Gas Development Activities Research Articles

Assessing potential effects of oil and gas development activities on groundwater quality near and overlying the Elk Hills and North Coles Levee Oil Fields, San Joaquin Valley, California

Groundwater resources are utilized near areas of intensive oil and gas development in California’s San Joaquin Valley. In this study, we examined chemical and isotopic data to assess if thermogenic gas or saline water from oil producing formations have mixed with groundwater near the Elk Hills and North Coles Levee Oil Fields in the southwestern San Joaquin Valley. Major ion concentrations and stable isotope compositions were largely consistent with natural processes, including mixing of different recharge sources and water-rock interactions. Trace methane concentrations likely resulted from microbial rather than thermogenic sources. Trace concentrations of benzene and other dissolved hydrocarbons in three wells had uncertain sources that could occur naturally or be derived from oil and gas development activities or other anthropogenic sources. In the mid-1990s, two industrial supply wells had increasing Cl and B concentrations likely explained by mixing with up to 15 percent saline oil-field water injected for disposal in nearby injection disposal wells. Shallow groundwater along the western margin of Buena Vista Lake Bed had elevated Cl, B, and SO4 concentrations that could be explained by accumulation of salts during natural wetting and drying cycles or, alternatively, legacy surface disposal of saline oil-field water in upgradient ephemeral drainages. This study showed that groundwater had relatively little evidence of thermogenic gas or saline water from oil and gas sources in most parts of the study area. However, the evidence for groundwater mixing with injected disposal water, and possibly legacy surface disposal water, demonstrates produced water management practices as a potential risk factor for groundwater-quality degradation near oil and gas fields. Additional studies in the San Joaquin Valley and elsewhere could improve understanding of such risks by assessing the locations, volumes, and types of produced water disposal practices used during the life of oil fields.

2023 Development and production review

Geopolitical uncertainty remained high in 2023 with Israeli actions in the Gaza strip, the continuing war in Ukraine and tension between China and several neighbouring countries. However, global inflationary pressures, surprisingly, eased during the year, and the prospect of a global recession faded from where it had been in 2022. In Australia continued activism around climate change issues, has impacted project developments and sentiment in the industry remained subdued. This paper looks back at the oil and gas production and development activities in Australia in 2023 providing historical context and trying to understand future implications for the industry. Liquefied natural gas (LNG) production in Australia remained close to record high levels although, not without problems. Both the Scarborough/Pluto 2 LNG project and the Barossa project continued to have legal and approval hurdles resulting in suspension of some execution activities. Elsewhere other projects continued with their plans, including the Kipper field in the Gippsland Basin, the Crux project in the Browse Basin and the Walyering project in the Perth Basin which was brought online in September 2023. The domestic markets also continued to have unique issues with major concerns about gas supply in the East, stalled developments and failing supply in the Northern Territory, and a renewed ban on any exports (including to other states) of gas from Western Australia.

Source characterization of volatile organic compounds at Carlsbad Caverns National Park

ABSTRACT Carlsbad Caverns National Park (CAVE), located in southeastern New Mexico, experiences elevated ground-level ozone (O3) exceeding the National Ambient Air Quality Standard (NAAQS) of 70 ppbv. It is situated adjacent to the Permian Basin, one of the largest oil and gas (O&G) producing regions in the US. In 2019, the Carlsbad Caverns Air Quality Study (CarCavAQS) was conducted to examine impacts of different sources on ozone precursors, including nitrogen oxides (NOx) and volatile organic compounds (VOCs). Here, we use positive matrix factorization (PMF) analysis of speciated VOCs to characterize VOC sources at CAVE during the study. Seven factors were identified. Three factors composed largely of alkanes and aromatics with different lifetimes were attributed to O&G development and production activities. VOCs in these factors were typical of those emitted by O&G operations. Associated residence time analyses (RTA) indicated their contributions increased in the park during periods of transport from the Permian Basin. These O&G factors were the largest contributor to VOC reactivity with hydroxyl radicals (62%). Two PMF factors were rich in photochemically generated secondary VOCs; one factor contained species with shorter atmospheric lifetimes and one with species with longer lifetimes. RTA of the secondary factors suggested impacts of O&G emissions from regions farther upwind, such as Eagle Ford Shale and Barnett Shale formations. The last two factors were attributed to alkenes likely emitted from vehicles or other combustion sources in the Permian Basin and regional background VOCs, respectively. Implications: Carlsbad Caverns National Park experiences ground-level ozone exceeding the National Ambient Air Quality Standard. Volatile organic compounds are critical precursors to ozone formation. Measurements in the Park identify oil and gas production and development activities as the major contributors to volatile organic compounds. Emissions from the adjacent Permian Basin contributed to increases in primary species that enhanced local ozone formation. Observations of photochemically generated compounds indicate that ozone was also transported from shale formations and basins farther upwind. Therefore, emission reductions of volatile organic compounds from oil and gas activities are important for mitigating elevated O3 in the region.

