Emissions of dangerous particulate pollution have fallen in Europe, but a hefty 88 percent of urban dwellers are still exposed to levels that breach UN standards, an official report said on Tuesday.

In its annual report on European air quality, the European Environment Agency voiced concern over particulate matter - microscopic specks of dust and soot, mostly caused by burning fossil fuels. Particulate matter measuring less than 10 microns, or 10 millionths of a meter, can lodge in the airways, causing respiratory problems.

More perilous still are smaller particles measuring less than 2.5 microns across, which can be breathed deep into the lungs and are so tiny they can cross over into the bloodstream.

The Copenhagen-based agency said emissions of PM10 had fallen by 14 percent in the EU between 2002-11, and those of PM2.5 by 16 percent.

But 33 percent of the EU's urban population lives in areas where pollution levels bust Europe's requirements for maximum exposure to PM10 - a benchmark measured on exposure averaged over 24 hours.

"European citizens often breathe air that does not meet the European standards," the EAA said. "The current pollution levels clearly impact on large parts of the urban population."

The figure rises to 88 percent if the far tougher, but nonbinding, guidelines for PM10 set by the UN's World Health Organization are considered.

The EAA also said that 98 percent of European urbanites live in areas that were above UN guidelines for ozone, a molecule that, at ground level, is caused by a chemical reaction between sunlight and fossil fuel emissions and is another irritant for the airways.

Separately, a European study published on Tuesday in The Lancet Respiratory Medicine journal found exposure to even low levels of PM2.5 during pregnancy increased the risk of a baby with a low birth weight.

Low birth weight - considered to be less than 2.5 kilograms after 37 weeks of pregnancy - is linked to respiratory problems in childhood and cognitive difficulties.

(China Daily 10/16/2013 page11)