Diagnosis and Carbon Footprint: Rapid Tests, a More Sustainable Solution
Share
PCR Tests: A Precision Tool with High Energy Demands
The PCR test (Polymerase Chain Reaction) is renowned for its precision and sensitivity. In laboratories, it can detect trace amounts of genetic material, whether from viruses, bacteria, or other pathogens.
However, this method requires heavy and energy-intensive infrastructure:
- Specialized Equipment: The thermocyclers used to perform cycles of denaturation, annealing, and extension consume significant electricity. This high consumption results from constant temperature oscillations, ranging rapidly between 50°C and 95°C throughout the process. These repeated thermal variations require continuous heating and cooling, significantly contributing to their energy footprint.
- Logistics: Samples often need to be transported under refrigerated conditions, increasing the carbon footprint. One study highlighted that even for short distances (less than 5 km), transporting PCR samples from the veterinary clinic to the analysis laboratory generates a significant carbon impact¹. In addition to sample transport, PCR kits themselves must be stored at -20°C, requiring continuous refrigeration throughout the supply chain, further contributing to energy consumption.
- Analysis Time: A standard PCR test takes several hours, requiring prolonged equipment operation. It is not just the PCR process itself that is energy-intensive, but the entire analysis workflow, including sample preparation, nucleic acid extraction, data processing, and results management, each with a significant carbon footprint.
- Waste Production: The use of plastic consumables, such as tubes and pipette tips, as well as disposable equipment (gloves, gowns, masks), contributes to the generation of non-recyclable waste. A recent study¹ compared the environmental impact of PCR tests and rapid tests during the COVID-19 pandemic. It concluded that PCR tests, based only on the waste generated by their use, have an environmental cost that is significantly higher than rapid tests—up to five times greater—primarily due to the complexity of the process, which requires more resources to complete.
In summary, while PCR offers generally superior precision, it is associated with a high ecological footprint and significant energy costs.
Rapid Diagnostic Tests: Simplicity with Low Energy Impact
Rapid diagnostic tests are designed to detect specific pathogen proteins, such as viral antigens. These tests, often used for on-site diagnostics, provide clear advantages in terms of sustainability and practicality.
- No Complex Equipment Required: These tests do not need sophisticated laboratory equipment and can even be used without any energy, significantly reducing energy consumption.
- Quick Results: Results are available in 5 to 15 minutes, with no complex or energy-intensive steps involved.
- Portability and Accessibility: Easy to transport and store, they minimize the need for refrigerated logistics as they can be stored at room temperature. Generally, samples do not need refrigeration, as the analysis can be performed on-site.
- Reduced Waste: Although each test is single-use, the absence of complex processes greatly limits the production of additional waste.
Does more precision lead to better health benefits?
Recently, a study¹ also examined the health benefits of PCR tests and Rapid Tests for COVID. Surprisingly, the results show that there are no clear advantages in terms of overall effectiveness for PCR tests compared to Rapid Tests. Of course, these results were specifically evaluated for COVID tests and cannot be fully extrapolated to other pathologies, infectious or not, whether in human or veterinary contexts. The potential reasons behind this lack of clear health benefits will be explored in a forthcoming article that will delve deeper into the relationship between analytical performance and clinical relevance.
Comparison of Environmental Impacts
|
Criteria |
PCR Test |
Rapid Diagnostic Test |
|
Energy Consumption |
High (thermocyclers, refrigeration) |
Low (no equipment required) |
|
Diagnostic Time |
Long (several hours) |
Short (5-15 minutes) |
|
Transport |
Requires a cold chain for both samples and PCR kits. Samples often transported from veterinary care to the analysis laboratory. |
Easy transport, no special requirements. Sample processed directly on-site. |
|
Waste Produced |
High (plastic materials used throughout the long process) |
Moderate (test packaging only) |
Reducing Carbon Footprint with Hybrid Strategies
To meet both environmental needs and diagnostic precision requirements, a hybrid approach can be considered:
- Rapid Tests for Initial Screening: Use rapid tests as a primary tool for cases requiring immediate diagnosis.
- PCR for Necessary Confirmations: Reserve PCR for situations where confirmation or maximum sensitivity is essential, such as in complex cases or emerging epidemics.
Additionally, integrating eco-friendly solutions, such as solar-powered equipment or recyclable consumables, can further help reduce the overall carbon footprint.
Conclusion: Informed Choices for a Sustainable Future
Rapid Diagnostic Tests stand out as an eco-friendly and cost-effective solution for on-site diagnostics, especially when energy resources are limited. While PCR tests remain indispensable for their precision in certain cases, their use should be optimized to avoid excessive energy consumption. By choosing the right tool at the right time, it is possible to combine diagnostic efficiency, cost reduction, and environmental commitment.
References:
1 Courdier S, Bouchet A, Karlen M, Boucher J, D’Acremont V, Vernez D (2025) The direct emissions related to Global Warming Potential of different types of diagnostic tests at different phases of the COVID pandemic: A climate-focused life-cycle assessment. PLOS Clim 4(1): e0000561.
Follow us on Bluesky