Study of the Dynamics and Risk of the Organophosphate Pesticide Chlorpyrifos and its Degradation Product TCP in La Fe Reservoir, Antioquia

ABSTRACT : This doctoral thesis presents a study of the dynamics of Chlorpyrifos (an organophosphate pesticide) and its degradation product 3,5,6-trichloro-2-pyridinol in La Fe reservoir, an artificial tropical mountain reservoir. The main objective of this work is to contribute to a deeper scientific understanding of the degradation pathways, fate, and associated risk of the organophosphate pesticide Chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol in shallow freshwater bodies in tropical latitudes, through the application of passive sampling. Passive sampling with Semipermeable Membrane devices allowed estimating Chlorpyrifos concentrations in a range of 0.002-0.31 µg/L in the reservoir, while for estimating 3,5,6-trichloro-2-pyridinol concentrations, an in-situ calibration was carried out using deuterated desisopropyl atrazine as a performance reference compound, which enabled the calculation of a sampling rate of 0.015 L/day to find 3,5,6-trichloro-2-pyridinol concentrations in a range of 0.020-0.436 µg/L. Additionally, significant presence of Chlorpyrifos (0.17-1.93 µg/kg) and 3,5,6-trichloro-2-pyridinol (966.8-3949.2 µg/kg) was found in the sediments. A water quality modeling approach was performed using the United States Environmental Protection Agency Water Quality Analysis Simulation Program 8.4 model, which proved useful for conducting a probability assessment. The model indicates that Chlorpyrifos and 3,5,6-trichloro-2-pyridinol enter the reservoir through the sediments, although more data is needed to establish definitive conclusions. Finally, an assessment of environmental risk from acute and chronic exposure was conducted, both for human health and water and sediment. It was found that the Palmas Espíritu Santo tributary presents the highest risk from acute exposure in the water column, while 3,5,6-trichloro-2-pyridinol concentrations are significantly low, indicating low risk. However, both compounds in the sediments, although not exceeding the ∑TU>1 value, show values that indicate the need to address and control Chlorpyrifos concentrations in the tributary basins of the reservoir. Similarly, the assessment of environmental risk from chronic exposure to Chlorpyrifos in the tributaries indicates a high level of risk. Meanwhile, 3,5,6-trichloro-2-pyridinol concentrations represent low levels of risk. However, in the sediments, Chlorpyrifos indicates a high risk, especially in the tributaries, while 3,5,6-trichloro-2-pyridinol shows a high level and, therefore, concern in the reservoir mixing zone with Pantanillo pumping.

• Autores: Gomez Arguello, Mayra Alejandra
• Tipo de recurso: Doctoral thesis
• Fecha de publicación: 2024
• Institución: Universidad de Antioquia
• Repositorio: Repositorio UdeA
• Idioma: eng
• OAI Identifier: oai:bibliotecadigital.udea.edu.co:10495/40190
• Acceso en línea: https://hdl.handle.net/10495/40190
• Palabra clave: Evaluación y Mitigación de Riesgos; Risk Evaluation and Mitigation; Muestreo; Sampling; Calidad del agua; Water quality; Plaguicidas; Pesticides; Muestreo Pasivo; Producto de Degradación; http://aims.fao.org/aos/agrovoc/c_5739; https://id.nlm.nih.gov/mesh/D000073938
• Rights: openAccess
• License: https://creativecommons.org/licenses/by-nc-sa/4.0/