What about anomalies in NO2? An average Human body contains 10 times more nitrogen than sulphur, and they are definitely gonna escape into the atmosphere as oxides(NOx) if the body is being burned. I think there should also be a spike in NO2 if a mass cremation big enough to elevate SO2 so much actually happened. So far I haven't heard anyone talking about NO2 and I haven't seen any anomalies on that.