As part of Dr. Kim Anderson's lab, Sarah Allan investigates compounds known as polycyclic aromatic hydrocarbons (PAHs). PAHs, which form part of fossil fuels and are a byproduct of combustion, are environmental contaminants that can have a range of toxic effects including cancer and birth defects. Allan's lab focuses on where PAHs originate, how they move and are converted in the environment, and the effects these chemicals have on people and other organisms. Allan has recently been testing samples collected via "passive sampling devices" to determine the concentration of PAHs in environments affected by the Gulf of Mexico oil spill. Allan also researches PAH toxicity through her study of how these chemicals affect developing zebrafish embryos.