Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
20
pubmed:dateCreated
2001-10-31
pubmed:abstractText
Three field experiments were performed to assess the clearance, uptake, and exchange kinetics of polychlorinated biphenyls (PCBs) between grass and the atmosphere using mixed- and single-species grass (Holcus lanatus). In the clearance experiment, the grass was artificially contaminated by equilibration with diluted Aroclor vapor then exposed to field air, and the rates of depletion were monitored by sampling at regular intervals to determine clearance rate constants. In the uptake experiment, the uptake of PCBs from the ambient atmosphere was followed in growing grass at ambient concentrations for 3 and 6 weeks by analysis of segmented samples along the length of the sward. In the third experiment, diurnal temperature-driven changes in grass concentrations were measured. The results indicate that the grass is behaving as a two-compartment system: (1) a fast-exchanging surface adsorption site with a response time of hours and a capacity essentially independent of K(OA), the octanol-air partition coefficient and (2) a slow responding site with a response time of weeks, the capacity of which is related to K(OA). The kinetic and equilibrium phenomena involved in grass-air exchange are thus complex and are not adequately described by simple first-order rate constants and equilibrium partitioning coefficients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0013-936X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4066-73
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Grass-air exchange of polychlorinated biphenyls.
pubmed:affiliation
Department of Chemical Engineering and Applied Chemistry, University of Toronto, ON, Canada. hayley.hung@ec.gc.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't