Assessing the Potential for Pesticide Leaching for the Pine Forest Areas of Tenerife

Abstract

Currently, no guidelines cover use of pesticides in the forested areas of the Canary island of Tenerife. An index-based model (Li) was used to rank the leaching potential of 50 pesticides that are, or could be, used for management purposes in the pine forest areas of Tenerife. Once the pesticides with the greatest leaching potential were identified, regional-scale groundwater vulnerability assessments, with consideration for data uncertainties, were generated using soil, climatic, and chemical information in a geographic information system framework for all pine forest areas of the island. Process-based simulations with the pesticide root zone model for the areas and pesticides of highest vulnerability were conducted to quantitatively characterize the leaching potentials. Carbofuran, hexazinone, picloram, tebuthiuron, and triclopyr were each identified as being potential leachers.

Assessment of the exposure to organochlorine pesticides, PCBs and PAHs in six species of predatory birds of the Canary Islands, Spain

“…The first factor is most likely to be the major cause because many organochlorine pesticides have been used in this area in the past. There are no reliable data regarding the consumption of these products; however, until the political awareness of pesticide consumption in recent years, the pesticide consumption in the islands was as high as 12 times (N200 kg/Ha, 42% insecticides) than that of the rest of the country (Diaz-Diaz and Loague, 2001;MAGRAMA, 2006). Several circumstances could explain this high use of pesticides, such as the weather conditions that favor the occurrence of pests and the fact that many farmers abuse pesticides by implementing scheduled preventative treatments, overdosing, and continue to ignore basic instructions regarding their use.…”

“…Geographically, the Islands are part of the African continent; however, from historical, economic, political and sociocultural points of view, the Canaries are European. Notably, large quantities of organochlorine pesticides have been used in the past in this archipelago because of the important role of agriculture in the economy of the region (Diaz-Diaz and Loague, 2001). For this reason, the levels of POP contamination in the human population of the archipelago have been deeply studied.…”

Assessing Ground Water Vulnerability with the Type Transfer Function Model in the San Joaquin Valley, California

“…Index and overlay methods simplify or neglect the physical processes and characterize vulnerability as a qualitative measure of relative leaching potential. Therefore, these methods are particularly suited to and have been predominantly used for applications at the regional scale, as they usually only require the determination of statistical relationships, based on selected soil and chemical properties, and net annual recharge (e.g., Blanke, 1999; Diaz‐Diaz and Loague, 2001; Khan and Liang, 1989; Loague, 1994; Loague et al, 1990; Mills, 2004). Process‐based simulation models of leaching are generally based on the numerical solution of Richards' equation with the advection–dispersion equation.…”