Cantidad de publicaciones: 4
Adsorption–Desorption Behaviour of Imidacloprid, Thiamethoxam, and Clothianidin in Different Agricultural Soils
Briceño, G., Palma, G., Schalchli, H., Durán, P., Llafquén, C., Huenchupán, A., Rodríguez-Rodríguez, C., Diez, M.C., 2025. Adsorption–Desorption Behaviour of Imidacloprid, Thiamethoxam, and Clothianidin in Different Agricultural Soils. Agriculture 15, 1380. https://www.mdpi.com/2077-0472/15/13/1380#
Abstract: This study evaluated the adsorption and desorption of imidacloprid (IMI), thiamethoxam (THM) and clothianidin (CLO) in an andisol (Freire soil) and an inceptisol (Chufquén soil) from southern Chile with different organic matter and clay contents. The soils had a slightly acidic pH and clay and clay-loam textures. The tests were carried out at 20 °C with CaCl2 0.01 M as the electrolyte. Kinetic experiments were performed and isotherms were fitted to the pseudo-second-order, Elovich, Weber–Morris, Freundlich and Langmuir models. The kinetics were best described by the pseudo-second-order model (R2 > 0.99), indicating chemisorption; the rate was the highest for THM, although IMI and CLO achieved the highest retention capacities. The Chufquén samples, with lower organic matter but 52% clay, exhibited the highest Kf and qm of up to 12.4 and 270 mg kg−1, respectively, while the Kd (2.3–6.9 L kg−1) and Koc (24–167 L kg−1) coefficients revealed a moderate leaching risk. THM was the most mobile compound due to its high solubility. Desorption was partially irreversible (H = 0.48–1.48), indicating persistence in soil. FTIR analysis confirmed the interaction with O-Al-O/O-O-Si-O groups without alterations in the mineral structure. In the soils examined in this study, the clay fraction and variable-charge minerals, rather than organic matter, were more closely associated with the adsorption behaviour of these NNIs.
Individual and mixture effect of selected high-hazard pharmaceuticals on aquatic primary producers
Montiel-Mora, J.R., Lizano-Fallas, V., Méndez-Rivera, M., Marín-González, A., Cambronero-Heinrichs, J.C., Rodríguez-Rodríguez, C.E., 2025. Individual and mixture effect of selected high-hazard pharmaceuticals on aquatic primary producers. Ecotoxicology. https://doi.org/10.1007/s10646-025-02885-w
Abstract: The extensive use of pharmaceuticals has led to their occurrence in surface waters due to insufficient treatment processes for their removal. Their environmental impact remains largely unexplored for certain trophic levels, particularly plants and algae. Pharmaceuticals often occur in mixtures with other pollutants, highlighting the need for comprehensive toxicological assessments that evaluate their combined interactions. This study evaluated the acute toxicity of four high-hazard pharmaceuticals -diphenhydramine, fluoxetine, ketoprofen, and trimethoprim- and their binary mixtures, on the green microalgae Raphidocelis subcapitata and the aquatic macrophyte Lemna gibba. For individual compounds, R. subcapitata growth rate was inhibited in all cases, with fluoxetine, ketoprofen and diphenhydramine exhibiting moderate toxicity (EC50 = 0.34, 0.14, and 4.88 mg/L, respectively), while trimethoprim showed low toxicity (EC50 = 332.35 mg/L). Similar trends were observed in L. gibba, except for diphenhydramine, which also showed low toxicity (EC50 = 26.57 mg/L). Binary mixtures demonstrated a synergistic interaction towards the microalgae in the presence of ketoprofen, except ketoprofen-trimethoprim combination (antagonism, p < 0.0001). In contrast, most interactions in L. gibba exhibited antagonism, except ketoprofen-fluoxetine (synergism, p = 0.0042). Differences were observed between the two model organisms for individual compounds and mixtures. No correlation was found between L. gibba experimental data and QSAR predictions derived from R. subcapitata. Our results highlight the need for: i. further studies including mixtures of relevant pharmaceuticals; ii. caution in the use of predictive models or extrapolation between taxa; and iii. the inclusion of fluoxetine and ketoprofen as priority compounds in future risk assessments.
