"Phytoscreening": the use of trees for discovering subsurface contamination by VOCs.
We tested the possibility of using tree cores to detect unknown subsurface contamination by chlorinated volatile organic compounds (Cl-VOCs) and petroleum hydrocarbons, a method we term "phytoscreening". The scope and limitations of the method include the following: (i) a number of widespread Cl-VOC contaminants are readily found in tree cores, although those with very high vapor pressures or low boiling points may be absent; (ii) volatile petroleum hydrocarbons were notwell-expressed in tree cores; (iii) trees should be sampled during active evapotranspiration and from directions that are well exposed to sunlight; (iv) there is not necessarily a direct correlation between concentrations measured in tree cores and those in the subsurface; (v) detection of a contaminant in a tree core indicates that the subsurface is contaminated with the pollutant; (vi) many possible causes of false negatives may be predicted and avoided. We sampled trees at 13 random locations in the Tel Aviv metropolitan area and identified Cl-VOCs in tree coresfromthree locations. Subsequently, subsurface contamination at all three sites was confirmed. Phytoscreening is a simple, fast, noninvasive, and inexpensive screening method for detecting subsurface contamination, and is particularly useful in urban settings where conventional methods are difficult and expensive to employ.
Sorek
A
A
Institute of Soil, Water and Environmental Sciences, The Volcani Center, Agricultural Research Organization, POB 6, Bet Dagan 50250 Israel.
Atzmon
N
N
Dahan
O
O
Gerstl
Z
Z
Kushisin
L
L
Laor
Y
Y
Mingelgrin
U
U
Nasser
A
A
Ronen
D
D
Tsechansky
L
L
Weisbrod
N
N
Graber
E R
ER
D029781:Cupressus / Q000378:metabolism*; D004784:Environmental Monitoring; D006838:Hydrocarbons / Q000378:metabolism*; D007557:Israel; D019684:Magnoliopsida / Q000378:metabolism*; D014197:Trees; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D014881:Water Supply / Q000032:analysis
D006838:Hydrocarbons; D014874:Water Pollutants, Chemical