Though it is common to see environmental videos of birds caught in plastic, less well known is that, like cats, seabirds love to eat it.

Paracelsus famously noted that the dose makes the poison but in the 1990s some activist scientists began claiming that any dose is a poison, so even if birds excrete the plastic, chemicals can "bioaccumulate" and cause harm.

While that notion remains controversial, a new paper in Environmental Monitoring and Contaminants Research engages in a What If? scenario based on an analysis of 32 species of seabirds sampled from around the globe. They worry that if estimates are correct, in the next 30 years nearly all species of seabirds may have ingested plastic at some point. If bioaccumulation is real biology, it could cause a problem.

The science community disagrees it is a worry outside known chemicals like lead and mercury and others. Chemicals added to bind, stabilize or otherwise improve plastic used in food packing and fishing gear and more do not leach or accumulate in biological tissues as they are kneaded into the polymer matrix during plastic production, but if oily components in digestive fluids can act as organic solvents to facilitate leaching, then the authors say it might be possible.

During a pandemic, when we want people to take a COVID-19 vaccine, it is difficult to read fantastic claims about biology that alleges scientists simply have not discovered yet, when those are the claims people opposed to the COVID-19 vaccine make. How accurate is it in this instance?

To make their case, the scholars analyzed oil from the preen gland, located just above the tail, from 145 seabirds in 16 different locations around the world. By examining the chemical concentrations in this oil, the researchers can determine the contaminant burden of the bird’s internal fat stores. They procured the oil by wiping the gland, which can be done without harm to the bird. They also examined the preen gland oil and stomach contents of 54 bird carcasses found on the beaches.

The researchers found one additive accumulated in 16 of the birds, and other additives in 67 of the birds.

So it did accumulate. Is it harmful? The authors concede there is no evidence there is a reason for concern, the study is exploratory, so they only state that 10 percent or more of the world’s seabirds may be able to accumulate chemicals directly from ingesting plastics.