A Review of Commuter Exposure to Ultrafine Particles and Its Health Effects (Luke D. Knibbs, Tom Cole-Hunter, Lidia Morawska) Presented by Kevin Ngyuen & Kevin Mandich

Why does this interest us? Portland has many avid cyclists and bike commuters Is cycling in urban areas healthy? How does driving compare to cycling?

Question Wait…What are UFPs? – CO produced in large amounts by vehicular combustion – <100 nm A human hair is about 60,000 nm How does the mode of travel affect exposure to ultrafine particles (UFPs)?

Methods Reviewed 47 previously-performed studies from cities in USA, UK, Australia, Italy, Canada, Netherlands etc. Derived trip-weighted average exposure level per transport mode Focused only on general trends

Results X-axis is number of trips per mode Y-axis is UFP exposure in thousands of particles per cubic-centimeter 3000 individual trips Tunnels are unique microenvironment Error bars denote the trip-weighted standard deviation

Significance of the Results This investigation further supports the health benefits of bicycle commuting beyond the obvious cardio- vascular advantages. It is also interesting that walking presents such a high exposure to UFPs. This is most likely due to pace (time).

Relevance to Sustainability Supports bicycling as healthy alternative to vehicle commuting. More cyclists would mean fewer drivers and fewer UFPs. Fewer UFPs would mean healthier air to breathe!

What the Heck? Error bars denote the trip-weighted standard deviation? How do these comparisons help since they were not done in under similar conditions? Health effects such as airway irritation and inflammation were noted from separate studies, but nothing directly related to the presented UFP exposure results

Future Experiments Perform a multi-mode study under similar weather patterns, balanced traffic volume and speeds, established routes, similar interior ventilation etc. Study health effects on the same subjects as those participating in the UFP exposure study

Questions?