Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2003-12-16
pubmed:abstractText
Methyl-parathion (MeP) was introduced into constructed wetlands for the purpose of assessing the importance of distance from the source of contamination and the role of emergent vegetation on the acute toxicity to Hyalella azteca (Crustacea: Amphipoda). A vegetated (90% cover: mainly Juncus effuses) and a nonvegetated wetland (each with a water body of 50 x 5.5 x 0.2 m) were each exposed to a simulated MeP storm runoff event. H. azteca was exposed for 48 h in the laboratory to water samples taken from the wetlands at a distance of 5, 10, 20, and 40 m from the pesticide inlet 3 h, 24 h, 96 h, and 10 days following application. Methyl-parathion was detected throughout the nonvegetated wetland, whereas the pesticide was only transported halfway through the vegetated wetland. A repeated-measure three-way analysis of variance (ANOVA) using time, location, and vegetation indicated significantly lower toxicity in the vegetated wetland. Furthermore, the mortality decreased significantly with both increasing distance from the inlet and time (48-h LC50 +/- 95% CI: 9.0 +/- 0.3 microg/L). A significant three-way interaction of time x vegetation x location confirmed higher toxicity at the inlet area of the nonvegetated wetland immediately after contamination. Significant linear regressions of maximum mortality (independent of time) versus distance from the pesticide inlet indicated that 44 m of vegetated and 111 m of nonvegetated wetland would reduce H. azteca mortality to < or = 5%. These results suggest that vegetation contributes to reduced MeP effects in constructed wetlands.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0090-4341
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
331-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Acute toxicity of methyl-parathion in wetland mesocosms: assessing the influence of aquatic plants using laboratory testing with Hyalella azteca.
pubmed:affiliation
USDA-Agricultural Research Service, National Sedimentation Laboratory, P.O. Box 1157, Oxford, Mississippi 38655, USA. Ralf.Schulz@syngenta.com
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.