Mariano J. Gotelli, Centro de Investigaciones Toxicológicas S.A., Av. Juan B. Alberdi 2986, (1406) Buenos Aires, Argentina, Tel 54 11 4613 1100, Fax 54 11 4613 3707, Email: mgotelli@ciquime.org.ar
Alfredo Lo Balbo, Centro de Investigaciones Toxicológicas S.A., Av. Juan B. Alberdi 2986, (1406) Buenos Aires, Argentina, Tel 54 11 4613 1100, Fax 54 11 4613 3707, Email: lbalbo55@hotmail.com
Adrián López, Centro de Investigaciones Toxicológicas S.A., Av. Juan B. Alberdi 2986, (1406) Buenos Aires, Argentina, Tel 54 11 4613 1100, Fax 54 11 4613 3707, Email: laboratorio@ciquime.org.ar
Carlos Gotelli, Centro de Investigaciones Toxicológicas S.A., Av. Juan B. Alberdi 2986, (1406) Buenos Aires, Argentina, Tel 54 11 4613 1100, Fax 54 11 4613 3707, Email: cgotelli@ciquime.org.ar

A chemical industry which produce hexachlorocyclohexane (HCH) used to place its solid waste product in a nearby yard.  This industrial plant worked from 1960 to 1978.  During this period, this waste product was unloaded in knolls and unevenly spread over the yard.  On some occasions it was mechanically spread away.  At present time, this contaminated piece of land has an extension of 16 hectares and the HCH concentrations varies from 1 to 2000 mg/Kg of dry soil.  On account of economic difficulties it was impossible to carry out a soil remediation, for this reason a forestation was performed in which Eucalyptus dunni trees were planted.  This forestation plan was put into effect in october/november 1997.  By now the trees are in an average of 6 meters high.  In June 1998, March 2003 and February 2005 efficiency tests were performed for which trees and soils located in places with different concentration of HCH were selected.  Lower leaves and log of wood were taken away from these selected plants and analysed in a laboratory, as well as the corresponding soil samples.  The growing period of these plants is about 20 years.  During this time, a great quantity of HCH from the soil is expected to be bioaccumulated in the trees.  We still do not know if the HCH will suffer any king of transformation inside the woody structure of the three or it will just be stored in the plants.  The final destination of these trees is still uncertain but a strong possibility is to incinerate them (sacrifice)

Accumulation of Heavy Metals by Cucumber and Brassica juncea Under Different Cultivation Conditions

Ryuji Takeda, Department of Applied Biological Chemistry, Graduate School of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, Japan 
Yukiko Sato, Department of Environmental Management, Graduate School of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, Japan
Rumi Yoshimura, Department of Applied Biological Chemistry, Graduate School of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, Japan
Sadao Komemushi, Department of Environmental Management, Faculty of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, Japan, Tel: +81-742-43-7437, Fax: +81-742-1445
Akiyoshi Sawabe, Department of Applied Biological Chemistry, Faculty of Agriculture, Kinki University, 3327-204, Nakamachi, Nara, Japan, Tel: +81-742-43-7092, Fax: +81-742-1445 Email: sawabe@nara.kindai.ac.jp

Pollution by heavy metals from industries, the storage of polluted wastes, and agricultural fertilizer pose a serious threat to human health.  These pollutants may pass into the soil where plant uptake or leaching to groundwater can contaminate the food chain.  Phytoremediation is the technique that removed contaminants in environment by plants, and is researched in world, recently.  This process, termed evapotranspiration, is responsible for moving contamination into the plant shoots as well. Because contamination is translocated from the roots to the shoots, which are harvested, contamination is removed while leaving the original soil undisturbed.    Some plants that are used in phytoextraction strategies are termed "hyperaccumulators", which are plants that achieve a shoot to root metal-concentration ratio greater than one.

Brassica juncea is known as Pb hyperaccumulator well. And cucumber is well used to understand transportation mechanism of heavy metals.  Because the sap of cucumber is easy to collecting. We focused to whether the temperature related to the transportation of heavy metal. Cucumber and Brassica juncea were used to this research. These plants were cultivated under hydroponics with Pb (60 to 600 ppm).  The cultivation temperature has been changed from 8 degrees to 30 degrees for 96hours. We measured Pb concentration and GSH concentration and protein concentration every 24 hours. Pb concentration was measured by AAS after ashed with microwave system, GSH and protein concentrations were measured after crushing with liquid nitrogen by HPLC.  As for the cucumber, at 25 degrees the amount of absorption of lead was the maximum.  However as for Brassica juncea, at 12 degrees the amount of absorption of lead was the maximum.  This result shows that the accumulation time of the heavy metal is different in each plant.  And it was shown that GSH and the protein related closely to the accumulation of the heavy metal and the cultivation temperature. 

Water Velocity Effects on Heavy Metal Accumulation in Tissues of Hydroponically Grown Scirpus validus

Peter T. Weiss, Valparaiso University, 1900 Chapel Drive, Valparaiso, IN 46383, Tel: 219-464-5123, Fax: 219-464-5065, Email: Peter.Weiss@Valpo.edu
Andrew D. Westbrook, Insite Engineering, 3 Garrett Place, Carmel, NY 10512, Tel: 845-225-9690, Fax: 845-225-9717, Email: awestbrook@insite-eng.com.
John S. Gulliver, St. Anthony Falls Laboratory, University of Minnesota, #2 Third Avenue S.E., Minneapolis, MN 55414, Tel: 612-625-4080, Fax: 612-626-7750, Email: Gulli003@umn.edu
David D. Biesboer, Department of Plant Biology, University of Minnesota, 220 Biological Sciences Center, 1445 Gortner Avenue, St. Paul, MN 55108, Tel: 612-615-1799, Fax: 612-625-1738
Jeffrey D. Weiss, Barr Engineering Company, 4700 W 77^th St., Minneapolis, MN 55435, Tel: Phone: 952-832-2600, Fax: 952-832-2601

The uptake of cadmium, copper, lead, and zinc by hydroponically grown Scirpus validus was investigated.  The roots of the plants were exposed to a continually recycled, nutrient enriched, synthetic stormwater that was dosed with heavy metals to concentrations typically found in urban stormwater runoff.  The plants were divided into six groups and the roots of each group were exposed to different but constant water velocities.  The heavy metal concentrations in the roots and stems of all plants were determined and compared after three weeks.  Metal accumulation in roots was significantly increased for water velocities between 1.3 and 6.0 cm s^-1.  In a second experiment, the roots of all plants were exposed to a single, constant velocity for approximately 11 weeks.  Every two weeks the concentration metals of the roots and stems were determined for a sub-sample of the treated plants.  The concentration of metals in the roots plateaued after three weeks indicating that accumulation of metals was dependent upon root growth for the last several weeks of the experiment.  At the end of the experiment, however the root concentration for each metal was substantially higher than the roots of control plants.  Accumulation of metals in the stem after three weeks appears to be a function of velocity for copper and zinc, but only the long-term accumulation rate of zinc was noticeably increased by increased water velocity.  The results suggest that the long-term accumulation by the roots of hydroponic Scirpus validus can be increased by increasing water velocity.

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