An integrated approach to identify the source apportionment of potentially toxic metals in shale gas exploitation area soil, and the associated ecological and human health risks

Public awareness of the potential environmental risks of shale gas extraction has increased in recent years. However, the status and environmental risks of potentially toxic metals (PTMs) in shale gas field soil remain unclear. A total of 96 topsoil samples were collected from the first shale gas exploitation area in China. The sources of nine PTMs in the soils were identified using positive matrix factorization and correlation analysis, and the ecological and human health risks of toxic metals from different sources under the two land use types were calculated. The results showed that mean pollution load index (PLI) values for farmland (1.18) and woodland (1.40) indicated moderate pollution, As, Cd and Ni were the most serious contaminants among all nine PTMs. The following four sources were identified: shale gas extraction activities (43.90%), nature sources (31.90%), agricultural and traffic activities (17.55%) and industrial activities (6.55%). For ecological risk, the mean ecological risk index (RI) values for farmlands (161.95) and woodlands (185.27) reaching considerable risk. The contribution ratio of shale gas extraction activities for farmlands and woodlands were 5.70% and 8.90%, respectively. Regarding human health risk, noncarcinogenic risks for adults in farmlands and woodlands were negligible. Industrial activities, agricultural and traffic activities were estimated to be the important sources of health risks. Overall, shale gas extraction activities had little impact on the ecological and human health risk. This study provides scientific evidence regarding the soil contamination potential of shale gas development activities.

Does shale gas exploitation contribute to regional sustainable development? Evidence from China

Shale gas is a growing contributor to China's natural gas production. It is seen as a key component of the country's energy transition. As a major shale gas producing region, Chongqing has large shale gas production and high expectations for its future development. However, it is unclear how regional sustainability will be affected by this shale gas boom. To help answer this question, this paper establishes a sustainability assessment framework covering three economic-social-environmental dimensions and 21 specific indicators; obtains a composite sustainability index (CSI) of districts and counties in the Chongqing region based on the Entropy Weight Method (EWM); and then empirically analyses the impacts of shale gas development in Fuling and neighbouring districts by using the Synthetic Control Method (SCM). Our results show that the level of sustainable development in Chongqing has a fluctuating increase, with a rapid rise in the CSI for the sample area, but shale gas development activities do not contribute significantly. Further analysis shows that the CSI is relatively stable when weights are changed and indicators are substituted, and the scale of the shale gas industry may limit its impact on sustainable development. The synthetic control results for sub-dimensional sustainability indices are also not significant. However, the potential for sustainability levels in the environmental dimension and in region adjacent to shale gas field to be affected by shale gas development is greater. Developers and governments can focus on assessing these two aspects if shale gas production is larger.

Development and production review 2022

The Petroleum Exploration Society of Australia (PESA) Year in Review Development and Production review looks back at the oil and gas production and development activities in Australia in 2022, with a look at both the historical context of these activities, and the future implications. With the invasion of Ukraine, increasing inflationary pressures, supply chain problems, the prospect of a global recession looming, the impact of COVID-19 still lingering, and increased activism around climate change issues, sentiment was subdued for most of the year, yet there were still several highlights and events. Liquefied natural gas (LNG) production again hit record high levels although, as expected, Australia lost its position as the top LNG exporting country in the world to the USA. The development of the Scarborough/Pluto 2 LNG project continued, as did the Barossa project, although the latter hit legal and approval hurdles resulting in suspension of drilling activities (which are not expected to impact the overall schedule). Final investment decisions were taken on the further development of the Kipper field in the Gippsland Basin, the Crux project in the Browse Basin and the Walyering project in the Perth Basin. The domestic markets continue to have unique issues with major concerns about gas supply in the East co-existing with stalled developments and falling supply in the Northern Territory in stark contrast to the West, where there is significant development and take-over activity.

