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Assessing the Quality of Freshwaters in a Protected Area within the Tagus River Basin District (Central Portugal)
Author(s) -
Silva Emília,
Pereira Ana Carina,
Estalagem Soraia Patrícia,
MoreiraSantos Matilde,
Ribeiro Rui,
Cerejeira Maria José
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2012.0010
Subject(s) - environmental science , water quality , atrazine , chlorpyrifos , pesticide , surface water , metolachlor , environmental chemistry , terbuthylazine , groundwater , hydrology (agriculture) , european union , environmental engineering , ecology , biology , chemistry , geology , geotechnical engineering , economic policy , business
Water‐sediment quality was assessed in an agricultural zone of a protected area within the Tagus River basin district (central Portugal) combining chemical analysis to 12 pesticide compounds and whole toxicity testing using the bacterium Vibrio fischeri , the algae Pseudokirchneriella subcapitata , the crustacean Daphnia magna , and the midge Chironomus riparius . The herbicides alachlor, atrazine ethofumesate, metolachlor, terbuthylazine, the insecticides chlorfenvinphos and chlorpyrifos, and the metabolite 3,4‐dichloroaniline were detected in surface water samples at four sites and in groundwater samples from six wells, during four sampling occasions. Measured concentrations were compared with parametric values for human consumption, groundwater quality standards, and environmental quality standards applicable to surface water established in European Union legislation. Most severe adverse effects were noted on the growth of P. subcapitata and lethality of D. magna in nondiluted water samples. Taking into account the values calculated by the method of toxic unit summation for pesticide mixtures, it was not possible to link the pesticides found to the toxicity detected in the water samples. Conducting this study with chemical analyses and biotests provided a more comprehensive quality assessment and realistic picture of the environmental samples analyzed, although additional studies are needed to evaluate the performance of mixture models for predicting mixture toxicity. This study underlines the importance of chemical analysis and whole toxicity testing as tools for assessing the impact of human activity on the status of water, mainly in protected zones.