Inhaled anesthetics such as nitrous oxide (N2O), and halogenated gasses largely remain unmetabolized by patients during surgical procedures. Post-surgically they are exhaled where they enter the atmosphere in the operating room, a danger to medical staff, and then escape to the outside air where their greenhouse gas emission properties contribute to global warming. But that’s not all, halogenated gasses made up of chlorofluorocarbons or fluorinated hydrocarbons also damage the ozone layer.
CO2 is the greenhouse gas of headlines followed by CH4. Why? The former is produced by almost every modern human activity and it persists in the atmosphere for thousands of years.
CH4 lasts in the atmosphere on average a little more than a decade but its heat-absorbing capacity as a greenhouse gas is as much as 80 times greater than CO2, which is why the recent IPCC reports have stressed the need to tackle CH4 leaking natural gas and oil wells as an immediate priority.
Nitrous oxide (N2O) also is emitted by human industrial processes contributing to atmospheric warming. But as an anesthetic gas in use for more than 150 years, it has 298 times the greenhouse gas impact of CO2 and persists in the atmosphere for more than a century.
Finally, we have the halogenated gasses: chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), and perfluorocarbons (PFCs) with greenhouse gas properties thousands to tens of thousands of times more potent than CO2. These go by the names Halothane, Enflurane, Isoflurane, Sevoflurane, and Desflurane. How long do they persist in the atmosphere? It ranges from Sevoflurane at 1.2 years, to Isoflurane’s 3.6, and Desflurane’s 10.
A typical mid-sized US hospital, of which there were 7,380 in 2022, goes through 1,000 litres of these chemicals annually. In the journal Anesthesia Progress, a 2012 article estimated the equivalent greenhouse gas emissions contribution from these anesthetics equal to 4,780 tons of CO2 per year. That amounts to 35.27 million tons in total or the emissions equivalent of 8.8 million cars annually.
There are anesthetic gas capture technologies that can be installed in operating rooms. These are designed to extract the gasses before they escape to the outside. CONTRAfluran is one of these systems that separate, sterilize and store recaptured Desflurane and Sevoflurane from within the operating room environment allowing the hospital to sell the anesthetics back to their pharmaceutical producers. Another company Blue-Zone Technologies has produced Deltasorb and Centralsob canister systems that attach to anesthetic administering equipment in the operating room to limit emissions.
An article appearing in a 2017 edition of The Lancet, asks the above question. It notes that the overall benefit of anesthetic gasses needs to be in the environmental calculation. It also points to other areas of medical practice that need scrutiny in looking at the profession’s environmental impact. The article has produced ten examples of where medicine can make better choices. These include:
In Part 2 on this topic, we look at inhalers and their global warming potential.
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Think about what a 2.5% increase means over four years. Rounding down that is approximately 0.6% per year and when you calculate that annual growth you produce the following values:
In 37 years at the current rate of CO2 increases, we could see a 90 point increase, that is, if we continue to pay lip service to the carbon problem of our modern industrial model.
It should be of deep concern to all humanity that the paradigm of our existence threatens our existence as we know it.
At 499 ppm the 2 Celsius (3.6 Fahrenheit) degree rise that represents the upper limit of the Paris Climate Agreement becomes unachievable. The science used to calculate that upper limit was based on CO2 peaking at 450 ppm. At 499 we’ll be well over that.
Cold comfort comes from the tracking CO2 output from human activity for the last three years. Statisticians tell us CO2 output numbers have been flat, that current human activity hasn’t increased the amount of carbon being pumped into the air. The stated reason, the closing of coal-fired power plants with conversion to the burning of natural gas, combined with an increase in renewable energy.
Of equal concern is the measuring of other industrial greenhouse gasses being produced. What about methane (CH4) levels? What about nitrous oxides (NOx)? Are we measuring their atmospheric concentrations with the same degree of rigour as CO2? In a paper published in the last week in the Proceedings of the National Academy of Sciences, it notes that since 1850 CH4 in the atmosphere has doubled, and after a period of stability from 2000 to 2007 has been rising again. Since CH4 comes from both natural (cow flatulence and melting permafrost) and industrial sources (oil and natural gas fields) one could theorize that a combination of hydraulic fracturing in the United States and permafrost melt increases could explain the rise since 2007. But the paper further comments that the “current surface observation network” for CH4 is inadequate to the task and measuring the gas requires a level of diligence equal to what is being done with CO2.
As for NOx, an equally potent greenhouse gas, the trend indicates that it too is increasing in emission volume in the 21st century. What is the believed cause? Fossil fuel combustion, application of fertilizers containing nitrogen, and the burning of forests in tropical areas. As in the case of CH4, NOx emission tracking lacks the resources deployed to study CO2.
