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Microfibres, Microplastics and Pollution

The loss of fibres from synthetic textiles during washing, and the persistence of these fibres in aquatic ecosystems, has in the past few years emerged as an area of major concern.

Scientific research on microplastic pollution has started only recently, gaining momentum as study after study has revealed the growing prevalence in marine, freshwater and terrestrial environments.

Natural fibres such as wool are biodegradable. They do not accumulate in the environment but break down naturally to harmless compounds. However, in conjunction with a project on the use phase of wool products, IWTO's Wool LCA TAG is currently evaluating information on the loss of natural fibres in the environment, the rate at which they biodegrade, and the potential for impacts or concern.


We need to talk about plastics

As plastic has become cheap and readily available, its use has incresed 200-fold: the latest data shows that global production of plastic resins and fibers increased from 2 million metric tons in 1950 to more than 400 million metric tons in 2015, outgrowing most other man-made materials. The pace of plastic production shows no signs of slowing. Of the total amount of plastic resins and fibers produced from 1950 to 2015, roughly half was produced in the last 13 years.

Synthetic textiles are a major user of plastic, now consuming 588 million tonnes per year. As the use of plastics increases, so does the generation of plastics waste.

Because plastic degrades very slowly, if at all, the amount of waste is growing rapidly. Microplastics, defined as particles and fibres < 5mm in diameter, are a particular concern because of their rapid accumulation in aquatic environments and on beaches where there is an estimated 2000 kg per square meter globally.

Microplastics arise either from fragmentation of larger pieces of waste (secondary sources) or from direct release (primary sources). 

It is estimated that globally 3.2 million tons of microplastics are released per year from primary sources such as the road abrasion of synthetic tyres and the shedding of fibres during washing of textiles such as nylon, acrylic and polyester. This second type of direct release is referred to as microfibres.

Microfibre impact

Microfibres is the term used to refer to this second main type of microplastics pollution. As wash-water drains from laundry machines and moves through waste sytems to treatment plants, microfibres are carried along. They slip through wastewater treatment plants into marine and freshwater systems, accumulating in oceans and shorelines where they can enter the food chain through ingestion by aquatic organisms.

Ingestion has a negative impact on organisms, sometimes causing death through starvation as plastic replaces food in the stomach.

Understanding of the impacts on human health of consumption of seafood containing microfibres is still in its infancy but it has now been shown that while most of the fibres pass through the body a small fraction is retained. Recent measurements found that more than 80% of the world's drinking water contains microfibers.

Microplastics also occur in soils due to the use of wastewater treatment sludge as fertiliser though less is known of the fate and effects in soil systems.  

A natural difference

Natural fibres biodegrade naturally in a relatively short period in warm, moist conditions. Therefore, they do not accumulate in soils the way plastic fibres do.

There is evidence that natural fibres would also biodegrade in oceans, with one study finding that a pair of wool gloves would biodegrade in marine environments in one year. 

Wool has been shown to be biodegradable in marine environments, in laboratory and on-site testing. In vitro experiments in New Zealand showed surface damage to wool fibres after 21 days incubation in sea water. Degradation of wool fibres in situ in Lyttleton Harbour was clear after three months, and at eight months bacteria that degrade protein had increased, the fibre surfaces were pitted, and the structure of wool fibres had deteriorated.  Visual observations, microscopic studies and microbial analyses confirmed the action of the wool degrading bacteria. In contrast to terrestrial biodegradation, degradation of wool in the marine environment was not dominated by actinomycete and fungal components of the microflora but by marine bacteria. 

What wool can do

It is IWTO’s position that a  key action to reduce microsynthetic fibre pollution must involve reducing consumption of synthetic fibres both through maximising the proportion of natural fibre in global textile products and avoiding purchase through retaining and reusing clothing.

In particular wool's natural properties support less frequent, lower impact washing, greater durability, and established pathways for recycling. These properties also combine to mean that fewer garments need to be produced adding to the benefits of not adding to microplastic pollution.


Read More

Wool & Sustainability: In the Industry and On the Farm

Wool Reuse & Recycling

IWTO's Work on Wool & the Environment

Wool LCA

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