NOx attacks lung tissue. It is common for any chronic exposure to damaging agents to be associated with an increased cancer risk, but NOx shows a distinct correlation while, for example, SO2 does not. But, saying "cancer-causing NOx" is somewhat sensationalistic IMHO, especially when considering the points made by tbuelna.
Here's an hour-long video on this topic. Towards the end, one investigator reveals that he found a set of tables in his ECU code with distance over time limits that match the testing criteria, and there's logic to disable the AdBlue dosing if it's not staying within the limits. He backs up his findings with dyno testing.
Daniel Lange (DLange), Felix "tmbinc" Domke: The exhaust emissions scandal („Dieselgate“)
Well while we're discussing the theoretical adverse effects of NOx, I can contribute in that in cases of large quantities of exposure, one of the more immediate fatal consequences is known as "odema of the lungs" This occurs when the body recognises that the interior lining of the lungs has been damaged and the lungs start to produce large quantities of fluids in an attempt to repair the damage. The problem is, this is extremely similar to drowning..fluid in the lungs in both cases and you wake up dead. Twice in my underground career (35 years ago) I coughed up large quantities of blood due to excessive exposure to blasting fumes which contain, EXTREMELY large percentages of NOx. WE always know when its present because it gives the blast smoke a very characteristic red colour. I probably inhaled more NOx on those two occassions than 10,000 people in Los Angeles would inhale in their collective lifetimes. If I die tomorrow, its not likely to be due to NOx exposure. This issue REALLY is blown out of proportion by the tree huggers.
Funny you should say that , that was another observation from my blasting days, the guys who smoked could re=enter the smoke a lot sooner than I could... I guess all the tar etc inside their lungs protected them from the NOx
The smoking gun is that the actual ECU code reportedly contains the 'distance over time' limits of the test cycle.
One thing I'm confused on is that I thought that the original VW Dieselgate was for cars that didn't have the SCR system with the AdBlue urea injection. The cheat found here relates to a car with the SCR system.
It's the same/similar. It originated with the vehicles that did not have SCR, but evidently they continued using it, presumably in the interest of reducing AdBlue consumption.
It is entirely conceivable that the SCR catalyst, even on the newer models with SCR, was designed and sized to be just barely adequate for the light engine loads seen during the official test procedure, and that running the engine at the higher loads often seen in real world driving will not adequately react the NH3 and NOx. If that is the case then cranking up the AdBlue dosing rate is not going to fix them.
But, at least those cars HAVE an AdBlue storage and dosing system. If they have to change the SCR catalyst for a bigger one, so be it.
Image attached is the 'punch line' for those that don't have time to review the whole thing (slides or video, links already provided just above). The six straight lines were reportedly found in the form of tables in the ECU code; they’re piecewise Time & Distance descriptions of something. The wiggly line is the Time & Distance integration of the defined Test Conditions. BTW, Mr Lange traced the logic right through to the AdBlue dosing, and backed-up his findings with a dyno run.
