock of environmental justice (EJ) is daunting. It is at once a scholarly field, an ongoing social movement, and an administrative imperative adopted by government agencies and incorporated into legislation. Moreover, within academia, it is multidisciplinary and multimethodological, comprising scholars who do not always speak to one another. Any review of EJ is thus necessarily restrictive. This article explores several facets of EJ activism. One is its coalitional and "inside-outside" orientation. EJ activists are constantly forming alliances with other stakeholders, but these coalitions do not flout the importance of engaging with formal institutions. The review next turns to one set of such institutions-the courts and regulatory agencies-to see how well EJ claims have fared there. I then survey scientific findings that have been influenced by EJ. The review concludes with future directions for activists and scholars to consider: the changing nature of EJ coalitions, fragmentation within EJ and with other fields, the historical roots of environmental injustice, and opportunities for stronger infusion of the EJ lens.

Outcomes of the Halliburton Loophole: Chemicals regulated by the Safe Drinking Water Act in US fracking disclosures, 2014-2021

Hydraulic fracturing (fracking) has enabled the United States to lead the world in gas and oil production over the past decade; 17.6 million Americans now live within a mile of an oil or gas well (Czolowski et al., 2017). This major expansion in fossil fuel production is possible in part due to the 2005 Energy Policy Act and its "Halliburton Loophole," which exempts fracking activity from regulation under the Safe Drinking Water Act (SDWA). To begin quantifying the environmental and economic impacts of this loophole, this study undertakes an aggregate analysis of chemicals that would otherwise be regulated by SDWA within FracFocus, an industry-sponsored fracking disclosure database. This paper quantifies the total disclosures and total mass of these chemicals used between 2014 and 2021, examines trends in their use, and investigates which companies most use and supply them. We find that 28 SDWA-regulated chemicals are reported in FracFocus, and 62-73% of all disclosures (depending on year) report at least one SDWA-regulated chemical. Of these, 19,700 disclosures report using SDWA-regulated chemicals in masses that exceed their reportable quantities as defined under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Finally, while the most common direct-supplier category is "company name not reported," Halliburton is the second-most named direct supplier of SWDA regulated chemicals. Halliburton is also the supplier most frequently associated with fracks that use SDWA regulated chemicals. These results show the necessity of a more robust and federally mandated disclosure system and suggest the importance of revisiting exemptions such as the Halliburton Loophole.

Health Symptoms and Proximity to Active Multi-Well Unconventional Oil and Gas Development Sites in the City and County of Broomfield, Colorado

City and County of Broomfield (CCOB) residents reported over 500 health concerns between January 2020 and December 2021. Our objective was to determine if CCOB residents living within 1 mile of multi-well unconventional oil and gas development (UOGD) sites reported more frequent health symptoms than residents living > 2 miles away. We invited 3993 randomly selected households to participate in a health survey. We applied linear regression to test associations between distance to UOGD and summed Likert scores for health symptom categories. After covariate adjustment, respondents living within 1 mile of one of CCOB's UOGD sites tended to report higher frequencies of upper respiratory, lower respiratory, gastrointestinal and acute symptoms than respondents living more than 2 miles from the sites, with the largest differences for upper respiratory and acute symptoms. For upper respiratory and acute symptoms, scores differed by 0.81 (95% CI: 0.06, 2.58) and 0.75 (95% CI: 0.004, 1.99), respectively. Scores for adults most concerned about air pollution, noise and odors trended higher within 1 mile for all symptom categories, while scores among adults least concerned trended lower. Scores trended higher for lower respiratory, gastrointestinal and acute symptoms in children living within 2 miles of UOGD, after covariate adjustment. We did not observe any difference in the frequency of symptoms reported in unadjusted results. Additional study is necessary to understand relationships between proximity to UOGD and health symptoms.

The association of unconventional natural gas development with diagnosis and treatment of internalizing disorders among adolescents in Pennsylvania using electronic health records

BACKGROUND

Unconventional natural gas development (UNGD) introduces physical and psychosocial hazards into communities, which could contribute to psychosocial stress in adolescents and an increased risk of internalizing disorders, common and impactful health outcomes.

OBJECTIVES

To evaluate associations between a 180-day composite UNGD activity metric and new onset of internalizing disorders, overall and separately for anxiety and depressive disorders, and effect modification by sex.

METHODS

We used a nested case-control design from 2008 to 2016 in 38 Pennsylvania counties using electronic health records from adolescent Geisinger subjects. Cases were defined by at least two diagnoses or medication orders indicating new onset of an internalizing disorder, and controls frequency-matched 4:1 on age, sex, and year. To evaluate associations, we used generalized estimating equations, with logit link, robust standard errors, and an exchangeable correlation structure within community.

RESULTS

We identified 7,974 adolescents (65.9% female, mean age 15.0 years) with new onset internalizing disorders. There were no associations when we used data from the entire study period. When restricted to years with higher UNGD activity (2010-2016), comparing the highest to lowest quartile, UNGD activity was associated (odds ratio [95% confidence level]) with new onset internalizing disorders (1.15 [1.06, 1.25]). Associations were slightly stronger for depressive disorders. Associations were only present in females (p = 0.009).

DISCUSSION

This is the first epidemiologic study of UNGD in relation to adolescent mental health, an important health outcome in a potentially susceptible group to the environmental and community impacts of UNGD. UNGD activity was associated with new onset internalizing disorders in females in this large sample in an area of active UNGD.

Assessing Exposure to Unconventional Oil and Gas Development: Strengths, Challenges, and Implications for Epidemiologic Research

PURPOSE OF REVIEW

Epidemiologic studies have observed elevated health risks in populations living near unconventional oil and gas development (UOGD). In this narrative review, we discuss strengths and limitations of UOG exposure assessment approaches used in or available for epidemiologic studies, emphasizing studies of children's health outcomes.

RECENT FINDINGS

Exposure assessment challenges include (1) numerous potential stressors with distinct spatiotemporal patterns, (2) critical exposure windows that cover long periods and occur in the past, and (3) limited existing monitoring data coupled with the resource-intensiveness of collecting new exposure measurements to capture spatiotemporal variation. All epidemiologic studies used proximity-based models for exposure assessment as opposed to surveys, biomonitoring, or environmental measurements. Nearly all studies used aggregate (rather than pathway-specific) models, which are useful surrogates for the complex mix of potential hazards. Simple and less-specific exposure assessment approaches have benefits in terms of scalability, interpretability, and relevance to specific policy initiatives such as set-back distances. More detailed and specific models and metrics, including dispersion methods and stressor-specific models, could reduce exposure misclassification, illuminate underlying exposure pathways, and inform emission control and exposure mitigation strategies. While less practical in a large population, collection of multi-media environmental and biological exposure measurements would be feasible in cohort subsets. Such assessments are well-suited to provide insights into the presence and magnitude of exposures to UOG-related stressors in relation to spatial surrogates and to better elucidate the plausibility of observed effects in both children and adults.

Spatiotemporal Correlation Analysis of Hydraulic Fracturing and Stroke in the United States

Hydraulic fracturing or fracking has led to a rapid growth of oil and gas production in the United States, but the impact of fracking on public health is an important but underresearched topic. We designed a methodology to study spatiotemporal correlations between the risk of fracking and stroke mortality. An annualized loss expectancy (ALE) model is applied to quantify the risk of fracking. The geographically and temporally weighted regression (GTWR) model is used to analyze spatiotemporal correlations of stroke mortality, fracking ALE, and nine other socioeconomic- and health-related factors. The analysis shows that fracking ALE is moderately correlated with stroke mortality at ages over 65 in most states of fracking, in addition to cardiovascular disease and drug overdose being positively correlated with stroke mortality. Furthermore, the correlations between fracking ALE and stroke mortality in men appear to be higher than in women near the Marcellus Shale, including Ohio, Pennsylvania, West Virginia, and Virginia, while stroke mortality among women is concentrated in the Great Plains, including Montana, Wyoming, New Mexico, and Oklahoma. Lastly, within two kilometers of the fracking mining activity, the level of benzene in the air was found to be significantly correlated with the fracking activity in Colorado.

