Greenhouse gas emissions are not the only generally recognised environmental threat. The growing debate over risks caused by fine particulate matter has also been noted. The questions included in earlier surveys, approaching the issue in many different ways in their statements, unanimously show that the particles are seen as a serious threat to health. In the current survey, the focus was on the source of the particulate matter. The respondents were asked to evaluate seven potential sources according to their significance as a source of particulate emissions.

The evaluated sources were put in a steadily declining order. Traffic was considered the worst emission source. Nearly all respondents saw fuels and exhaust gases as a significant source of particulate matter (91% considered it very or fairly significant). Another traffic-related factor, dust from streets and roads, took the second place (81%). Industry and its burning processes was also often considered a producer of particulate matter (75%). Trans-boundary pollution was also placed comparatively high on the list (60%) [Figure 16.].

The significance of energy production and power plants remains somewhat lower. The energy industry is not, however, let off the hook in any way; more than half of the respondents (53%) saw it as a significant source of emissions. The opinions of various demographic groups are fairly uniform here. Women consider the effect of energy production significant more often than men. Those who oppose nuclear power put more blame on the energy industry than those in favour of nuclear power (not included in the figure).

According to the answers, the least problematic source of emissions was the domestic burning of wood (fireplaces, sauna stoves using wood as fuel). Four out of five (80%) put only minor or no significance on these. Even though the purpose of this study is not to judge right or wrong information, it must be stated that Finns are not entirely right here. According to calculations by the Finnish Environment Institute (SYKE) for 2005, domestic burning of wood is the largest single source of emissions of particulate matter with a 25% share of all particulate emissions. The same institute estimates the share of energy production at 23% and the share of traffic at 14%.

Respondents also consider forest fires and other fires to have little significance. The events of the year relating to this issue, such as the smoke from forest fires in Russia that plagued Finland for a long time, may still be reflected in the estimates. These events probably also affect the estimates on particulates in trans-boundary pollution.