Latest Research from the Finlayson-Pitts lab
Barbara Finlayson-Pitts has a storied career in Atmospheric Chemistry dating back to the early 1970s. She has studied air quality issues from most every angle and published groundbreaking research into the causes and effects of pollution particles in our air from both natural and man-made sources (for example, sea salt or combustion of fuels). Recently she’s expanded her field of study into agriculture as she investigates neonicotinoid (NN) pesticides.
Since their introduction in 1991, NNs have largely supplanted the use of other pesticides due to their lower mammalian toxicity. NNs are often used as seed coatings and, as systemic pesticides, they are taken up and translocated throughout the plant so that biting insects such as aphids are exposed. NNs are now ubiquitous in the environment and have been detected at locations far removed from their application sites; for example, in blowing dust, in wildflowers, and in honey samples collected around the world. The use of NNs has been associated with a decline in pollinators such as bees — critical for food production — and the European Union has imposed restrictions on the use of the major compounds in this class of pesticides.
While the toxicity to humans of the parent NN is low, it is not known how they interact with other atmospheric oxidants and how this might change their toxicity. There are lessons to be learned from the use of malathion to control the Mediterranean fruit fly, where its oxidation products that form rapidly in air are much more toxic than malathion itself. The goal of her research team is to determine whether the same is true of NNs by exposing the NN to light or atmospheric oxidants under controlled conditions in the laboratory, then measuring the kinetics and products of these reactions.
The Finlayson-Pitts research group has shown that the major NN that is in use around the world, imidacloprid, upon absorption of light, indeed does form a product that is more toxic than imidacloprid. Their experiments showed for the first time that the only gas phase product was nitrous oxide, which is a potent greenhouse gas. The chemical structures of NNs are similar in some respects to compounds used in certain pharmaceuticals and munitions. Her group is studying model compounds to understand how different functional groups and combinations of functional groups of these compounds determine their chemistry in air. Clearly, comprehending the atmospheric chemistry of NNs is challenging… but fun!
Along with her collaborations with UCI researchers and acknowledged experts from around the world, Barbara takes great pride in the many talented and hard-working researchers who have served in her group. They range from under-graduates to grad students to postdoctoral fellows to project scientists, from high school interns to international exchange students to an astronaut, even one team member who has been working in her labs since the 1980s! She was an early voice for women in chemistry, supporting them for faculty and high-level research positions, and through the years she has included team members from all kinds of backgrounds. Like her trailblazing research, Barbara is a pioneer of diversity in science.
