title: The sensitivity of an hydroponic lettuce root elongation bioassay to metals, phenol and wastewaters.
abstract: The root elongation bioassay is one of the most straightforward test methods used for environmental monitoring in terms of simplicity, rapidity and economy since it merely requires filter paper, distilled water and Petri dishes. However, filter paper as a support material is known to be problematic as it can reduce the sensitivity of the test. The newly developed hydroponic method reported here differs from the conventional root elongation method (US EPA filter paper method) in that no support material is used and the exposure time is shorter (48 h in this test versus 120 h in the US EPA test). For metals, the hydroponic test method was 3.3 (for Hg) to 57 (for Cu) times more sensitive than the US EPA method with the rank orders of sensitivity, estimated from EC50 values, being Cu≥Cd>Ni≥Zn≥Hg for the former and Hg≥Cu≥Ni≥Cd≥Zn for the latter methods. For phenol, the results did not differ significantly; EC50 values were 124 mg L(-1) and 108-180 mg L(-1) for the hydroponic and filter paper methods, respectively. Lettuce was less sensitive than daphnids to wastewaters, but the root elongation response appears to be wastewater-specific and is especially sensitive for detecting the presence of fluorine. The new hydroponic test thus provides many practical advantages, especially in terms of cost and time-effectiveness requiring only a well plate, a small volume of distilled water and short exposure period; furthermore, no specialist expertise is required. The method is simpler than the conventional EPA technique in not using filter paper which can influence the sensitivity of the test. Additionally, plant seeds have a long shelf-life and require little or no maintenance.
authors.affiliation: Division of Life Science, Incheon National University, 119, Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea; Lab of Plant Growth Analysis, Ghent University Global Campus, Songomunhwa-Ro, 119 Yeonsu-Gu, Incheon 21985, Republic of Korea.
authors.forename: Jihae
authors.initials: J
authors.lastname: Park
authors.affiliation: Division of Life Science, Incheon National University, 119, Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea.
authors.forename: Jeong-Hyun
authors.initials: JH
authors.lastname: Yoon
authors.affiliation: Lab of Plant Growth Analysis, Ghent University Global Campus, Songomunhwa-Ro, 119 Yeonsu-Gu, Incheon 21985, Republic of Korea.
authors.forename: Stephen
authors.initials: S
authors.lastname: Depuydt
authors.affiliation: Korea Coast Guard Metropolitan Police, 130, Haedoji-ro, Yeonsu-gu, Incheon 21995, Republic of Korea.
authors.forename: Jung-Woo
authors.initials: JW
authors.lastname: Oh
authors.affiliation: Institute of Public Health and Environments Researcher, 471, Seohae-daero, Jung-gu, Incheon 22320, Republic of Korea.
authors.forename: Youn-Min
authors.initials: YM
authors.lastname: Jo
authors.affiliation: National Institute of Environmental Research, 42, Hwangyeong-ro, Seo-gu, Incheon 22689, Republic of Korea.
authors.forename: Kyungtae
authors.initials: K
authors.lastname: Kim
authors.affiliation: School of Marine Science & Engineering, Plymouth University, Plymouth, Devon PL4 8AA, United Kingdom.
authors.forename: Murray T
authors.initials: MT
authors.lastname: Brown
authors.affiliation: Green-pioneer, R&D center, 169, Gaetbeol-ro, Yeonsu-gu, Incheon 21999, Republic of Korea; Department of Cosmetic Science & Management Graduate School, 119, Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea; Institute of Green Environmental Research Center, 169, Gaetbeol-ro, Yeonsu-gu, Incheon 21999, Republic of Korea; Department of Marine Science, Incheon National University, 119, Academy-ro, Yeonsu-gu, Incheon 22012, Republic of Korea. Electronic address: hanalgae@hanmail.net.
authors.forename: Taejun
authors.initials: T
authors.lastname: Han
mesh_terms: D001681:Biological Assay / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods*; D018527:Hydroponics / Q000379:methods*; D018545:Lactuca / Q000187:drug effects* / Q000254:growth & development; D019216:Metals, Heavy / Q000633:toxicity*; D019800:Phenol / Q000633:toxicity*; D018517:Plant Roots / Q000187:drug effects* / Q000254:growth & development; D012639:Seeds / Q000187:drug effects / Q000254:growth & development; D018675:Toxicity Tests / Q000379:methods; D062065:Wastewater / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D019216:Metals, Heavy; D019800:Phenol; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Daphnia; Lettuce; Metals; Phenol; Root elongation; Wastewater