An economic way of reducing health, environmental, and other pressures of urban traffic: a decision analysis on trip aggregation.

Background: Traffic congestion is rapidly becoming the most important obstacle to urban development. In addition, traffic creates major health, environmental, and economical problems. Nonetheless, automobiles are crucial for the functions of the modern society.

Does mechanistic understanding help in risk assessment--the example of dioxins.

Risk assessment is based on scientific information, in part on "regulatory toxicology", i.e., studies following protocols accepted by national or international authorities, and in part on fundamental scientific information clarifying the mechanisms of toxicity and giving a better possibility to evaluate also the findings of routine safety studies.

Reduction potential of urban PM2.5 mortality risk using modern ventilation systems in buildings.

Unlabelled: Urban PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 microm) is associated with excess mortality and other health effects.

Characterization of model error in a simulation of fine particulate matter exposure distributions of the working age population in Helsinki, Finland.

Exposure models are needed for comparison of scenarios resulting from alternative policy options. The reliability of models used for such purposes should be quantified by comparing model outputs in a real situation with the corresponding observed exposures. Measurement errors affect the observations, but if the distribution of these errors for single observations is known, the bias caused for the population statistics can be corrected.