Perchlorate content of plant foliage reflects a wide range of species-dependent accumulation but not ozone-induced biosynthesis

• Published in: Environmental pollution (1987) 2014-01, Vol.184, p.690-696
• Main Authors: Grantz, D.A., Burkey, K.O., Jackson, W.A., Vu, H.-B., McGrath, M.T., Harvey, G.
• Format: Article
• Language: English
• Subjects: Air Pollutants - toxicity; Air pollution; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; ClO4; Crop contamination; Crops; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Exposure; Flux; Foliage; Fundamental and applied biological sciences. Psychology; Gas exchange; Humans; In vitro testing; Oxidants; Ozone; Ozone - toxicity; Perchlorate; Perchlorates; Perchlorates - metabolism; Plant Leaves - drug effects; Plant Leaves - metabolism; Plants (organisms); Vegetation
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2013.03.048

Perchlorate (ClO4−) interferes with uptake of iodide in humans. Emission inventories do not explain observed distributions. Ozone (O3) is implicated in the natural origin of ClO4−, and has increased since pre-industrial times. O3 produces ClO4−in vitro from Cl−, and plant tissues contain Cl− and redox reactions. We hypothesize that O3 exposure may induce plant synthesis of ClO4−. We exposed contrasting crop species to environmentally relevant O3 concentrations. In the absence of O3 exposure, species exhibited a large range of ClO4− accumulation but there was no relationship between leaf ClO4− and O3, whether expressed as exposure or cumulative flux (dose). Older, senescing leaves accumulated more ClO4− than younger leaves. O3 exposed vegetation is not a source of environmental ClO4−. There was evidence of enhanced ClO4− content in the soil surface at the highest O3 exposure, which could be a significant contributor to environmental ClO4−. •Exposure to ozone in crop species does not induce accumulation nor biosynthesis of perchlorate.•Older leaves accumulate more perchlorate than younger leaves.•Soil surface may accumulate perchlorate following exposure to ozone.•Species differ greatly in accumulation of perchlorate from the rhizosphere, independent of ozone.•Ozone exposed vegetation is not a candidate source of environmental perchlorate. Exposure of crop species to ozone did not lead to biosynthesis or greater accumulation of foliar perchlorate. Older leaves accumulated more perchlorate than younger leaves.