Waves break against the shore,
every quiver spitting scree
and scum
into the warm
and flawless sky;
heavy mouthfuls of
unseen waste
that cut
and prod
and delve.
We try to count the cost
with eyes too wide to see,
every breath a sharp
and rancid taste
of what we failed to save.
This poem is inspired by recent research, which has found that the microplastics in Auckland’s air are equal to 3 million plastic bottles every year.
Over the last 70 years, 8.3 billion metric tons of plastic have been produced globally. Only 9% of these have been recycled, with the rest either incinerated or released into the environment. Nanoplastics are tiny particles that range between 1 and 100 nanometres in size (for scale one nanometre is equal to one billionth of a metre), meaning that they can potentially enter cells, cross the blood-brain barrier, and build up in organs such as the testicles, liver, and brain. Similarly, microplastics (i.e., materials containing particles that are less than 5 millimetres in size) have also been detected in human lungs and in the lung tissue of cancer patients, indicating that the inhalation of atmospheric microplastics is an exposure risk to humans. However, given the difficulty of detecting such small particles, it is likely that researchers have been dramatically undercounting the amount of airborne microplastics.
In this new study, researchers in Auckland, New Zealand have used sophisticated chemical methods to find and analyse particles as small as 0.01 millimetres. Using this approach, the researchers calculated that 74 metric tonnes of microplastics are dropping out of the atmosphere and onto the city every year, the equivalent of more than three million plastic bottles falling from the sky. The average number of airborne microplastics detected in Auckland in one square metre in a single day was found to be 4,885. This compares with estimates from other, previous studies of 771 in London, 275 in Hamburg, and 110 in Paris. Given that these are all cities that have traditionally been assumed to be much higher polluters than Auckland, it is likely that we have been significantly underestimating the extent of this issue. Whilst the waves breaking in the Hauraki Gulf may play a key role in Auckland’s problem by transmitting water-borne microplastics into the air, future work is now clearly needed at a global level to quantify exactly how much plastic we are breathing in.