About 8% of the total. Monthly water samples were taken from inflows from 5 surrounding bogs. The average results were 0.58 microplastics/litre. To put this in context, it is about 25% lower than the microplastic concentration in the rainwater tests.
Were there differences in microplastics between the 5 inflowing streams?
No difference. All inflows contained a few microplastics, likely carried by wind or rainfall onto the back bogs. One of those 5 inflows is the North River (MacDonald Bay), which passes by highways and Bottle Lake. There was no statistically significant difference among the 5 inflows.
The risks of outliers. The column on the left shows the results of 13 of the 14 inflow samples. The column on the right shows all 14 inflow samples. One questionable sample was taken that is extremely different from the others. Was there temporary pollution at FR75M? Was there contamination in processing? Did last summer’s drought concentrate pollution? No one knows. The difference shows how scientific results can change when sample sizes are small. There are concerns about ignoring outliers, but in the following charts we focus on the 13 predictable samples.
