Probably a typo km/m2 >>kg/m2
We can see the anomaly in SO2 actual from the NASA data itself: https://so2.gsfc.nasa.gov/pix/special/time_sres/time_series.html
This clearly shows some crazy spikes right then and there for Eastern Asia. Look at the scale, ffs, its off the charts:
And there's also a weird data hole around Feb 2 (0 everywhere).
Doesn't mean we know what it was from, but it cannot be denied that there are/were crazy spikes in SO2 over that region recently.
Yes there no unhealthy level of SO2 in Hawaï right now:
Which means that the SO2 concentration is below 0.10 ppm (part per million)
0.1 ppm is close to 300μg/m3
At 9:00 UTC Windy showed less than 100μg/m3, so this level was unhealthy.
But at 12:00UTC, the figure raised to 400μg/m3
(With modified colors)