Upon completion of training and patient confidentiality agreements, DHA provided access to electronic health records (EHRs) within the Military Health System (MHS) GENESIS and Joint Legacy Viewer systems at Tripler Army Medical Center. A roster of 28,601 persons served by the contaminated water source during the exposure window of November 20, 2021–March 18, 2022, was obtained from the DHA’s Defense Occupational and Environmental Health Readiness System (DOEHRS).⁹ We then selected from 4 nonmutually exclusive subgroups of persons on the roster who sought care through the military health network, including persons with International Classification of Diseases, tenth revision (ICD-10) diagnosis codes for toxic effects,^a persons with ICD-10 codes of clinical interest,^b persons with pregnancy-related ICD-10 codes from visits during November 20, 2021 to June 18, 2022, and persons with multiple (>2) clinic visits during the study period (November 20, 2021–February 24, 2023). In total, we completed full medical chart abstraction on 653 persons.¹⁰

Descriptive analyses were conducted to examine reported mental health conditions among individuals potentially exposed to jet fuel-contaminated water. To provide appropriate descriptive statistics for this public health investigation, we abstracted deidentified data from medical records including demographic information, medical history, laboratory tests, imaging, medications, referrals, and visit summaries. We reviewed charts and categorized all symptoms and conditions, including those related to mental health (Table 2), for adults aged >18 years using the following case definitions: (1) “preexisting and unchanged” if documented before November 20, 2021, and considered stable; (2) “worsening preexisting” if documented as present before November 20, 2021, with evidence of worsening in >2 medical visits after November 20, 2021; (3) “persistent new” if documented on or after November 20, 2021, and lasting ≥3 months; or, (4) “acute” if first documented on or after November 20, 2021, and resolved <3 months. These definitions are not mutually exclusive; patients could be represented in more than one category based on symptoms or conditions reflected in the medical records. We recorded frequency of referrals to psychiatry, behavioral health, and other mental health-related specialties. We also assessed mental health medication use through active medication lists in the EHR during the year before November 20, 2021, and the period after November 20, 2021, through February 24, 2023, among the entire sample of adult persons. Medications were grouped together by pharmacological class. Medications were included only if they had an indication for mental health use, such as antihistamines used for anxiety. We designed a survey in REDCap to collect medical chart abstraction data. SAS^® v9.4 (SAS Institute, Inc., Cary, North Carolina) was used for data cleaning and analysis.

This activity was reviewed by CDC, deemed not research, and was conducted consistent with applicable federal law and CDC policy (45 C.F.R. part 46.102(l)(2), 21 C.F.R. part 56; 42 U.S.C. §241(d); 5 U.S.C. §552a; 44 U.S.C. §3501 et seq.); consenting was not required under Department of Defense Manual 6025.18.

We completed full medical chart abstraction for 653 of the 28,601 persons identified on the DOEHRS roster.¹⁰ The mental health analysis was limited to adults aged ≥18 years (n = 411) within this cohort (Table 1). Pediatric patients (n = 242) were excluded from the mental health analysis. The majority were female (n = 245; 59.6%), White race (n = 217; 52.8%), and non-Hispanic (n = 273; 66.4%). Based on available beneficiary data, 40.1% (n = 165) were active-duty military service members, 44.3% (n = 182) were dependents, and the remaining 15.6% (n = 64) included military reservists or guardsmen, civilian employees, retirees, or were of unknown beneficiary status. In total, 123 adults (29.9%) had at least ≥1 worsening preexisting mental health condition or symptom; 86 adults (20.9%) had ≥1 persistent new mental health condition or symptom during the study period. These classifications are not mutually exclusive. Demographic data can be found in the supplemental table.

The most documented worsening preexisting mental health conditions were anxiety disorders (n = 37; 9%), depressive disorders (n = 14; 3.4%), and sleep disorders (including insomnia) (n = 12; 2.9%) (Table 1). The most common worsening preexisting mental health symptoms were related to anxiety (n = 38; 9.2%), depression, low mood, or anhedonia (n = 21; 5.1%), and sleep difficulty (n = 15; 3.6%). Significant mental health conditions documented as persistent new conditions included adjustment disorders (n = 17; 4.1%) and anxiety disorders (n = 8; 1.9%). The most documented persistent new mental health symptoms were related to anxiety (n = 19; 4.6%), depression, low mood, or anhedonia (n = 13; 3.2%), and stress (n = 11; 2.7%).

