Open Pit Research Articles

Palaeodepositional environment, implications of Glossopteris flora, and organic matter characteristics from the Lower Permian, Karo Open Cast Mine, East Bokaro Coalfield, Damodar Basin, India

The present study deals with the Early Permian floral diversity, palaeoenvironment, palaeoclimate and depositional setting using a multiproxy approach that includes morphotaxonomy, palynology, and organic geochemistry of Karo OCM (Open Cast Mine), East Bokaro Coalfield, Damodar Gondwana Basin, India. The Permian sediments of Peninsular India are widely regarded as fluvial, along with some marine incursions. The macroplant fossil assemblage exhibits the presence of Glossopteridales, comprising Glossopteris, Gangamopteris, and Vertebraria, as well as Coniferales, which includes Noeggerathiopsis. The palynological assemblage encompasses the dominance of the striate bisaccate pollen Faunipollenites sp. and the sub-dominance of the non-striate bisaccate pollen Scheuringipollenites sp. with glossopterid affinities. The megafloral and palynofloral assemblage confirms the biostratigraphical age to be Late Barakar palynoflora of Kungurian affinity. The studied morphological characteristics, including small to large Glossopteris leaves exhibiting a lanceolate shape, acute apices, and acute cuneate or tapering bases, as well as entire margins with narrower lamina and narrow meshes, suggest the existence of a dense forest with the prevalence of a warm and humid climate during their deposition. The organic geochemical characterization based on functional group and biomarker analyses reveals the diagenetic effects on organic matter. Aliphatic symmetric (∼2865–2855 cm-1) and asymmetric stretching (∼2930–2910 cm-1) peaks are identifiable in coal samples, whereas they are absent in carbonaceous shale. The A-factor vs. C-factor plot suggests that the kerogen type is type III, which can generate mainly gaseous kerogen. The vitrinite reflectance studies (Rr av. 1.1%) show increased maturity of the samples, which is supported by the n-alkane distribution pattern and the absence of hopane terpenoids. The Indian floral assemblages in contemporary of southern Gondwana continents reveal a stronger inclination/affinity with the flora of Africa than that of South America, thereby supporting the age to be of Artinskian–Kungurian.

Оценка влияния различных газов на давление в шинах при выделении тепла

Transportation of minerals during open-pit mining works is mainly provided by heavy vehicles. One of the most dangerous accidents during the operation of vehicles in open-pit mines is the destruction of large-scale tires. The main cause of the destruction of tires is heating of rubber causing the increase of pressure of injected gas and change of properties of tire material. Apart from friction processes and rubber deformation causing heating of wheels, the temperature of tires can increase when affected by external heat sources. At coal mines, sources of auto-ignition of fossil fuels often located along the road shoulders and sometimes on the road surface can be additional sources of heat for the vehicles. According to the calculations, the increase in tire pressure does not depend on the type of gas injected. The temperature rise in tires, however, is significantly affected by the specific heat capacity and the density of the gas used. According to the conducted studies, carbon dioxide is a more effective gas compared with air or nitrogen. With a certain amount of heat emitted in the tire, air or nitrogen heats up from 0 to 100 °С, while the temperature of carbon dioxide will increase only to 72 °С. Due to heating, the air and nitrogen pressure in the tires will increase from 6 to 8.2 atm, whereas carbon dioxide pressure will increase only to 7.5 atm. Unlike air, carbon dioxide is not involved in the combustion and oxidation of heated rubber. Methane and its homologs are even more effective. For example, propane injected into tires, when emitting the same amount of heat, will heat up from 0 only to 28 °С, and its pressure will increase from 6 to 6.6 atm. The combustion of these hydrocarbons can be prevented by using inhibitors. Thus, adding 2–3 % of freons will make these gases non-flammable and explosion-proof.

