Uptake of monosodium methanearsonate (MSMA) by vascular aquatic plants

Abstract

The herbicide MSMA is used extensively for grass control in non‐edible crops and for chemical mowing along roadside rights‐of‐way. Herbicide may reach adjacent water bodies either by accidental application or by runoff from sprayed plots. This study utilized floating, submerged and rooted plant species in hydroponic solution to monitor the uptake of trace levels of the herbicide from aqueous concentrations of 5 and 10 μg/ml, respectively. Plant species included Eichhornia crassipes, Ceratophyllum demer‐sum, Alternanthera philoxeroides and Hygrophila lacustris. