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

Background: Unconventional natural gas development (UNGD) produces environmental contaminants and psychosocial stressors. Despite these concerns, few studies have evaluated the health effects of UNGD. Objectives: We investigated associations between UNGD activity and symptoms in a cross-sectional study in Pennsylvania. Methods: We mailed a self-administered questionnaire to 23,700 adult patients of the Geisinger Clinic. Using standardized and validated questionnaire items, we identified respondents with chronic rhinosinusitis (CRS), migraine headache, and fatigue symptoms. We created a summary UNGD activity metric that incorporated well phase, location, total depth, daily gas production and inverse distance–squared to patient residences. We used logistic regression, weighted for sampling and response rates, to assess associations between quartiles of UNGD activity and outcomes, both alone and in combination. Results: The response rate was 33%. Of 7,785 study participants, 1,850 (24%) had current CRS symptoms, 1,765 (23%) had migraine headache, and 1,930 (25%) had higher levels of fatigue. Among individuals who met criteria for two or more outcomes, adjusted odds ratios for the highest quartile of UNGD activity compared with the lowest were [OR (95% CI)] 1.49 (0.78, 2.85) for CRS plus migraine, 1.88 (1.08, 3.25) for CRS plus fatigue, 1.95 (1.18, 3.21) for migraine plus fatigue, and 1.84 (1.08, 3.14) for all three outcomes together. Significant associations were also present in some models of single outcomes. Conclusions: This study provides evidence that UNGD is associated with nasal and sinus, migraine headache, and fatigue symptoms in a general population representative sample. Citation: Tustin AW, Hirsch AG, Rasmussen SG, Casey JA, Bandeen-Roche K, Schwartz BS. 2017. Associations between unconventional natural gas development and nasal and sinus, migraine headache, and fatigue symptoms in Pennsylvania. Environ Health Perspect 125:189–197; http://dx.doi.org/10.1289/EHP281


Models of past disease and moderate symptoms
. Stratified survey design, response frequencies, and sampling weights Table S2. Associations of UNGD with current CRS, stratified by date of symptom onset Table S3. Sensitivity analysis of the effects of sampling weights on associations between UNGD and symptoms Table S4. Sensitivity analysis of different time averaging periods for UNGD activity Table S5. Associations of UNGD with past CRS and moderate levels of fatigue Table S6. Selected characteristics of individuals in the fourth quartile of UNGD, compared to those in other quartiles Table S7. Effect of place type (township, borough, or census tract in city) on associations of UNGD with symptoms

Models of Past Disease and Moderate Symptoms
In our primary analysis, 2889 study participants were classified as neither cases nor controls.
These individuals did not meet case criteria and were excluded from the reference group because of past CRS, intermediate likelihood of migraine headache, and/or moderate fatigue symptoms.
In a sensitivity analysis, we created two logistic regression models in which we re-classified some of these excluded individuals as cases. The purpose of this analysis was to determine whether UNGD was associated with less severe or past symptoms. In the first model ("past CRS"), the case group comprised all study participants who met criteria for past CRS (as defined in the main text) but who did not meet criteria for migraine headache or higher levels of fatigue (n = 1238). In the second model ("moderate fatigue"), cases were all individuals with moderate levels of fatigue (defined as the third quartile of fatigue; 19 ≤ fatigue score < 28) but who did not meet criteria for current CRS or migraine headache (n = 1132). Both models compared cases to the reference group, described in the main text, of individuals with no past or current CRS, no migraine headache symptoms, and lower levels of fatigue (n = 1380). Both models were adjusted for sex, race/ethnicity (non-Hispanic white vs. other), age (linear and quadratic terms), receipt of Medical Assistance (never vs. ever), and smoking status (never vs. former and current). In addition, the past CRS model was adjusted for centered body mass index. Based on EHR data, we stratified the source population by race/ethnicity and prior probability of having CRS. We then oversampled racial/ethnic minorities and individuals more likely to have CRS. a Excludes respondents with residential addresses outside Pennsylvania (n = 62). b Sampling weights were calculated by dividing the total number of individuals identified in the stratum by the number of survey respondents. Models compared individuals with current CRS (and no other primary outcome) to a reference group with no current or past CRS, no migraine headache symptoms, and lower levels of fatigue.
Models used sampling weights to account for the stratified survey design and response rates. The highest weight was truncated to the value of the second-highest weight. Models included these covariates: sex, race/ethnicity (white non-Hispanic vs. other), centered age (years), square of centered age, Medical Assistance (never vs. ever), smoking status (never vs. current and former), and centered body mass index. Individuals with unknown body mass index were excluded. Participants with current CRS were excluded from this analysis if their questionnaire responses did not provide enough information for us to determine whether their date of CRS onset occurred before or after January 1, 2006. UNGD activity was averaged over the 90 days prior to the survey. Abbreviations: UNGD, unconventional natural gas development; CRS, chronic rhinosinusitis.
Each model compared individuals with symptoms to a reference group with no current or past CRS, no migraine headache symptoms, and lower levels of fatigue. Models included these covariates: sex, race/ethnicity (white non-Hispanic vs. other), centered age (years), square of centered age, Medical Assistance (never vs. ever), and smoking status (never vs. current and former). UNGD activity was averaged over the 90 days prior to the survey. a These models also included centered body mass index. Because individuals with unknown body mass index were excluded, these case counts are slightly lower than those reported in the main text. Abbreviations: UNGD, unconventional natural gas development; CRS, chronic rhinosinusitis.
In all models, the reference group consisted of individuals with no current or past CRS, no migraine headache symptoms, and lower levels of fatigue. All models used sampling weights to account for the stratified survey design and response rates. The highest sampling weight was truncated to the value of the second-highest weight. All models included these covariates: sex, race/ethnicity (white non-Hispanic vs. other), centered age (years), square of centered age, Medical Assistance (never vs. ever), smoking status (never vs. current and former). a These models included centered body mass index. Because individuals with missing body mass index were excluded, these case counts are slightly lower than those reported in the main text. The reference group for both models consisted of individuals with no current or past CRS, no migraine headache symptoms, and lower levels of fatigue. Models used sampling weights to account for the stratified survey design and response rates. The highest sampling weight was truncated to the value of the second-highest weight. Both models included these covariates: sex, race/ethnicity (white non-Hispanic vs. other), centered age (years), square of centered age, Medical Assistance (never vs. ever), smoking status (never vs. current and former). In addition, the past CRS model included centered body mass index.  Abbreviations: UNGD, unconventional natural gas development; CRS, chronic rhinosinusitis. Covariates in the base model were sex, race/ethnicity, centered age (linear and quadratic terms), smoking status, Medical Assistance. CRS models also included centered body mass index. The reference group for all models consisted of individuals with no current or past CRS, no migraine headache symptoms, and lower levels of fatigue. All models used sampling weights, and the highest weight was reduced to the value of the second-highest weight.