Determining the directions of dangerous ecogeochemical impact of surface reservoirs of highly mineralized mine and open pit waters using a complex of geological and geophysical data

The issues of effective use of geological and geophysical methods for spatial assessment of dangerous ecogeochemical impact of storage ponds of highly mineralized mine and open pit waters are considered. An example of such an object is the Svystunovo gully (volume – 12 million m3), into which water is pumped out from all working open pits and mines of Southern and partially Central Kryvbas. To solve ecogeochemical problems associated with dangerous influence of such storage ponds, a well-known method for restoring Precambrian fault systems using a complex of geological, geophysical and geomorphological data was taken. At all research scales, based on the results of calculations of the significance of “weights” of fault signs, a clear trend was revealed for predominance of diagonal fault systems with strike azimuths: 35° - 305° and 45° - 315°. The spatial combination of tectonic information with results of detailed electrical exploration work made it possible to identify local directions of propagation of dangerous ecogeochemical influence of the studied storage pond of highly mineralized waters by anomalies of decrease / increase in geoelectric resistance in the emerging geochemical block of local system of integrated environmental monitoring of Southern Kryvbas.

Strategic planning of open pit mining operations using the Micromine Beyond Optimiser

Modern software products allow to determine the quantity and quality of ore at any point of the deposit and, accordingly, to identify the optimal pit shell using specialized algorithms. Such algorithms make it possible to create the final open pit shell even with a broken bottom for several neighboring ore bodies. Currently, optimization solutions in the mining industry require the determination of the maximum present value of profit or the minimum stated costs. It allows to make strategic planning decisions. Strategic planning of open-pit mining operations in the development of mineral deposits in Ukraine can be implemented using the Micromine Beyond Pit Optimizer. The authors considered the parameters that affect the boundaries of the pit field and the optimization criteria.

Century-long recovery of mycorrhizal interactions in European beech forests after mining

Abstract Background and aims Ecological restoration strategies are emerging globally to counteract biodiversity loss and ecosystem degradation. However, restored ecosystems may not reach undisturbed biodiversity and functionality. One reason of this limited success may be a focus on short-term recovery of diversity, composition, or isolated functions. These simplified metrics may underestimate the real time ecosystems need to recover. Thus, studies of more complex metrics, like biotic interactions, at larger timescales, are essential to understand ecosystem recovery. Methods Using molecular identification, we assessed the recovery of the interactions between ectomycorrhizal (EcM) fungi and European beech (Fagus sylvatica L.) in two opencast iron mines in use since the fourteenth century and abandoned over 107 and 148 years. Results Species richness, species diversity, Basidiomycota/Ascomycota abundance ratio and taxonomic distinctness of EcM fungi recovered to undisturbed values, whereas species composition was still different. Certain fungal functional traits (i.e. exploration and sporocarp types) also reached undisturbed values. Differences in soil pH and NH4+ affected the composition of the EcM communities associated with beech, suggesting that mining caused a long-term impact in soil biogeochemistry, that directly impacted beech-EcM interactions. Conclusion Mycorrhizal interactions require more than 150 years to recover following mining. Contrary to the rapid recovery response provided by simple metrics like species richness, recovery metrics with more ecological information, like the identity of plant-EcM interactions, may be still capturing signals of incomplete recovery.

Heavy Metal-Laden Particulate Dust Alters Transcriptional Regulation in Human Colonoids

Chronic heavy metals exposure in the southwestern United States co-occurs with greater incidences of metabolic and digestive diseases, particularly in the Indigenous and Hispanic populations. There is a need to understand how particulate heavy metals drive this dysbiotic state and propose a molecular explanation as a result of these exposures. Previously, our group demonstrated human colonoids to be a relevant model for investigating the physiological impact of environmental toxicants on the intestinal tract. The objective of this study is to elucidate the mechanism behind the transcriptional and cellular changes present in the intestinal epithelia upon acute exposure to non fissile uranium particulate dust. We hypothesize that non-fissile uranium exposure biases the differentiation of progenitor cells in the crypt to secretory roles through miRNA regulation. Colonoids were exposed (18 hours) to non-fissile uranium dust obtained from the Jackpile uranium mine, one of the largest open pit uranium mines, located on the Laguna Pueblo in New Mexico. Control and dust-exposed colonoids (n=3 unique donors) were digested into single cells and processed for droplet-based single cell sequencing (scRNAseq). Upon exposure, enteroendocrine cells (EEC) expanded >4 fold, along with increases in serotonin and PYY, as well as goblet cells (>3 fold) which indicates changes to the secretory lineage. Downstream pathway analysis found microRNAs miR-625-3p, miR-320a, miR-29b-3p to be differentially expressed. These results suggest that acute uranium dust exposure induces changes in differentiation pathways which are modulated by regulatory miRNAs. We would like to expand these findings by performing miRNA sequencing and comparing miRNA expression profiles between UBD exposed and control samples. Our results also provide an improved understanding of uranium dust’s impact on the gastrointestinal system, which may inform other physiological studies on the health of individuals exposed to heavy metals. This study was funded by K01DK106323, R56ES034400, P42ES025589, P20GM121176, P20GM130422, and AGA SURF. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Stability Analysis of Jointed Rock Slopes Based on the Universal Elliptical Disc Model

