Medical waste is not only waste which we should dispose of anyways, but it also poses some health hazards in most cases.
What would be some good ways to dispose of such medical waste (syringes for vaccinations, medical waste of testing covid patients) so that it is sustainable as well as safe ? Can this even be done given the high amounts of medical waste that would be produc ?
The issue with syringes is size and sanitation. Unfortunately, plastics are cheap, malleable, and can be easily sterilized. And with such a vast need for these kinds of needles at the moment, the materials used aren't likely to change.
These things do have to be disposed of separately from normal waste and treated carefully as to avoid exposing people to contaminated materials. Medical waste is collected separately and either sanitized and dumped, or incinerated.
Nivedita is probably right in that until new technology is available, the carbon emissions is probably unavailable. Utilizing plastics that don't leach as many toxics into the surrounding environment is a good next step.
As far as I know, medical waste is considered hazardous because it can infect people or cause other health risks to people and nature. It is not possible to landfill it. It is incinerated to avoid contact with the environment. The process of dealing with medical waste is pretty straightforward because it all just gets burned in a massive chimney. Probably the only thing that can be done to make this waste less environmentally degrading is that the toxic chemicals that are released during incineration are captured and converted to less harmful substances and stored carefully. The carbon released is probably unavoidable, but the toxic chemicals are avoidable.