Hexachlorocyclohexane phytoremediation using of a contaminated site in Argentina.

In 1996, a diagnostic study performed in a 16-ha field located in Buenos Aires Province (Argentina), where a chemical industry produced 1,2,3,4,5,6-hexachlorocyclohexane (HCH) from 1960 to 1978, showed contamination with HCH ranging from 10 to 20,000 mg kgdry soil (706.4 mg kg average). For remediation purposes, a forestation plan was put into practice in 1997 employing approximately 12,300 seedlings which by 2016 where fully grown into trees that formed a forest where local fauna can be found. Midterm analysis done in 2005, when trees had developed into 8-10 m high trees, indicated that HCH was incorporated into leaves and logs and soil phytoremediation was progressing. Final quantitation analysis of HCH in soil performed in 2016 demonstrated that the 97.2% of the field area was effectively decontaminated with 98.1% overall average efficiency. Thus, this work is the first global example of a successful employment of trees for HCH phytoremediation purposes at field scale. These results may encourage other researchers to test the ability of to phytoremediate soils contaminated with other chlorinated compounds like polychlorinated biphenyls (PCBs), polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).