Mobility of pesticides in water, sediment, plants and soils, including soil columns

Understanding mobility of pesticides is an important part of environmental toxicology and chemistry. Pesticides need to be mobile enough to allow them to be transported to the site of action. On the other hand, pesticides that are too mobile will rapidly dissipate once applied to the target area and contaminate water and sediment. Many factors can affect the mobility of pesticides in soil and water including soil characteristics, pesticide properties, and timing of application.

Picture of a soil column experiment. The packed soil column is placed vertically in a formulated insecticide which moves up the column through capillary action, to determine how far a pesticides will travel in soil.Research in the lab has primarily focused on the transport of herbicides and their metabolites through soil profiles and into groundwater and surface water bodies. Recent research has focused on testing various formulations for their ability to increase the mobility of insecticides. Using formulations to increase mobility is essential for ensuring that insecticides are capable of moving through the soil to reach the habitats of ground-dwelling insect pest such as termites.


Some relevant publications:

Zhao, S., J.B. Belden, J.H. Cink, and J.R. Coats. 2010. Mobility of five termiticides in soil columns. Chapter in Proceedings of the 2010 NCUE. NCUE, Portland, OR, pp 169-174

Arthur, E.L., P.J. Rice, P.J. Rice, T.A. Anderson, and J.R. Coats.  1998.  Mobility and degradation of pesticides and their degradates in intact soil columns, Chapter 7 in Environmental Behavior of Pesticides:  The Lysimeter Concept.  F. Führ, J. Plimmer, R. Hance, and J. Nelson, eds.  American Chemical Society, Washington, D.C. pp. 88-114.

Kruger , E.L., B.  Zhu, and J.R. Coats. 1996. Relative mobilities of atrazine, five atrazine degradates, metolachlor, and simazine in soils of Iowa.  Environ. Toxicol. Chem. 15: 691-695.

Kruger, E.L., P.J. Rice, J.Anhalt, T.A. Anderson, and J.R. Coats. 1996. Use of undisturbed soil columns under controlled conditions to study the fate of [14C]deethylatrazine, J. Agric. Food Chem. 44: 114-1149.

Somasundaram, L., J.R. Coats, V.M. Shanbhag, and K.D. Racke. 1991. Mobility of pesticides and their hydrolysis metabolites in soil. Environ. Toxicol. Chem. 10: 185-194.

Degradation and persistence of insecticides, herbicides, fungicides, including natural products

It is important to understand the degradation and persistence of pesticides in soil and water in order to maximize pesticide efficacy while minimizing any detrimental effects they may have on the ecosystem. Degradation and persistence of pesticides can be affected by a wide variety of factors including properties of the pesticides (water solubility, volatility, polarity), properties of the soil or water (pH, temperature, soil composition), and resistance to degradation (biological, chemical, photo).

The lab has an extensive history of studying the degradation and persistence of pesticides in terrestrial and aquatic ecosystems. Though much of the research has focused on conventional herbicides, such as atrazine and metolachlor, the fate of natural insecticides, like thymol, has also been studied.


Some relevant publications:

Hu, Dingfei, Keri Henderson, and Joel Coats. 2009. Fate of transformation products of synthetic chemicals. Chapter  in The Handbook of Environmental Chemistry, vol. 2, Part P. Alistair Boxall, editor, Springer-Verlag, Berlin, Germany. pp. 103-120.

Hu, Dingfei, and Joel Coats. 2008. Evaluation of the environmental fate of thymol and phenethyl propionate in the laboratory. 2008. Pest Manag. Sci. 64: 775-779.

Rice, P.J., T.A. Anderson, and J.R. Coats. 2004. Effect of sediment on the fate of metolachlor and atrazine in surface water. Environ. Toxicol. Chem. 23: 1145-1155.  

Coats, J.R. and H. Yamamoto, Editors.  2003.  Environmental Fate and Effects of Pesticides.  American Chemical Society, Washington, D.C., 300 pp.

Arthur, E.L., B.S. Perkovich, T.A. Anderson, J.R. Coats. 2000. Degradation of an atrazine and metolachlor herbicide mixture in pesticide-contaminated soils from two agrochemical dealerships in Iowa. Water Air Soil Pollut. 119: 75-90.