Some american members of LG, said that diesel is greener to the environment.
The World Health Organization (WHO) ruled that diesel engines emit carcinogenic gases that increase the risk of lung cancer.
Read here , and here (Original hebrew article) .

"Greener" is not a 1-dimensional value, and it can never be

For example the diesel :

Maybe it emits less CO2 for the same power output ? If yes, then it is affecting less the O3 layer. Now the question may be whether it is used in proximity to people or in an isolated remote location where there is less concern about intoxication

Maybe it emits more toxic materials, but ones which are easier to filter out from the smoke

Diesel engines can work with biodiesel blends, now this opens a whole new debate of fossilized diesel vs biodiesel and so on



The same as lighting...

Which lightbulb is the least efficient ? Incandescent !!! If you are running on hydro power anyway, why care about efficiency ? Better carer about toxic materials in the lamps (or in their production, which puts LED together with the rest)...

If you are running on a private solar system, your energy resource is limited (panel area, battery capacity etc), but you dont pollute by the watt. So use mercury and magnetic fluorescent lamps due to their relative efficiency (vs incandescent), high reliability (vs pretty much anything else), and long life (so no driving the car from isolated rural area to buy replacement ballasts and lamps often)

Looking at it in 1 dimension is just one of the errors that the lamp/ballast ban crowd make

Ash: The CO2 don't affect the ozone layer, but the greenhouse effect.

Diesel fueled engines get a better rap for being greener than gasoline powered engines because the efficiency factors are slightly higher.   As far as emissions are concerned it varies. There have been plenty of mixed messages over the years in our area, nut no hard proof. I work as a diesel service technician, and for many years the problem was trying to reduce NOx levels and and hydrocarbons as well. If an engine ran cool the hc levels rose and the NOx levels dropped. If the engine ran hot the NOx levels rose and the hydrocarbons dropped.  Then cummins started using exhaust gas re circulation valves, and now problem solved.  Do you guys use DPF on any diesel powered engines in Israel?

I don't know, but the israeli Department of Transportation, are working according to the european emission standards: The Euro standard.

The emission limits were in Europe split: Strict for gasoline, but way more relaxed for diesel cars. If you compare the limits and their introduction, comparable limits for diesels lag about 10..15 years in their introduction date. That difference was artificially made to not wipe out diesel passenger cars from the market by the emission limits.

For many years was technically impossible for diesel engines to meet emission levels (CO, "NOx", "HC", but mainly solid particles,...) quite easily attainable with gasoline (mainly after the introduction of the catalytic conversion and the lambda based mixture feedback control in 80's; this was not feasible for diesels, as the same system would get quickly clogged that time). After that the limits for gasoline nearly didn't changed (what changed were only the requirements for onboard diagnostic), but limits for diesels tighten up significantly (so the gap is now smaller).
But that was possible only due to heavy investments into diesel development and by sacrificing the robustness against fuel contamination. During that time gasoline engines didn't changed (neither the "hardware", nor their control algorithms) for nearly 20 years, except the diagnostic features. So no wonder, the diesels gain during that time quite significant lead in their efficiency - it was not because they are diesels, but because of the heavy investments into their development.
And because of that investments, there is very strong lobby in bending legal conditions (defining "dangerous pollutants" and their emission limits - see above, fuel taxes - diesel have about 2/3 of gasoline tax here) so, the diesels remain attractive even beside the higher costs and extreme sensitivity for the fuel quality (mixing a liter of diesel into 10 liter of gasoline mean only a bit lower power and no damage at all for all modern gasoline engines, while mixing 1 liter of gasoline into 50 liters of diesel fuel is deadly for any modern diesel's).

When (about 5 years ago) gasoline engines started to take some features from diesels, their fuel consumption immediately dropped by nearly 30% (mainly below 50% load - the dominant operation regime in cars), so when counting for specific combustion heat of the fuel, the efficiency is nearly the same as with diesels, but with way lower weight, so ending up with quite similar fuel consumption.

Its funny you mention that,because around here we started using diesel particulate filters (DPF) since 2007 as a federal requirement. These dpf units are basically a catalytic converter with a muffler added on. For every so many hours of operations these engines must go in to regeneration mode to heat up and clean off the catalyst. It must be mice to have your diesel fuel cheaper than gasoline.  Around here we pay more for diesel than gasoline. On a side note, I used to work as a mechanic at the Portland international airport in Portland, Oregon,  and all of us had to be cautious around airplanes when they would start up. Mainly because the kerosene smell was strong. Kerosene is a known carcinogen and it's related to diesel fuel, so it wouldn't surprise me if diesel was a carcinogen as well.

It was the introduction of the DPF, what to largest extent closed the gap between diesel and gasolione engine emissions, but still they are worse than the gasoline's (it bring the diesel emissions to the levels of gasoline's manufactured in early 90's).
The DPF idea is not as new, but the older diesels emit so much solid particles, such device would either clog and/or have to regenerate for nearly the same time as the engine is normally running - what would increase the total fuel consumption so, it would be way worse than gasolines...
And unlike the catalytic converter in gasolines, the DPF need the engine to be operated at higher RPM with reduced power in order to allow the regeneration (enough not combusted air should pass the engine in order to provide the oxygen for the regeneration burner to operate). That mean cruising for some time using lower gear than normally required. Automatic gearbox could take care of it automatically , but with manuals the driver should select the gear against natural economic driving style.
As a consequence, the DPF usually get regularly clogged, official garages solved that issue by replacing the DPF (quite costly item)...

And here, in most of Europe, the lower taxes make the diesel sale price slightly lower (these days about 35CZK/l, so about $6.6/gal) than the gasoline (about 37CZK/l, so nearly $7/gal).