A discrete fracture network (DFN) represents the random distribution of fractures within rock masses in three dimensions and has been widely used in the stability analysis of jointed rock slopes. This study introduces a novel method for constructing three-dimensional DFN models to address the limitations of traditional circular or polygon-based models. This method employs the universal elliptical disc (UED) model, combined with the discrete element method (DEM) in 3DEC, for the probabilistic analysis of jointed rock slope stability. The paper begins with an explanation of the fundamental principles of the UED model, and continues to detail the procedures for creating a three-dimensional DFN using the UED model and for analyzing slope stability using the DEM. An open-pit mine rock slope in the USA serves as a case study to illustrate the application of the proposed method. This approach facilitates the integration of the UED model into 3DEC and offers a more realistic depiction of the three-dimensional DFN, which enhances both the accuracy and efficiency of stability analysis in jointed rock slopes.

Application of remote sensing techniques for estimation and mapping of iron oxides and iron-containing minerals in open pits of the Kryvyi Rih iron ore basin

The purpose of this study is to use remote sensing data to map the deposits of the Kryvyi Rih iron ore basin. Several methods for estimating iron oxide content have been applied and tested. Using image processing techniques, color composites, band ratios and supervised classification, a map of rocks with different iron oxide contents in the Inhulets and Skeliuvats-Magnetite deposits was create. The proposed method uses six Landsat 9 bands to map iron-bearing minerals and rocks (spectra 1, 3, 4 and 5) and hydroxyl (spectra 1, 5 and 7), which are easily visible in the pictures of the operation land images. The final identification of iron deposition was based on the difference in reflectivity of iron oxide content. The Kryvyi Rih iron ore basin is an excellent environment for remote sensing experiments for iron ore identification. Quite large-scale outcrops of ore bodies with pronounced reflection spectra are observe at the deposits. The large extent of development of ferruginous horizons makes them easy to diagnose using Landsat series satellites.

Parametric evolutions of explosive fracture zones in the explosion of series of blasthole charges with a complex structure

The purpose of the paper is to specify calculations of a rock mass fracture zone in the explosion of series of blasthole charges with a complex structure under mathematical modelling of their interaction if parts of the blasting agent are spaced along the well length by means of an inert material. The parts are blasted sequentially. Therefore, dynamic load of exploded rock mass has been analyzed depending upon a blasting order of the charges and their parts. Originality is to define more exactly the regularities of interaction between explosive energy of blasthole charges with the specific design and rock mass enclosing them. The developed methods help identify usability of the explosives, designed by the authors, and simplify calculations of drilling-and-blasting description. It has been proved that selection of charge mass with different ratios of their parts in the sequential wells, and variation in lag intervals between the explosions make it possible to control a process of rock mass loading depending upon the specific mining and geological conditions if features of a force field are known. The findings expand methodological basis as for design of open pits while favouring implementation of explosive charges which structure is proposed by the authors.

