Birds are under threat due to plastic pollution (Image: Eye Ubiquitous)
Manufacturers add the toxins to help plastic function better and they include flame retardants, UV filters, colourants and phthalates, which keeps it flexible.
But the danger these pose to wildlife has been dubbed a “veiled pandemic” by scientists because, unlike other plastic litter that creatures can get entangled in or swallow, it can’t be seen.
Prof Jon Blount, from Exeter University’s Centre for Ecology and Conservation, has been studying eggs of Cornish Herring Gulls – an endangered species on the UK’s “red list”.
He found phthalates in each of the 13 he examined – at levels of up to 282% the safe limit for humans. He said: “Concerns are rapidly rising about these plastic additive chemicals. It’s the unseen part of the iceberg.
“We are aware of the plastic pollution problem because we can see it. But we cannot see the chemicals, which are, potentially at least, a far greater risk.”
Prof Blount is preparing another study to track the gulls to the source of their food and determine what impact the chemicals passed on from mothers have on developing chicks.
He said: “We don’t know whether the level of phthalates, for example which we found in the eggs, are at a level which will cause an impact on development and survival and so on.
“But it seems highly likely. Firstly, any chemical contamination exposure at that critical stage in life when cell populations are being established is likely to be harmful. And we know the level of some of these phthalates exceed the daily tolerable intake levels set by regulatory bodies for humans by some considerable degree.”
Research into the contamination of other bird species is limited but there is no doubt “the chemicals are turning up all over the place”, including in the oceans of the Arctic,” he added.
“If we find what we think we might find in a year or two, then we can engage with stakeholders and government and let them know about the results. It’s entirely possible that exposure to these chemicals could be impacting on breeding success, therefore over long periods of time impacting on the viability of populations.”
However he pointed out that recycling plastics is not a panacea, as the process itself releases chemicals. But he added: “It’s important to raise awareness.”