Tuesday, February 20
Scripps Seaside Forum Auditorium
11:30 a.m. Pizza will be served
12:00 p.m. Talks begin
Please join us for the Institutional Seminar Series lunch forum sponsored by the Director's office featuring the following speakers:
The Dynamic Interaction of Life and Landscape
Natural landscapes are often viewed as the scenic backdrop on which life grows; when the landscape changes, biota responds passively to this change. A new view is emerging in which landscapes represent an ever-changing canvas shaped by dynamic interactions between life and landscape, through erosion, sediment transport through rivers and alteration of rock to produce soil. Life probably strongly influences the evolution of topography at all scales although evidence of the impact of life in mountains has been elusive. The converse is also true–landscapes affect life through bottom-up controls. Landscape connectivity and substrate composition can act as a primary control on biodiversity and flora biomass and productivity. In this talk, I will discuss our approach coupling geochemical techniques, mostly involving cosmogenic nuclides, and remotely sensed data of topography and flora to show how vegetation can control topography at the scale of individual mountain stream catchments and how topography impacts life.
Do air quality alerts benefit public health?
Ambient air pollution is a major health risk globally. To reduce adverse health effects on days when air pollution is high, government agencies worldwide have implemented air quality alert programmes. Globally, air quality alert programmes represent one of the most common public responses to protect the population from air pollution. Understanding whether these programmes indeed result in any observable public health benefits has important implications. Despite their widespread use, little is known about whether these programmes produce any observable public-health benefits.
We conducted a study in Toronto, Canada to evaluate the effectiveness of such programmes using a Regression Discontinuity approach. By emulating randomization through a natural experiment, this approach overcomes the vulnerability of observational studies to bias from unmeasured confounding and, thus, enables valid causal inference about air quality alerts. With population characteristics and the air quality alert programme of this study resembling those of the USA and many European countries, our results will be highly generalisable to many other regions.
We found that in this population-based cohort, the air quality alert programme was related to some reductions in respiratory morbidity, but not any other health outcome examined. This finding suggests that issuing air quality alerts alone has a limited effect on public health and that implementing enforced public actions to reduce air pollution on high pollution days could be warranted. Together with accumulating evidence of substantial burden from long-term air pollution exposure, this study underscores the need for further strengthening of global efforts that can lead to long-term improvement of overall air quality.