Use of Biomarkers and Predicted Environmental Concentrations to Select Relevant Pesticides Applied to Soil
Juan Carlos Sánchez Meza, Universidad Autónoma del Estado de México, México
Pedro Avila Pérez, Instituto Nacional de Investigaciones Nucleares, México
Manuel Borja Salin, Instituto Tecnológico de Toluca, México
Víctor F. Pacheco Salazar, Universidad Autónoma del Estado de México, México
Tom LaPoint, North Texas University

Use of Biomarkers and Predicted Environmental Concentrations to Select Relevant Pesticides Applied to Soil

Student Presenter

Juan Carlos Sánchez Meza, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq Paseo Tollocan S/N, Toluca, Estado de México, CP. 50000, México, Tel: (722)2173890, Email: juancsm58@gmail.com
Pedro Avila Pérez, Gerencia de Ciencias Ambientales, Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa, Ocoyoacac, Estado de México; C.P. 52750, México Tel:  +52(55) 53297200 Email: pap@inin.gob.mx
Manuel Borja Salin, Posgrado en Ingeniería Ambiental, Instituto Tecnológico de Toluca, A.C. Av. Instituto Tecnológico s/n, Ex-Rancho La Virgen Metepec, Estado de México, C.P. 52140, México. Tels: (52) (722) 2087200 Fax: (52) (722) 2087201 al 04 Email: Manuel_borja00@yahoo.com.mx
Víctor F. Pacheco Salazar, Facultad de Química, Universidad Autónoma del Estado de México, Paseo Colón esq Paseo Tollocan S/N, Toluca, Estado de México, CP. 50000, México, Tel: (722)2173890
Tom LaPoint, Applied Sciences Institute, North Texas University (UNT), USA, Email: LaPoint@unt.edu

In our country, many different types of pesticides may be applied to cut flower crops in order to protect them. Two groups of these compounds, organophosphate (OP) and carbamate (CA) are used in high quantities. Both of them produce inhibition of cholinesterase activity in different organisms. This characteristic is used to identify the presence of these compounds with fast tube tests. On the other hand, some lixiviation models like PESTAN and others have been used in ecological risk assessment studies to get the Predicted Environmental Concentrations (PEC) of pesticides in soil. The aim of this research is to determine if PEC of several OP and CA compounds applied to a flower crop area, will show any correlation with inhibition of cholinesterase activity detected in soil extracts. Samples of surface soil (0 – 30 cm in depth) and subsurface soil (30 to 60 cm in depth) were taken from a flower crop area in which, during the last two years, OP pesticides (like acephate, dimetoate and methyl parathion), and CA pesticides (like carbendazim, carbofuran and metomil) were applied. Weekly loads of these pesticides were registered to estimate the annual load of each compound. Physicochemical analysis and relative inhibition of cholinesterasic activity were developed for each soil sampled. PEC values were estimated using PESTAN (US-EPA) lixiviation model for each pesticide considering the data of physicochemical analysis of each soil sampled. From all pesticides tested only acephate and metomilo showed a significant correlation (p < 0.01) between PEC values and inhibition cholinesterase activity of soil extracts. These results suggest that inhibition of cholinesterase activity observed in soil extracts is produced mainly by these two pesticides. Further studies could be oriented to measure concentrations of acephate and metomil to develop actions to reduce their environmental impact.  

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