[dmentat]

I live in a Swedish city, and I recently visited the local "garbage burning" power plant. It's not like the trash is just burned and the fumes released into the atmosphere, they pass through like 10-15 different types of filters removing and recycling different particles. The fumes that finally are released supposedly have a very negligible environmental impact. I'd link you some sources, but I got this information first-hand from the plant engineers, not sure where to look.

[fetbaffe]

Yes, emission from dioxin has been reduced by 99% since the 1980s beacuse of better filtering and much higher temperatures when burning the garbage.

From Naturvårdsverket (Swedish Environmental Protection Agency)

In Swedish http://www.naturvardsverket.se/Stod-i-miljoarbetet/Vaglednin...

Google translate http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=...

[sbierwagen]

  much higher temperatures

How's the nitrogen oxide levels, then?

[fetbaffe]

There exist a NOx tax (since 1992) for polluting the air with nitrogen oxides when burning garbage. But how much a furnace pollutes when doing that, not sure at all.

The amount of polluted nitrogen oxides to the level of produced energy unit has dropped some the last few years, but not much.

The general nitrogen oxide levels in Sweden has been reduced since the 90s according to this source

In Swedish http://www.miljomal.se/Miljomalen/Alla-indikatorer/Indikator...

"Från 1990 till 2011 har utsläppen minskat från cirka 270 000 ton till cirka 145 500 ton. Det är en minskning på 46 procent."

"From 1990 to 2011, emissions have been reduced from about 270 000 tonnes to around 145 500 tonnes. This is a decrease of 46 percent."

Google translate http://translate.google.com/translate?sl=sv&tl=en&js=n&prev=...

The source is from Miljömål (Environment Goal),site runned by Swedish Environmental Protection Agency