Sustainable Approach to Manufacturing
Green engineering means designing products for sustainable manufacture and use. That is, reducing waste and pollution during manufacture, promoting sustainability throughout the product’s life cycle, and minimizing the impact on both the environment and human health without sacrificing either efficiency or economic viability. The Sandestin Declaration of 2003 laid out the general principles of green engineering as:
The holistic use of systems analysis and integration of environmental impact assessment tools
Conservation of and improvement of natural ecosystems combined with the protection of human health
Using life cycle thinking in all engineering activities
Ensuring the safety of all materials and inputs and outputs
Minimizing the depletion of natural resources
Waste prevention
These principles are especially important when engineering for the healthcare field, as, while this sector has as its goal the protection of human health, it’s a very energy-intensive field, as well as being one of the largest producers of waste, emissions, and environmental pollutants that affect human health.
Globally, healthcare accounts for four-and-a-half percent of global greenhouse gas emissions. If worldwide healthcare were a country, according to the organisation Do No Harm, it would be the world’s fifth-largest emitter. The United Kingdom’s National Health Service alone emits 18 tons of CO2 each year.
As for pollution, during the first seven months of the COVID-19 pandemic, India alone generated more than 33,000 tons of medical waste. And the global market for medical waste management is expected to grow from an estimated $6.8 billion in 2020 to $9 billion by 2025.
So, how can green engineering strategies help to make healthcare less polluting, more sustainable, and better for people and the environment in general?
Life Cycle Strategies: Sustainable PPE
Disposable personal protective equipment is a major source of waste and pollution. No to mention the fact that its production is a significant source of emissions. According to a study in the British Medical Journal, the use of disposable masks and isolation gowns alone in 2020 produced carbon dioxide emissions equivalent to 78 coal fired power plants running simultaneously.
We’re used to thinking of single-use PPE as safer and more convenient. However, this same study found that reusable PPE is not only safe, but it’s also cheaper and, of course, produces significantly less waste. As an example, the use of reusable gowns at large US medical centers has saved hundreds of tons of waste from being sent to landfills, while saving nearly 50 percent of the per-gown cost. Moreover, the switch to reusables did not affect infection rates. Another US study found that using reusable respirators with filters, rather than single use N95 masks, could have reduced waste generation by 81 percent during the first six months of the COVID-19 pandemic, while costing 80 percent less. As for safety, many of the respirators in the study exhibited comparable or even greater safety than the single use masks.
The COVID-19 pandemic may be over, but the demand for single use PPE continues to grow. This is one area in which green principles for manufacture and use, applied throughout the life cycle of products, could make a real impact in both emissions and waste production.
Environmental Impact Mitigation: Green Facilities
Healthcare buildings are another area in which green engineering principles could really make a difference. The necessarily stringent hygiene standards and round-the-clock operation of these facilities mean they consume significant energy and produce significant amounts of waste, pollution, and emissions. Several recent studies have shown that we can do better.
Energy Consumption
There are several ways to reduce energy consumption by healthcare facilities through the design of the facilities themselves. Factors such as building size and orientation, window placement, and green roof construction can reduce the amount of energy needed for operations by 30 to 80 percent. Renewable power sources, such as solar panels, can lower fossil fuels consumption, and smart energy systems can also help to conserve energy. Reducing fossil fuels consumption can be cheaper, too. The Boston Medical Center, for example, saved $25 million in energy costs by switching to solar energy, and the Cleveland Clinic saved $50 million by investing in energy efficient buildings.
Additional progress can be made by refurbishing older buildings and retrofitting them with greener technology, as well as by training employees to use resources more efficiently.
Waste and Pollution
Switching from single use equipment and PPE is just one way in which healthcare facilities can reduce waste and pollution. According to the World Health Organization, only 15 percent of medical waste can be classified as hazardous. Reducing waste from this remaining 85 percent through sterilization and reuse, as well as recycling, is low-hanging fruit. McGill University Health Centre in Canada, for example, recycled 52 tons of electronic devices over the course of a decade, and saved between $1.1 and $1.5 million each of those years.
Emissions
Building with locally sourced building materials reduces the amount of travel required to transport those materials, and therefore travel-related emissions. Switching from single use PPE and equipment to reusables can reduce the emissions created to produce this equipment. And converting from fossil fuel power to renewable power can also go far toward reducing overall emissions.
Human Health Impact
A study of US hospitals has shown that integrated green design results in a higher satisfaction rate amongst patients. Improving internal environment quality can result in better outcomes for both patients and employees.
Furnishing materials are, perhaps, a less obvious but equally important place where green design can mean better outcomes in terms of human health. Much has been made of using antimicrobial materials such as copper for surfaces, or adding antimicrobial agents to surface materials in order to minimize the spread of infection. However, a recent study found that adding antimicrobial agents to surfaces did not, in fact, reduce infection rates during the COVID-19 pandemic. In fact, using these agents can have negative effects on human health, including but not limited to contributing to antimicrobial resistance. By contrast, designing buildings with adequate lateral ventilation and upper and lower diffusers on the sidewall can reduce the exposure of healthcare workers to virus laden particles by more than 70 percent.
Toward Greener Healthcare Design
Green engineering principles have the potential to transform healthcare products and facilities in a way that benefits patients, practitioners, communities, and the planet. Some of the ways in which these principles can be applied are obvious; others are, perhaps less so. In either case, the field has everything to gain by going green.