Sierra is an environmental epidemiologist whose work focusses on the multifaceted health effects of sound and air quality in both outdoor and indoor environments around the world. Sierra also has a particular interest in using novel approaches for measuring and modelling spatial distributions of environmental exposures as well as quantifying environmental burdens of disease to inform policy and practice.

Sierra also has experience working in the public sector at the intersection of science and policy, having previously worked as an Environmental Public Health Scientist at the UK Health Security Agency in the Air Quality and Noise and Public Health teams, as well as with Health Canada in the Exposure Assessment section.