So we have three potent greenhouse gasses contributing to mean atmospheric temperature increases, with a good handle on one, CO2, and far less on the other two. Should we assume that when we begin to bend the CO2 output curve downward we will also see CH4 and NOx declines? Or do we need to be addressing each of the three differently with individual global strategies?
With President Donald Trump in office, and with Scott Pruitt at the head of the Environmental Protection Agency (EPA), we have chief climate policy influencers from the second largest carbon polluter on the planet paying little attention to what I have described above. The President has defined climate change as a “hoax.” And the head of the EPA, a non-scientist has expressed his opinion that CO2 is not a “primary contributor” to global warming. Don’t ask the President or the new EPA head about CH4 and NOx. Neither will register.
This week the United States government has indicated it will announce whether the country will honour the commitments made in the Paris Climate Agreement. The head of EPA has described the agreement as a “bad deal” for the United States.
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What they don’t talk about is the impact increased CO2 has on the oceans of the world. Most studies of the ocean talk about increasing acidification. What they don’t talk about is the impact of climate change on other gasses in the ocean, in particular, oxygen. A newly published study appearing in Research Letters in the February 16, 2017, issue of the journal Nature, analyzes data from the last five decades, looking at salinity, temperature and gas mix in the world’s oceans at multiple depths.
Projecting their findings which show a decline over the past 5 decades, the researchers project an additional 7% decline in oxygen content with “detrimental consequences for fisheries and coastal economies.” The study accumulates observations available from ocean surveys dating back to 1903. Oxygen levels, the study notes, show regional variation. But one thing clearly stands out. Overall, the oceans are trending towards dangerous deoxygenation. The study further notes a growing number of “dead zones” in the ocean where oxygen levels are in such low concentration that most animal life is untenable.
The scientists further correlate the oxygen decline with ocean warming. Oxygen solubility appears to be directly impacted by surface warming, and as the ocean cycles water vertically, the impact is reduced levels in deeper waters. The research assessed the entire water column continuously since 1960. In some areas of the ocean oxygen levels declined 4% per decade. The largest decreases were found in the Arctic, North and Tropical Pacific, Southern Ocean surrounding Antarctica, and the South Atlantic. These areas accounted for almost 60% of the total oxygen decline. In the water column, large losses were observed at depths from 2,000 meters to the ocean floor.
Based on these findings climate modelers project accelerated oxygen losses going into the next century at rates 25% greater than what has been observed from collected data. The end result increased volumes of anoxic water, that is dead zones, with substantial changes to ocean ecosystems.
The other impact oxygen depletion will have is the production of nitrous oxide (N2O). This potent greenhouse gas can be found in the upper 500 meters of the ocean water column. Deoxygenation plus surface ocean warming from increases in the atmospheric temperatures, when combined, are seen as agents for N2O production. Adding another greenhouse gas to the mix which includes CO2 and methane (CH4) will further accelerate overall warming of the planet.
States Matthew Long, an oceanographer at the National Center for Atmospheric Research, “It is alarming to see this signal begin to emerge clearly in the observational data. Since ocean deoxygenation is intrinsically linked to climate warming, substantial action to mitigate climate change will be required to reverse the trend of oxygen loss.”
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Professor Gouma is also director of the Center for Nanomaterials and Sensor Development at the university and it is this particular expert knowledge that has led to the development of what will become a first response detection system available over the counter for under $20.
The manufacturing process for creating the micro-spaghetti nanowires is called electrospinning, a process that involves shooting a liquid ceramic compound through a syringe into an electrical field. The electrospun fibers crystallize as tiny threads that are captured on an aluminum backing.
Electrospinning is a technology of the 21st century. It is simple and versatile allowing manufacturers to easily fabricate nanostructures on an industrial scale for use in electronics, photonics, pharmacology, and chemical engineering. A single syringe of liquid ceramic can produce a nanowire that can stretch from the Earth to the Moon. Different nanowires can be designed to be sensitive to specific molecules. A particular nanowire could detect nitrous oxide, associated with asthma and stress-related illnesses. A nanowire could be used to detect ammonia, a marker for kidney disease, or acetone, indicating diabetes. Nanowires could be used to detect the presence of viruses, e-coli, anthrax, salmonella, high cholesterol levels and different cancers.
Breathalyzers have been around for awhile. So why is this device worth talking about? Because it takes the technology from institutions like hospitals, or police departments, and turns it into a mass market, consumer product. The device is still undergoing testing but we should soon see breathalyzers using this technology on drugstore shelves.
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