Search results for "risk quotient"
showing 3 items of 3 documents
Pesticides in the Ebro River basin: Occurrence and risk assessment
2016
In this study, 50 pesticides were analyzed in the Ebro River basin in 2010 and 2011 to assess their impact in water, sediment and biota. A special emphasis was placed on the potential effects of both, individual pesticides and their mixtures, in three trophic levels (algae, daphnia and fish) using Risk Quotients (RQs) and Toxic Units (TUs) for water and sediments. Chlorpyrifos, diazinon and carbendazim were the most frequent in water (95, 95 and 70% of the samples, respectively). Imazalil (409.73 ng/L) and diuron (150 ng/L) were at the highest concentrations. Sediment and biota were less contaminated. Chlorpyrifos, diazinon and diclofenthion were the most frequent in sediments (82, 45 and 2…
Pesticide contamination in water and sediment of the aquatic systems of the Natural Park of the Albufera of Valencia (Spain) during the rice cultivat…
2021
The Natural Park of the Albufera (Valencia, Spain) is a Mediterranean wetland where rice cultivation dominates the agricultural activity. The purpose of this study was to offer broader information about the current state of the wetland assessing the contamination by pesticides in four aquatic habitats during the rice cultivation period in 2016. Liquid chromatography with tandem mass spectrometer (UHPLC-MS/MS) was used to determine the pesticides in water and sediment samples from the rice fields, Lake Albufera and irrigation and outlet channels. 21 pesticides were detected in our samples (seven already forbidden by European legislation). Higher values than 10000 ng L of accumulated pesticid…
Occurrence of selected antibiotics and antiretroviral drugs in Nairobi River Basin, Kenya.
2015
In this paper, we investigated the occurrence of three antibiotics (sulfamethoxazole, trimethoprim and ciprofloxacin) and three antiretroviral (lamivudine, nevirapine and zidovudine) drugs in the Nairobi River Basin, Kenya. The analytical procedure involved extraction using solid phase extraction followed by liquid chromatography-electrospray ionization tandem mass spectrometry (SPE-LC-ESI-MS/MS). In this study, 40 sites were selected for sampling, including 38 sites along the rivers and 2 wastewater treatment effluent sites. All the studied compounds were detected with sulfamethoxazole having the highest detection frequency of 97.5% and ciprofloxacin had the lowest at 60%. The results show…