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

Abstract

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. We estimated that ~13% and 3% people in Alberta reside, respectively, within 1.5 km of an active well and 1.5 km of a flare. Our analysis suggests that racial and socioeconomic disparities exist in residential proximity to active wells, with people of Aboriginal identity and people with less education being more exposed to active wells than the general population. We found increased odds of cardiovascular-related (1.13-1.29 for low active well density) and respiratory-related (1.07-1.19 for low active well density) outcomes with exposure to wells. Close to 100 countries produce oil and gas, making this a global issue. There is an important need for additional studies from other producing jurisdictions outside the United States.

Keywords: CanCHEC; DAD; air pollutants; air quality; methane; nitrous oxide; oil and gas.

Figure 1

Number of active wells and facilities per square kilometer during the years 2016–2021 in Alberta, Canada. NA = No data reported or no wells present.

Figure 2

Estimated PM_2.5 density per DA, NOx density per DA, and VOCs density per DA for Alberta, Canada, during the years 2016–2021. The emission units for the three pollutants are initially kg per km² per year. Then, the DAs with emissions estimates are divided in 10 equal parts (deciles). Thus, each decile has the same number of DAs. DAs with zero (gray) indicates that no emissions were reported.

Figure 3

The estimated proportion of people per dissemination area living near (<1 km) an active oil or gas well during the study period in Alberta, Canada, during the years 2016–2021. A zoomed-in (25-km radius) picture of the two largest cities of Alberta: Edmonton and Calgary.

Figure 4

The summary statistics for individuals listed in the DAD database by age category (A), location (B), and sex (C). Urban/rural is defined using the Statistical Area Classification type (SACtype). For this study, SACtype descriptions 1 (census subdivision with census metropolitan area), 2, and 3 are designated as urban and categories 4 to 8 (census subdivision withing territories, outside of census agglomeration) as rural.

Figure 5

The association between well density (abandoned and active, respectively in black and red), TROPOMI NO2 (in dark red), and cardiovascular- and respiratory-related outcomes in Alberta Canada, adjusted for sex (in orange), age (in purple), location (in grey), and income (in dark blue). QABTIPPE (Neighbourhood Income Quintile Before Tax) was used as a proxy for income. Abandoned and active well densities and TROPOMI NO2 concentrations were classified into four categories (zero/very low to high). * p < 0.5; ** p < 0.01; *** p < 0.001.