Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Impact of microplastics (unleached and leached of additives) on the growth of white mustard (Sinapis alba) and perennial ryegrass (Lolium perenne). (#63)

Helena Ruffell 1 , Fiona Given 1 , Claudia Allan 1 , Claudia Meisrimler 1 , Olga Pantos 2 , Brett Robinson 1 , Sally Gaw 1
  1. University of Canterbury, Ilam, CANTERBURY, New Zealand
  2. Institute of Environmental Science and Research, Christchurch, New Zealand

Microplastics are an emerging contaminant of concern for the terrestrial environment. These persistent contaminants have an associated burden of chemicals (inherent and acquired) which may be released into the environment, and subsequently be taken up by plants and animals.1 The impact of microplastics in soil on plant growth has previously been investigated in pot trials using a range of polymer types and plastic concentrations. Reported toxic effects of soil microplastics on plants include delayed germination, reduced growth, and an increase in the production of reactive oxygen species.2 Published studies on the influence of chemical additives in the microplastic particles are sparse, and those which have mainly focused on the impacts of adding the leachate only to the growing medium.3 Only limited studies have attempted to determine if the reported effects of microplastics on plants are due to the microplastics or the additives.

 

To address this data gap, two pot trials using leached and unleached MPs were undertaken. The first trial was with white mustard, Sinapis alba, and the second with perennial ryegrass, Lolium perenne. Leached and unleached microplastics < 1 mm (polyester (PET); polyethylene (PE); and polylactic acid (PLA)) were added to the pot soil at 1% (dry weight) as separate treatments. The impacts of leached and unleached microplastics on physiological parameters including growth and oxidative stress along with uptake of essential and toxic trace elements will be discussed.

  1. Allan, I.J., Samanipour, S., Manoli, K., Gigault, J., Fatta-Kassinos, D., 2022. Examining the relevance of the microplastic-associated additive fraction in environmental compartments. ACS ES&T Water 2, 405-413.
  2. Zhou, J., Wen, Y., Marshall, M.R., Zhao, J., Gui, H., Yang, Y., Zeng, Z., Jones, D.L., Zang, H., 2021. Microplastics as an emerging threat to plant and soil health in agroecosystems. Sci. Total Environ. 787, 147444.
  3. Menicagli, V., Balestri, E., Biale, G., Corti, A., La Nasa, J., Modugno, F., Castelvetro, V., Lardicci, C., 2022. Leached degradation products from beached microplastics: A potential threat to coastal dune plants. Chemosphere, 135287.