Depositional Environment and Lithofacies Analyses of Eocene Lacustrine Shale in the Bohai Bay Basin: Insights from Mineralogy and Elemental Geochemistry

AbstractThe effect of various depositional parameters including paleoclimate, paleosalinity and provenance, on the depositional mechanism of lacustrine shale is very important in reconstructing the depositional environment. The classification of shale lithofacies and the interpretation of shale depositional environment are key features used in shale oil and gas exploration and development activity. The lower 3rd member of the Eocene Shahejie Formation (Es3x shale) was selected for this study, as one of the main prospective intervals for shale oil exploration and development in the intracratonic Bohai Bay Basin. Mineralogically, it is composed of quartz (avg. 9.6%), calcite (avg. 58.5%), dolomite (avg. 7%), pyrite (avg. 3.3%) and clay minerals (avg. 20%). An advanced methodology (thin‐section petrography, total organic carbon and total organic sulfur contents analysis, X‐ray diffraction (XRD), X‐ray fluorescence (XRF), field‐emission scanning electron microscopy (FE‐SEM)) was adopted to establish shale lithofacies and to interpret the depositional environment in the lacustrine basin. Six different types of lithofacies were recognized, based on mineral composition, total organic carbon (TOC) content and sedimentary structures. Various inorganic geochemical proxies (Rb/Sr, Ca/(Ca + Fe), Ti/Al, Al/Ca, Al/Ti, Zr/Rb) have been used to interpret and screen variations in depositional environmental parameters during the deposition of the Es3x shale. The experimental results indicate that the environment during the deposition of the Es3x shale was warm and humid with heightened salinities, moderate to limited detrital input, higher paleohydrodynamic settings and strong oxygen deficient (reducing) conditions. A comprehensive depositional model of the lacustrine shale was developed. The interpretations deduced from this research work are expected to not only expand the knowledge of shale lithofacies classification for lacustrine fine‐grained rocks, but can also offer a theoretical foundation for lacustrine shale oil exploration and development.

Quantifying spatial characteristics of the Bowhead Whale Aerial Survey Project (BWASP) survey design

The Bowhead Whale Aerial Survey Project (BWASP) has been conducted annually since 1979 in the Alaskan Beaufort Sea to monitor the distribution and relative abundance of the Bering-Chukchi-Beaufort (BCB) stock of bowhead whales (Balaena mysticetus) during their autumn migration. BWASP was created to specifically address broad-scale research and management questions related to bowhead whale ecology, with particular interest in the potential effects of oil and natural gas exploration, development and production activities on the BCB bowhead whales. With elevated concerns about climate change, increasing oil and gas activities and the forecasted increase in vessel traffic, it is expected that interest in the BWASP dataset will also increase in order to evaluate effects of these anthropogenic activities on BCB bowhead whales and indigenous whaling. The following analysis quantified the spatial characteristics of the BWASP survey design and provided guidelines for the types of investigations that the BWASP data can potentially address. Sampling lags (transect spacing) in the BWASP survey design of approximately 20km along the east/west axis of the study area limit the spatial scale of phenomena that can be detected using data from a single BWASP survey. Therefore, BWASP data are relatively uninformative for studying variability in distribution or relative abundance along the east/west axis over short time scales (one survey) and within small areas measuring less than approximately 20km. In addition, computer simulations showed spatial heterogeneity in the long-term survey coverage probability (the probability that a given location will be included in a survey having an assumed effective search width under the BWASP survey design). Pooled transects created from simulated surveys resulted in a repeating diamond pattern in which coverage probability was low. Analyses incorporating data from many BWASP surveys should account for this spatial heterogeneity, via either the survey coverage probabilities or quantification of survey effort; otherwise estimates of variables such as relative density, density, or habitat use may be biased. The BWASP surveys have increased understanding of the broad-scale patterns of bowhead distribution, relative abundance and behaviour. The utility of this dataset in informing other questions will depend upon the scale of the ecological phenomena under investigation and the analytical scales used to address the questions.

A Brighter Future Dependent on Which Path is Navigated

The Petroleum Exploration Society of Australia (PESA) Year in Review Development and Production review looks back at the oil and gas production and development activities in Australia in 2021, with a look at both the historical context of these activities, and the future implications.