And what is dangerous on the airplane's exhaust when starting is mot the kerosene itself, but the fine soot from the poor burning (when the turbine/compressor is barely moving and the burner is cold). The fine soot particles are, what make it a prominent lung carcinogen...
By the way the same exit all the diesels without DPF...

It's interesting that you said official garages replaced dpfs when they clog. Around here when such an occurrence happens we over ride the electronic control module with dealer authorized software and perform a regen. The DPF usually clogs up from drivers not allowing.regens to occur

Regeneration in the car work only till some deposit level, than the regeneration could be done onboard, as you mentionned.
When the soot deposit exceed some level so it become really clogged (and that is the time, when the engine quit working and so force drivers to seek help), the car is not able to regenerate it anymore.
What work at this stage (beside replacing the units) is disassembling the exhaust system and use propane torch to regenerate it manually outside the car.
But due to some reason carmaker's brand services do not do this. Why exactly, I don't know, it could be worker's safety, risk of damaging the filter so it won't work afterwards and maybe even the fear, than the clogging was caused by some malfunction in the car, what would not be treated properly, because according to official service manuals, such treatment should never be necessary.

Regeneration in the car work only till some deposit level, than the regeneration could be done onboard, as you mentionned.
When the soot deposit exceed some level so it become really clogged (and that is the time, when the engine quit working and so force drivers to seek help), the car is not able to regenerate it anymore.
What work at this stage (beside replacing the units) is disassembling the exhaust system and use propane torch to regenerate it manually outside the car.
But due to some reason carmaker's brand services do not do this. Why exactly, I don't know, it could be worker's safety, risk of damaging the filter so it won't work afterwards and maybe even the fear, than the clogging was caused by some malfunction in the car, what would not be treated properly, because according to official service manuals, such treatment should never be necessary.

We don't use a torch for cleaning them out. The ones around here have two hi temp exhaust claps holding it together. What we do is we simply remove and disassemble the unit, attach a disposable collector bag on one end and we use compressed air to blow the particulates out. We do this while wearing a respirator mask. The collector bags get taken to the hazardous east plant nearby.

Frequently the filter is part of the longer exhaust pipe together with mufflers, all crimped together, so disassembling it so you could access the ceramic mesh is impossible.
The "torch" method uses the standard regeneration mechanism, what should have happened in the car. But as it is high temperature with plenty of excess oxygen, it burn out the soot quite well even when completely clogged (in that case the hot gases first few seconds return back, but a passage burn through the clogging quite quickly, so the reaction take over on the catalyst, heating it up and so cleaning it in the rather normal way)

Frequently the filter is part of the longer exhaust pipe together with mufflers, all crimped together, so disassembling it so you could access the ceramic mesh is impossible.
The "torch" method uses the standard regeneration mechanism, what should have happened in the car. But as it is high temperature with plenty of excess oxygen, it burn out the soot quite well even when completely clogged (in that case the hot gases first few seconds return back, but a passage burn through the clogging quite quickly, so the reaction take over on the catalyst, heating it up and so cleaning it in the rather normal way)

Is it a requirement where you are from that the DPF isn't serviceable for safety practices?  Around here you just need to be certified to service DPF via continuing education courses.

Is it a requirement where you are from that the DPF isn't serviceable for safety practices?  Around here you just need to be certified to service DPF via continuing education courses.

I don't think it is required for the vehicle certification itself. There the DPF should be working according to specification (checked by the car's onboard diagnostic for cars according to Euro4 and later standards and once per 4 years on the technical check performed by the authorized test station), but how you maintain it to meet that requirement, nobody care. Of course it should be certified component (what it remain even after manual regeneration - it is still the original, certified filter).

But I don't know, what is mandated by related worker's safety standards (I'm not a proffessional car service man, so I do not know them), if such manual regeneration is not considered due to some reason  as too risky operation.

Car maker's brand services generally do not do that, because such procedure isn't in official car maker's service manuals.
But independent services (generally used for post-guarantee maintenance for most family cars) generally do this regeneration as an alternative to replacing the DPF.
Maybe the reason is, than the cars serviced in brand services are mostly used as commercial vehicles with heavy use, so they suffer way less from the effects of cold engine and what are sold after about 3 years (about the economical lifetime of such vehicles, usually it mean about 150..250kkm). The commercial usage pattern usually mean more frequent longer trips, so that are better conditions for the DPF regeneration, so the problems do not appear with these new cars. And if they do, most frequently it could well be some real defect.
Family cars usually "recruit" from the used cars, so either it is the time, when first problems with DPF start (generally), or the family car use pattern cause higher rate of soot deposition, so the regeneration become insufficient.
So it could well be, than official brand services practically never come in contact with a car, where the DPF clog solely due to operating pattern of the car, without any real fault, so the manuals are not updated accordingly.

And moreover cars with DPF are not as long on the market here and my experience is, than brand services are very conservative about adopting any new procedure, they first require such procedure to be officially recommended by the manufacturer. I remember for one nice case of that: On Skoda Felicia 1.3MPI (1997 till end of the production) the throttle flap body gradually collect deposits of fine dust. It changed the shape of the flap body, changing it's regulation characteristic, in extreme cases till the engine didn't hold the idle. The altered characteristic was evaluated by the engine control unit as worn out potentiometer, so the official manual initially ask for the complete throttle valve replacement (about CZK3500). After about a year of use of this engine configuration, the people figured out, than the dust is the real problem, so clean out with a cloth solve it. It took another 3..4 years for the official Skoda service to add the "cleanness" check into the "Throttle flap potentiometer" error troubleshooting checklist, so the services stop replacing good units when they were only dirty...

I'd like to see what one of your DPFs looks like.