Well, I'm afraid this commenter has sufficiently gotten under my skin that I've continued the discussion.
I responded to...
"...I did read that 12/013 study showing that Lab. rats survived breathing truck diesel exhaust, but that was just rats, renowned survivors of unhealthy conditions such as sewers, rubbish tips etc. And if you think that lower Pm concentrations can justify higher than permitted NOX levels, think again, because NOX is what causes that horrible choking effect experienced by our bicycling friends above. You may claim that I am smelling "non-existent odours" but that is just your clearly prejudiced opinion. Arguing about what you or I can or cannot smell is a pointless exercise, unprovable either way. I shall continue to assert that neither I nor anybody else should have to breathe what I am aware of every time I have to follow even a latest model diesel vehicle on the road, and if you want to believe it holds no health hazards, then you breathe it.But please do not come here attempting to justify your use of it by claiming you cannot smell it, even in your garage.I and no doubt many others can do so, and dislike it intensely.
Lastly, in referring to the signatories to the open letter which was the subject of the original report here, as 'Big Business', I was being quite factual, with no suggestion of any Conspiracy theory. They were, in pressing such views, clearly, simply "pushing their Barrows", a saying which I suggest you familiarise yourself with, to understand its meaning, and spelling."
With...
"...Rats have been used routinely in inhalation studies. LC50 levels have been established based on lab rat survival rates at various concentrations of subject gases/vapors. NO2 (a component of NOx; NOx = NO + NO2) was the limiting factor in the ACES diesel exhaust study. The 4.2 ppm NO2 limit in the "high exposure" chamber is almost 100 times the ambient air quality standard limits for NO2 (0.053 ppm in the U.S.)
Even if real-world NOx emission rates from late-model diesels are as high as the one study you cite suggests, it's still less than half what the U.S. EPA says 1990s-era petrol cars emitted (~2 grams/mile). Even then, all areas in the U.S. meet the NO2 National Ambient Air Quality Standards (NAAQS) and have since 1998. And there's still the study that shows that real-world NOx emissions from diesel trucks have been reduced by 98%.
In fact, I breath diesel exhaust regularly, not only from my own diesel car in an enclosed garage, but following diesel cars and trucks on the highway. New diesel pickup trucks can easily be identified from behind; the tailpipes are large and ventilated. The large OTR trucks have DEF tanks clearly visible. I never smell any odor coming from the post-2007 diesels, yet I can clearly smell the exhaust of pre-2007 diesel trucks and buses. I can smell the exhaust of diesel farm tractors from as much as 1 km away if the wind direction is right.
Europe effectively required filters (DPF) on diesels after September 2011 (Euro 5b). I suspect the commenters here are misidentifying pre-2012 diesel car models for post-2012 models."
We'll see if the commenter wishes to continue this discussion.