Concurrent 13. Presentation for: 2021 Development and production review

Presented on Wednesday 18 May: Session 13 The Petroleum Exploration Society of Australia (PESA) Year in Review Development and Production review looks back at the oil and gas production and development activities in Australia in 2021, with a look at both the historical context of these activities, and the future implications. With the impact of COVID-19 continuing throughout the year, and increased awareness of the impact of emissions on climate change there were several notable highlights and events for the year. Liquefied natural gas (LNG) production hit record high levels and confirmed Australia as the current top LNG exporting country in the world. Two major LNG-related projects were sanctioned: Barossa in March 2021, and Scarborough/Pluto 2 in November 2021 and the Moomba Carbon Capture and Storage project was also sanctioned in November. The domestic market looked a lot like the classic novel ‘A Tale of Two Cities’ with major concerns about gas supply in the East contrasting with significant discoveries and development in the Perth Basin in the West. To access the presentation click the link on the right. To read the full paper click here

Source apportionment and specific risk assessment of heavy metals in sediment: Application to the Typical Bay, China

In order to expound the spatial distribution characteristic, sources and potential ecological risk of Heavy Metals in Liaodong Bay, China, the surface sediments were collected to be analyzed from 61 sites. The research results showed that the spatial distribution characteristic of heavy metals concentration in Liaodong Bay was obviously discrepant, where the north was higher than the south, and the west was higher than the East. The ecological risk status of Liaodong Bay sediment was at the level of “Moderate Risk”. Hg and Cd were the main factors of pollution that caused the highest ecological risk. Source apportionment of heavy metal indicated that Hg and Cd in Liaodong Bay sediments might be introduced by petrochemical industry projects and offshore oil and gas development activities. Pb, Zn and Cu mainly came from the use of fossil fuels and chemical production processes, while As mainly came from agriculture.

2021 Development and production review

The Petroleum Exploration Society of Australia (PESA) Year in Review Development and Production review looks back at the oil and gas production and development activities in Australia in 2021, with a look at both the historical context of these activities, and the future implications. With the impact of COVID-19 continuing throughout the year, and increased awareness of the impact of emissions on climate change there were several notable highlights and events for the year. Liquefied natural gas (LNG) production hit record high levels and confirmed Australia as the current top LNG exporting country in the world. Two major LNG-related projects were sanctioned: Barossa in March 2021, and Scarborough/Pluto 2 in November 2021 and the Moomba Carbon Capture and Storage project was also sanctioned in November. The domestic market looked a lot like the classic novel ‘A Tale of Two Cities’ with major concerns about gas supply in the East contrasting with significant discoveries and development in the Perth Basin in the West.

Methane Growth Rate Estimation and Its Causes in Western Canada Using Satellite Observations

AbstractIn this study, the GOSAT Proxy Retrieval (v9.0) data product of column‐averaged dry‐air mole fractions of atmospheric methane (XCH4) for the period 2009–2019 was analyzed to detect methane (CH4) trends in the three western Canadian provinces where oil and gas development activities have changed significantly over the last decade. Although we found statistically significant increasing XCH4 trends in all subdomains (northeast British Columbia‐NE, Alberta‐AB, southern Saskatchewan‐SK), XCH4 trends are not higher than the background trend (7.25 ± 0.30 ppb/yr) and enhancement trends (ΔXCH4, after removing the background quantity) are not detectable at any subdomain during 2009–2019. For further insight into trends in all subdomains, we divided the whole period (2009–2019) into two shorter periods (2009–2013 and 2014–2019) and estimated trends. We found XCH4 trends are higher than background trends particularly in the AB and SK subdomains during 2009–2013, and their ΔXCH4 trends are positive and also marginally statistically significant. However, we do not find any detectable ΔXCH4 trend if we consider either long‐term (2009–2019) or the second shorter period (2014–2019), suggesting local emission sources are dominating year to year fluctuation. From the source attribution analysis, we found both wetland and oil and gas sectors are controlling the CH4 growth rate in western Canada, but the oil and gas sector is the dominant driver in NE and SK subdomains. We also found the satellite‐based average ΔXCH4 trend (15.43 ± 8.19%/yr) between 2009 and 2013 likely reflects a trend in oil and gas CH4 emissions in AB and SK for the same period.

