Microplastic emissions via air and compost from an industrial composting facility in England

ABSTRACT

Composting provides a sustainable method of processing biodegradable waste but is often contaminated with plastic. We quantified and characterised microplastics in air and compost samples from an industrial aerobic green waste composting facility in England. Compost samples were taken at different stages of the process; air samples were taken onsite, upwind, and downwind. Microplastics were found in compost from all stages of the process at levels comparable to those reported for marine sediments; higher concentrations were found in the screening stages of the composting process (mean 9.0 (IQR: 7.1) and 9.0 (IQR: 7.4) MPs 5 g-1 (dw), for 30 mm and 10 mm screened material, respectively). Airborne microplastics were found onsite (32–49 MP m⁻³), upwind (1 MP m⁻³) and downwind (3 MP m⁻³). Composting facilities represent a potential source of microplastics and point of entry to the wider environment. Further investigation into other sites and processes is warranted.

KEYWORDS:

• Microplastic
• compost
• waste
• airborne microplastic
• soil
• agriculture
• air quality

Acknowledgments

This study was funded by the Chartered Institution of Wastes Management (CIWM) via their Masters support programme. Philippa Douglas’ time was part-funded by the Medical Research Council (MRC)-Centre for Environment and Health via an early career research fellowship. Stephanie Wright’s time was funded by the MRC (MR/R026521/1). This work was partly supported by the National Institute for Health Research (NIHR) Health Protection Research Unit (HPRU) in Environmental Exposures and Health (NIHR200880) at Imperial College London.

The authors thank Kathy Nicholls from the Environment Agency (EA), Tina Benfield from CIWM, and Jenny Grant from the Renewable Energy Association (REA) for helping us identify a composting facility to conduct our sampling, and the composting facility staff for their hospitality and help when we conducted the sampling. The authors thank Emma Marczylo from the UK Health Security Agency (UKHSA) for allowing us to use a portable weather monitor (Kestrel™ 3000).

The views expressed are those of the authors and not necessarily those of CIWM, MRC, NIHR, EA, REA, UKHSA or the Department of Health and Social Care.

Disclosure statement

The work presented in this manuscript adheres to the ethical and legal requirements of the study country, the UK. The authors confirm that they have prepared the complete text. The authors of this manuscript do not have any conflicts of interest.

Notes

1. Personal communications with the Chartered Institute of Wastes Management (CIWM) and the Environment Agency, May–June 2017.

Additional information

Funding

The work was supported by the Chartered Institution of Wastes Management; Medical Research Council [MR/R026521/1]; National Institute for Health Research [NIHR200880].