Heavy metal and arsenic accumulating fern species as potential ecological indicators in As-contaminated abandoned mines

Ferns are good ecological indicators of arsenic accumulation in contaminated abandoned mines. The rhizomes of ferns were analyzed for arsenic and other heavy metals using inductively coupled plasma-mass spectrometry. In addition, we examined the ribulose-bisphosphate carboxylase (rbcL) gene isolated from the indigenous species of ferns at the pithead, tailings and soil sites in the vicinity of the Myoungbong abandoned mine, Republic of Korea. A search of the GenBank database revealed that the predicted amino acid sequence of this gene was homologous with 99% of Pteridium aquilinum As-2 (EU476184), 99% of Deparia petersenii As-6 (EU476188), 97% of Deparia lobatocrenata As-8 (EU476190), and 98% of Deparia conilii As-7 (EU476189). High concentrations of heavy metals (arsenic, 17.6 mg/kg in rhizomes and 2690 mg/kg in soil; copper, 17.1 mg/kg in rhizomes and 40.7 mg/kg in soil; cadmium, 2.9 mg/kg in rhizomes and 12.2 mg/kg in soil; lead, 41.9 mg/kg in rhizomes and 135 mg/kg in soil; zinc, 27.0 mg/kg in rhizomes and 172 mg/kg in soil) were found in P. aquilinum As-2 (EU476184) from the Myoungbong mine area, which may play an important role as ecological indicators of the contaminated areas.