Influence of shale gas development on core forests in the subtropical karst region in southwestern China

Core forests are an important component of forest landscapes and wildlife habitat. Although the core forests were damaged during the development of shale gas sites, it remain unclear how much damage the shale gas development has caused to this ecologically vulnerable region. We analyzed high-resolution remote sensing images of a shale gas development area in 2012, 2014, and 2017 in the karst region in southwestern China. The results showed that the core forest area decreased by approximately 4.0% from 2012 to 2017. Of this decrease, approximately 32.3% was related to the shale gas development activities, while 67.7% was related to other human activities, i.e., agricultural lands and residential developments. Approximately 5.6% of the decrease in the core forest was for new pipelines, with 0.5 ha occurred in 2012–2014 and 248.6 ha occurred in 2014–2017. Of the shale gas development activities, the pipeline constructions were most detrimental to the core forest. The patchiness of the core forest increased by 8.2% from 2012 to 2017 by the expansions of dry fields, towns, and settlements. The core forest Effective Mesh Size (MESH) decreased by 86.3%, primarily caused by the shale gas development pipelines. In conclusion, human activities that were not directly related to shale gas development were the main driver of the core forest decreases. The pipelines caused most losses of the core forest among the shale gas activities and the impacts deteriorated as the shale gas development proceeds. Therefore, we propose that new shale gas pads should be placed adjacent to existing shale gas pipelines and new shale gas pipelines should be constructed in parallel with existing roads to reduce the damages on core forest.

Geological and Bioregional Assessments: a tale of two basins

The Australian Government’s $35.4 million Geological and Bioregional Assessment (GBA) Program is assessing the potential impacts of shale, tight and deep coal gas development on water and the environment in the Beetaloo, Isa and Cooper GBA regions. This paper compares the outcomes of impact assessments for the Beetaloo and Cooper GBA regions, highlighting the role that local geology, hydrogeology, ecology and regulatory regimes play when assessing potential impacts of unconventional gas development. Unconventional gas development activities between basins are broadly consistent, involving drilling, stimulation of the reservoir (typically through hydraulic fracturing), production and processing of hydrocarbons, export to market and decommissioning and rehabilitation. The characteristics of these activities and their potential impacts are strongly influenced by local factors including the geology, environment, industry practices and regulatory regimes. While subsurface impacts associated with hydraulic fracturing and well integrity are considered unlikely in both regions, regional geology means there is greater stratigraphic separation between target resources and overlying aquifers in the Beetaloo Sub-basin than in the Cooper Basin. Local ecological conditions and species influence the nature of potential impacts on protected matters in the two basins, which are mostly associated with surface disturbance and spills or accidental release of fluids. A key similarity between the two regions is the broadly consistent regulation and management of potential impacts in the two basins. Preliminary results of the causal network analysis indicate that mitigation measures are available for all pathways in which unconventional gas resource development activities may have the potential to impact on endpoints.

Using Current Legal Tools to Achieve Net Zero Greenhouse Gas Emissions from New and Existing Federal Oil and Gas Leases

Fossil fuel development on federal lands accounts for 24% of all U.S. carbon dioxide (CO2) emissions. These emissions can be reduced significantly by requiring federal oil and gas development activity to mitigate greenhouse gas (GHG) emissions. The Bureau of Land Management (BLM) has authority to define the terms and conditions of new oil and gas leases and to impose conditions of approval on existing leases at the drilling stage. Using this authority, the BLM could require net zero emissions on some existing and all new oil and gas leases without waiting for congressional action or regulatory changes. Applying existing legal tools would allow for continued energy production while a long-term climate strategy is developed, and still drive significant GHG emission reductions in the meantime. Additionally, green jobs would be created by incentivizing oil and gas operators to generate offset credits by plugging the more than 2 million orphaned or abandoned oil and gas wells that litter the landscape. Finally, the incentive to plug idle wells and retire leases early would reward operators for deciding to keep some fossil fuel resources in the ground.

