Date Published: July 31, 2018
Publisher: Public Library of Science
Author(s): Matthew J. Eckelman, Jodi D. Sherman, Andrea J. MacNeill, Jonathan Alan Patz
Abstract: BackgroundHuman health is dependent upon environmental health. Air pollution is a leading cause of morbidity and mortality globally, and climate change has been identified as the single greatest public health threat of the 21st century. As a large, resource-intensive sector of the Canadian economy, healthcare itself contributes to pollutant emissions, both directly from facility and vehicle emissions and indirectly through the purchase of emissions-intensive goods and services. Together these are termed life cycle emissions. Here, we estimate the extent of healthcare-associated life cycle emissions as well as the public health damages they cause.Methods and findingsWe use a linked economic-environmental-epidemiological modeling framework to quantify pollutant emissions and their implications for public health, based on Canadian national healthcare expenditures over the period 2009–2015. Expenditures gathered by the Canadian Institute for Health Information (CIHI) are matched to sectors in a national environmentally extended input-output (EEIO) model to estimate emissions of greenhouse gases (GHGs) and >300 other pollutants. Damages to human health are then calculated using the IMPACT2002+ life cycle impact assessment model, considering uncertainty in the damage factors used. On a life cycle basis, Canada’s healthcare system was responsible for 33 million tonnes of carbon dioxide equivalents (CO2e), or 4.6% of the national total, as well as >200,000 tonnes of other pollutants. We link these emissions to a median estimate of 23,000 disability-adjusted life years (DALYs) lost annually from direct exposures to hazardous pollutants and from environmental changes caused by pollution, with an uncertainty range of 4,500–610,000 DALYs lost annually. A limitation of this national-level study is the use of aggregated data and multiple modeling steps to link healthcare expenditures to emissions to health damages. While informative on a national level, the applicability of these findings to guide decision-making at individual institutions is limited. Uncertainties related to national economic and environmental accounts, model representativeness, and classification of healthcare expenditures are discussed.ConclusionsOur results for GHG emissions corroborate similar estimates for the United Kingdom, Australia, and the United States, with emissions from hospitals and pharmaceuticals being the most significant expenditure categories. Non-GHG emissions are responsible for the majority of health damages, predominantly related to particulate matter (PM). This work can guide efforts by Canadian healthcare professionals toward more sustainable practices.
Partial Text: Among high-income countries, most environmentally mediated death and disability are due to cardiovascular disease, respiratory illness, and cancer. These are all epidemiologically linked to air pollution, which is the single largest driver of environmentally mediated mortality, responsible for one in eight deaths globally [1,2]. In Canada alone, it is estimated that more than 20,000 premature deaths each year are attributable to air pollution . In addition, global health risks from climate change are rapidly rising. Climate change is presently responsible for an estimated 141,000 deaths globally each year from changing patterns of infectious diseases, food and water scarcity, and extreme weather events. Climate change has been identified as a major public health priority of the 21st century [4–6], as it is projected to result in an additional 250,000 deaths annually between 2030 and 2050 .
Life cycle emissions and consequent health damages of Canada’s healthcare sector were estimated using standard input-output life cycle assessment (IO-LCA) techniques, which model the natural resources required and pollutants emitted throughout the life cycle of a good or service (its use plus supply chain) on the basis of how much that good or service costs. Thus, IO-LCA models use monetary expenditures as their primary input. The IO-LCA approach is in widespread use around the world and forms the basis for consumption-based environmental accounting, such as calculating embodied energy and carbon at national and international levels. For example, Environment Canada reports national GHG emissions from fuel combustion from both production and consumption perspectives, relying on IO-LCA modeling results in order to account for emissions from Canadian consumption .