It’s on our shelves. It fills our oceans. It’s in our food. And, these days, it’s pretty much guaranteed to be inside you too. Based on the undeniable testimony of once beautiful beaches and starkly-compromised stretches of sea, one of mankind’s most ubiquitous creations has turned toxic and now threatens its very existence – plastic. Or so we have been led to believe.

Even should you have been resident in the depths of the Marianas Trench for the last year or so, it can’t have escaped your attention that the tide has turned against this most multi-purpose of polymers. In state rooms from Britain to Singapore as well as within the boardrooms of such behemoths as KFC or Coca-Cola, there is a sudden, almost startled, awareness that single-use plastic is the Fifth Horseman of the looming eco-apocalypse.

Even more surprising, in a world characterised by climate change cynicism and declining-glacier deniers, there seems to be a degree of consensus that tackling this particular problem is a genuine priority. Sadly, this is probably because even the least green-minded government official can see for themselves that the world is already drowning in plastic.

Though some plastic waste is either incinerated or ends up as landfill, only a small amount – perhaps 10 percent – gets recycled. The vast majority of all surplus-to-requirements plastics ends up being carried out to sea. Whether washed up on beaches or carried along on waves, it doesn’t so much find its way into the environment as, we are ominously informed, actually become part of it.

We are already apparently seeing its effects. At present, it is estimated that more than 100,000 sea creatures die every year either from consuming plastics or by getting enmeshed within them. In the case of coral, an entity that takes years or even decades to mature and grow, its numbers are said to have declined by more than 50 percent over the last 30 years, largely because of plastic contamination, although disease and global warming have also taken their toll.

Then there’s the Great Pacific Garbage Patch – set between Hawaii and California, at 1.6 million sq.km, it is the largest of the world’s super-huge floating trash sites. An established danger to marine life and a clear environment hazard, the Patch also continues to grow at an alarming rate.

Interestingly – and this is where things start to get a little less clear – the environmentally aware activities of most consumers won’t make any real difference to its expansion or dispersion. This is largely because, contrary to popular belief, coffee cups and the mesh that holds together six-packs of beer are not necessarily the Big Bads when it comes to oceanic contamination.

In reality, 46 percent of the waste plastic that constitutes the Pacific Garbage Patch was actually derived from the equipment used by industrial fishing fleets. Even the remaining 54 percent is not down to Starbucks or Stella Artois, with it largely comprising other professional angling gear – notably ropes, guides, crustacean traps, crates and a miscellany of other maritime paraphernalia. The balance is made up by debris from the 2011 tsunami that devastated Japan, which accounts for maybe 20 percent of the whole.

If the current welter of scientific research has proved anything, it’s shown that, while empty soda bottles and takeaway meal wrappers might mar beachscapes across the world, inadvertently choking a seagull or two along the way, everyday waste is not the biggest global danger. Indeed, it’s clear that certain supposed evidence of the peril it presents has been exaggerated if not wilfully distorted.

Take the oft-repeated statistic that 500 million plastic straws are used – and discarded – in America every single day. It’s a figure that’s so huge, so tailor-made to prompt behavioural change (with a number of companies having already banned their use) that the anti-straw movement has gone from being a quaint notion to becoming a seriously belligerent environmental force.

While compelling it might be, it’s a statistic that falls apart even under the most cursory of  examinations. Firstly, even if the 500 million figure is true and even if all such straws are washed out to sea every day, on an annual basis, that’s still only 0.2 percent of global plastic wastage. Secondly – and even more fundamentally – the 500 million figure is based on the uncorroborated work of one individual – Milo Cress.

In 2011, Milo took it upon himself to estimate the scale of daily straw usage across the US. To this end, he called a number of local fast-food restaurants and straw manufacturers and then extrapolated his findings on a national basis. Unfortunately, at the time, Milo was not employed by a recognised scientific institution or government body. This was, in part, due to the fact that he was nine years old at the time. Nevertheless, this schoolboy’s apparent findings have been taken as fact by many environmentalists and now shape policies and help define priorities.

While such digressions have clearly clouded the issue, there is still enough proper science around to cause genuine concern, not least about the way that singleuse plastics enter the food chain. According to a study by the Scrippe Institution of Oceanography in San Diego, the fish population of the Pacific is ingesting plastic at a rate of between 12,000 to 24,000 tonnes per year. To put this into perspective, pretty much every time you tuck into a sushi roll or fillet of fish, you’re also treating yourself to a – probably unhealthy – dose of artificial polymers.

These come in the form of tiny plastic particles – known as microplastics and often less than a millimetre in length – which are now ubiquitous throughout the world’s oceans. Perhaps more worryingly, they also fairly ubiquitous in our own bodies.

Thankfully – while plastic isn’t likely to feature on any good diet guide any time soon – the jury is still out as to whether these minuscule particles are inherently harmful. While some polymer-derivatives – notably Bisophenal A (BPA), which can be absorbed through the skin and is utilised in everything from DVD cases to fruit-juice packets – have been tentatively linked to cancers, neurological issues and hormone imbalances, plastics are still seen as relatively low down on most respectable likely-to-kill-you lists. Indeed, mercury and a number of other naturally-occurring heavy metals are far more likely to see you off peremptorily.

To complicate matters still further, several scientists have claimed that seabird toxicity tests have shown that ingesting plastics may actually extend their lifespan. This is, supposedly, because potentially toxic materials (such as heavy metals and even radioactive particles) may bind to any such plastic and pass harmlessly through the bird. Of course, an equal number of scientists dispute this particular notion, finding it specious in the extreme.

As with many environmental issues then, the problem is knowing who and what to believe. With undisputed data hard to find and with many serious studies open to interpretation, it is clearly a challenge for the environmentally-minded citizen to know what to do for the best. The problem is of course compounded when fundamentally flawed – if well-meaning – pseudo-science, such as the 500 million straw myth, is accepted at face value and widely circulated.

While foregoing fast-food bendy straws and taking your own mug to Costa Coffee clearly isn’t going to harm the environment, it might be foolish to believe it’s actively going to improve the situation. Indeed, with just five countries creating more than half the world’s plastic waste and with industrial fishing fleets accounting for much of the oceanic contamination, it might be better for individuals to lobby for greater national and corporate responsibility rather than to berate any wayward straw wastrels.