Prevalence and risk factors of post-acute sequelae of SARS-CoV-2 (PASC) among veterans in the airborne hazards and open burn pit registry: a prospective, observational, nested study.

BACKGROUND: Veterans have unique military risk factors and exposures during deployment that may augment their risk of post-acute sequelae of SARS-CoV-2 (PASC). The purpose of this study is to identify potential risk factors for PASC among Veterans in the national Airborne Hazards and Open Burn Pit Registry (AHOBPR). METHODS: This prospective observational study consisted of a semi-structured interview conducted via phone or videoconference from November 2021 to December 2022 among a stratified random sample of deployed Veterans nested within the national AHOBPR with laboratory-confirmed SARS-CoV-2 infection. PASC was defined as persistent new-onset symptoms lasting more than 2 months after initial SARS-CoV-2 infection. Deployment history, airborne hazards exposure and symptoms were obtained from the AHOBPR self-assessment questionnaire completed prior to SARS-CoV-2 infection (past). Post-infection symptoms and health behaviors obtained at study interview (present) were used to test the hypothesis that deployment experience and exposure increases the risk for PASC. RESULTS: From a sample of 212 Veterans, 149 (70%) met criteria for PASC with a mean age of 47 ± 8.7 years; 73 (49%) were women and 76 (51%) were men, and 129 (82.6%) continued to experience persistent symptoms of SARS-CoV-2 (596.8 ± 160.4 days since initial infection). Neither exposure to airborne hazards (OR 0.97, CI 0.92-1.03) or to burn pits (OR 1.00, CI 0.99-1.00) augmented risk for PASC. CONCLUSIONS: PASC is highly common among Veterans enrolled in the AHOBPR, but we did not observe any unique military risk factors (e.g., airborne hazards exposure) that augmented the risk of PASC. Our findings may provide guidance to clinicians in the VHA network to administer appropriate care for Veterans experiencing PASC.

Alternative crop residue management practices to mitigate the environmental and economic impacts of open burning of agricultural residues.

Deliberate open burning of crop residues emits greenhouse gases and toxic pollutants into the atmosphere. This study investigates the environmental impacts (global warming potential, GWP) and economic impacts (net cash flow) of nine agricultural residue management schemes, including open burning, fertilizer production, and biochar production for corn residue, rice straw, and sugarcane leaves. The environmental assessment shows that, except the open burning schemes, fossil fuel consumption is the main contributor of the GWP impact. The fertilizer and biochar schemes reduce the GWP impact including black carbon by 1.88-1.96 and 2.46-3.22 times compared to open burning. The biochar schemes have the lowest GWP (- 1833.19 to - 1473.21 kg CO2-eq/ton). The economic assessment outcomes reveal that the biochar schemes have the highest net cash flow (222.72-889.31 US$2022/ton or 1258.15-13409.16 US$2022/ha). The expenditures of open burning are practically zero, while the biochar schemes are the most costly to operate. The most preferable agricultural residue management type is the biochar production, given the lowest GWP impact and the highest net cash flow. To discourage open burning, the government should tailor the government assistance programs to the needs of the farmers and make the financial assistance more accessible.

Barriers and Facilitators to Administering Burn Pit Registry Exams in VHA Facilities.

INTRODUCTION: The Veterans Health Administration (VHA) established the Airborne Hazards and Open Burn Pit Registry (AHOBPR) in 2014 to address exposure concerns for veterans who have served in military operations in Southwest Asia and Afghanistan. By 2021, over 236,086 veterans completed the online questionnaire and 60% requested an AHOBPR examination. Of those requesting an exam, only 12% had an exam recorded in their medical record. This article summarizes barriers and facilitators to delivering AHOBPR exams and shares lessons learned from facilities who have successfully implemented burn pit exams for veterans. MATERIALS AND METHODS: We (I.C.C and J.H.) constructed a key performance measure of AHOBPR examination (the ratio of examinations performed in facility over examinations assigned to a facility) to identify top performing facilities and then used stratified purposeful sampling among high-performing sites to recruit a diverse set of facilities for participation. We (P.V.C. and A.A.) recruited and interviewed key personnel at these facilities about their process of administering burn pit exams. Rapid qualitative methods were used to analyze interviews. RESULTS: The ratio of exams performed to exams assigned ranged from 0.00 to 14.50 for the 129 facilities with available information. Twelve interviews were conducted with a total of 19 participants from 10 different facilities. We identified 3 barriers: Unclear responsibility, limited incentives and competing duties for personnel involved, and constrained resources. Facilitators included the presence of an internal facilitator, additional staff support, and coordination across a facility's departments to provide care. CONCLUSIONS: Gaps across many VHA facilities to provide AHOBPR exams may be understood as stemming from organizational issues related to clear delegation of responsibility and staffing issues. VHA facilities that wish to increase AHOBPR exams for veterans may need additional administrative and medical staff.

