Illustration: Elena Scotti (Photos: Shutterstock)
GarbageThis week, we are writing about waste and trash, examining the junk that dominates our lives, and digging through garbage for treasure.  

The world is trash. Even leaving aside the garbage of regular citizens—the many stadiums’ worth of shit and piss, plastic cups and pill bottles, scrapped cars and dead dogs dispensed of every day, every hour of every day—there is the world-withering, endlessly-accumulating waste of the industrial variety, which could toxify every inch of the globe, or at least those few inches that haven’t been toxified already. There is such an astonishing quantity and variety of waste coursing in, around and above the planet that it can be easy to think of all of it as one dense, destructive substance—but there are degrees. Some kinds of trash are worse than other kinds, and it is worth knowing which is which, as we hover in the mudroom of apocalypse.

And so, for this week’s Giz Asks, we reached out to a number of experts—in geography, paleobiology, environmental science, engineering and more—to figure out the absolute worst trash that humans produce.


Josh Lepawsky

Associate Professor, Geography, Memorial University, and leader of the Reassembling Rubbish research project, a five year examination of the issue of e-waste

Here’s the thing: there is no universal human who creates the same trash of the same type, tonnage, or toxicity everywhere on Earth. There is also no universal human experience of the harms from different kinds or amounts of wastes and the different forms of damage they can inflict.

Household trash put out for curbside pickup in many US or Canadian cities often contain chemicals from ordinary household cleaning products that can be acutely poisonous and lethal. When you look at statistics for death and injury on the job, being a trash collector is about as dangerous as being a firefighter.

Radioactive wastes from nuclear power generation might grip the imagination of a ‘worst waste’ since their harmful effects last thousands of years. Yet, that kind of longevity is relevant to other types of wastes like plastics and their associated chemicals, even in ordinary municipal landfills.

Other wastes, like persistent organic pollutants (POPs) released from herbicides, pesticides, and a range of other industrial applications, can travel great distances from where they are initially manufactured or used, for example in industrial agriculture. Yet, POPs harm people and wildlife at great remove and who have nothing to do with the applications to which those chemicals are put, especially through the biomagnification of these toxicants in food chains.


Jan Zalasiewicz

Professor, Paleobiology, University of Leicester

We’re spoilt for choice, in trying to work out what our most dangerous trash is. The millions of tons of plastics that are circulating through the oceans–and through the bodies of myriad sea-creatures, often with lethal effect? The pesticides and other persistent organic pollutants still being poured across landscapes, and that are prime suspect in the crash of insect populations worldwide? The radioactive pollutants that are still scattered in dumpsites worldwide, and that will be dangerous for millennia? All these are large and growing problems for the health of our planet – and for our own health and that of our children, not to put too fine a point on it.

I suspect, though, that our most dangerous trash is the one we cannot see, or feel, or smell, or touch. Hanging in the sky above us is something of the order of a trillion tons of carbon dioxide, mostly a by-product of our voracious appetite for burning fossil fuels, and mostly released in the last century (and that we now are adding tens of billions of tons to each year). That’s the equivalent of about one hundred and fifty thousand great Pyramids of Khufu. Or, separate it out as a layer of pure carbon dioxide gas around our planet, and it would be about a meter thick – and growing thicker by about a millimeter every fortnight.

This is the trash that–in the gargantuan amounts we are emitting–is already altering the heat balance of our planet, heating both atmosphere and oceans–and acidifying our oceans, too, and slowly driving life-giving oxygen from them. Unless we actively remove it, this extra, unwanted, carbon dioxide will be there for many thousands of years. This is the trash that can really, truly alter the character of a planet, and threaten the lives of its inhabitants. With this particular trash, it really is time to clean up.


Travis P. Wagner

Professor, Department of Environmental Science & Policy, University of Southern Maine

The award goes to high-level nuclear waste. This includes primarily spent (used) radioactive fuel from civilian reactors and wastes related to nuclear weapons under the purview of the U.S. Department of Energy. High-level nuclear waste is thermally very hot, highly radioactive, and toxic. Although in comparison to larger quantity wastes (e.g., coal combustion ash, hydraulic fracturing-fracking waste, and mining waste) the quantity of high-level radioactive waste is small, it is its longevity that is a major concern, and gets it my vote for the worst trash we generate.

