Sociodemographic and Population Exposure to Upstream Oil and Gas Operations in Canada.

Canada, as one of the largest oil and gas producer in the world, is responsible for large emissions of methane, a powerful greenhouse gas. At low levels, methane is not a direct threat to human health; however, human health is affected by exposure to pollutants co-emitted with methane. The objectives of this research were to estimate and map pollutants emitted by the oil and gas industry, to assess the demographic of the population exposed to oil and gas activities, and to characterize the impact of well density on cardiovascular- and respiratory-related outcomes with a focus on Alberta.

Sweet and sour: A quantitative analysis of methane emissions in contrasting Alberta, Canada, heavy oil developments.

Cold heavy oil production with or without sand (CHOPS, or CHOP) are prevalent methods of oil extraction in western Canada. CHOP(S) sites account for over 40% of all reported vented methane (CH) from oil production in Alberta, and high rates of CH emissions have been confirmed in independent measurement studies. In this study, we used truck-based surveys coupled with qualitative optical gas imaging (OGI) to quantify and characterize methane emission rates and sources at nearly 1350 and 940 well sites in two major CHOP(S) developments respectively in 2016 and 2018.

Methane emissions from upstream oil and gas production in Canada are underestimated.

Methane emissions were measured at 6650 sites across six major oil and gas producing regions in Canada to examine regional emission trends, and to derive an inventory estimate for Canada's upstream oil and gas sector. Emissions varied by fluid type and geographic region, with the heavy oil region of Lloydminster ranking highest on both absolute and intensity-based scales. Emission intensities varied widely for natural gas production, where older, low-producing developments such as Medicine Hat, Alberta showed high emission intensities, and newer developments in Montney, British Columbia showed emission intensities that are amongst the lowest in North America.

Methane flux from flowback operations at a shale gas site.

We report measurements of methane (CH) mixing ratios and emission fluxes derived from sampling at a monitoring station at an exploratory shale gas extraction facility in Lancashire, England. Elevated ambient CH mixing ratios were recorded in January 2019 during a period of cold-venting associated with a nitrogen lift process at the facility. These processes are used to clear the well to stimulate flow of natural gas from the target shale.

Occurrence and origin of groundwater methane in the Stellarton Basin, Nova Scotia, Canada.

Groundwater methane (CH) in areas of fossil fuel development has been a recent focus of study as high CH concentrations pose water quality concerns and potential explosive hazards. In 2013, a provincial study in Nova Scotia identified areas with elevated groundwater CH. However, due to limited data, the specific sources and local distribution of CH in those areas remain unknown.

Large loss of CO in winter observed across the northern permafrost region.

Recent warming in the Arctic, which has been amplified during the winter, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO). However, the amount of CO released in winter is highly uncertain and has not been well represented by ecosystem models or by empirically-based estimates. Here we synthesize regional observations of CO flux from arctic and boreal soils to assess current and future winter carbon losses from the northern permafrost domain.

Methane emissions from abandoned coal and oil and gas developments in New Brunswick and Nova Scotia.

Energy reserves have been exploited in the Atlantic Canadian provinces since the early 1600s, and many fossil fuel extraction sites have been abandoned over this long history of energy development. Oil, natural gas, and coal extraction sites are a source of greenhouse gas emissions, particularly for methane (CH). In this study, we used multiple sampling methods to measure CH from abandoned coal mine openings in Nova Scotia and a legacy oilfield in New Brunswick.

Assessing the utility of dissolved organic matter photoreactivity as a predictor of in situ methylmercury concentration.

Methylmercury (MeHg) bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter (DOM) and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration.

Atmospheric impacts of a natural gas development within the urban context of Morgantown, West Virginia.

The Marcellus Shale Energy and Environment Laboratory (MSEEL) in West Virginia provides a unique opportunity in the field of unconventional energy research. By studying near-surface atmospheric chemistry over several phases of a hydraulic fracturing event, the project will help evaluate the impact of current practices, as well as new techniques and mitigation technologies. A total of 10 mobile surveys covering a distance of approximately 1500 km were conducted through Morgantown.

Quantifying the effects of photoreactive dissolved organic matter on methylmercury photodemethylation rates in freshwaters.

The present study examined potential effects of seasonal variations in photoreactive dissolved organic matter (DOM) on methylmercury (MeHg) photodemethylation rates in freshwaters. A series of controlled experiments was carried out using natural and photochemically preconditioned DOM in water collected from 1 lake in June, August, and October. Natural DOM concentrations doubled between June and August (10.

Continuous measurement of soil carbon efflux with Forced Diffusion (FD) chambers in a tundra ecosystem of Alaska.

Soil is a significant source of CO2 emission to the atmosphere, and this process is accelerating at high latitudes due to rapidly changing climates. To investigate the sensitivity of soil CO2 emissions to high temporal frequency variations in climate, we performed continuous monitoring of soil CO2 efflux using Forced Diffusion (FD) chambers at half-hour intervals, across three representative Alaskan soil cover types with underlying permafrost. These sites were established during the growing season of 2015, on the Seward Peninsula of western Alaska.

Soil moisture effects on the carbon isotope composition of soil respiration.

The carbon isotopic composition (delta(13)C) of recently assimilated plant carbon is known to depend on water-stress, caused either by low soil moisture or by low atmospheric humidity. Air humidity has also been shown to correlate with the delta(13)C of soil respiration, which suggests indirectly that recently fixed photosynthates comprise a substantial component of substrates consumed by soil respiration. However, there are other reasons why the delta(13)CO(2) of soil efflux may change with moisture conditions, which have not received as much attention.

Characterisation of spatial variability and patterns in tree and soil delta13C at forested sites in eastern Canada.

Wholistic isotopic studies provide a necessary foundation on which to build conceptual understanding of ecosystem development processes and provide the basis for further isotopic studies at a site or within an ecophysiological region. This study seeks to broadly characterise delta(13)C spatial variability and spatial patterns within soils and canopy tissues at five forest research sites in eastern Canada. We observe consistent and predictable patterns of leaf delta(13)C variation within trees and a consistent offset between woody and leafy tree tissues.