Managing upstream oil and gas emissions: A public health oriented approach

Oil and natural gas are the largest primary global energy sources, and upstream gas emissions from these fuels can impact global climate change and local public health. This paper employs a public health-oriented perspective that reviews grey and academic literature, industry data, technical reports, and policy trends to highlight issues of emissions monitoring. We identify gaps in the existing landscape of emissions reduction strategies and highlight options for addressing them. Policy recommendations include the use of new digital monitoring technologies to better understand causes of emission events, to create data-driven oil and gas regulations, and to begin accurately measuring the volumes of gases released during oil and gas production. Areas for future research relating to emissions and public health impacts are outlined to further enable oil and gas policy discussions.

Drinking water, fracking, and infant health

This study assesses the health risks associated with drinking water contamination using variation in the timing and location of shale gas development (SGD). Our novel dataset, linking health and drinking water outcomes to shale gas activity through water sources, enables us to provide new estimates of the causal effects of water pollution on health and to isolate drinking water as a specific mechanism of exposure for SGD. We find consistent and robust evidence that drilling shale gas wells negatively impacts both drinking water quality and infant health. These results indicate large social costs of water pollution and provide impetus for re-visiting the regulation of public drinking water.

Exposure to a mixture of 23 chemicals associated with unconventional oil and gas operations alters immune response to challenge in adult mice

The prevalence of unconventional oil and gas (UOG) operations raises concerns regarding the potential for adverse health outcomes following exposure to water tainted by mixtures of UOG associated chemicals. The potential effects that exposure to complex chemical mixtures has on the immune system have yet to be fully evaluated. In this study, effects on the immune system of adult mice exposed to a mixture of 23 chemicals that have been associated with water near active UOG operations were investigated. Female and male mice were exposed to the mixture via their drinking water for at least 8 weeks. At the end of the exposure, cellularity of primary and secondary immune organs, as well as an immune system function, were assessed using three different models of disease, i.e. house dust mite (HDM)-induced allergic airway disease, influenza A virus infection, and experimental autoimmune encephalomyelitis (EAE). The results indicated exposures resulted in different impacts on T-cell populations in each disease model. Furthermore, the consequences of exposure differed between female and male mice. Notably, exposure to the chemical mixture significantly increased EAE disease severity in females, but not in male, mice. These findings indicated that direct exposure to this mixture leads to multiple alterations in T-cell subsets and that these alterations differ between sexes. This suggested to us that direct exposure to UOG-associated chemicals may alter the adult immune system, leading to dysregulation in immune cellularity and function.

Chronic disaster impact: the long-term psychological and physical health consequences of housing damage due to induced earthquakes

OBJECTIVES

To evaluate the long-term (psychosomatic) health consequences of man-made earthquakes compared with a non-exposure control group. Exposure was hypothesised to have an increasingly negative impact on health outcomes over time.

SETTING

Large-scale gas extraction in the Netherlands causing earthquakes and considerable damage.

PARTICIPANTS

A representative sample of inhabitants randomly selected from municipal population records; contacted 5 times during 21 months (T1: N=3934; T5: N=2150; mean age: 56.54; 50% men; at T5, N=846 (39.3%) had no, 459 (21.3%) once and 736 (34.2%) repeated damages).

MAIN MEASURES

(Psychosomatic) health outcomes: self-rated health and Mental Health Inventory (both: validated; Short Form Health Survey); stress related health symptoms (shortened version of previously validated symptoms list). Independent variable: exposure to the consequences of earthquakes assessed via physical (peak ground acceleration) and personal exposure (damage to housing: none, once, repeated).

RESULTS

Exposure to induced earthquakes has negative health consequences especially for those whose homes were damaged repeatedly. Compared with a no-damage control group, repeated damage was associated with lower self-rated health (OR:1.64), mental health (OR:1.83) and more stress-related health symptoms (OR:2.52). Effects increased over time: in terms of relative risk, by T5, those whose homes had repeated damage were respectively 1.60 and 2.11 times more likely to report poor health and negative mental health and 2.84 times more at risk of elevated stress related health symptoms. Results for physical exposure were comparable.

CONCLUSION

This is the first study to provide evidence that induced earthquakes can have negative health consequences for inhabitants over time. It identifies the subpopulation particularly at risk: people with repeated damages who have experienced many earthquakes. Findings can have important implications for the prevention of negative health consequences of induced earthquakes.

Air pollution, methane super-emitters, and oil and gas wells in Northern California: the relationship with migraine headache prevalence and exacerbation

BACKGROUND

Migraine-an episodic disorder characterized by severe headache that can lead to disability-affects over 1 billion people worldwide. Prior studies have found that short-term exposure to fine particulate matter (PM_2.5), nitrogen dioxide (NO₂), and ozone increases risk of migraine-related emergency department (ED) visits. Our objective was to characterize the association between long-term exposure to sources of harmful emissions and common air pollutants with both migraine headache and, among patients with migraine, headache severity.

METHODS

From the Sutter Health electronic health record database, we identified 89,575 prevalent migraine cases between 2014 and 2018 using a migraine probability algorithm (MPA) score and 270,564 frequency-matched controls. Sutter Health delivers care to 3.5 million patients annually in Northern California. Exposures included 2015 annual average block group-level PM_2.5 and NO₂ concentrations, inverse-distance weighted (IDW) methane emissions from 60 super-emitters located within 10 km of participant residence between 2016 and 2018, and IDW active oil and gas wells in 2015 within 10 km of each participant. We used logistic and negative binomial mixed models to evaluate the association between environmental exposures and (1) migraine case status; and (2) migraine severity (i.e., MPA score > 100, triptan prescriptions, neurology visits, urgent care migraine visits, and ED migraine visits per person-year). Models controlled for age, sex, race/ethnicity, Medicaid use, primary care visits, and block group-level population density and poverty.

RESULTS

In adjusted analyses, for each 5 ppb increase in NO₂, we observed 2% increased odds of migraine case status (95% CI: 1.00, 1.05) and for each 100,000 kg/hour increase in IDW methane emissions, the odds of case status also increased (OR = 1.04, 95% CI: 1.00, 1.08). We found no association between PM_2.5 or oil and gas wells and migraine case status. PM_2.5 was linearly associated with neurology visits, migraine-specific urgent care visits, and MPA score > 100, but not triptans or ED visits. NO₂ was associated with migraine-specific urgent care and ED visits, but not other severity measures. We observed limited or null associations between continuous measures of methane emissions and proximity to oil and gas wells and migraine severity.

CONCLUSIONS

Our findings illustrate the potential role of long-term exposure to multiple ambient air pollutants for prevalent migraine and migraine severity.

Unconventional Natural Gas Development and Hospitalization for Heart Failure in Pennsylvania

BACKGROUND

Growing literature linking unconventional natural gas development (UNGD) to adverse health has implicated air pollution and stress pathways. Persons with heart failure (HF) are susceptible to these stressors.

OBJECTIVES

This study sought to evaluate associations between UNGD activity and hospitalization among HF patients, stratified by both ejection fraction (EF) status (reduced [HFrEF], preserved [HFpEF], not classifiable) and HF severity.