GEOMONITORING OF THE OPEN-PIT MINE SLOPES DURING SUBSOIL DEVELOPMENT

The concept of geomonitoring and its role in developing the mining industry as a case study of the development of copper and zinc deposits in central Kazakhstan ("East Saryoba" mine) has been considered. As a crucial element of the geomonitoring concept, the control of the open-pit mine's slope stability has been examined. Geomonitoring is being treated as a combination of geodetic monitoring data and geomechanical properties of the surrounding rocks to analyze the possible slopes' collapses. The refined approach of geomonitoring has been developed to provide appropriate reliability and accuracy. The technology is based on complex knowledge about the geological structure of the object of monitoring and applying state-of-the-art geodetic methods. Research on the geomechanical properties of the open-pit mine has been carried out. The results of these studies have been used to determine the collapse zones of the slopes of the open-pit mine. The limit values for the slopes' collapse zone and inclination angle for the prospective excavation regions in the open-pit mine have been calculated using the equilibrium state equation. Those values, namely, the size of the collapse zone and the slope's inclination angle, were used for the geodetic target setup. As a case study, the displacements of these targets were measured using robotic total stations placed on the control points over the geodetic network. For the installation of both geodetic equipment during the geomonitoring design and accomplishment, the authors developed the permanent measuring station construction, which provides fast and accurate centering. The first results showed that the problem of the geomonitoring design could be solved based on geomechanical rock properties accounting and their combination with the results of geodetic measurements.

Pre-feasibility Assessment Based on Engineering Design of a Limestone Open Pit Mine

Pre-feasibility Assessment Based on Engineering Design of a Limestone Open Pit Mine

Container technology for transporting rock masses in quarries

Container technology for transporting rock masses in quarries

Spatiotemporal change characteristics of vegetation coverage in Shangwan Mine of China's Shendong Mining Area.

The coal mining might cause the disturbance to the vegetation and the disturbance impacts might exist the differences for different areas, and few literatures compared and analyzed different disturbed areas based on the location of the mining face, and paid attention to the post mining self-healing effects of vegetation. Here, this paper selected the GaoFen multispectral images during 2017-2021 to study different areas of Shangwan Mine which includes the old mining area more than 5 years after mining, the new working face underground mined in 2018 and 2019, the natural growth control area and the open-pit mining affected area. The spatiotemporal changes of the surface fraction vegetation coverage (FVC) were analyzed in each area and the correlation between vegetation coverage and climatic factors was studied. The results showed that: (1) The overall vegetation coverage showed a moderate decrease trend in fluctuation from 2017 to 2021. The Open-pit mining affected areas showed the largest decline, reaching 68.3%. The FVC in the underground mining areas had a downward trend, but self-healing effect after mining was also observed. (2) The overall FVC in the study area was positively correlated with the number of precipitation days. (3) There were differences in the sensitivity to mining disturbance for different landform in the underground mining areas. (4) Although the FVC in the Old mining areas had recovered to the level of Natural growth control area, but the annual fluctuation was larger, which might mean lower ecological stability.

Pelaksanaan Reklamasi Lahan Pasca Tambang PT Rekasindo Guriang Tandang di Bengkulu

Coal mining in Indonesia is generally carried out using open pit mining methods, thereby disrupting and destroying the ecosystem and natural balance, causing negative impacts that result in environmental damage. Therefore, sustainable development with an environmental perspective is important for every nation and country that wants to protect its natural resources. The main cause of damage to the ecosystem or environment is humans. This research was conducted using a qualitative approach method. According to Williams (1988), the qualitative method is an approach that in the research proposal, process, hypothesis, going into the field, data analysis and data conclusions up to writing uses aspects of trends, non-numerical calculations, situational descriptive, interviews, in-depth analysis, deep. contents, snowballs and stories. The research findings regarding the study of the implementation of ex-mining land reclamation at PT Rekasindo Guriang Tandang's Coal Mining Business License in North Bengkulu Regency, Bengkulu Province are regarding community knowledge and participation in reclamation activities, land preparation, implementation of activities, equipment, costs, and commitment of directors or managers. The implementation of reclamation activities at PT Rekasindo Guriang Tandang did not go well because the plant growth success rate was low and plant growth was less than optimal. So the government and Mining Business License (IUP) managers need to take policies to involve the community more to play a more active role in reclamation activities carried out in areas around their environment.

