The environmental impact of the EMS supply chain

Objective: To estimate the life cycle emissions of U.S. EMS systems, including emissions from supply chain process, and identify the components of the supply chain that contribute most to those emissions. Methods: The websites for 200 randomly selected U.S. cities and counties were searched to obtain publicly available EMS budget information for the two most recent budget years. Where line-item budgets were available, the consumer price index was used to convert expenditures to standard year (2002) amounts. Published input-output-based emissionsmultipliers, accounting for emissions from the upstream and downstream processes associated with any product or service, were then used to calculate "indirect" emissions related to those expenditures. We also calculated the volume of diesel, gasoline, and natural gas consumed by each system (amount spent average price), and used volume-based multipliers to calculate emissions from "direct" energy consumption. "Indirect" and "direct" emissions were summed to calculate life cycle emissions. Results: Detailed line-item budgets were available for nine EMS systems located in seven states (population: 7,500 to 400,000; annual response volume: 1,200 to 90,000; average expenditures: $50 ± 20 per capita, $290 ± 128 per response). Over 16 total budget years, these EMS systems spent a combined $94.7 million (in 2002 dollars) and generated 21,877 tons of carbon dioxide equivalent (CO2e) emissions, or 231 tons CO2e per $1 million of expenditure. Total EMS-related life cycle emissions for the U.S. were estimated at 3 million tons CO2e annually (95% CI: 2.3 to 3.6 million tons CO2e). The non-energy supply chain contributed 25% of EMS-related life cycle emissions. Purchases ofmedical supplies and equipment were the largest contributor to supply chain emissions (25%), followed by vehicle purchases/ leases (19%) and vehicle maintenance (10%). Other notable contributors were administrative processes (billing, financial and professional services, 10%), office supplies and equipment (8%), and pharmaceuticals and medical gasses (3%). Conclusions: Direct emissions, primarily from vehicle fuel consumption, are the clear priority for EMS sustainability initiatives, but the supply chain accounts for 25% of EMS-related emissions. Reducing waste in the EMS supply chain could have dual benefits of reducing system operational costs and reducing greenhouse gas emissions