Summary of the second Netherlands Research Program on Particulate Matter (BOP II)

Elevated levels of particulate matter are mainly caused by human activity. It is concluded that besides carbon, particulate matter mainly consists of nitrogen and sulfur: their contribution to particulate matter appears to be twice as large than previously assumed. About 1/3 of the anthropogenic particulate matter is of Dutch origin and 2/3 originates in foreign countries. For this reason, not only national but also international policy measures are necessary in order to decrease particulate matter concentrations.

Contribution from traffic to particulate matter is limited

Agriculture and traffic are the main sources of particulate matter emissions in the Netherlands. Focusing on traffic, it is shown that the contribution from local traffic to particulate matter is relatively small with respect to other sources: the concentrations close to busy streets are elevated by approximately 15% with respect to the surrounding. Due to this the options, in order to reduce particulate matter concentrations by local policy measures are limited.

Contribution traffic to soot and heavy metals emissions relevant

Particulate matter includes soot and heavy metals. If one zooms in into these components, traffic is shown to be a major source: the concentrations of soot and heavy metals are locally two to three times higher along busy streets and roads in the Netherlands. Soot comes from the exhaust of cars and heavy metals are released by wear of brake discs and tires. This insight offers the possibility to affect the concentrations of these components by local policy measures. This is especially important because both soot and heavy metal probably have higher negative effects on human health than other components of particulate matter.

Netherlands Research Programs on Particulate Matter to reduce uncertainties about particulate matter (BOP and BOP II)

The goal of the Netherlands Research Programs on Particulate Matter (BOP, 2007-2009 and BOP II 2010-2012) is to reduce uncertainties about particulate matter (PM) and the number of policy dilemmas. The Netherlands Environmental Assessment Agency (PBL) took the lead in the first version op the program (BOP). It is a framework of cooperation involving the Energy research Centre of the Netherlands (ECN), PBL, the Environment and Safety Division of the National Institute for Public Health and the Environment (RIVM) and TNO Built Environment and Geosciences. The BOP II program is the successor, in which PBL plays a more limited role.