Using isotope-geochemical criteria for Olympiadinskoye gold deposit gas system genesis diagnosis

The authors studied modern gas manifestations spatially associated with the ore deposits in the Kaitbinskaya lithological-facies zone of the Yenisei Ridge. The purpose of the research is to obtain scientifically based data on the genesis of gaseous and vaporous fluids in various sampling environments of the Vostochny open-pit mine of the Olympiadinskoye gold deposit: rocks, natural waters, free-flowing gases from blastholes and air of the surface atmosphere. It has been conducted a complex of field and analytical works including degassing, gas chromatography, pyrolysis of the organic substance of lithified and metamorphosed deposits, analysis of carbon isotopic composition in carbon dioxide and methane in fluidal systems. In order to study normal gas-geochemical field (natural background) of the work area an atmospheric geochemical survey was carried out at the reference site – an “environmentally friendly” site with the minimal influence of technogenic factors. It has been determined that the surface atmosphere of the site had been formed due to the landscape and geomorphological conditions of the Kaitbinskaya lithological-facies zone as well as fluidal systems of deep horizons. The latter, due to the presence of an extensive network of disruptive disturbances and diffusion-filtration processes of mass transfer reached the zone of exploratory geochemical sounding. The conducted pyrolytic studies of rocks have proved that within the open section of the Vostochny open-pit mine the organic substance of the Kordinskaya series of the lower Riphean deposits has implemented its oil and gas generation potential and cannot serve the formation source of abnormal gas fields of the Olympiadinskoye gold deposit. The studied gas systems are polygenic in nature and, being allochthonous to the host sediments, are formed without the participation of gases from the upper generating (bio) zone. According to isotope-geochemical criteria, these are mainly endogenous and naphthidogenic fluids identical to the gas condensate accumulations of the Yurubcheno-Tokhomskaya oil and gas accumulation zone.

A stacked deep multi-kernel learning framework for blast induced flyrock prediction

Blasting operations are widely and frequently used for rock excavation in Civil and Mining constructions. Flyrock is one of the most important issues induced by blasting operations in open pit mines, and therefore needs to be well predicted in order to identify the safety zone to prevent the potential injuries. For this purpose, 234 sets of blasting data were collected from Sungun Copper Mine site, and a stacked deep multi-kernel learning (SD-MKL) framework was proposed to estimate the blast induced flyrock with confidence accuracy. The proposed model uses the stacking-based representation learning framework (S-RL) to achieve deep learning on small-scale training sets. A multi-kernel learning model (MKL) is used as the base module of S-RL framework, which uses a multi-feature fusion strategy to generate multiple kernels with different kernel length in order to reduce the effort in tuning hyperparameters. In addition, this study further enhanced the predictive capability of SD-MKL by introducing the boosting method into the S-RL framework and hence proposed a boosted SD-MKL model. For comparison purpose, several existing machine learning models were implemented, i.e., kernel ridge regression (KRR), support vector machine (SVM), random forest (RF), gradient boosting decision tree (GBDT), ensemble deep random vector functional link (edRVFL), SD-KRR and SD-SVM. Our experimental results showed that the proposed boosted SD-MKL achieved the best overall performance, with the lowest RMSE of 0.21/1.73, MAE of 0.08/0.78, and the highest VAF of 99.98/99.24.

