Ironically, after years of wool’s durability being a key promotion point, it might yet be its ability to break down at the end of its life that proves a compelling quality to promote to consumers. Richard Rennie spoke to lead researcher Stephen Ranford about what makes wool an environmentally friendlier option than plastic for the world’s oceans.
The level of plastics in the world’s oceans has reached truly staggering proportions.
In the relatively short period of only 50 years 160 million tonnes are estimated to be floating around the planet and a report released last year estimated by 2050 the weight of plastic will exceed that of fish in the sea.
AgResearch senior scientist Steve Ranford describes that amount of plastic as one of the greatest global challenges facing humans, with an impact that means we might be literally eating plastic without even realising it.
“While figures for total plastics are themselves quite staggering, the real risks to ocean food chains and sea life is in the microfibre plastics. These are less than 5mm in size that can be ingested by sea life and even possibly ultimately by humans eating seafood.”
Estimates are of the 12.5m tonnes of plastics put into the oceans every year, 3.2m tonnes are plastic particles less the 5mm in size.
One source is from wearing and washing synthetic clothing and other materials in washing machines.
Tiny fibres come loose with every wash and travel with water into drains and ultimately ocean outfalls with household grey water.
They then pass into the marine food chain and evidence exists of zooplankton ingesting floating micro plastics that then end up in bigger organisms, including whales. A significant tonnage reaches the deep sea floor, representing a risk of being fed on by bottom dwellers.
It is expected wool fibres, being a natural fibre made largely of protein, will break down at a faster and more environmentally absorbable rate than plastic products in the ocean.
Ranford’s team is working alongside Scion scientists to study the impact salt water has on the rate and method of wool fibre’s breakdown.
Past land-based research has given scientists some reassurance their hypothesis about wool’s benign ability to break down in marine environments will yield some encouraging outcomes.
“Earlier AgResearch work has included grinding up a piece of 100% wool carpet, burying it and then studying its effect on dry matter yield which increased between 24% and 82% in the study crop.”
The breakdown took place from two weeks to six months and the yield increase reflected wool’s natural organic components that count key nutrients like carbon (50%), calcium, sulphur, nitrogen , phosphorous, potassium and magnesium.
“So there is already proof that wool has this very positive end of life/recycling story to tell and, really, it’s a feature that has not been considered that much before when considering the tonnage of plastics entering the environment.”
As the world’s enormous spirals of plastic waste in the oceans threaten to join and expand, the wool industry is working hard to raise the profile of its natural fibre.
“The International Wool Textile Organisation (IWTO) already has some clear, industry-agreed standards that are already addressing environmental credentials, including animal welfare standards, scouring and processing techniques. These are all largely as a result of European Union requirements responding to consumer demands.
“These companies are operating with protein fibres in a sensitive way and now further scientific evidential information needs to be put in front of consumers to help them choose products.”
Many of the wool standards and processes now in play have also been sourced from New Zealand innovation work and Ranford hopes the results of the research on breakdown will provide more data for those standards.
He acknowledges there has been something of a gap in research over wool’s capacity to break down in an environmentally friendly way, with greater focus more on its naturalness as a fibre, performance when worn and animal welfare .
“There was some early work done during the Kuwait Gulf war period when wool-based oil booms were developed and that indicated bacterial and fungal breakdown did occur in marine environments.”
Scion’s researchers will use laboratory and pilot plant equipment to measure wool samples in a simulated marine environment for 90 days.
Sensors are providing in-situ data on breakdown rates and conversion of elements, including carbon, during the process.
But researchers are also curious about wool’s ability to maintain its durability and wearability despite it breaking down in a relatively short time in earlier soil-based experiments.
“You typically wash a wool item less frequently than other apparel items and it maintains its appearance and wearability for a long time.
“But if you did want to down cycle and biodegrade it at the end of its life you can also use it to grow plants.
“It is a fascinating, resilient product in the way it can maintain its life as a fibre when laundered correctly but will also have quite a positive effect at the end of that product life.”
