advertisement

Infectious Diseases

Updated 17 July 2020

OPINION | Covid-19: What is the risk from waste?

Are waste service workers becoming infected with SARS-CoV-2 through their work? Professor Wolfgang Preiser explains the science and puts the risks in perspective.

  • During the coronavirus pandemic, waste service employees are now widely acknowledged as essential service providers   
  • The burning question, though, is if these workers are getting infected through their work
  • Although South African waste producers are generally inconsiderate, the chances of getting infected through handling refuse are relatively small

Since the Covid-19 pandemic reached South Africa, many households have experienced changes to their refuse collection schedules. Most of these delays are due to waste depots closing temporarily after cases of Covid-19 occurring among staff. 

The work done by waste service employees, as is the case with staff at supermarket tills, is enjoying unaccustomed appreciation during the pandemic. They are now widely acknowledged as essential service providers, doing a physically tough, and not well-paid job, which was previously only noticed when the waste bin had not been emptied.

Are these newly respected essential workers becoming infected through their work? Is handling of household waste an occupational hazard? Are the precautionary measures introduced by municipalities sufficient? 

Manageable risk

It has been shown that under laboratory conditions (where many things are quite artificial but can be strictly  controlled) the aetiological agent, SARS-CoV-2, can "survive" (a better term would be "remain infectious") for between hours to several days, depending on the type of surface, temperature, moisture, presence of UV light, and so on. 

Guidelines are in place for the disposal of waste from households where someone is in quarantine (i.e. has been exposed and may be incubating infection, is not sick [yet] but could be infectious a day or two before symptoms start) or in isolation (i.e. is ill and known or suspected to be infected but does not need hospital admission). 

Potentially infectious waste such as used masks, gloves, or tissues, that have been in contact with a patient should be double-bagged and kept for a minimum of five days before being put out with the domestic waste. The reason for the five day waiting period is that the virus will not "survive" that long; even with no further measures, there will be no infectious virus left.

However, undoubtedly there are currently numerous undiagnosed cases of Covid-19 in affected communities, mostly people who are infected but not ill, or with only mild illness. These households will likely handle their contaminated waste with no special precautions, which means that potentially infectious items end up in the waste bin.

Risk of infection should be small

This too should not be much to worry about if those who handle the waste use gloves (not single-use medical latex ones which give a false sense of protection in most scenarios, but robust working gloves that can be washed or cleaned after use), avoid touching their faces, and regularly wash their hands or use alcohol-based hand rub, especially before drinking, eating or smoking. 

If municipal workers have been properly trained and equipped with the necessary protective equipment, and because they handle bins and bags rather than the waste itself, their risk of picking up infection from other people's rubbish should be small.

But still, cases of Covid-19 seem to be quite common among municipal solid waste staff. There is one major risk factor that likely explains this – other people, especially colleagues. 

Usually, a staff member becomes infected in their community and then inadvertently exposes other staff while working together. This is seen in many occupations, yet the risk of working together with colleagues who unknowingly may be infected, and infectious, is often underestimated.

This is true even for medical staff. When exposed to infectious patients, they wear appropriate personal protective equipment (PPE) but during breaks or on the way to and from work they interact with colleagues at close quarters and without precautions and may become exposed. I have not seen any studies, but would imagine that the same is true for municipal waste workers. It is not the actual work that poses a risk but the workplace which brings with it close and prolonged contact with co-workers.

What about waste-pickers?

So what about informal waste handlers? This largely unsupported informal industry provides an income to hundreds of thousands of people and accounts for most of South Africa's recycling, often recycling for the better-off who do not bother to recycle their waste.

Even though informal waste pickers usually have closer contact with waste items than staff who empty bins, there is probably not too much to worry about recyclables (PET or glass bottles, tins, paper, and so on). Even if someone for example coughed into their hand and did not wash it before disposing of a food or drinks container, it is unlikely that the virus would remain infectious for long on the container. Used tissues and masks may be an issue, though. If there is quite a large amount of secretions containing a lot of virus, the "dirt" may shield the virus and allow it to remain infectious for longer. 

Sadly, the sorry state of this neglected sector of the economy means that informal waste handlers will usually not have access to protective equipment, gloves and hand sanitisers, or the necessary training to use them even if they had them (when used inappropriately gloves can make matters worse rather than safer). 

So, those going through household waste in search of recyclables are at risk in places where there is rampant community transmission, like currently here in Cape Town.

What can we do? 

There would be no problem if those who generate the waste were considerate enough to separate their recyclables into clear bags and put them on top of the bin. This would spare waste pickers from having to forage through the contaminated mixed rubbish in search for recyclables. It should not take a pandemic to realise that subjecting others to go through one's rubbish is degrading and potentially dangerous. What about tuberculosis? HIV? Antibiotic-resistant pathogenic bacteria?

And no, this is not their choice but their only way of making a living – which all will agree is far preferable to not earning an income or turning to crime. This sector should be getting more recognition and support. Covid-19 could serve as a wake-up call, but so far there is little evidence of that happening in South Africa.

The Covid-19 pandemic and the various levels of lockdown it necessitated have had some positive, albeit temporary, environmental side effects. It has led to people generating more waste through being at home, cleaning out and eating in, and also throwing away things like masks, sanitising wipes and gloves. Recycling systems in many countries have stalled. 

The amount of waste most people generate was unsustainable to start with and must not be allowed to get even worse. The United Nations Environment Programme (UNEP) describes waste management as an essential public service in the fight against the pandemic and has published a number of useful fact sheets. 

Unforgivable preexisting problems

Widespread concerns about hygiene have been seized upon by the plastics industry that had seen its fortunes starting to change. Under the pretext of protecting from infection, unjustified bans on reusable shopping bags, coffee cups and other items have been implemented. Such bans are largely unnecessary; no-one should let themselves be fooled into thinking that going back to disposables will protect them from Covid-19.

Putting one's recyclables out separately for waste-pickers and if possible composting one's own biodegradable (kitchen and garden) waste are great and quite simple steps to start with. My municipal bin does not smell, as it does not contain biodegradable waste, which goes onto the compost heap, and it is 4/5 empty, as there are also no bulky recyclables.

As in so many spheres, the pandemic has revealed unforgivable preexisting problems. "Forcing" people to sift through one's rubbish has been and remains inhumane. Throwing away large amounts of mixed rubbish to fester in landfills and generate methane, a greenhouse gas many times more potent than carbon dioxide, is unsustainable and wasteful.

Like many, I also complain about inconsiderate bin-pickers leaving behind a mess – but the ultimate culprits are those of us who are too ignorant or simply too lazy to help them with a little extra effort so that they can go about their business in a dignified way. Let us make this one of the good things to come from the pandemic.

*Wolfgang Preiser is Professor and Head of the Division of Medical Virology, Department of Pathology, Faculty of Medicine & Health Sciences at Stellenbosch University, and National Health Laboratory Service (NHLS) Tygerberg. 

*He writes in his personal capacity.

*This article was produced by Spotlight – health journalism in the public interest. Sign up for our newsletter.

Image credit: