Opening plastic packaging, such as plastic bags and bottles, may contribute to the generation of small amounts of microplastics – small plastic particles less than 5 mm long – during daily tasks, according to a new study.
Microplastics are generally believed to originate directly from industry, for example as cosmetic exfoliates, or indirectly from the breakdown of larger plastic items over time.
However, the contribution of daily tasks such as cutting, tearing or twisting open plastic packaging and containers has not been fully understood.
University of Newcastle researcher Dr Cheng Fang and environmental remediation colleagues in China and Australia, including Professor Youhong Tang and Liwei Wu at Flinders University, monitored the generation of microplastics during the tearing open of chocolate packaging, cutting of sealing tapes and opening of plastic bottle caps.
The generation of microplastics during these processes was confirmed using chemical tests and microscopy.
The authors found that different shapes and sizes of microplastics were generated during tearing or cutting.
These included fibres, fragments or triangles, ranging from nanometres to millimetres in size. Fragments and fibres were generated most often.
The authors estimated that 10 to 30 nanograms (0.00001–0.00003 milligrams) of microplastics may be generated per 300 centimetres of plastic during cutting or twisting, depending on the opening approach and conditions of the plastic, such as stiffness, thickness or density.
The results suggest that everyday activities such as opening plastic bags and bottles could be additional sources of small quantities of microplastics; however, their risk, possible toxicity and how they may be ingested are not yet resolved and further research into human exposure is needed.
The University of Newcastle, with scientists at Harbin Institute of Technology, Tiangong University, Chinese Academy of Sciences, Xiamen, and Flinders University conducted the study with funding from CRC CARE (Cooperative Research Centre for Contamination Assessment and Remediation). It was published last week in Scientific Reports (Springer Nature) DOI: 10.1038/s41598-020-61146-4
Modelling for the paper, including Raman characterisations of microplastics, was conducted at the Australian Microscopy and Microanalysis Research Facility at Flinders University.
‘Microplastics generated when opening plastic packaging’ by Zahra Sobhani, Yongjia Lei, Youhong Tang, Liwei Wu, Xian Zhang, Ravi Naidu, Mallavarapu Megharaj and Cheng Fang (March 2020) was published in Scientific Reports.