Lower tier toxicity risk assessment of agriculture pesticides detected on the Río Madre de Dios watershed, Costa Rica

Abstract

Costa Rica is a tropical country with one of the highest biodiversity on Earth. It also has an intensive agriculture, and pesticide runoff from banana and pineapple plantations may cause a high toxicity risk to non-target species in rivers downstream the plantations. We performed a first tier risk assessment of the maximum measured concentrations of 32 pesticides detected over 4 years in the River Madre de Dios (RMD) and its coastal lagoon on the Caribbean coast of Costa Rica. Species sensitivity distributions (SSDs) were plotted in order to derive HC values for each pesticide, i.e., hazard concentrations for 5 % of the species, often used as environmental criteria values in other countries. We also carried out toxicity tests for selected pesticides with native Costa Rican species in order to calculate risk coefficients according to national guidelines in Costa Rica. The concentrations of herbicides diuron and ametryn and insecticides carbofuran, diazinon, and ethoprophos exceeded either the HC value or the lower limit of its 90 % confidence interval suggesting toxic risks above accepted levels. Risk coefficients of diuron and carbofuran derived using local guidelines indicate toxicity risks as well. The assessed fungicides did not present acute toxic risks according to our analysis. Overall, these results show a possible toxicity of detected pesticides to aquatic organisms and provide a comparison of Costa Rican national guidelines with more refined methods for risk assessment based on SSDs. Further higher tier risk assessments of pesticides in this watershed are also necessary in order to consider pesticide water concentrations over time, toxicity from pesticide mixtures, and eventual effects on ecosystem functions.

Challenges and ways forward in pesticide emission and toxicity characterization modeling for tropical conditions

“…Alves et al 2013). Arias-Andrés et al (2018) presented specific acute toxicity data with tropical native species (earthworm).…”

“…For example, Bocquené and Franco (2005) found pesticides in water and sediment from rivers in Martinique, Pillai (1986) in soil and air in India, and Dickinson and Lepp (1984) in non-agricultural plants and soils in Kenya. Moreover, Arias-Andrés et al (2018) observed ecotoxicity effects of pesticides on freshwater organisms in Costa-Rica, and Peters et al (1997) on marine organisms in tropical conditions. Pesticides have also been detected in food crops grown in tropical regions, which might exceed the recommended maximum residue limits (e.g.…”

Assessing the ecological impact of banana farms on water quality using aquatic macroinvertebrate community composition

“…The fact that Oligochaetes, normally very tolerant to low oxygen levels, are only found at upstream sites further supports this conclusion (Fig 2 ). Oligochaetes have been found to be relatively sensitive to fungicides (Cuppen et al 2000 ), which have been found in surface waters downstream banana farms in streams nearby (Castillo et al 2000 ; Diepens et al 2014 ; Arias-Andrés et al 2016 ; Echeverría-Sáenz et al 2016 ; Rämö et al 2016 ). Thus, pesticides used by banana farms may be influencing patterns shown in the biplots presented here (Fig.…”

“…A major contributor of agrochemicals to the surrounding environment is the large-scale banana production, which receives an average of 57.5 pesticide applications per year as well as 2775 kg/ha of synthetic fertilizers (Bellamy 2013 ; Bravo et al 2013 ). Several of the pesticides used in banana production have been detected in the aquatic environment downstream of banana production areas (Castillo et al 2006 ), some in concentrations expected to have acute or chronic toxic effects on aquatic organisms according to toxicity values derived from laboratory toxicity tests (Diepens et al 2014 ; Arias-Andrés et al 2016 ; Rämö et al 2016 ).…”

Polycyclic Aromatic Hydrocarbons Have Adverse Effects on Benthic Communities in the Baltic Sea: Implications for Environmental Status Assessment

“…Here, the measured environmental concentration (MEC) is compared to the reference sediment values in Löf et al (2016). The MEC-to-reference values ratio is the RQ, and RQ exceeding 1 for a metal suggests that it may pose a toxicity risk to the environment (EFSA, 2013;Arias-Andres et al, 2018). The sum of these RQ values was calculated for each station and used in statistical analyses since all metals correlated significantly and highly to RQ (Pearsons r ≥ 0.90 except for As, Hg and Co, which had values of 0.73-0.89; Supplementary Table 6) and to each other (mean r = 0.80, with only exception being As and Hg, which were not significantly correlated; Supplementary Table 6).…”