20th February 2020 8:03 am

How to identify, measure and count microplastic fibres

How to identify, measure and count microplastic fibres 

How to Identify Microplastic Fibres

A microplastic fibre is :

• Often coloured
• Equally thick along its length, 
• Can bend in a three dimensional way
• Can fray or split at the ends or along its length
• Does not contain any cells or organic structures inside the fibre ( but can be coated with these)
• Can be clear or whitish in colour

Microplastic fibres can be confused with algae, cobweb, natural fibres from wool or cotton

Identification is often not easy.

Sometimes it is too difficult to be sure. In these cases, give results as number of definite, and number of possible fibres.         

This image is at x40 magnification. It is a sample taken from drinking water.

How to Measure Microplastic Fibres

Mark on the filter paper, one millimetre, ten millimetres then estimate the length and width of fibre. 

If the object is visible to the eye without a microscope, place a ruler next to it and estimate the  length.  

How to Count Microplastic Fibres

Counting from filter paper – If the fibres are well separated and easy to see, start at one end of the paper and move the paper slowly across, counting all the fibres. Either repeat this three times or get three people to count the same filter. Average the results. 

Count definite and possible fibres.

Counting from a petri dish – count the fibres by methodically looking at all the petri dish. 

If the fibres are in a tangle and there are a lot of them, state this. Estimate the number if possible. 

Stephanie Matthews Nov 2019