Plastic pollution is so prevalent that there’s nary a place on earth that is untouched by it, and the problem goes far beyond unsightly beaches and parks. A new study has found that flying insects contribute to plastic contamination by eating microplastics in polluted waters and carrying them through the air.
Microplastics – pieces of plastic less than 5 millimeters in size – remain in the bodies of mosquitoes and other waterborne insects, even after they become adults and take wing, according to researchers in the U.K.
The findings raise concerns that birds and other animals that eat insects are also becoming contaminated with microplastics and that the microscopic particles are working their way up the food chain.
And according to Amanda Callaghan at England’s University of Reading, the finding means that insects and animals that wouldn’t normally have access to microplastics may be consuming the contaminants, including spiders and bats. [2]
For the study, researchers from the University of Reading in England and Queen’s University in Belfast, Northern Ireland, inserted 2 microscopic particles of polystyrene into young mosquitoes and observed the winged creatures throughout their life cycles. Each piece of polystyrene weighed a mere 1 gram per cubic centimeter. [1]
The team discovered that the microplastics were still in the mosquitoes’ systems as they passed through each life cycle and eventually became flying adults.
The authors wrote:
“The transfer of microplastics to the adults represents a potential aerial pathway to contamination of new environments. Thus, any organism that feeds on terrestrial life phases of freshwater insects could be impacted by MPs found in aquatic ecosystems.”
The U.S. Environmental Protection Agency (EPA) explains that mosquitoes and other freshwater insects are consumed by birds, amphibians, fish, and other insects.
It is unfortunately quite common to read reports of sea animals being entangled by plastics, or washing ashore dead with a belly full of plastic bags and bottles.
However, most of the plastics in the ocean – 90% – are microplastics so small that they are invisible to the naked eye, measuring less than 10 millimeters in length. Even if a marine animal tried to avoid consuming plastic waste, it would be nearly impossible for them to do so. [3]
The Mariana Trench, the deepest point known in the world’s oceans, was once believed to still be in pristine condition. But in 2017, scientists made the grim discovery that the trench had not escaped plastic pollution, and was in fact in no better shape than some of the most polluted waterways in the world.
Just like you can’t see most of the stars in the night sky, you can’t see most of the plastic pollution threatening the planet. In fact, there are more microplastics in the ocean alone than stars in the sky. Let that sink in for a minute. [1]
Emma Priestland, from the charity Friends of the Earth, commented:
“This disturbing study raises real concerns about the prevalence of plastic pollution: it really is prevalent everywhere, not just the marine environment.”
She added:
“Knowing that plastic can be transferred from the larval stage to the adult mosquito, which then serves as food to a multitude of larger animals, highlights the urgency with which we need to drastically reduce our plastic consumption.”
Sources:
[1] CNN
[2] CNBC
[3] Smithsonian Magazine
Featured image credit: Current Biology, Wright et al. (altered)