We also assessed mental health-related referrals documented in the medical records during the study period. Among the 411 adults, 68 (16.5%) received psychiatry referrals and 25 (6.1%) received consults for behavioral health or counseling. The behavioral health referrals also included consults to neuropsychology, mental health, and neuropsychiatry.

We reviewed 1,581 individual medications documented in the medical and pharmacy records of the 411 adults. Of those, 119 (29%) adults had ≥1 mental health-related medication documented at any time during the period reviewed, November 2020–February 2023, for a total of 237 prescriptions. A mean of 2 mental health medications per adult were prescribed, with a range of 1–7 medications per person. After the exposure event in November 2021, 109 (26.5%) adults had ≥1 mental health medication prescribed. In 13 of 16 reviewed mental health-related medication classes, more medications were prescribed after November 2021 than before (Table 2). Antipsychotic prescriptions increased from 0.2% to 1.5% of adults from November 2021 to February 2023. Antihistamine prescriptions for mental health increased from 0.5% to 2.9% of adults after the exposure event. Similarly, hormones used for sleep-related complaints (i.e., melatonin) and hypnotics increased in use from 0.2% to 1.0% and 0% to 2.2%, respectively, from November 2021 to February 2023. Atypical antidepressant prescriptions increased from 1.2% to 4.9% of adults. Serotonin-norepinephrine reuptake inhibitors (SNRIs) (1.2% vs 3.2%), selective serotonin reuptake inhibitors (SSRIs) (4.4% vs 8.5%), and serotonin antagonists (1.2% vs 2.2%) also increased in documented use during the 15 months after November 20, 2021. Thirteen medication records could not be classified because of missing start date information.

The November 2021 jet fuel leak and resulting drinking water contamination event disrupted the population using the JBPHH distribution system.¹¹ Our assessment found 29.9% of sampled adults had ≥1 preexisting mental health condition or symptom that worsened during the 15 months after the exposure event. Among preexisting and worsening conditions, we found that adjustment disorders, anxiety, depression, stress, and sleep disorders (insomnia or sleep difficulty) were most commonly documented.

Our analysis examined reported symptoms and diagnoses beyond the acute period of JP-5 exposure and found new mental health concerns persisting for ≥3 months in approximately 20% of adults sampled. Persistent new conditions commonly included adjustment disorders, fatigue or malaise, anxiety, depression, and stress. Our findings support previous community assessment results that reported persistent mental health symptoms in this potentially exposed population.⁸ The frequency of mental health referrals demonstrates the need for ongoing access to care and mental health services. The University of Hawaii and community partners have developed a third-party health registry to fully understand the long-term health effects on the population exposed to JP-5.¹²

We found certain classes of mental health medications were used more frequently after the jet fuel contamination incident, particularly antipsychotics, antidepressants, and sleep-related medications. This finding suggests that mental health symptoms may have become more prevalent following the contamination event.

We obtained data from chart reviews of adults sampled through DOEHRS who visited the clinic during the study period. Therefore, the sample might be susceptible to selection bias. These data did not capture personal experiences of those who chose to seek care outside the military medical system or who did not disclose their symptoms to military health care providers. Our findings are limited by a low selection rate, as we abstracted medical charts from 653 of the 28,601 (2.3%) persons identified on the DOEHRS roster and included 411 persons in the mental health study. We are unable to determine level of potential JP-5 exposure to individuals, and this study did not seek to determine causality of mental health effects. Psychosocial effects of the contamination event itself may have contributed to mental health concerns, such as fear and anxiety related to the water supply, misinformation, stress from relocation, and job stress, among others.¹³ The COVID-19 pandemic was ongoing during this incident and also resulted in societal disruptions.⁷ The medication analysis was based on EHR medications listed as active, though we could not determine if patients were taking these medications.

Our analysis highlights the need for mental health awareness, education, and access to care during and after environmental disasters, including large-scale water contamination events. Robust and organized disaster response efforts can provide community support during contamination events; prevent or address misinformation; and allow for clear communication that mitigates panic, anger, and distrust. Longitudinal studies would be helpful to fully understand the long-term mental health effects among this population. Continued access to mental and behavioral health care services should be considered for this population. The University of Hawaii’s Red Hill registry will allow for continued monitoring of long-term mental health outcomes related to contaminated water exposure.¹²

The supplementary material for this article can be found at http://doi.org/10.1017/dmp.2025.10207.