DelAzulPestRisk is a risk-based chemical ranking model based on human and local biota toxicities that estimates the integrated risk of pesticides in water from their extensive (concentration, risk) and intensive (persistence, bioaccumulation) chemical properties. The model is built on two modules: human health risk factor (estimated based on the probabilistic cancer and non-cancer health risk by using U.S. Environmental Protection Agency models applied to a bathing exposure scenario) and biota health risk factor (quantified on the basis of the probabilistic toxicity exposure ratio -PEC/PNEC-for three local representatives of water biota multiplied by an amplification factor supported by the persistence and bioaccumulation potential). The model was applied to shallow creeks of Tres Arroyos County, Argentina, which flow across wheat and soybean agricultural lands, and in whose waters were detected many organochlorine pesticides (α, γ , y, δ-HCH, aldrin, heptachlor, γchlordane, endosulfan, endosulfan sulphate, dieldrin, and DDD). Dieldrin, aldrin, and heptachlor generated the worst potential effects-due mainly to the cancer and non-cancer dermal health risk-although this was not a significant environmental threat. DelAzulPestRisk is a screening assessment tool for water management purposes that become useful in countries lacking efficient water quality control systems.

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The aim of the study is to assess the probabilistic non-cancer and cancer risks by recreational bathing in Tres Arroyos creeks (southeastern Buenos Aires Province, Argentina). In these waters, hazardous substances (heavy metals, pesticides) have been detected, possibly related to agricultural activities. To assess such risk, USEPA models in aggregated (exposure through accidental oral water intake and dermal contact simultaneously) and cumulative approaches (combined exposure to more than one substance) were applied, performed for bathers of 5, 10, 15, and 20 years old. The results show that chronic bathing in these waters is not harmful at the concentrations and the exposure scenarios considered. Arsenic was the riskiest substance for both non-cancer and cancer effects, affecting mainly the youngest age group, and the accidental water intake during bathing was the most relevant pathway of exposure. On the other hand, the study highlights the key role of the frequency and duration of the bath event. We discuss the results in light of a previous paper of our authorship concluding that the health risk assessment is a valid alternative to analyze recreational water quality, which, unfortunately, is unused by water management agencies in Argentina.

Using the USEPA methodology we estimated the probabilistic chronic risks for calves and adult cows due to pesticide exposure through oral intake of contaminated surface and ground waters in Tres Arroyos County (Argentina). Because published data on pesticide toxicity endpoints for cows are scarce, we used threshold levels based on interspecies extrapolation methods. The studied waters showed acceptable quality for cattle production since none of the pesticides were present at high-enough concentrations to potentially affect cow health. Moreover, ground waters had better quality than surface waters, with dieldrin and deltamethrin being the pesticides associated with the highest risk values in the former and the latter water compartments, respectively. Our study presents a novel use of the USEPA risk methodology proving it is useful for water quality evaluation in terms of pesticide toxicity for cattle production. This approach represents an alternative tool for water quality management in the absence of specific cattle pesticide regulatory limits.