There is no working technology yet that can fully treat or neutralize high-level nuclear waste; the only management approach is isolated storage and time to allow for natural radioactive decay. The radioisotopes produced in reactors remain hazardous from a few days to many thousands of years. The U.S. EPA has set an acceptable emission standard for the first 10,000 years of long-term, safe storage, referred to as the compliance period. (They also set an emission standard for the second phase; 10,000 to 1 million years.) To put this in perspective, assuming each human generation is 25 years, 400 generations of Americans will have to maintain safe storage of the waste.

Yet we do not have a long-term strategy to safely manage this waste. Very early in my career, back in 1987, I was reviewing environmental documents for the long-term repository proposed for Yucca Mountain, NV. More than 30 years later, we have no permanent disposal repository planned or proposed for high-level nuclear waste in the U.S. (In 2010, Yucca Mountain was deemed not workable and we have no other candidate sites.) Because the generation of the waste continues, we have to store it somewhere, which means primarily next to where it is generated. The waste is being stored temporarily in 40-feet deep water pools (74%) or in dry steel-concrete casks (26%). Currently there is approximately 90,000 metric tons stored at 80 sites (5 government sites, and 75 commercial sites) in 35 states with the majority of these sites east of the Mississippi River. The US generates about 2,000 metric tons each year. Given the expected life span of commercial reactors, the total estimate to be generated by the US will be about 140,000 metric tons. The impacts of climate change are also a consideration. Sea level rise could impact spent fuel storage at 13 civilian plants that were built in coastal areas.

So, in summary, as long as there are no leaks, all should be good. But in practical terms, can we store a highly problematic waste for 10,000 years without leaks? Unless scientists or engineers in the next 10,000 years develops technology to better manage it—fingers crossed.


Joseph Gardella

Professor, Chemistry, University of Buffalo, SUNY

I work with contaminated abandoned industrial (many of the chemical industry) sites, storage of radiologicals from WW2 uranium production for the atomic bombs, here in the region of Love Canal.

Yet I think the most insidious and dangerous trash is plastics from petroleum. Most consumer plastics packaging, and most plastics trash generally, are plastics that were invented from petroleum byproducts in the 30s, 40s and 50s. I’m a polymer (plastics) scientist myself, and can say that there have been three decades of development of biodegradable plastics that could be used as a substitute for plastics like polyethylene (HDPD and LDPE in the recycling jargon) and polypropylene (PP), which come from petroleum and last a long time, and for polystyrene (PS) and polyvinyl chloride (PVC), which are made from monomers (the basic building block of a plastic) that are carcinogens.

We have invented plant-based plastics that biodegrade, but the subsidies we as a country and society offer to the petroleum industry keep us stuck with ancient technology because it’s “cheaper.” These end up in drinking supplies like the Great Lakes, Rivers and streams as microplastics and broken pieces of other plastics.

Plastic pollution in the ocean is a crisis, and in the Great Lakes it’s a big problem, too.

So, plastics. The future really is great but... not for old, shitty plastic that will not break down.


R. Ryan Dupont

Professor, Civil and Environmental Engineering, Utah State University, whose research focuses on wastewater reuse, stormwater harvesting, waste reduction and pollution prevention, and sustainable waste treatment systems

Humans generate a great variety of trash as a by-product of our modern industrial society. Much of the waste is biodegradable and can cause adverse impacts to humans and the environment if not managed properly, but these materials eventually biodegrade and become part of natural material cycles.

The waste components that are not biodegradable pose the greatest risks to us and the environment, because they can persist for long time periods and can migrate great distances from where they were disposed of. Natural physical weathering processes act on these materials to physically degrade them; the degraded products get physically smaller, but don’t degrade to more basic, elemental components.

In the trash or solid waste category, the material that poses the greatest risk to us and the environment, because it has a long lifetime, and because of its tendency to migrate long distances from its disposal location, is plastic, particularly that made into thin films and bags. Single use plastic bags and films are made of non-renewable materials which produce hazardous waste when they are made; the bags and films are difficult to recycle and contaminate many recycling streams, they easily blow in the wind from landfills, garbage trucks, etc., they can be carried into waterways and streams where they are physically weathered to form microplastic beads and fibers that have contaminated drinking water supplies and aquatic environments, they can be ingested by wildlife to undesirable ends, and are generally a nuisance everywhere they are found.

Much of this material is produced for consumer “convenience,” yet there is a growing demand to ban these materials and provide consumers with reusable, more durable and sustainable alternatives. For many, many reasons, elimination of this waste component of our modern trash is not only feasible, but the right thing to do.


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