I want to say one word to you. Just one word. 'Plastics'. So goes the dialogue in a scene from The Graduate, filmed in 1967. Fast forward to 2019, and it’s not hard to imagine that this might be the answer to an exam question, ‘Name one of the planet’s biggest environmental problems’. While plastics might have many desirable properties – they are durable, lightweight, cheap – the corollary to that set of properties could easily be: persistent, buoyant, abundant.

Hardly a week goes by without a story emerging about how or where plastics have turned up in an unexpected place. If it’s not in the local creek or Sydney Harbour, it’s at the bottom of the Mariana Trench, photographed by a remote-controlled deep-sea submersible. Any number of famous people are having their say, with even the Prince of Wales lamenting how he was ignored 40 years ago when he raised concerns about plastics.

The problem is well illustrated by the piles of recyclable waste that have been growing around Australia following the refusal of several countries in Asia to take any more of our contaminated ‘recyclable’ wastes. Disposable nappies contain plastic, so used ones must be recyclable, so the thinking seems to go. Never mind that the plastic tube of caulking compound is still a quarter full; it’s made of plastic so it must be recyclable.

The sight of an ephemeral urban creek in western Melbourne, with the reed beds festooned with waste plastic items, got me thinking about the pathways by which plastic items and materials make their way into the environment. The empty soft-drink bottle doesn’t go directly from the factory to the creek. Fishing line and plastic mesh don’t leap off jetties and boats, fatally attracted to sea life. No. The common vector is the human hand. The disposable cup, the plastic bag, nearly every piece of plastic got into the environment by human action. Why should this be so?

I’d suggest that a major factor is that the positive attributes I listed for plastics all lend themselves to plastic items being used only once. It’s the ‘single-use’ item that is discarded. If something is designed for repeated use, there is a strong chance that someone will take care of it and seek to use it again. The proliferation of single-use items has fostered the throw-away mentality.

Perhaps the exemplar is the story of cutlery and crockery on planes. Fifty years ago, the knives and forks were likely to be metal, but the tea/coffee cups were often lightweight melamine, and all were intended for multiple use. The spectre of hijacking put an end to metal cutlery, but the quest for light weight, and lower costs, has seen the disposable item come to the fore; plates, cups, trays, spoons, all used once and then thrown away. Qantas has recently sought to make a virtue of this, with a recent flight that produced no items for landfill. All the food and beverage containers were compostable, but still only single use. Maybe the environmental footprint of washing a planeload of reusable items is greater than that of using compostable, single-use items, but it’s all the same approach. Use once, throw away.

So, the answer is obvious. It consists of one word: people. It’s people who are to blame for the piles of plastic clogging up the water and the land. The question is, which is easier – changing the human behaviours that cause littering and pollution, or going down the biodegradable and compostable path. However, to do the latter still requires the former. People need to recognise what is recyclable or compostable, and then take action to ensure this can happen. Unfortunately, collection systems for recyclable and compostable materials are almost identical to those for more intractable wastes. It’s all a black box (well, a big green bin) that solves the problem for us. A truck empties your domestic wheelie bin once a week or fortnight. It seems that many householders lack the knowledge to make the right the decision. The ACT Government has recognised this, and is running an awareness campaign to improve the composition of the recyclable waste stream. We await the outcome with interest. The old manual systems of collection, usually employing a two-person team (a truck driver and a runner), with separate crews for paper and glass items, were effective at segregating the waste but were labour intensive. Now, one driver in a truck collects the comingled contents of the bin, and sorting becomes someone else’s problem. Except, we can now see that it’s a problem for all of us. With the recent financial collapse of a Victorian recycling company, things may get worse before they get better.