The high levels of nitrogen dioxide pollution measured in previous years remained unchanged. More than half of the stations in urban areas near traffic measured exceedances of the allowable annual mean of 40 micrograms (μg) nitrogen dioxide (NO₂) per cubic metre (m³) air. Particulates also continued to exceed limit values. Compared to earlier years, 2013 was nevertheless a year which registered some of the lowest levels of pollution. This is no reason for an all clear signal, says Thomas Holzmann, Vice-President of UBA. "The particulate limit value was only exceeded at about three per cent of all measuring stations, which although it may seem low does not accurately reflect the health impact of particulates on public health, especially in consideration of the much stricter air quality guidelines recommended by the World Health Organization (WHO).” read more