The carbon footprint of pathology testing

Abstract

Objectives:To estimate the carbon footprint of five common hospital pathology tests: full blood examination; urea and electrolyte levels; coagulation profile; C-reactive protein concentration; and arterial blood gases.Design, setting: Prospective life cycle assessment of five pathology tests in two university-affiliated health services in Melbourne. We included all consumables and associated waste for venepuncture and laboratory analyses, and electricity and water use for laboratory analyses.Main outcome measure: Greenhouse gas footprint, measured in carbon dioxide equivalent (CO 2 e) emissions.Results: CO 2 e emissions for haematology tests were 82 g/test (95% CI, 73-91 g/test) for coagulation profile and 116 g/test (95% CI, 101-135 g/test) for full blood examination. CO 2 e emissions for biochemical tests were 0.5 g/test CO 2 e (95% CI, 0.4-0.6 g/test) for C-reactive protein (low because typically ordered with urea and electrolyte assessment), 49 g/test (95% CI, 45-53 g/test) for arterial blood gas assessment, and 99 g/test (95% CI, 84-113 g/test) for urea and electrolyte assessment. Most CO 2 e emissions were associated with sample collection (range, 60% for full blood examination to 95% for coagulation profile); emissions attributable to laboratory reagents and power use were much smaller. Conclusion:The carbon footprint of common pathology tests was dominated by those of sample collection and phlebotomy. Although the carbon footprints were small, millions of tests are performed each year in Australia, and reducing unnecessary testing will be the most effective approach to reducing the carbon footprint of pathology. Together with the detrimental health and economic effects of unnecessary testing, our environmental findings should further motivate clinicians to test wisely.The known: Health care ultimately generates 7% of national carbon emissions in Australia. A considerable proportion of the cost of health care in Australia is associated with pathology services (12% of Medicare spending). The new:The overall carbon footprints of five common hospital pathology tests, measured as carbon dioxide equivalent (CO 2 e) emissions, ranged between 0.5 and 116 g CO 2 e, equivalent to driving a car between 3 m and 0.8 km. The implications:Opportunities to reduce the carbon footprint of pathology testing are limited. The greatest environmental benefit can be achieved by reducing unnecessary testing. Environmental impact, together with cost-effectiveness and health outcomes, should be considered when ordering tests. 25 Bell KJL, Doust J, Glasziou P, et al. Recognizing the potential for overdiagnosis: are high-sensitivity cardiac troponin assays an example? Ann Intern Med 2019; 170: 259. 26 Bjørn Morten H. Too much technology. BMJ 2015; 350: h705. 27 Spelman D. Inappropriate pathology ordering and pathology stewardship. Med J Aust 2015; 202: 13-15. https://www.mja. com.au/journ al/2015/202/1/inapp ropri atepatho logy-order ing-and-patho logy-stewa rd ship 28 Pathirana T, Clark J, Moynihan R. Mapping the drivers of overdiag...

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“…Process-based LCAs arrive at an environmental cost for an item or activity based upon directly measured material inputs and using LCI databases that report emissions associated with those materials. For example, recent process-based healthcare analyses of blood pressure cuffs, 75 and pathology tests 76 measured the weights, compositions, and actual use of such items in detail. Process-based LCAs tend to focus on a small, targeted, easily defined product or process and are excellent for making comparisons (e.g.…”

The carbon footprint of pathology testing

“…To the Editor : The Royal College of Pathologists of Australasia (RCPA) is concerned with some of the conclusions drawn in the article by McAlister and colleagues 1. We support the suggestion that there are opportunities for reducing waste and carbon dioxide emissions in pathology laboratories and, with the RCPA Quality Assurance Programs, we encourage laboratories to reduce their environmental impact whenever possible.…”

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“…Reducing carbon emissions by health care requires clear understanding of current emission levels and their sources. McAlister and his co‐authors describe their assessment of the carbon footprint of five pathology tests commonly performed in hospitals . They found that sample collection, because of the consumables involved, is the most carbon‐intense component of a pathology test.…”