Carbon Footprint

BackgroundClimate change threatens to undermine the past 50 years of gains in public health. In response, the National Health Service (NHS) in England has been working since 2008 to quantify and reduce its carbon footprint. This Article presents the latest update to its greenhouse gas accounting, identifying interventions for mitigation efforts and describing an approach applicable to other health systems across the world.MethodsA hybrid model was used to quantify emissions within Scopes 1, 2, and 3 of the Greenhouse Gas Protocol, as well as patient and visitor travel emissions, from 1990 to 2019. This approach complements the broad coverage of top-down economic modelling with the high accuracy of bottom-up data wherever available. Available data were backcasted or forecasted to cover all years. To enable the identification of measures to reduce carbon emissions, results were disaggregated by organisation type.FindingsIn 2019, the health service's emissions totalled 25 megatonnes of carbon dioxide equivalent, a reduction of 26% since 1990, and a decrease of 64% in the emissions per inpatient finished admission episode. Of the 2019 footprint, 62% came from the supply chain, 24% from the direct delivery of care, 10% from staff commute and patient and visitor travel, and 4% from private health and care services commissioned by the NHS.InterpretationThis work represents the longest and most comprehensive accounting of national health-care emissions globally, and underscores the importance of incorporating bottom-up data to improve the accuracy of top-down modelling and enabling detailed monitoring of progress as health systems act to reduce emissions.FundingWellcome Trust.

The EAT-Lancet Commission has proposed a planetary health diet. We propose the development of the Planetary Health Diet Index (PHDI) based on this proposed reference diet. We used baseline dietary data obtained through a 114-item FFQ from 14,779 participants of the Longitudinal Study on Adult Health, a multicenter cohort study conducted in Brazil. The PHDI has 16 components and a score from 0 to 150 points. Validation and reliability analyses were performed, including principal component analyses, association with selected nutrients, differences in means between groups (for example, smokers vs. non-smokers), correlations between components and total energy intake, Cronbach's alpha, item-item correlations, and linear regression analysis between PHDI with carbon footprint and overall dietary quality. The mean PHDI was 60.4 (95% CI 60.2:60.5). The PHDI had six dimensions, was associated in an expected direction with the selected nutrients and was significantly (p p < 0.001) with a higher overall dietary quality and lower carbon footprint. Thus, we confirmed the PHDI validity and reliability.

BackgroundThe aim of this study was to estimate the carbon footprint and financial cost of decontaminating (steam sterilization) and packaging reusable surgical instruments, indicating how that burden might be reduced, enabling surgeons to drive action towards net-zero-carbon surgery.MethodsCarbon footprints were estimated using activity data and prospective machine-loading audit data at a typical UK in-hospital sterilization unit, with instruments wrapped individually in flexible pouches, or prepared as sets housed in single-use tray wraps or reusable rigid containers. Modelling was used to determine the impact of alternative machine loading, opening instruments during the operation, streamlining sets, use of alternative energy sources for decontamination, and alternative waste streams.ResultsThe carbon footprint of decontaminating and packaging instruments was lowest when instruments were part of sets (66-77 g CO2e per instrument), with a two- to three-fold increase when instruments were wrapped individually (189 g CO2e per instrument). Where 10 or fewer instruments were required for the operation, obtaining individually wrapped items was preferable to opening another set. The carbon footprint was determined significantly by machine loading and the number of instruments per machine slot. Carbon and financial costs increased with streamlining sets. High-temperature incineration of waste increased the carbon footprint of single-use packaging by 33-55 per cent, whereas recycling reduced this by 6-10 per cent. The absolute carbon footprint was dependent on the energy source used, but this did not alter the optimal processes to minimize that footprint.ConclusionCarbon and financial savings can be made by preparing instruments as part of sets, integrating individually wrapped instruments into sets rather than streamlining them, efficient machine loading, and using low-carbon energy sources alongside recycling.

PurposeIntravitreal injections (IVIs) are among the most frequently performed ophthalmic procedures and have been associated with a substantial carbon footprint. Travel-associated emissions are considered a key driver of IVIs' carbon footprint; however, no study in a country with a decentralised healthcare system has assessed IVI-related emissions. Here, the IVI-associated carbon footprint in an urban German tertiary referral centre was investigated.MethodsIn total, 340 patients were included. The carbon footprint was assessed based on the distance travelled by patients and accompanying persons, the mode of transport, and postoperative follow-up visits. Demographic data, treatment indication, and the injected medication were collected.ResultsThe average travel-associated CO2 equivalent (CO2eq) for a single IVI was 11.1 kg. Of this, 9.1 kg CO2eq and 2 kg CO2eq were due to travel to the injection clinic and to follow-up visits, respectively. Anti-VEGF treatment for common diseases such as age-related macular degeneration and diabetic macular edema was associated with a lower CO2eq compared with treatment of patients suffering from less prevalent conditions such as uveitis (10.8 kg vs. 15.6 kg). The majority of patients (49%) travelled by public transport (median distance: 22.4 km); patients travelling by car (33%) usually covered longer distances (median distance: 61.5 km).ConclusionTravel is a meaningful contributor to the carbon footprint of IVIs. Mitigation may be achieved by various approaches, such as longer-acting therapeutic agents or bilateral injections. To implement strategies for more sustainable IVIs, ophthalmologists may be encouraged by local and national bodies to incorporate environmental criteria into their practice.