Carbon footprints stemming from health care have been found to be variable, from 3% of the total national CO2 equivalent (CO2e) emissions in England to 10% of the national CO2e emissions in the USA. We aimed to measure the carbon footprint of Australia's health-care system. We did an observational economic input-output lifecycle assessment of Australia's health-care system. All expenditure data were obtained from the 15 sectors of the Australian Institute of Health and Welfare for the financial year 2014-15. The Australian Industrial Ecology Virtual Laboratory (IELab) data were used to obtain CO2e emissions per AUS$ spent on health care. In 2014-15 Australia spent $161·6 billion on health care that led to CO2e emissions of about 35 772 (68% CI 25 398-46 146) kilotonnes. Australia's total CO2e emissions in 2014-15 were 494 930 kilotonnes, thus health care represented 35 772 (7%) of 494 930 kilotonnes total CO2e emissions in Australia. The five most important sectors within health care in decreasing order of total CO2e emissions were: public hospitals (12 295 [34%] of 35 772 kilotonnes CO2e), private hospitals (3635 kilotonnes [10%]), other medications (3347 kilotonnes [9%]), benefit-paid drugs (3257 kilotonnes [9%]), and capital expenditure for buildings (2776 kilotonnes [8%]). The carbon footprint attributed to health care was 7% of Australia's total; with hospitals and pharmaceuticals the major contributors. We quantified Australian carbon footprint attributed to health care and identified health-care sectors that could be ameliorated. Our results suggest the need for carbon-efficient procedures, including greater public health measures, to lower the impact of health-care services on the environment. None.

Objectives: Hospitals are significant contributors to natural resource depletion and environmental change. Our objective was to establish the extent to which hospital environmental sustainability has been studied and the key issues that emerge for policy, practice and research. Methods: The PubMed, Engineering Village, Cochrane and King's Fund databases were searched for articles relating to hospital environmental sustainability published in English between 1 January 1990 and 1 October 2013. Further studies were found by review of reference lists. One hundred ninety-three relevant articles were found and 76 were selected for inclusion in the review. Results: Common research themes were identified: hospital design, direct energy consumption, water, procurement, waste, travel and psychology and behaviour. Some countries (particularly the United Kingdom) have begun to invest systematically in understanding the environmental effects of hospitals. We found large variability in the extent of the evidence base according to topic. Research regarding the architectural fabric of hospital buildings is at a relatively mature stage. Similarly, there is a developed research base regarding devices and technologies used within hospitals to reduce the environmental effects of direct hospital energy and water use. Less is known about the clinical, psychological and social factors that influence how health care professionals use resources, travel to/from hospital, and interact with the buildings and technologies available. A significant part of the environmental footprint of hospitals relates to clinical practice, e.g. decisions regarding the use of pharmaceuticals and medical devices. Medical ‘cradle to grave’ life cycle assessment studies have been published to understand the full financial and environmental costs of hospital activities. The effects of preventive or demand management measures which avoid unnecessary hospital procedures are likely to be much greater than incremental changes to how hospital procedures are performed. Conclusions: There remain significant gaps in the evidence base on hospital sustainability. Assessments of environmental impacts and natural resource use are beginning to be produced, both at the level of individual hospitals and at the health system level. These are an important start, but in many areas do not yet provide sufficiently detailed information to guide decision-making. There are many areas where the interests of patients and the environment coincide, but others where tensions exist. Rising resource costs and climate change mitigation measures are likely to create an increasing stimulus for research on hospital sustainability. Such research will benefit from inter-disciplinary coordination across research funders and countries.

Background. An innovative approach to choosing hospital equipment is to consider the environmental costs in addition to other costs and benefits. Methods. We used life cycle assessment to model the environmental and financial costs of different scenarios of replacing reusable anaesthetic equipment with single-use variants. The primary environmental costs were CO₂ emissions (in CO₂ equivalents) and water use (in litres). We compared energy source mixes between Australia, the UK/Europe, and the USA. Results. For an Australian hospital with six operating rooms, the annual financial cost of converting from single-use equipment to reusable anaesthetic equipment would be an AUD$32 033 (£19 220), 46% decrease. In Australia, converting from single-use to reusable equipment would result in an increase of CO₂ emissions from 5095 (95% CI: 4614–5658) to 5575 kg CO₂ eq (95% CI: 5542–5608), a 480 kg CO₂ eq (9%) increase. Using the UK/European power mix, converting from single-use (5575 kg CO₂ eq) to reusable anaesthetic equipment (802 kg CO₂ eq) would result in an 84% reduction (4873 kg CO₂ eq) in CO₂ emissions, whilst in the USA converting to reusables would have led to a 2427 kg CO₂ eq (48%) reduction. In Australia, converting from single-use to reusable equipment would more than double water use from 34.4 to 90.6 kilolitres. Conclusions. For an Australian hospital with six operating rooms, converting from single-use to reusable anaesthetic equipment saved more than AUD$30 000 (£18 000) per annum, but increased the CO₂ emissions by almost 10%. The CO₂ offset is highly dependent on the power source mix, while water consumption is greater for reusable equipment.

Pathology testing and diagnostic imaging together contribute 9% of healthcare's carbon footprint. Whilst the carbon footprint of pathology testing has been undertaken, to date, the carbon footprint of the four most common imaging modalities is unclear. We performed a prospective life cycle assessment at two Australian university-affiliated health services of five imaging modalities: chest X-ray (CXR), mobile chest X-ray (MCXR), computerised tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US). We included scanner electricity use and all consumables and associated waste, including bedding, imaging contrast, and gloves. Analysis was performed using both attributional and consequential life cycle assessment methods. The primary outcome was the greenhouse gas footprint, measured in carbon dioxide equivalent (CO₂e) emissions. Mean CO₂e emissions were 17·5 kg/scan for MRI; 9·2 kg/scan for CT; 0·8 kg/scan for CXR; 0·5 kg/scan for MCXR; and 0·5 kg/scan for US. Emissions from scanners from standby energy were substantial. When expressed as emissions per additional scan (results of consequential analysis) impacts were lower: 1·1 kg/scan for MRI; 1·1 kg/scan for CT; 0·6 kg/scan for CXR; 0·1 kg/scan for MCXR; and 0·1 kg/scan for US, due to emissions from standby power being excluded. Clinicians and administrators can reduce carbon emissions from diagnostic imaging, firstly by reducing the ordering of unnecessary imaging, or by ordering low-impact imaging (X-ray and US) in place of high-impact MRI and CT when clinically appropriate to do so. Secondly, whenever possible, scanners should be turned off to reduce emissions from standby power. Thirdly, ensuring high utilisation rates for scanners both reduces the time they spend in standby, and apportions the impacts of the reduced standby power of a greater number of scans. This therefore reduces the impact on any individual scan, maximising resource efficiency. Healthy Urban Environments (HUE) Collaboratory of the Maridulu Budyari Gumal Sydney Partnership for Health, Education, Research and Enterprise MBG SPHERE. The National Health and Medical Research Council (NHMRC) PhD scholarship