Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Developing a fast and reliable method to analyse Microplastics in environmental Sand and Sediment samples (#22)

Julia E Jaeger 1 , Robert Symons 2 , Sasha Koreshkova 1 , Mahyar Ghanadi 3 , Lokesh P Padhye 3
  1. Eurofins Environment Testing, Dandenong South, VIC, Australia
  2. Eurofins Environment Testing Australia, Girraween, NSW, Australia
  3. Department of Civil and Environmental Engineering, The University of Auckland, Auckland, New Zealand

Plastic, an indispensable material, has seen an exponential increase in production, with over 9 billion metric tons produced since 1950. Disposal and recycling haven't kept pace with the demand, resulting in a significant proportion of plastic waste ending up in the environment and contaminating our land, air, and oceans as microplastics. Toxicological studies have shown that microplastics can cause various adverse health and ecological effects.

While microplastics were first detected in the environment in 1972, it is only in the last 20 years that testing methodologies have been significantly advanced. Substantial efforts are currently being made worldwide to standardize methodologies for sampling and analysis, as well as the availability of suitable reference materials.

Three years ago, we established the first commercial laboratory for microplastic testing in Australia, using the Laser Direct Infrared (LDIR) Chemical Imaging System. We have combined these methodologies with our learnings from operating an ISO17025 accredited environmental laboratory. With our current setup, we can provide a determination of the particle enumeration, size, morphology, colour, and identification of microplastics in different environmental matrices, including clean and dirty waters, soils, biosolids, sand, sediment, and biota. We have implemented stringent quality control and blank measures to reduce the uncertainty of the results, and we aim to gain accreditation within the next year. To benchmark our laboratory, we participated in an international proficiency study by Southern California Coastal Water Research Project (SCCWRP). These results have been published in a peer-reviewed journal. Additionally, in collaboration with the University of Auckland, we have developed an improved sand and sediment analysis method. This new approach involves analysing a larger volume (100g) of sand to assess the microplastics load around Auckland's harbors. We have also conducted a comparative study with our original method using 5 g to ensure the accuracy and reliability of results.