The Survey Says

[RH77]

Originally Posted by Big Dave

Strange you mention asthma. After 1980, SO2 ambient concentrations declined but asthma cases have increased by the same margin. Maybe a whiff of SO2 has a therapeutic effect.

What is your source? Perhaps the overall average of rural locations U.S. vs. places like urban L.A. show a decrease.

I rarely ever use this in this forum, but my job is to study trends in disease and the effect of pharmaceutical drugs to be either accepted or rejected by the FDA for that disease/condition. My foundation in this career was to study Asthma across 14 studies and validate data (from Pediatric cases to the Elderly). I saw real patient diaries of symptoms from places like rural Nebraska to Los Angeles.

Cross-referencing confidential data with published effects of PM/SO2/NOx, a clear trend shows that dense, urban areas suffer with the old Diesel tech (including ex-US locales like London). I mean this in the utmost of respect -- consider multiple studies, their Scientific weight, and form your own educated opinion.

RH77

[DifferentPointofView]

I have asthma and thing that really bothers me the most is cigarette smoke, cats, and dry grassy/pollen infested air. gas and diesel fumes I'm not sure, but I'm pretty normal until I get around that stuff. It starts with my eyes itching and burning then me wheezing. cigarette smoke is the worst though.

[Big Dave]

I'll defer on the incidence of asthma, but as for the overall ambient concentrations I refer to the report the EPA is required to submit to congress every four years by the statute enabling the formation of the EPA.

For all my dislike of the EPA, one thing thing they do well is monitor air quality. They have a network of thousands of monitors scattered about the country, mostly in urban/suburban areas. These monitors automatically measure concentration of "criteria" pollutants every twenty minutes. The national average is the average of 26000 samples a year at each location - literally millions of samples annually. They sample for the following:

PM10 (particulate matter of less than 10 microns diameter)
SO2
NOx
Ozone (surrogate for LA-style smog)
CO
Lead

Since 1976, when monitoring really got going, the national average concentration for each pollutant is way, way down. Lead has almost disappeared from the air. PM10 is down 60%. SO2 is down 70%, Ozone is down 40%. Carbon monoxide is down 90%.

A smaller particle called PM2.5 (2.5 microns or less) has become an item of interest. As a rule PM2.5 concentrations are about 5% of the PM10 concentrations.

All trends have been steadily down but are tailing to flat as they hit the asymptote. From here on, any improvements will be very small and very, very expensive. Two exceptions. Air quality could substantially improve if the failed New Source Review program were replaced with what was called Clear Skies. The big exception is that a huge improvement in air quality would be realized if the nation substituted nuclear energy for fossil fuel for electric power generation. PM10, SO2, NOx, and ozone would effectively disappear if nuclear took over.

The diesel particulate thing is an example of very small improvements for a hideous price. Not only does Tier II wreck the efficiency of diesel engines, but the ultra-low sulfur requirements mean that diesel fuel (and jet fuel, heating oil, and kerosene) have to be run through the Klaus Train four times instead of the previous two times. This has caused diesel to become more expensive than unleaded gas by 30-50 cents per gallon.

[RH77]

Good reply, Dave.

I agree that the "Clear Skies" (ugh, I even hate saying it) initiative was not at all as advertised.

I followed the transition of Diesel over the last couple of years, and I have been convinced with the [EPA's] data that it has definitely been worth it. IIRC, as we learn more about these pollutants, the PM 2.5 is small enough to imbed itself in the deep regions of lung, absorb into the bloodstream and cause hardening of the arteries, etc. It's nasty stuff.

But I'm kinda seeing why Diesel is more expensive now, which stinks.

RH77

[roflwaffle]

Ultrafines have been implicated in heart disease, and not really looked at AFAIK, probably because we don't have any method of dealing with them in any engine. IIRC the push to eliminate larger particles has made these more common.

[LostCause]

All I know is that I am glad local transit buses have switched to natural gas. Nothing is worse then sitting behind a diesel and breathing in fumes.

In any case, clean technology is plentiful. Particulate traps, Adblue/Urea injection, EGR, turbo-compounding, VNT, low-sulfur fuel. All may have issues, but health > economy in my mind.

- LostCause