... all this is filtered out and deposited, and not 'emitted'.
Impossible. As the article I cited states, as much as 10% is EMITTED in an old plant, and as little as 1% in a 'new' plant. You even contradict yourself: "The majourity [sic] of ash ... [is] ... collected and deposited."
Even with 1% escaping, the US still emits TONS of raw radioactive Uranium and Thorium into the atmosphere.
90% of the ash in Germany is transformed into construction material for roads and houses.
This point is also addressed in the cited article:
During combustion the radionuclides are retained and concentrated in the flyash and bottom ash, with a greater concentration to be found in the flyash. The concentration of uranium and thorium in bottom and flyash can be up to ten times greater than for the burnt coal, while other radionuclides such as Pb-210 and K-40 can concentrate to an even greater degree in the flyash. Some 99% of flyash is typically retained in a modern power station (90% in some older ones). While much flyash is buried in an ash dam, a lot is used in building construction. Table 3 gives some published figures for the radioactivity of ash. There are obvious implications for the use of flyash in concrete.
Take a look at table 3 - these figures are for Germany. The first numeric column is Uranium, the next Thorium, and the last Potassium. The figures are Bq/kg.
Germany ash 6-166 3-120 125-742
Germany slag 68-245 76-170 337-1240
According to google, the average cinder block weighs 26-33 lbs (11.8-15 kg). If 75% of a 15kg cinder block's mass is average ash, every single cinder block has 6536 Bq of activity. That's a little shy of 436 BED per block. A cinder block building 20'x20'x10' uses (conveniently) 15 8x8x16 inch blocks in each dimension for each wall, so that's a total of 900 blocks. That's 5,882,625 Bq for the building.
Wikipedia says "In the United States about 131 million tons [118,841,195,700 kg] of fly ash are produced annually by 460 coal-fired power plants. A 2008 industry survey estimated that 43% of this ash is re-used." In the US, that means 51,101,714,151 kg of ash representing an average of 777 Bq/kg (a staggering 39.7 x 10^12 Bq of total activity) being put in close proximity to people per year. That's 2,647,068,793,022 (2.65 x 10^12) BEDs per YEAR, or around 9000 BED/person/yr in the US (round number assuming 300x10^6 people).