METHODS

We evaluated the odds of hospitalization among patients with HF seen at Geisinger from 2008 to 2015 using electronic health records. We assigned metrics of UNGD activity by phase (pad preparation, drilling, stimulation, and production) 30 days before hospitalization or a frequency-matched control selection date. We assigned phenotype status using a validated algorithm.

RESULTS

We identified 9,054 patients with HF with 5,839 hospitalizations (mean age 71.1 ± 12.7 years; 47.7% female). Comparing 4th to 1st quartiles, adjusted odds ratios (95% confidence interval) for hospitalization were 1.70 (1.35 to 2.13), 0.97 (0.75 to 1.27), 1.80 (1.35 to 2.40), and 1.62 (1.07 to 2.45) for pad preparation, drilling, stimulation, and production metrics, respectively. We did not find effect modification by HFrEF or HFpEF status. Associations of most UNGD metrics with hospitalization were stronger among those with more severe HF at baseline.

CONCLUSIONS

Three of 4 phases of UNGD activity were associated with hospitalization for HF in a large sample of patients with HF in an area of active UNGD, with similar findings by HFrEF versus HFpEF status. Older patients with HF seem particularly vulnerable to adverse health impacts from UNGD activity.

Biological effects of inhaled hydraulic fracturing sand dust. I. Scope of the investigation

Hydraulic fracturing ("fracking") is a process in which subterranean natural gas-laden rock is fractured under pressure to enhance retrieval of gas. Sand (a "proppant") is present in the fracking fluid pumped down the well bore to stabilize the fissures and facilitate gas flow. The manipulation of sand at the well site creates respirable dust (fracking sand dust, FSD) to which workers are exposed. Because workplace exposures to FSD have exceeded exposure limits set by OSHA, a physico-chemical characterization of FSD along with comprehensive investigations of the potential early adverse effects of FSDs on organ function and biomarkers has been conducted using a rat model and related in vivo and in vitro experiments involving the respiratory, cardiovascular, immune systems, kidney and brain. An undercurrent theme of the overall hazard identification study was, to what degree do the health effects of inhaled FSD resemble those previously observed after crystalline silica dust inhalation? In short-term studies, FSD was found to be less bioactive than MIN-U-SIL® 5 in the lungs. A second theme was, are the biological effects of FSD restricted to the lungs? Bioactivity of FSD was observed in all examined organ systems. Our findings indicate that, in many respects, the physical and chemical properties, and the short-term biological effects, of the FSDs share many similarities as a group but have little in common with crystalline silica dust.

Petro-riskscapes and environmental distress in West Texas: Community perceptions of environmental degradation, threats, and loss

Unconventional oil and gas development (UOGD) expanded rapidly in the United States between 2004-2019 with resultant industrial change to landscapes and new environmental exposures. By 2019, West Texas' Permian Basin accounted for 35% of domestic oil production. We conducted an online survey of 566 Texans in 2019 to examine the implications of UOGD using three measures from the Environmental Distress Scale (EDS): perceived threat of environmental issues, felt impact of environmental change, and loss of solace when valued environments are transformed ("solastalgia"). We found increased levels of environmental distress among respondents living in counties in the Permian Basin who reported a 2.75% increase in perceived threat of environmental issues (95% CI = -1.14, 6.65) and a 4.21% increase in solastalgia (95% CI = 0.03, 8.40). In our subgroup analysis of women, we found higher EDS subscale scores among respondents in Permian Basin counties for perceived threat of environmental issues (4.08%, 95% CI= -0.12, 8.37) and solastalgia (7.09%, 95% CI= 2.44, 11.88). In analysis restricted to Permian Basin counties, we found exposure to at least one earthquake of magnitude ≥ 3 was associated with increases in perceived threat of environmental issues (4.69%, 95% CI = 0.15, 9.23), and that county-level exposure to oil and gas injection wells was associated with increases in felt impact (4.38%, 95% CI = -1.77, 10.54) and solastalgia (4.06%, 95% CI = 3.02, 11.14). Our results indicate increased environmental distress in response to UOGD-related environmental degradation among Texans and highlight the importance of considering susceptible sub-groups.

Exposure assessment of adults living near unconventional oil and natural gas development and reported health symptoms in southwest Pennsylvania, USA

Recent research has shown relationships between health outcomes and residence proximity to unconventional oil and natural gas development (UOGD). The challenge of connecting health outcomes to environmental stressors requires ongoing research with new methodological approaches. We investigated UOGD density and well emissions and their association with symptom reporting by residents of southwest Pennsylvania. A retrospective analysis was conducted on 104 unique, de-identified health assessments completed from 2012-2017 by residents living in proximity to UOGD. A novel approach to comparing estimates of exposure was taken. Generalized linear modeling was used to ascertain the relationship between symptom counts and estimated UOGD exposure, while Threshold Indicator Taxa Analysis (TITAN) was used to identify associations between individual symptoms and estimated UOGD exposure. We used three estimates of exposure: cumulative well density (CWD), inverse distance weighting (IDW) of wells, and annual emission concentrations (AEC) from wells within 5 km of respondents' homes. Taking well emissions reported to the Pennsylvania Department of Environmental Protection, an air dispersion and screening model was used to estimate an emissions concentration at residences. When controlling for age, sex, and smoker status, each exposure estimate predicted total number of reported symptoms (CWD, p<0.001; IDW, p<0.001; AEC, p<0.05). Akaike information criterion values revealed that CWD was the better predictor of adverse health symptoms in our sample. Two groups of symptoms (i.e., eyes, ears, nose, throat; neurological and muscular) constituted 50% of reported symptoms across exposures, suggesting these groupings of symptoms may be more likely reported by respondents when UOGD intensity increases. Our results do not confirm that UOGD was the direct cause of the reported symptoms but raise concern about the growing number of wells around residential areas. Our approach presents a novel method of quantifying exposures and relating them to reported health symptoms.

A new approach to categorization of radiologic inflammation in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent condition. Clinical diagnosis requires subjective evidence (i.e. symptoms) and objective evidence of inflammation (e.g. sinus computed tomography [CT]). Few studies have assessed differences in common CT scoring approaches for CRS, the Lund-Mackay (LM) system and its modified version (mLM); none in a general population sample. The aims of this study were to answer the following: (1) Is mLM superior to LM? (2) Should nasal cavity opacification be included in scoring? (3) How should location-specific scores be utilized? (4) If location-specific scores are summed, what should be the cutoff? (5) Are associations of opacification with symptoms observed when using different measurement approaches? We scored sinus CTs using LM and mLM from 526 subjects selected from a larger CRS study. Exploratory factor analysis (EFA) assessed similarity of mLM and LM. Latent class analysis (LCA) identified subgroups of sinus opacification patterns. Factors associated with group membership and relations with nasal and sinus symptoms (NSS) guided clinical relevance. EFA suggested no differences between LM and mLM, or after addition of nasal cavity opacification. LCA identified three opacification groups: no/mild, localized, and diffuse. Males were 2.7x more likely to have diffuse opacification than females, as were those with asthma or hay fever. A LM cutoff of 3 had similar performance to the currently used 4. Diffuse opacification was associated with nasal blockage and smell loss. Differing patterns of opacification may be clinically relevant, improving measurement of objective evidence in studies of CRS and sinus diseases.

