"Plasticosis:" New disease in birds highlights dangers of microplastics
Scientists have described a new disease called plasticosis, which is directly caused by – you guessed it – plastic waste in the environment. While the disease has so far only been identified in the digestive tracts of seabirds, the scale of the problem suggests it could be widespread in other species and different parts of the body.
Plastic is one of the most ubiquitous materials in our modern world, so it’s not surprising that it’s also among the most common pollutants. Huge amounts of the stuff are accumulating from the Arctic to the Antarctic, from the deepest ocean trenches to the tallest mountain peaks. Microscale plastic fragments have been detected in the bodies of fish, birds, whales, seals, farm animals and humans, and the extent of the biological damage they cause is still being investigated.
For the new study, scientists from London’s Natural History Museum have now examined the ill effects on the health of a seabird species known as flesh-footed shearwaters, which previous studies have found to be among the most plastic-contaminated birds in the world. In doing so, the team found that the birds’ symptoms were so consistent that it warranted describing a new disease.
Plasticosis got its name due to its similarity to other fibrotic diseases caused by inorganic materials, like silicosis and asbestosis. Tiny shards of plastic become lodged in the birds’ digestive tracts, causing chronic inflammation and scarring that leads to a host of other problems.
The team found that exposure to microplastics inflames and scars the proventriculus, the first chamber of their stomach, until it eventually starts to break down. That can stunt the glands that secrete digestive compounds, which can affect their vitamin absorption and make them more vulnerable to infection and parasites. In extreme cases, chicks can starve to death because their stomachs become full of undigestible plastic.
For those that survive, plasticosis seems to stunt their growth. Larger amounts of plastic were associated with smaller overall weight and shorter wings.
So far, plasticosis has only been documented in the digestive systems of these flesh-footed shearwaters, but given how common the pollutant is, the team says it’s likely that the disease affects other species as well, and could cause similar scarring in other parts of the body. Investigating this could be an important step for future work.
The research was published in the Journal of Hazardous Materials.
Source: Natural History Museum