Surface Elevation Change Monitoring Based on ICESat-2 Satellite Altimetry Data

The ICESat-2 (Ice, Cloud and Land Elevation Satellite-2), launched by NASA on September 18, 2018, offers higher precision in surface elevation monitoring. This study aims to investigate the surface elevation changes over different time periods in the Delong and Bulianta open-pit mines in Wulanmuren Township, Ordos City, using ICESat-2 laser data. The study utilizes the spatial distribution information of each photon from ATL03 (terrain elevation data) and the classification information of each photon from ATL08 (vegetation canopy height and surface elevation data) to extract surface photon elevation data for different periods in the same area. The precision of ICESat-2 satellite elevation data is validated using the on-board radar data from Henan Polytechnic University's Feima unmanned aerial vehicle D2000 in Jiaozuo City, Henan Province.Results indicate that in the No.1 area of the Delong open-pit mine, the surface subsided by approximately 16.3 meters between November 14, 2019, and November 10, 2021, due to soil removal operations. In the No.2 and No.3 areas of the Bulianta open-pit mine, the surface was uplifted by 3.1 meters and 13.6 meters, respectively, between May 16, 2019, and August 13, 2020, due to backfilling after mining. Additionally, the No.4 area was uplifted by about 10.5 meters between November 14, 2019, and November 10, 2021.Furthermore, the accuracy assessment yielded the following results: R2=0.956, RMSE=0.324, and MAE=0.105 meters, indicating that ICESat-2 data can be used as scientific data for inverting surface elevation changes.

Does diet quality moderate the long-term effects of discrete but extreme PM2.5 exposure on respiratory symptoms? A study of the Hazelwood coalmine fire

In 2014, a fire at an open cut coalmine in regional Victoria, Australia burned for 6 weeks. Residents of the nearby town of Morwell were exposed to smoke, which included high levels of fine particulate matter (PM2.5). We investigated whether the long-term effects of PM2.5 on respiratory health were moderated by diet quality. A cross-sectional analysis was conducted of data collected 8.5 years after the mine fire from 282 residents of Morwell and 166 residents from the nearby unexposed town of Sale. Primary outcomes were respiratory symptoms. Exposure was coalmine fire-related PM2.5 and diet quality was assessed as Australian Recommended Food Score (ARFS) derived using the Australian Eating Survey (AES). The moderating effect of diet quality on respiratory outcomes associated with PM2.5 was assessed using logistic regression models, adjusting for potential confounders. Diet quality was poor in this sample, with 60% in the lowest category of overall diet quality. Overall diet quality and fruit and vegetable quality significantly attenuated the association between PM2.5 and prevalence of chronic cough and phlegm. Sauce/condiment intake was associated with a greater effect of PM2.5 on COPD prevalence. No other moderating effects were significant. The moderating effects of overall diet quality and vegetable and fruit intake aligned with a priori hypotheses, suggesting potential protective benefits. While more evidence is needed to confirm these findings, improving diets, especially fruit and vegetable intake, may provide some protection against the effects of smoke exposure from fire events.

Research on chlorine salt antifreeze road dust suppressants for open-pit coal mines

In addressing the significant challenge of trucking road dust emanating from open-cast coal mines, the prevalent method of conventional water sprinkling for dust removal on transport roads has proven suboptimal. This inadequacy is attributed to the pronounced mobility of truck transport roads, substantial dust loads, and extensive open dust sources. Particularly in cold mining regions, the use of water in winter exacerbates the issue by causing icy road surfaces, thereby increasing the risk of truck skidding and overturning, posing a severe hazard to both mine safety and the well-being of truck drivers. A pragmatic imperative exists to devise a solution that effectively addresses both anti-freezing and dust suppression in open-pit coal mine roads, while minimizing corrosive impact. Against the backdrop of Hebei Open-pit Coal Mine in Huolin, Inner Mongolia, this study focuses on the development of a chloride salt antifreeze-type road dust inhibitor tailored for open-pit transportation roads. The proprietary anti-freezing dust suppressant achieves a freezing point as low as −36.4 °C, exhibiting corrosion efficiency merely at 56.5% of that of water. Notably, the effective dust suppression duration surpasses that of water by a factor of 150, resulting in a 53% reduction in dust suppression costs. This innovation is specifically applicable to high-cold and arid surface coal mines in northern regions and similar mining contexts. It offers technical support for the establishment of environmentally sustainable practices in surface coal mines, representing a pivotal step toward the realization of green mining initiatives.

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

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. 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. 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. Duration of deployment to military bases with open burn pits. Diagnosis of asthma, chronic obstructive pulmonary disease, interstitial lung disease, hypertension, myocardial infarction, congestive heart failure, ischemic stroke, and hemorrhagic stroke. 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. 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.