Lagging and Flagging: Air Pollution, Shale Gas Exploration and the Interaction of Policy, Science, Ethics and Environmental Justice in England

The science on the effects of global climate change and air pollution on morbidity and mortality is clear and debate now centres around the scale and precise contributions of particular pollutants. Sufficient data existed in recent decades to support the adoption of precautionary public health policies relating to fossil fuels including shale exploration. Yet air quality and related public health impacts linked to ethical and environmental justice elements are often marginalized or missing in planning and associated decision making. Industry and government policies and practices, laws and planning regulations lagged well behind the science in the United Kingdom. This paper explores the reasons for this and what shaped some of those policies. Why did shale gas policies in England fail to fully address public health priorities and neglect ethical and environmental justice concerns. To answer this question, an interdisciplinary analysis is needed informed by a theoretical framework of how air pollution and climate change are largely discounted in the complex realpolitik of policy and regulation for shale gas development in England. Sources, including official government, regulatory and planning documents, as well as industry and scientific publications are examined and benchmarked against the science and ethical and environmental justice criteria. Further, our typology illustrates how the process works drawing on an analysis of official policy documents and statements on planning and regulatory oversight of shale exploration in England, and material from industry and their consultants relating to proposed shale oil and gas development. Currently the oil, gas and chemical industries in England continue to dominate and influence energy and feedstock-related policy making to the detriment of ethical and environmental justice decision making with significant consequences for public health.

Residential Proximity to Oil and Gas Development and Birth Outcomes in California: A Retrospective Cohort Study of 2006-2015 Births

BACKGROUND

Studies suggest associations between oil and gas development (OGD) and adverse birth outcomes, but few epidemiological studies of oil wells or inactive wells exist, and none in California.

OBJECTIVE

Our study aimed to investigate the relationship between residential proximity to OGD and birth outcomes in California.

METHODS

We conducted a retrospective cohort study of 2,918,089 births to mothers living within 10 km of at least one production well between January 1, 2006 and December 31, 2015. We estimated exposure during pregnancy to inactive wells count (no inactive wells, 1 well, 2-5 wells, 6+ wells) and production volume from active wells in barrels of oil equivalent (BOE) (no BOE, 1-100 BOE/day, >100 BOE/day). We used generalized estimating equations to examine associations between overall and trimester-specific OGD exposures and term birth weight (tBW), low birth weight (LBW), preterm birth (PTB), and small for gestational age birth (SGA). We assessed effect modification by urban/rural community type.

RESULTS

Adjusted models showed exposure to active OGD was associated with adverse birth outcomes in rural areas; effect estimates in urban areas were close to null. In rural areas, increasing production volume was associated with stronger adverse effect estimates. High (>100 BOE/day) vs. no production throughout pregnancy was associated with increased odds of LBW [odds ratio (OR)=1.40, 95% confidence interval (CI): 1.14, 1.71] and SGA (OR=1.22, 95% CI: 1.02, 1.45), and decreased tBW (mean difference = -36 grams, 95% CI: -54, -17), but not with PTB (OR=1.03, 95% CI: 0.91, 1.18).

CONCLUSION

Proximity to higher production OGD in California was associated with adverse birth outcomes among mothers residing in rural areas. Future studies are needed to confirm our findings in other populations and improve exposure assessment measures. https://doi.org/10.1289/EHP5842.

Critical evaluation of human health risks due to hydraulic fracturing in natural gas and petroleum production

The use of hydraulic fracturing (HF) to extract oil and natural gas has increased, along with intensive discussions on the associated risks to human health. Three technical processes should be differentiated when evaluating human health risks, namely (1) drilling of the borehole, (2) hydraulic stimulation, and (3) gas or oil production. During the drilling phase, emissions such as NOx, NMVOCs (non-methane volatile organic compounds) as precursors for tropospheric ozone formation, and SOx have been shown to be higher compared to the subsequent phases. In relation to hydraulic stimulation, the toxicity of frac fluids is of relevance. More than 1100 compounds have been identified as components. A trend is to use fewer, less hazardous and more biodegradable substances; however, the use of hydrocarbons, such as kerosene and diesel, is still allowed in the USA. Methane in drinking water is of low toxicological relevance but may indicate inadequate integrity of the gas well. There is a great concern regarding the contamination of ground- and surface water during the production phase. Water that flows to the surface from oil and gas wells, so-called 'produced water', represents a mixture of flow-back, the injected frac fluid returning to the surface, and the reservoir water present in natural oil and gas deposits. Among numerous hazardous compounds, produced water may contain bromide, arsenic, strontium, mercury, barium, radioactive isotopes and organic compounds, particularly benzene, toluene, ethylbenzene and xylenes (BTEX). The sewage outflow, even from specialized treatment plants, may still contain critical concentrations of barium, strontium and arsenic. Evidence suggests that the quality of groundwater and surface water may be compromised by disposal of produced water. Particularly critical is the use of produced water for watering of agricultural areas, where persistent compounds may accumulate. Air contamination can occur as a result of several HF-associated activities. In addition to BTEX, 20 HF-associated air contaminants are group 1A or 1B carcinogens according to the IARC. In the U.S., oil and gas production (including conventional production) represents the second largest source of anthropogenic methane emissions. High-quality epidemiological studies are required, especially in light of recent observations of an association between childhood leukemia and multiple myeloma in the neighborhood of oil and gas production sites. In conclusion, (1) strong evidence supports the conclusion that frac fluids can lead to local environmental contamination; (2) while changes in the chemical composition of soil, water and air are likely to occur, the increased levels are still often below threshold values for safety; (3) point source pollution due to poor maintenance of wells and pipelines can be monitored and remedied; (4) risk assessment should be based on both hazard and exposure evaluation; (5) while the concentrations of frac fluid chemicals are low, some are known carcinogens; therefore, thorough, well-designed studies are needed to assess the risk to human health with high certainty; (6) HF can represent a health risk via long-lasting contamination of soil and water, when strict safety measures are not rigorously applied.

Unconventional oil and gas development and health outcomes: A scoping review of the epidemiological research

BACKGROUND

Hydraulic fracturing together with directional and horizontal well drilling (unconventional oil and gas (UOG) development) has increased substantially over the last decade. UOG development is a complex process presenting many potential environmental health hazards, raising serious public concern.

AIM

To conduct a scoping review to assess what is known about the human health outcomes associated with exposure to UOG development.

METHODS

We performed a literature search in MEDLINE and SCOPUS for epidemiological studies of exposure to UOG development and verified human health outcomes published through August 15, 2019. For each eligible study we extracted data on the study design, study population, health outcomes, exposure assessment approach, statistical methodology, and potential confounders. We reviewed the articles based on categories of health outcomes.

RESULTS

We identified 806 published articles, most of which were published during the last three years. After screening, 40 peer-reviewed articles were selected for full text evaluation and of these, 29 articles met our inclusion criteria. Studies evaluated pregnancy outcomes, cancer incidence, hospitalizations, asthma exacerbations, sexually transmitted diseases, and injuries or mortality from traffic accidents. Our review found that 25 of the 29 studies reported at least one statistically significant association between the UOG exposure metric and an adverse health outcome. The most commonly studied endpoint was adverse birth outcomes, particularly preterm deliveries and low birth weight. Few studies evaluated the mediating pathways that may underpin these associations, highlighting a clear need for research on the potential exposure pathways and mechanisms underlying observed relationships.

CONCLUSIONS

This review highlights the heterogeneity among studies with respect to study design, outcome of interest, and exposure assessment methodology. Though replication in other populations is important, current research points to a growing body of evidence of health problems in communities living near UOG sites.