Environmental surveillance and adverse neonatal health outcomes in foals born near unconventional natural gas development activity

Studies of neonatal health risks of unconventional natural gas development (UNGD) have not included comprehensive assessments of environmental chemical exposures. We investigated a clustering of dysphagic cases in neonatal foals born between 2014 and 2016 in an area of active UNGD in Pennsylvania (PA),USA. We evaluated equine biological data and environmental exposures on the affected PA farm and an unaffected New York (NY) farm owned by the same proprietor. Dams either spent their entire gestation on one farm or moved to the other farm in late gestation. Over the 21-month study period, physical examinations and blood/tissue samples were obtained from mares and foals on each farm. Grab samples of water, pasture soil and feed were collected; continuous passive sampling of air and water for polycyclic aromatic hydrocarbons was performed. Dysphagia was evaluated as a binary variable; logistic regression was used to identify risk factors. Sixty-five foals were born, 17 (all from PA farm) were dysphagic. Odds of dysphagia increased with the dam residing on the PA farm for each additional month of gestation (OR = 1.4, 95% CI 1.2, 1.7, p = 6.0E-04). Males were more likely to be born dysphagic (OR = 5.5, 95% CI 1.2, 24.5, p = 0.03) than females. Prior to installation of a water filtration/treatment system, PA water concentrations of 3,6-dimethylphenanthrene (p = 6.0E-03), fluoranthene (p = 0.03), pyrene (p = 0.02) and triphenylene (p = 0.01) exceeded those in NY water. Compared to NY farm water, no concentrations of PAHs were higher in PA following installation of the water filtration/treatment system. We provide evidence of an uncommon adverse health outcome (dysphagia) in foals born near UNGD that was eliminated in subsequent years (2017–2019) following environmental management changes. Notably, this study demonstrates that domestic large animals such as horses can serve as important sentinels for human health risks associated with UNGD activities.

Human-Induced Seismicity: Risk perceptions in the State of Oklahoma

Technologies such as hydraulic fracturing and wastewater injection can elicit strong and sometimes diverging reactions among the public, particularly when there is uncertainty about the associated risks. Understanding how people are weighing potential benefits in the context of these risks can help to address some of the challenges associated with people’s responses, such as community conflict and social disruption—especially when multiple risks intersect, as in the case of induced seismicity. As a relatively new phenomenon, perceived risk of induced seismicity remains an underexplored area in hazards and risk analysis research. Prior work on hydraulic fracturing has revealed that a complex variety of factors influences how the public in a given area perceives the overall impacts, risks, and value of oil and gas operations. This article focuses on findings derived from in-depth interviews and informal conversations with 36 Oklahomans as part of a larger study of social responses to induced seismicity in that state and Colorado. These findings center around participants’ reported concerns, problems, benefits, and new opportunities associated with oil and gas development, including the ways in which participants weigh the costs and benefits of oil and gas development activities—particularly hydraulic fracturing—within the context of induced seismicity.

Impact of natural gas production on nitrogen dioxide and sulphur dioxide over Northeast British Columbia, Canada

Northeast British Columbia (BC) Canada, is a region in which natural gas production has undergone rapid development since 2007. We used nitrogen dioxide (NO2) and sulphur dioxide (SO2) data products of the Ozone Monitoring Instrument (OMI) to assess the impact of natural gas development activity on air quality in this region from 2005 to 2018. We noticed that values of both pollutants were elevated in the immediate vicinity of large emission sources within the Montney formation and Horn River Basin – regions, which have experienced an increase in unconventional natural gas activities. Places with elevated NO2 Vertical Column Densities (VCDs) are Fort St. John, Taylor, and Dawson Creek located in the Montney formation, and higher SO2 VCDs are found near the Fort Nelson gas plant situated in the Horn River and Liard Basin areas. Although all the OMI data products consistently reported relatively high NO2 VCDs in the same areas, VCD values vary substantially with data products largely due to differences in Air Mass Factor (AMF) calculations. The rate of increase in NO2 VCDs and mass between 2005 and 2018 in the Dawson Creek area was assessed at 2.34% yr−1 and 4.32% yr−1, respectively, and these rates of change are statistically significant. Although we obtained an overall increasing trend for NO2 in Northeast BC, we also noticed a decreasing trend in the period of 2011–2013, which may be attributed, in part, to compliance and enforcement of regulations concerning flaring activities from oil and gas activities in Northeast BC, or due to less development activities. From our analysis, we suggest that the current air quality monitoring network in Northeast BC should be expanded to capture the spatial distribution of SO2 by deploying one additional station near Fort Nelson equipped with meteorology and SO2 monitoring systems.

Oil and gas development activity and spontaneous preterm birth risk in California

Oil and gas development activity and spontaneous preterm birth risk in California