Introduction

In fiscal 2024, Osaka Prefecture ran a project to prevent marine plastic litter and promote plastic recycling. As part of it, Pirika was commissioned to study how plastic beads leak from bead products during household waste collection, and to create awareness tools. We carried out research and analysis, and made tools to help reduce bead leakage and scattering. This case describes the survey, what we learned, and the awareness tools we made.

Interest in marine plastic litter is growing. The "Osaka Blue Ocean Vision" aims to end new pollution from marine plastic litter by 2050, and an earlier target of 2040 has also been set. Osaka Prefecture is active on this issue, and discussions on preventing bead leakage from products such as bead cushions have been held mainly through the "Osaka Plastic Countermeasures Promotion Platform." A fiscal 2023 survey of microplastics in rivers found that beads made up a few percent of the microplastics found in rivers. A survey that year also showed that bead leakage during household waste collection occurred in more than half of the municipalities in the prefecture. Countermeasures are urgently needed.

1. Soft, light foam beads

Foam beads used in cushions, pillows and sofas are small, soft, round grains made by foaming plastic resin. Products filled with foam beads are light and fit the body, so they are comfortable to sit or sleep on. Made of materials such as expanded polystyrene (EPS), they absorb shock well and are flexible, so they are also widely used as cushioning and packing material.
However, although they are useful and comfortable, the beads in cushions are tiny, about 0.3 mm to 6 mm, and easily pick up static electricity. Once they scatter or leak, they are hard to collect and clean up. Recently, cases have been reported in which bead products that were not disposed of properly burst in garbage trucks during collection and spilled onto the road.

2. Understanding the situation through a questionnaire

We sent a questionnaire to the household waste collection departments of all 43 municipalities in Osaka Prefecture and 10 designated cities outside the prefecture. The aim was to understand current practice on how bead products are sorted and put out, how they are collected, how often they leak, how leaks are handled, and what is done to prevent them. We wanted to provide guidance for better responses and prevention during collection.

Here are some results. Asked whether beads had ever leaked while bead products were being collected, more than 60% of municipalities said yes. On problems caused by beads spilling onto roads, common answers were "cleaning up beads takes time and delays collection" and "we cannot collect all the beads even after cleaning." These answers show concern about smooth collection and about leakage into the environment. (All answers are published here, in Japanese.)

3. Experiment recreating bead leakage and testing collection methods

At a waste treatment facility in the prefecture, we ran an experiment to reproduce how bead products scatter and leak from a garbage truck during household waste collection. We put beads in garbage bags into the truck, estimated how many beads leaked when the bags burst, and compared how much each collection method recovered from the road and how the methods differed.
Based on a review of existing microplastics studies, we chose polystyrene foam beads with a grain size of 1 mm as the test product. We put the beads into a garbage truck loaded with waste under various conditions and recorded how they burst and scattered. From the bursting tests, we estimated that about 10 to 20% of beads leak when a bag of beads bursts in a garbage truck.
Next, we scattered beads on the road and measured how much a vacuum cleaner and a broom with a dustpan could collect. With either method, about 80 to 90% of the beads could be recovered. However, the test was done on flat asphalt. At real spill sites, the recovery rate is expected to be lower than in this test, because of gaps in the pavement, drains, changes in weather such as wind and rain, and limited time for cleaning during collection work.

4. Proposed countermeasures and awareness tools

Based on the questionnaire and the experiment, we proposed the following measures to prevent leakage of bead products during household waste collection.

• Putting products out for collection:recommend steps such as attaching a paper label that identifies the item as a bead product, and not taking the product apart

• Sharing collection problems:tell residents about cases where leaked beads disrupted waste collection, and encourage proper disposal

• Stronger resident awareness: use municipal websites, sorting guide booklets and smartphone apps to explain how to put out bead products properly

• Cooperation from makers and sellers: promote voluntary take-back and recycling, and add notes on how to dispose of beads in product manuals, to strengthen awareness of proper disposal (to be done in line with relevant laws)

•  Environmental awareness: explain that beads leaking into nature may affect not only the scenery of rivers and the sea but also ecosystems, and encourage proper disposal from this viewpoint
  
  

To promote these measures, we made a case book that summarizes proper ways to put out bead products, examples of leakage, countermeasures and collection methods. We also made illustrations, photos, videos and flyer and web page templates that municipalities can use freely. (The templates can be downloaded from the "Results" section of this page, in Japanese.)

Conclusion

This project showed how plastic beads leak from bead products during household waste collection, and pointed to effective countermeasures and ways of raising awareness. We hope the survey results, analysis and awareness tools will help municipalities in Osaka Prefecture deal with bead leakage. Pirika will keep working with organizations in Japan and abroad to develop new methods and propose effective measures to solve the problem of plastic leakage.

Osaka Plastic Countermeasures Promotion Platform results:here (Japanese)

Materials from the 2nd Osaka Plastic Countermeasures Promotion Platform meeting: here (Japanese)

Osaka Prefecture microplastics survey: here (Japanese)