Evaluating potential human health risks from modeled inhalation exposures to volatile organic compounds emitted from oil and gas operations

Some states and localities restrict siting of new oil and gas (O&G) wells relative to public areas. Colorado includes a 500-foot exception zone for building units, but it is unclear if that sufficiently protects public health from air emissions from O&G operations. To support reviews of setback requirements, this research examines potential health risks from volatile organic compounds (VOCs) released during O&G operations.We used stochastic dispersion modeling with published emissions for 47 VOCs (collected on-site during tracer experiments) to estimate outdoor air concentrations within 2,000 feet of hypothetical individual O&G facilities in Colorado. We estimated distributions of incremental acute, subchronic, and chronic inhalation non-cancer hazard quotients (HQs) and hazard indices (HIs), and inhalation lifetime cancer risks for benzene, by coupling modeled concentrations with microenvironmental penetration factors, human-activity diaries, and health-criteria levels.Estimated exposures to most VOCs were below health criteria at 500-2,000 feet. HQs were < 1 for 43 VOCs at 500 feet from facilities, with lowest values for chronic exposures during O&G production. Hazard estimates were highest for acute exposures during O&G development, with maximum acute HQs and HIs > 1 at most distances from facilities, particularly for exposures to benzene, 2- and 3-ethyltoluene, and toluene, and for hematological, neurotoxicity, and respiratory effects. Maximum acute HQs and HIs were > 10 for highest-exposed individuals 500 feet from eight of nine modeled facilities during O&G development (and 2,000 feet from one facility during O&G flowback); hematologic toxicity associated with benzene exposure was the critical toxic effect. Estimated cancer risks from benzene exposure were < 1.0 × 10^-5 at 500 feet and beyond.Implications: Our stochastic use of emissions data from O&G facilities, along with activity-pattern exposure modeling, provides new information on potential public-health impacts due to emissions from O&G operations. The results will help in evaluating the adequacy of O&G setback distances. For an assessment of human-health risks from exposures to air emissions near individual O&G sites, we have utilized a unique dataset of tracer-derived emissions of VOCs detected at such sites in two regions of intense oil-and-gas development in Colorado. We have coupled these emission stochastically with local meteorological data and population and time-activity data to estimate the potential for acute, subchronic, and chronic exposures above health-criteria levels due to air emissions near individual sites. These results, along with other pertinent health and exposure data, can be used to inform setback distances to protect public health.

Unconventional natural gas development and adverse birth outcomes in Pennsylvania: The potential mediating role of antenatal anxiety and depression

BACKGROUND

Studies have reported associations between unconventional natural gas development (UNGD) and adverse birth outcomes. None have evaluated potential mediating mechanisms.

OBJECTIVES

To evaluate associations between (1) UNGD and antenatal anxiety and depression and (2) antenatal anxiety and depression and preterm birth (<37 weeks gestation) and reduced term birth weight, (3) stochastic direct and indirect effects of UNGD on preterm birth and term birth weight operating through antenatal anxiety and depression, and (4) effect modification by family-level socioeconomic status.

METHODS

This retrospective cohort study included mothers without prevalent anxiety or depression at time of conception, who delivered at Geisinger in Pennsylvania between January 2009-January 2013. We assembled phase-specific UNGD activity data from public sources. Mothers were categorized as exposed (quartile 4) or unexposed (quartiles 1-3) based on average daily inverse distance-squared UNGD activity metric between conception and the week prior to anxiety or depression (cases) or the pregnancy-average daily metric (non-cases). We estimated associations with a doubly robust estimator (targeted minimum loss-based estimation) and adjusted for potential individual- and community-level confounding variables.

RESULTS

Analyses included 8,371 births to 7,715 mothers, 12.2% of whom had antenatal anxiety or depression. We found 4.3 additional cases of antenatal anxiety or depression per 100 women (95% CI: 1.5, 7.0) under the scenario where all mothers lived in the highest quartile of UNGD activity versus quartiles 1-3. The risk difference appeared larger among mothers receiving Medical Assistance (indicator of low family income) compared to those who did not, 5.6 (95% CI: 0.5, 10.6) versus 2.9 (95% CI: -0.7, 6.5) additional cases of antenatal anxiety or depression per 100 women. We found no relationship between antenatal anxiety or depression and adverse birth outcomes and no mediation effect either overall or when stratifying by Medical Assistance.

CONCLUSION

We observed a relationship between UNGD activity and antenatal anxiety and depression, which did not mediate the overall association between UNGD activity and adverse birth outcomes.

Assessing exposure to unconventional natural gas development: using an air pollution dispersal screening model to predict new-onset respiratory symptoms

Various exposure estimates have been used to assess health impact of unconventional natural gas development (UNGD). The purpose of this study was to (1) use an air pollution dispersal screening model and wind direction to characterize the air emissions from UNGD facilities at each residence and (2) assess association of this exposure estimate with respiratory symptoms. Respiratory symptoms were abstracted from health records of a convenience sample of 104 adults from one county in southwestern PA who had completed a standard clinical interview with a nurse practitioner. Using publicly available air emission data, we applied a "box" air pollution dispersion screening model to estimate the median ambient air level of CO, NO_x, PM 2.5, VOCs, and formaldehyde at the residence during the year health symptoms were reported. Sources and median emissions were categorized as north, south, east, or west of the residence to account for the effect of wind direction on dispersion. Binary logistic regression was performed for each respiratory symptom. Number of sources had varying magnitudes of association with some symptoms (i.e., cough, shortness of breath, and "any respiratory symptom") and no association with others (i.e., sore throat, sinus problems, wheezing). Air emissions were not associated with any symptom.

Assessing Agreement in Exposure Classification between Proximity-Based Metrics and Air Monitoring Data in Epidemiology Studies of Unconventional Resource Development

Recent studies of unconventional resource development (URD) and adverse health effects have been limited by distance-based exposure surrogates. Our study compared exposure classifications between air pollutant concentrations and “well activity” (WA) metrics, which are distance-based exposure proxies used in Marcellus-area studies to reflect variation in time and space of residential URD activity. We compiled Pennsylvania air monitoring data for benzene, carbon monoxide, nitrogen dioxide, ozone, fine particulates and sulfur dioxide, and combined this with data on nearly 9000 Pennsylvania wells. We replicated WA calculations using geo-coordinates of monitors to represent residences and compared exposure categories from air measurements and WA at the site of each monitor. There was little agreement between the two methods for the pollutants included in the analysis, with most weighted kappa coefficients between −0.1 and 0.1. The exposure categories agreed for about 25% of the observations and assigned inverse categories 16%–29% of the time, depending on the pollutant. Our results indicate that WA measures did not adequately distinguish categories of air pollutant exposures and employing them in epidemiology studies can result in misclassification of exposure. This underscores the need for more robust exposure assessment in future analyses and cautious interpretation of these existing studies.

Environmental Justice in Unconventional Oil and Natural Gas Drilling and Production: A Critical Review and Research Agenda

The drilling phase of oil and natural gas development is a growing area of environmental justice (EJ) research, particularly in the United States. Its emergence complements the longstanding EJ scholarship on later phases of the oil and gas commodity chain, such as pipeline transport, refining, and consumption. The growing scholarly attention to the EJ implications of drilling has been prompted by the surge in development of unconventional oil and gas resources in recent decades. More specifically, the oil and gas industry's adoption of horizontal drilling and hydraulic fracturing (a.k.a., "fracking" or "fracing") as methods for extracting oil and gas from a wider range of geologic formations has simultaneously heightened oil and gas production, brought extractive activities closer to more people, intensified them, and made well pad siting more flexible. Here, we provide a critical review of the novel EJ research questions that are being prompted by these on-the-ground changes in extractive techniques and patterns, propose an interdisciplinary conceptual framework for guiding EJ inquiry in this context, discuss key methodological considerations, and propose a research agenda to motivate future inquiry.