Deployment to Military Bases With Open Burn Pits and Respiratory and Cardiovascular Disease.

Importance: Many veterans who served in Afghanistan and Iraq during Operations Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) were deployed to military bases with open burn pits and exposed to their emissions, with limited understanding of the long-term health consequences. Objective: To determine the association between deployment to military bases where open burn pits were used for waste disposal and the subsequent risk of developing respiratory and cardiovascular diseases. Design, Setting, and Participants: This retrospective observational cohort study used Veterans Health Administration medical records and declassified deployment records from the Department of Defense to assess Army and Air Force veterans who were deployed between 2001 and 2011 and subsequently received health care from the Veterans Health Administration, with follow-up through December 2020. Data were analyzed from January 2023 through February 2024. Exposure: Duration of deployment to military bases with open burn pits. Main Outcomes and Measures: Diagnosis of asthma, chronic obstructive pulmonary disease, interstitial lung disease, hypertension, myocardial infarction, congestive heart failure, ischemic stroke, and hemorrhagic stroke. Results: The study population included 459 381 OEF and OIF veterans (mean [SD] age, 31.6 [8.7] years; 399 754 [87.0%] male). Median (IQR) follow-up from end of deployment was 10.9 (9.4-12.7) years. For every 100 days of deployment to bases with burn pits, veterans experienced increased adjusted odds for asthma (adjusted odds ratio [aOR], 1.01; 95% CI, 1.01-1.02), chronic obstructive pulmonary disease (aOR, 1.04; 95% CI, 1.02-1.07), hypertension (aOR, 1.02; 95% CI, 1.02-1.03), and ischemic stroke (aOR, 1.06; 95% CI, 0.97-1.14). Odds of interstitial lung disease, myocardial infarction, congestive heart failure, or hemorrhagic stroke were not increased. Results based on tertiles of duration of burn pit exposures were consistent with those from the continuous exposure measures. Conclusions and Relevance: In this cohort study, prolonged deployment to military bases with open burn pits was associated with increased risk of developing asthma, COPD, and hypertension. The results also point to a possible increased risk in ischemic stroke. The novel ability to use integrated data on deployment and health outcomes provides a model for additional studies of the health impact of environmental exposures during military service.

Burn Pit Smoke Condensate-Mediated Toxicity in Human Airway Epithelial Cells.

Burn pits are a method of open-air waste management that was common during military operations in Iraq, Afghanistan, and other regions in Southwest Asia. Veterans returning from deployment have reported respiratory symptoms, potentially from exposure to burn pit smoke, yet comprehensive assessment of such exposure on pulmonary health is lacking. We have previously shown that exposure to condensates from burn pit smoke emissions causes inflammation and cytotoxicity in mice. In this study, we explored the effects of burn pit smoke condensates on human airway epithelial cells (HAECs) to understand their impact on cellular targets in the human lung. HAECs were cultured at the air-liquid interface (ALI) and exposed to burn pit waste smoke condensates (plywood, cardboard, plastic, mixed, and mixed with diesel) generated under smoldering and flaming conditions. Cytotoxicity was evaluated by measuring transepithelial electrical resistance (TEER) and lactate dehydrogenase (LDH) release; toxicity scores (TSs) were quantified for each exposure. Pro-inflammatory cytokine release and modulation of gene expression were examined for cardboard and plastic condensate exposures. Burn pit smoke condensates generated under flaming conditions affected cell viability, with flaming mixed waste and plywood exhibiting the highest toxicity scores. Cardboard and plastic smoke condensates modulated cytokine secretion, with GM-CSF and IL-1ß altered in more than one exposure group. Gene expression of detoxifying enzymes (ALDH1A3, ALDH3A1, CYP1A1, CYP1B1, NQO1, etc.), mucins (MUC5AC, MUC5B), and cytokines was affected by several smoke condensates. Particularly, expression of IL6 was elevated following exposure to all burn pit smoke condensates, and polycyclic aromatic hydrocarbon acenaphthene was positively associated with the IL-6 level in the basolateral media of HAECs. These observations demonstrate that exposure to smoke condensates of materials present in burn pits adversely affects HAECs and that aberrant cytokine secretion and altered gene expression profiles following burn pit material smoke exposure could contribute to the development of airway disease.

Prevalence of Burn Pit Associated Symptoms Among US Veterans Who Utilize Non-Veteran's Affairs Private Healthcare.

