The healthcare industry today is faced with an increasing volume of medical wastes, driven by rising patient numbers and the growing use of disposable medical supplies. Improper disposal of medical wastes may pose health risks through the release of pathogens and toxic pollutants into the environment. While 85% of medical waste is classified as  non-hazardous, the remaining 15% is considered to be carcinogenic, infectious, toxic or radioactive and needs to be treated appropriately.

As per the Health Care Without Harm Organization, about 4.4% of the greenhouse gases emitted comes from the healthcare industry, making it the fifth largest contributor to global emissions. Used plastic gloves, syringes, tubing, trays form a significant amount of medical wastes. They are derived from petrochemicals and when incinerated or left in landfills, they release carbon dioxide (CO₂) and other pollutants. Wastes like linen, dressing packagings are often disposed of in landfills where they decompose anaerobically, emitting CO2 and methane, which is a highly potent GHG.

There have been significant advances in medical waste management which offer safer and eco-friendly solutions to this problem.

Smart waste disposal containers

Segregation of medical wastes is of paramount importance to ensure an effective waste disposal process. The use of smart waste disposal containers and tracking systems in medical facilities have been found to be very useful in addressing this problem. These containers use IoT to sort wastes and are fitted with sensors that indicate the fill level. This not only prevents overspilling of bins  but also allows waste management teams to schedule pickups as and when required, thus cutting transportation costs and reducing Carbon emissions. This also enables facilities to monitor waste generation trends and modify their processes to minimize waste 

Autoclaves

A wide range of wastes like used dressings, surgical gloves, gauzes, PPE and drapes can be neutralized using autoclaves. Medical wastes are placed in the autoclave which is under vacuum, and steam at high temperature and pressure is introduced for a certain amount of time. Under these conditions, harmful bacteria, viruses, fungi, and spores are killed. The non-infectious waste can then be sent to a landfill or composted. However, autoclaves are not suitable for pathological wastes, chemotherapy waste, needles and tubing.

Electron beam sterilization

This has emerged as a ground breaking technology in medical waste management. Unlike conventional treatment methods, it does not use heat or chemicals; high energy electrons are used to destroy pathogens. The process does not produce any harmful byproducts and can sterilize the wastes in a matter of seconds. There has been significant growth in the use of this technology in the Middle East region, owing to its efficiency and eco-friendly nature.

Microwave sterilization

As compared to autoclaves, microwave treatment is energy efficient, lowering operational costs. Manual intervention is minimal and it’s a quicker process. The medical wastes are pre-shredded and a bit of moisture is added. The microwave energy causes the water molecules in the waste to oscillate, thereby generating heat which inactivates the microbes. This method does not require high pressure conditions and is found to be effective in neutralizing resilient pathogens.

Chemical disinfection

Chemical treatment is the preferred method to treat liquid wastes. It involves the use of chemicals containing chlorine like sodium hypochlorite, chlorine dioxide. Chlorine compounds kill microorganisms and denature proteins, and also oxidize hazardous chemical constituents. Though this method is effective and cheap, it can produce toxins and other harmful byproducts. Alkaline solutions like sodium hydroxide and quick lime hydrolyse proteins. A major drawback of using alkaline solutions is the potential hazard of exposure, as they are corrosive and can cause skin irritation and damage lungs.

The use of automation and smart systems in medical waste sterilization not only enhances operational efficiency but also monitors critical parameters in real time, minimizing contamination risks. Moreover, smart systems can support data integration across healthcare and waste management networks, facilitating informed decision-making and compliance with health and environmental regulations. The integration of advanced technology, automation, and smart systems is imperative in medical waste management to minimize energy consumption, optimize resource use and reduce the environmental footprint.

Dr. Manjula Nair is an Assistant Professor in Chemical Engineering, School of Engineering and Physical Sciences (EPS), Heriot-Watt University Dubai.