Community Noise and Air Pollution Exposure During the Development of a Multi-Well Oil and Gas Pad

Unconventional oil and gas development (UOGD) in the United States is increasingly being conducted on multiwell pads (MWPs) and in residential areas. We measured air pollution, noise, and truck traffic during four distinct phases of UOGD: drilling, hydraulic fracturing, flowback, and production. We monitored particulate matter (PM_2.5), black carbon (BC), A-weighted (dBA), and C-weighted (dBC) noise using real-time instruments on 1 and 5 min time scales, and truck traffic for 4-7 days per phase at a large 22-well pad sited in a residential area of Weld County, Colorado. Hydraulic fracturing, which requires frequent truck trips to move supplies and diesel engines to power the process, had the highest median air pollution levels of PM_2.5 and BC and experienced the greatest number of heavy trucks per hour compared to other phases. Median air pollution was lowest during drilling at this MWP, possibly because an electric drill rig was used. The equivalent continuous noise level ( L_eq) exceeded guidelines of 50 dBA and 65 dBC for A-weighted and C-weighted noise, respectively, during all development phases. Our data show that these multiple stressors are present around the clock at these sites, and this work provides baseline measurements on likely human exposure levels near similarly sized MWPs.

A Systematic Review of the Epidemiologic Literature Assessing Health Outcomes in Populations Living near Oil and Natural Gas Operations: Study Quality and Future Recommendations

A systematic method was used to review the existing epidemiologic literature and determine the state of the scientific evidence for potential adverse health outcomes in populations living near oil and natural gas (ONG) operations in the United States. The review utilized adapted systematic review frameworks from the medical and environmental health fields, such as Grading of Recommendations, Assessment, Development and Evaluations (GRADE), the Navigation Guide, and guidance from the National Toxicology Program’s Office of Health Assessment and Translation (OHAT). The review included 20 epidemiologic studies, with 32 different health outcomes. Studies of populations living near ONG operations provide limited evidence (modest scientific findings that support the outcome, but with significant limitations) of harmful health effects including asthma exacerbations and various self-reported symptoms. Study quality has improved over time and the highest rated studies within this assessment have primarily focused on birth outcomes. Additional high-quality studies are needed to confirm or dispute these correlations.

Air Emissions from Natural Gas Facilities in New York State

While New York has banned fracking, new and expanded natural gas pipelines are being constructed across the state. Our previous studies have reported that compressor stations are a major source of air pollution at fracking sites. We have used two federal datasets, the U.S. Environmental Protection Agency's (EPA) National Emissions Inventory and Greenhouse Gas Inventory, to determine what is known concerning emissions from the compressor stations along natural gas pipelines in the state. From a total of 74 compressor stations only 18 report to EPA on emissions. In the seven year period between 2008 and 2014 they released a total of 36.99 million pounds of air pollutants, not including CO₂ and methane. This included emissions of 39 chemicals known to be human carcinogens. There was in addition 6.1 billion pounds of greenhouse gases release from ten stations in a single year. These data clearly underestimate the total releases from the state's natural gas transportation and distribution system. However, they demonstrate significant releases of air pollutants, some of which are known to cause human disease. In addition, they release large amounts of greenhouse gases that contribute to climate change.

Relationships between indicators of cardiovascular disease and intensity of oil and natural gas activity in Northeastern Colorado

BACKGROUND

Oil and natural gas (O&G) extraction emits pollutants that are associated with cardiovascular disease, the leading cause of mortality in the United States.

OBJECTIVE

We evaluated associations between intensity of O&G activity and cardiovascular disease indicators.

METHODS

Between October 2015 and May 2016, we conducted a cross-sectional study of 97 adults living in Northeastern Colorado. For each participant, we collected 1-3 measurements of augmentation index, systolic and diastolic blood pressure (SBP and DBP), and plasma concentrations of interleukin (IL)- 1β, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α). We modelled the intensity of O&G activity by weighting O&G well counts within 16 km of a participant's home by intensity and distance. We used linear models accounting for repeated measures within person to evaluate associations.

RESULTS

Adjusted mean augmentation index differed by 6.0% (95% CI: 0.6, 11.4%) and 5.1% (95%CI: -0.1, 10.4%) between high and medium, respectively, and low exposure tertiles. The greatest mean IL-1β, and α-TNF plasma concentrations were observed for participants in the highest exposure tertile. IL-6 and IL-8 results were consistent with a null result. For participants not taking prescription medications, the adjusted mean SBP differed by 6 and 1 mm Hg (95% CIs: 0.1, 13 mm Hg and -6, 8 mm Hg) between the high and medium, respectively, and low exposure tertiles. DBP results were similar. For participants taking prescription medications, SBP and DBP results were consistent with a null result.

CONCLUSIONS

Despite limitations, our results support associations between O&G activity and augmentation index, SBP, DBP, IL-1β, and TNF-α. Our study was not able to elucidate possible mechanisms or environmental stressors, such as air pollution and noise.

Characterizing Flaring from Unconventional Oil and Gas Operations in South Texas Using Satellite Observations

Over the past decade, increases in high-volume hydraulic fracturing for oil and gas extraction in the United States have raised concerns with residents living near wells. Flaring, or the combustion of petroleum products into the open atmosphere, is a common practice associated with oil and gas exploration and production, and has been under-examined as a potential source of exposure. We leveraged data from the Visible Infrared Imaging Spectroradiometer (VIIRS) Nightfire satellite product to characterize the extent of flaring in the Eagle Ford Shale region of south Texas, one of the most productive in the nation. Spatiotemporal hierarchical clustering identified flaring sources, and a regression-based approach combining VIIRS information with reported estimates of vented and flared gas from the Railroad Commission of Texas enabled estimation of flared gas volume at each flare. We identified 43887 distinct oil and gas flares in the study region from 2012 to 2016, with a peak in activity in 2014 and an estimated 4.5 billion cubic meters of total gas volume flared over the study period. A comparison with well permit data indicated the majority of flares were associated with oil-producing (82%) and horizontally drilled (92%) wells. Of the 49 counties in the region, 5 accounted for 71% of the total flaring. Our results suggest flaring may be a significant environmental exposure in parts of this region.

Unconventional natural gas development and hospitalizations: evidence from Pennsylvania, United States, 2003-2014

OBJECTIVES

To examine relationships between short-term and long-term exposures to unconventional natural gas development, commonly known as fracking, and county hospitalization rates for a variety of broad disease categories.

STUDY DESIGN

This is an ecological study based on county-level data for Pennsylvania, United States, 2003-2014.

METHODS

We estimated multivariate regressions with county and year fixed effects, using two 12-year panels: all 67 Pennsylvania counties and 54 counties that are not large metropolitan.

RESULTS

After correcting for multiple comparisons, we found a positive association of cumulative well density (per km²) with genitourinary hospitalization rates. When large metropolitan counties were excluded, this relationship persisted, and positive associations of skin-related hospitalization rates with cumulative well count and well density were observed. The association with genitourinary hospitalization rates is driven by females in 20-64 years group, particularly for kidney infections, calculus of ureter, and urinary tract infection. Contemporaneous wells drilled were not significantly associated with hospitalizations after adjustment for multiple comparisons.

CONCLUSIONS

Our study shows that long-term exposure to unconventional gas development may have an impact on prevalence of hospitalizations for certain diseases in the affected populations and identifies areas of future research on unconventional gas development and health.

