The carbon footprint of pathology testing

To the Editor: The recently published article by McAlister and colleagues1 highlights the importance of health care organisations becoming aware of their environmental impact. However, there are several misconceptions inherent in the analysis.

The first misconception is that pathology organisations may not be aware of their environmental responsibility. The available literature describes how laboratories can reduce their impact2 and, in addition, some laboratories have ISO 14001 certification, which demonstrates their compliance with international standards of environmental performance, efficient use of resources and reduction of waste.

The second misconception in the analysis is that pathology testing produces a significant carbon footprint compared with other health care activities. Data from the British National Health Service show that indicative carbon emissions from inpatient admission, additional bed‐day stay, and outpatient appointments are about 380, 80 and 50 kg carbon dioxide equivalent (CO₂e) emissions respectively, compared with 82 g CO₂e for a haematology test.3 The highest emissions were associated with the consumables used in the collection process or the transport of the reagents from the overseas manufacturer to the laboratory.

The third error is that there is significant overutilisation of pathology tests. While there is some overtesting,4 considerable evidence also shows widespread underutilisation of testing.4,5 A 15‐year meta‐analysis identified that, on average, the rate of pathology testing overuse was 20.6%, but the underuse was 44.8%.4 It is noteworthy that a 2018 systematic review and meta‐analysis found significant overutilisation in diagnostic imaging.5

It is essential that all organisations reduce their environmental footprint. Health care organisations must ensure they achieve this goal without compromising patient care. Focusing on carbon emissions for phlebotomy without understanding the role pathology testing plays in early diagnosis and monitoring of disease may lead to more expensive interventions, poor patient outcomes, and a greater impact on the environment.