It’s quite interesting to determine something like the LD50 of microplastic in earthworms and grasses which grow in that soil. It would be great if we could see a log-graph of plastic density versus when the effect drops off.
It’s also a good question to ask if it’s the plastic itself, or the impact of the plastic on pH. So for example if they added lime to keep the pH the same in both samples, does the effect in the plastic laced sample persist?
0.1% by mass seems like an incredibly high level. A cubic yard of topsoil (100 sq feet at a depth of 3 inches) weights about 1,000 pounds so 10 pounds of diffuse plastic in that area would be extraordinary.