OBJECTIVE: Do the 3.5 million US veterans, who primarily utilize private healthcare, have similar burn pit exposure and disease compared to the VA Burn Pit registry? METHODS: This is an online volunteer survey of Gulf War and Post-9/11 veterans. RESULTS: Burn pit exposure had significantly higher odds of extremity numbness, aching pain and burning, asthma, chronic obstructive pulmonary disease, interstitial lung disease, constrictive bronchiolitis, pleuritis, and pulmonary fibrosis. Chi-square did not reveal a difference in burn pit exposure and cancer diagnoses. CONCLUSIONS: These data demonstrate increased risk of neurological symptoms associated with burn pit exposure, which are not covered in the 2022 federal Promise to Address Comprehensive Toxics Act. Additional data will allow for the continued review and consideration for future medical benefits.

The Open Burning of Plastic Wastes is an Urgent Global Health Issue.

The open burning of mixed wastes that contain plastics is a widespread practice across the globe, resulting in the release of gas emissions and ash residues that have toxic effects on human and environmental health. Although plastic pollution is under scrutiny as a pressing environmental concern, it is often conflated with plastic litter, and the contribution of the open burning of plastics to air, soil, and water pollution gets overlooked. Therefore, campaigns to raise awareness about plastic pollution often end up leading to increased open burning. Many countries or regions where open burning is prevalent have laws in place against the practice, but these are seldom effective. In this viewpoint, we direct attention to this critical but largely overlooked dimension of plastic pollution as an urgent global health issue. We also advocate interventions to raise awareness about the risks of open burning and emphasize the necessity of phasing out some particularly pernicious plastics in high-churn, single-use consumer applications.

Associations Between Self-Reported Burn Pit Exposure and Functional Status, 1990-2021.

INTRODUCTION: The Airborne Hazards and Open Burn Pit Registry (AHOBPR) allows service members to self-report exposure to burn pits during military deployments and functional status (a composite metric of physical fitness status). This study investigated whether general exposure to burn pits, specific performance of burn pit duties, or the cumulative number of days deployed in Southwest Asia was associated with a change in functional status. MATERIALS AND METHODS: A retrospective cross-sectional analysis of 234,061 participants in the AHOBPR who completed questionnaires before August 2021 was conducted. Exposure was presumed if an individual reported any burn pits exposure during deployment or if an individual reported having to work at a burn pit as part of their duties and was quantified by the cumulative-reported exposure days. The outcome was the reported composite functional score. Statistical analysis used linear regression, which was adjusted for significant variables. A possible dose-response effect from cumulative deployment and burn pits exposure days was evaluated. Statistical significance was determined at P < 0.05. RESULTS: The burn pit exposure groups were notably different in size (exposed: 230,079, non-exposed: 3982) and were significantly different for all compared variables. There was a negative association between cumulative exposure days and functional score with a significant test for trend. There was a marginal positive significant association between cumulative deployment days and functional score with a significant test for trend. Reporting exposure to burn pit duties was also significantly associated with a lower functional score. CONCLUSION: This study suggests a dose-response relationship between cumulative burn pit exposure and decreased functional status. It also suggests a modest positive relationship between cumulative deployment days and reported function, which may represent a "healthy deployer" effect.

Emission characteristics of carbonyl compounds from open burning of typical subtropical biomass in South China.

Open biomass burning (OBB) is one of the largest primary emission sources for atmospheric carbonyl compounds, key precursors for ozone and secondary organic aerosol pollution. To clarify the carbonyl emissions, the comprehensive characteristics of C1-C10 carbonyl compounds from open burning of seven typical subtropical biomass in China were investigated in this study, which included subtropical plants and agricultural residues. Total 27 carbonyl compounds were detected. The total EFs were 2824 mg kg-1 with 95% confidence interval (CI) [2418, 3322] for burning subtropical plants and 4080 mg kg-1 with 95% CI [3446, 4724] for burning agriculture residues, respectively. The EFs were 2-3 orders of magnitude larger than previous values in China. Aliphatic aldehydes were the largest group of carbonyl groups, with acetaldehyde, as the most abundant carbonyl species (about 30% contribution). Formaldehyde, acetone, acrolein, glyoxal, methylglyoxal, butanone, isovaleraldehyde, and m-tolualdehyde were also found to be abundant and varying with the types of biomass burnt. Formaldehyde emission ratios to acetonitrile and CO were lower than those in previous studies both for burning plants and agricultural residues. There were significant variabilities in the emission ratios and factors among different types of OBBs. Strong positive correlations were found between carbonyl emissions and CO emissions and water content in biomass; furthermore, total carbonyl concentrations measured in the flaming stage were higher than those in the smoldering one. This study provides important fundamental measurement data on carbonyl emissions from burning typical subtropical plants and agricultural residues, which will help improve the quality of emission inventories and better understand the potential impacts of OBB on regional air quality in southern China.