Environmentally sustainable gastroenterology practice: Review of current state and future goals.

OBJECTIVES: The health-care sector contributes 4.6% of global greenhouse gas emissions, with gastroenterology playing a significant role due to the widespread use of gastrointestinal (GI) endoscopy. In this review, we aim to understand the carbon footprint in gastroenterology practice associated with GI endoscopy, conferences and recruitment, identify barriers to change, and recommend mitigating strategies. METHODS: A comprehensive search of PubMed, Embase, and the Cochrane Library was conducted to explore the carbon footprint in gastroenterology practice, focusing on endoscopy, inpatient and outpatient settings, and recruitment practices. Recommendations for mitigating the carbon footprint were derived. RESULTS: This narrative review analyzed 34 articles on the carbon footprint in gastroenterology practice. Carbon footprint of endoscopy in the United States is approximately 85,768 metric tons of CO2 emission annually, equivalent to 9 million gallons of gasoline consumed, or 94 million pounds of coal burned. Each endoscopy generates 2.1 kg of disposable waste (46 L volume), of which 64% of waste goes to the landfill, 28% represents biohazard waste, and 9% is recycled. The per-case manufacturing carbon footprint for single-use devices and reusable devices is 1.37 kg CO2 and 0.0017 kg CO2, respectively. Inpatient and outpatient services contributed through unnecessary procedures, prolonged hospital stays, and excessive use of single-use items. Fellowship recruitment and gastrointestinal conferences added to the footprint, mainly due to air travel and hotel stays. CONCLUSION: Gastrointestinal endoscopy and practice contribute to the carbon footprint through the use of disposables such as single-use endoscopes and waste generation. To achieve environmental sustainability, measures such as promoting reusable endoscopy equipment over single-use endoscopes, calculating institutional carbon footprints, establishing benchmarking standards, and embracing virtual platforms such as telemedicine and research meetings should be implemented.

Laser vibrometry from a moving ground vehicle.

We investigated the fundamental limits to the performance of a laser vibrometer that is mounted on a moving ground vehicle. The noise floor of a moving laser vibrometer consists of speckle noise, shot noise, and platform vibrations. We showed that speckle noise can be reduced by increasing the laser spot size and that the noise floor is dominated by shot noise at high frequencies (typically greater than a few kilohertz for our system). We built a five-channel, vehicle-mounted, 1.55 µm wavelength laser vibrometer to measure its noise floor at 10 m horizontal range while driving on dirt roads. The measured noise floor agreed with our theoretical estimates. We showed that, by subtracting the response of an accelerometer and an optical reference channel, we could reduce the excess noise (in units of micrometers per second per Hz(1/2)) from vehicle vibrations by a factor of up to 33, to obtain nearly speckle-and-shot-noise-limited performance from 0.3 to 47 kHz.