Apú, N., Rommes, F., Alvarado-Arias, M., Méndez-Rivera, M., Lizano-Fallas, V., 2025. Endocrine-disrupting pesticide exposure relevant to reproductive health: a case study from Costa Rica. Environ Monit Assess 197, 559. https://doi.org/10.1007/s10661-025-14011-8
Abstract: Global pesticide use has increased significantly over the past decade, leading to greater exposure to contaminants and associated health risks. Endocrine-disrupting pesticides have gained attention due to their strong association with human reproductive impairments and rising global infertility rates. In Costa Rica, studies have reported reduced fertility among agricultural workers and a higher prevalence of male infertility in regions with intensive pesticide use. However, the prioritization of pesticides detected in human fluids, based on their potential impact on reproductive health, has not been conducted. Here, analyzing human biomonitoring studies in the country over the last 25 years, 13 pesticides were identified and prioritized. Mancozeb ranked highest (14.8%), followed by dieldrin (12.1%) and chlorothalonil (12.0%). Eight criteria were used for prioritization, with non-carcinogenic risk, reported reproductive effects, and endocrine disruptor classification as key factors. This comprehensive approach highlights how multiple criteria collectively inform pesticide prioritization in relation to reproductive health risks. The findings indicated that while Costa Rica is a regional leader in pesticide biomonitoring, significant gaps remain, including limited data on unstudied pesticides and general population exposures. Establishing robust biomonitoring programs and public health surveillance systems to generate updated data and support evidence-based prevention policies is recommended. Additionally, the results of this study provide a valuable framework for guiding future research on the potential effects of pesticide mixtures.
Giraldo-Sanclemente, W., Pérez-Castillo, A.G., Monge-Muñoz, M., Chinchilla-Soto, C., Chavarría-Pérez, L., Alpízar-Marín, M., Zaman, M., 2025. Impact of urease inhibitor on greenhouse gas emissions and rice yield in a rainfed transplanting rice system in Costa Rica. Frontiers in Agronomy 7. https://doi.org/10.3389/fagro.2025.1518802
Abstract: Rice crop production intensification has become one of the most important sources of greenhouse gases. In rainfed rice production, urea is the most common nitrogen (N) fertilizer used in Costa Rica. Urea has low efficiency in crops, which is associated with high risk of N gaseous losses. The use of urea coated with the urease inhibitor NBPT has been identified as a mitigation strategy for ammonia losses. However, this can increase N input to the system, potentially leading to higher N2O and CH4 emissions in rice fields. In 2022, a rainfed rice transplanting trial was conducted on a tropical Inceptisol in Costa Rican Central Pacific region to analyze yield and quantify N2O and CH4 emissions. The plots of 6m x 6m, with an experimental design of five complete randomized blocks, were treated with three N-fertilization treatments: urea (U; 144 kg N ha−1), urea plus NBPT (UI; 144 kg N ha−1) and control plots (without N). Total N was splitted in four applications. The yield did not exhibit a significant difference (p>0.05) between U and UI treatments (U: 5.72 ± 0.97 t ha−1, and UI: 5.86 ± 1.12 t ha−1). There were no significant differences in yield-scaled N2O emissions (U: 4.4 ± 1.9 ug N2O-N kg−1rice, UI: 4.2 ± 1.9 ug N2O-N kg−1rice) or yield-scaled CH4 emissions (U: 0.32 ± 0.20 mg CH4 kg−1rice, UI: 0.33 16 ± 0.18 mg CH4 kg−1rice). Environmental factors and soil conditions such as temperature, pH, clay content, and specific cation exchange capacity could reduce the efficacy of NBPT. Under the experimental conditions, NBPT did not promote economic benefits, nor did it have an impact on greenhouse gas emissions.
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[/tabs]https://www.mdpi.com/2077-0472/15/13/1380# This study evaluated the adsorption and desorption of imidacloprid (IMI), thiamethoxam (THM) and clothianidin (CLO) in an andisol (Freire soil) and an inceptisol (Chufquén soil) from southern Chile with different organic matter and clay contents. The soils had a slightly acidic pH and clay and clay-loam textures. The tests were carried out at 20 °C with CaCl2 0.01 M as the electrolyte. Kinetic experiments were performed and isotherms were fitted to the pseudo-second-order, Elovich, Weber–Morris, Freundlich and Langmuir models. The kinetics were best described by the pseudo-second-order model (R2 > 0.99), indicating chemisorption; the rate was the highest for THM, although IMI and CLO achieved the highest retention capacities. The Chufquén samples, with lower organic matter but 52% clay, exhibited the highest Kf and qm of up to 12.4 and 270 mg kg−1, respectively, while the Kd (2.3–6.9 L kg−1) and Koc (24–167 L kg−1) coefficients revealed a moderate leaching risk. THM was the most mobile compound due to its high solubility. Desorption was partially irreversible (H = 0.48–1.48), indicating persistence in soil. FTIR analysis confirmed the interaction with O-Al-O/O-O-Si-O groups without alterations in the mineral structure. In the soils examined in this study, the clay fraction and variable-charge minerals, rather than organic matter, were more closely associated with the adsorption behaviour of these NNIs