Residential noise from nearby oil and gas well construction and drilling

Public concern about oil and gas (O&G) operations in residential areas is substantial. Noise from construction and drilling related to O&G operations may be greater than other phases of O&G operations; yet the impacts of audible and low-frequency noise during these operations are not extensively explored nor the effects on health well understood. This study documents the noise levels at a multi-well O&G well pad during construction and drilling in a residential area in Colorado. A-weighted (dBA) and C-weighted (dBC) noise measurements were collected at four locations during development over a 3-month period. The maximum 1-min equivalent continuous sound levels over a 1-month period were 60.2 dBA and 80.0 dBC. Overall, 41.1% of daytime and 23.6% of nighttime dBA 1-min equivalent continuous noise measurements were found to exceed 50 dBA, and 97.5% of daytime and 98.3% of nighttime measurements were found to exceed 60 dBC. Noise levels exceeding 50 dBA or 60 dBC may cause annoyance and be detrimental to health; thus, these noise levels have the potential to impact health and noise levels and associated health effects warrant further investigation.

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 (r_Spearman: -0.40 to -0.44) and with concentrations of bromoform and dibromochloromethane in surface water (r_Spearman: -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.

Environmental and individual PAH exposures near rural natural gas extraction

Natural gas extraction (NGE) has expanded rapidly in the United States in recent years. Despite concerns, there is little information about the effects of NGE on air quality or personal exposures of people living or working nearby. Recent research suggests NGE emits polycyclic aromatic hydrocarbons (PAHs) into air. This study used low-density polyethylene passive samplers to measure concentrations of PAHs in air near active (n = 3) and proposed (n = 2) NGE sites. At each site, two concentric rings of air samplers were placed around the active or proposed well pad location. Silicone wristbands were used to assess personal PAH exposures of participants (n = 19) living or working near the sampling sites. All samples were analyzed for 62 PAHs using GC-MS/MS, and point sources were estimated using the fluoranthene/pyrene isomer ratio. ∑PAH was significantly higher in air at active NGE sites (Wilcoxon rank sum test, p < 0.01). PAHs in air were also more petrogenic (petroleum-derived) at active NGE sites. This suggests that PAH mixtures at active NGE sites may have been affected by direct emissions from petroleum sources at these sites. ∑PAH was also significantly higher in wristbands from participants who had active NGE wells on their properties than from participants who did not (Wilcoxon rank sum test, p < 0.005). There was a significant positive correlation between ∑PAH in participants' wristbands and ∑PAH in air measured closest to participants' homes or workplaces (simple linear regression, p < 0.0001). These findings suggest that living or working near an active NGE well may increase personal PAH exposure. This work also supports the utility of the silicone wristband to assess personal PAH exposure.

Unconventional natural gas development and pediatric asthma hospitalizations in Pennsylvania

BACKGROUND

Pediatric asthma is a common chronic condition that can be exacerbated by environmental exposures, and unconventional natural gas development (UNGD) has been associated with decreased community air quality. This study aims to quantify the association between UNGD and pediatric asthma hospitalizations.

METHODS

We compare pediatric asthma hospitalizations among zip codes with and without exposure to UNGD between 2003 and 2014 using a difference-in-differences panel analysis. Our UNGD exposure metrics include cumulative and contemporaneous drilling as well as reported air emissions by site.

RESULTS

We observed consistently elevated odds of hospitalizations in the top tertile of pediatric patients exposed to unconventional drilling compared with their unexposed peers. During the same quarter a well was drilled, we find a 25% increase (95% CI: 1.07, 1.47) in the odds of being hospitalized for asthma. Ever-establishment of an UNGD well within a zip code was associated with a 1.19 (95% CI: 1.04, 1.36) increased odds of a pediatric asthma hospitalization. Our results further demonstrate that increasing specific air emissions from UNGD sites are associated with increased risks of pediatric asthma hospitalizations (e.g. 2,2,4-trimethylpentane, formaldehyde, x-hexane). These results hold across multiple age groups and sensitivity analyses.

CONCLUSIONS

Community-level UNGD exposure metrics were associated with increased odds of pediatric asthma-related hospitalization among young children and adolescents. This study provides evidence that additional regulations may be necessary to protect children's respiratory health from UNGD activities.

The pertinence of Sutton's law to exposure science: Lessons from unconventional shale gas drilling

Sutton's Law urges the medical practitioner to utilize the test that goes directly to the problem. When applied to exposure science, Sutton's Law would argue that the major emphasis should be on techniques that directly measure exposure in or close to the human, animal or ecosystem receptors of concern. Exposure science largely and appropriately violates Sutton's Law by estimating exposure based on information on emissions or measurements obtained at a distance from the receptors of concern. I suggest four criteria to help determine whether Sutton's law should be violated for an innovative technology, and explore these criteria in relation to potential human exposure resulting from unconventional gas drilling (UGD): (1) The technological processes possibly leading to release of the chemical or physical agents of concern are reasonably understood; (2) the agents of concern are known; (3) the source and geographical location of the releases can be reasonably identified; and (4) there is information about the likely temporal pattern of the releases and resulting pollutant levels in relation to the temporal patterns of receptor susceptibility. For UGD, the complexity of the technology including many possible release points at different time periods; the existence of three variable mixtures of chemical and physical agents as well as possible unknown reactants; the demonstrated large variation in releases from site to site; and deficiencies in transparency and regulatory oversight, all suggest that studies of the potential health impact of UGD should follow Sutton's Law. This includes the use of techniques that more directly measure exposure close to or within the receptors of concern, such as biological markers or through community-based citizen science. Understanding the implications of Sutton's Law could help focus scientific and regulatory efforts on effective approaches to evaluate the potential health and ecosystem implications of new and evolving technologies.

Shale gas development and infant health: Evidence from Pennsylvania

This research exploits the introduction of shale gas wells in Pennsylvania in response to growing controversy around the drilling method of hydraulic fracturing. Using detailed location data on maternal addresses and GIS coordinates of gas wells, this study examines singleton births to mothers residing close to a shale gas well from 2003 to 2010 in Pennsylvania. The introduction of drilling increased low birth weight and decreased term birth weight on average among mothers living within 2.5 km of a well compared to mothers living within 2.5 km of a permitted well. Adverse effects were also detected using measures such as small for gestational age and APGAR scores, while no effects on gestation periods were found. In the intensive margin, an additional well is associated with a 7 percent increase in low birth weight, a 5 g reduction in term birth weight and a 3 percent increase in premature birth. These results are robust to other measures of infant health, many changes in specification and falsification tests. These findings suggest that shale gas development poses significant risks to human health.

Setback distances for unconventional oil and gas development: Delphi study results

Emerging evidence indicates that proximity to unconventional oil and gas development (UOGD) is associated with health outcomes. There is intense debate about "How close is too close?" for maintaining public health and safety. The goal of this Delphi study was to elicit expert consensus on appropriate setback distances for UOGD from human activity. Three rounds were used to identify and seek consensus on recommended setback distances. The 18 panelists were health care providers, public health practitioners, environmental advocates, and researchers/scientists. Consensus was defined as agreement of ≥70% of panelists. Content analysis of responses to Round 1 questions revealed four categories: recommend setback distances; do not recommend setback distances; recommend additional setback distances for vulnerable populations; do not recommend additional setback distances for vulnerable populations. In Round 2, panelists indicated their level of agreement with the statements in each category using a five-point Likert scale. Based on emerging consensus, statements within each category were collapsed into seven statements for Round 3: recommend set back distances of <¼ mile; ¼-½ mile; 1-1 ¼ mile; and ≥ 2 mile; not feasible to recommend setback distances; recommend additional setbacks for vulnerable groups; not feasible to recommend additional setbacks for vulnerable groups. The panel reached consensus that setbacks of < ¼ mile should not be recommended and additional setbacks for vulnerable populations should be recommended. The panel did not reach consensus on recommendations for setbacks between ¼ and 2 miles. The results suggest that if setbacks are used the distances should be greater than ¼ of a mile from human activity, and that additional setbacks should be used for settings where vulnerable groups are found, including schools, daycare centers, and hospitals. The lack of consensus on setback distances between 1/4 and 2 miles reflects the limited health and exposure studies and need to better define exposures and track health.

Longitudinal evaluation of clustering of chronic sinonasal and related symptoms using exploratory factor analysis

BACKGROUND

Sinonasal symptoms are common and can have several underlying causes. When symptoms occur in specified patterns lasting 3 months or more they meet criteria for chronic rhinosinusitis (CRS). Approaches to CRS symptom measurement do not specify how to measure symptoms and treat specified sinonasal symptoms as generally interchangeable, suggesting that such symptoms should cluster on 1 or 2 latent factors.

METHODS

We used questionnaire responses to 37 questions on the presence, severity, bother, and frequency of cardinal sinonasal and related symptoms lasting 3 months, from 3535 subjects at 3 time points over 16 months. We completed 5 exploratory factor analyses (EFA) to identify symptom clustering, 1 for each time point and 2 for the differences between adjacent questionnaires. The baseline EFA was used to provide factor scores that were described longitudinally and examined by CRS status.

RESULTS

Five EFAs identified the same 5 factors (blockage and discharge, pain and pressure, asthma and cold/flu symptoms, smell loss, and ear and eye [mainly allergy] symptoms), with clustering determined by symptom frequency, severity, and degree of bother. Responses to individual questions showed changes over time but when combined into factor scores showed less longitudinal change. All symptom factor scores were progressively higher from never to past to current CRS status.

CONCLUSIONS

Although the current approaches to symptom characterization in CRS imply a single underlying latent construct, our results suggest that there are at least 3 latent constructs relevant to CRS. Further studies are needed to evaluate whether these clusters have identifiable underlying pathobiologies.

Associations of unconventional natural gas development with depression symptoms and disordered sleep in Pennsylvania

Environmental and community factors may influence the development or course of depression and sleep problems. We evaluated the association of unconventional natural gas development (UNGD) with depression symptoms and disordered sleep diagnoses using the Patient Health Questionnaire-8 and electronic health record data among Geisinger adult primary care patients in Pennsylvania. Participants received a retrospective metric for UNGD at their residence (very low, low, medium, and high) that incorporated dates and durations of well development, distance from patient homes to wells, and well characteristics. Analyses included 4,762 participants with no (62%), mild (23%), moderate (10%), and moderately severe or severe (5%) depression symptoms in 2014-2015 and 3,868 disordered sleep diagnoses between 2009-2015. We observed associations between living closer to more and bigger wells and depression symptoms, but not disordered sleep diagnoses in models weighted to account for sampling design and participation. High UNGD (vs. very low) was associated with depression symptoms in an adjusted negative binomial model (exponentiated coefficient = 1.18, 95% confidence interval [CI]: 1.04-1.34). High and low UNGD (vs. very low) were associated with depression symptoms (vs. none) in an adjusted multinomial logistic model. Our findings suggest that UNGD may be associated with adverse mental health in Pennsylvania.

Exposures and Health Risks from Volatile Organic Compounds in Communities Located near Oil and Gas Exploration and Production Activities in Colorado (U.S.A.)

The study objective was to use a preliminary risk based framework to evaluate the sufficiency of existing air data to answer an important public health question in Colorado: Do volatile organic compounds (VOCs) emitted into the air from oil and gas (OG) operations result in exposures to Coloradoans living at or greater than current state setback distances (500 feet) from OG operations at levels that may be harmful to their health? We identified 56 VOCs emitted from OG operations in Colorado and compiled 47 existing air monitoring datasets that measured these VOCs in 34 locations across OG regions. From these data, we estimated acute and chronic exposures and compared these exposures to health guideline levels using maximum and mean air concentrations. Acute and chronic non-cancer hazard quotients were below one for all individual VOCs. Hazard indices combining exposures for all VOCs were slightly above one. Lifetime excess cancer risk estimates for benzene were between 1.0 × 10⁻⁵–3.6 × 10⁻⁵ and ethylbenzene was 7.3 × 10⁻⁶. This evaluation identified a small sub-set of VOCs, including benzene and n-nonane, which should be prioritized for additional exposure characterization in site-specific studies that collect comprehensive time-series measurements of community scale exposures to better assess community exposures.

Prevalence, severity, and risk factors for acute exacerbations of nasal and sinus symptoms by chronic rhinosinusitis status

BACKGROUND

Nasal and sinus symptoms (NSS) are common to many health conditions, including chronic rhinosinusitis (CRS). Few studies have investigated the occurrence and severity of, and risk factors for, acute exacerbations of NSS (AENSS) by CRS status (current, past, or never met European Position Paper on Rhinosinusitis [EPOS] criteria for CRS).

METHODS

Four seasonal questionnaires were mailed to a stratified random sample of Geisinger primary care patients. Logistic regression was used to identify individual characteristics associated with AENSS occurrence and severity by CRS status (current long-term, current recent, past, never) using EPOS subjective symptoms-only (EPOSS ) CRS criteria. We operationalized 3 AENSS definitions based on prescribed antibiotics or oral corticosteroids, symptoms, and symptoms with purulence.

RESULTS

Baseline and at least 1 follow-up questionnaires were available from 4736 subjects. Self-reported NSS severity with exacerbation was worst in the current long-term CRS group. AENSS was common in all subgroups examined and generally more common among those with current EPOSS CRS. Seasonal prevalence of AENSS differed by AENSS definition and CRS status. Associations of risk factors with AENSS differed by definition, but CRS status, body mass index, asthma, hay fever, sinus surgery history, and winter season consistently predicted AENSS.

CONCLUSIONS

In this first longitudinal, population-based study of 3 AENSS definitions, NSS and AENSS were both common, sometimes severe, and differed by EPOSS CRS status. Contrasting associations of risk factors for AENSS by the different definitions suggest a need for a standardized approach to definition of AENSS.

Exposure Assessment Using Secondary Data Sources in Unconventional Natural Gas Development and Health Studies

Studies of unconventional natural gas development (UNGD) and health have ranked participants along a gradient of geographic information system (GIS)-based activity that incorporated the distance between participants' home addresses and unconventional natural gas wells. However, studies have used different activity metrics, making result comparisons across the studies difficult. The existing studies have only incorporated wells, without accounting for other components of development (e.g., compressors, impoundments, and flaring events), for which it is often difficult to obtain reliable data but may have relevance to health. Our aims were to (1) describe, in space and time, UNGD-related compressors, impoundments, and flaring events; (2) evaluate whether and how to incorporate these into UNGD activity assessment; and (3) evaluate associations of these different approaches with mild asthma exacerbations. We identified 361 compressor stations, 1218 impoundments, and 216 locations with flaring events. A principal component analysis identified a single component that was approximately an equal mix of the metrics for compressors, impoundments, and four phases of well development (pad preparation, drilling, stimulation, and production). However, temporal coverage for impoundments and flaring data was sparse. Ultimately, we evaluated three UNGD activity metrics, including two based on the existing studies and a novel metric that included well pad development, drilling, stimulation, production, and compressor engine aspects of UNGD. The three metrics had varying magnitudes of association with mild asthma exacerbations, although the highest category of each metric (vs the lowest) was associated with the outcome.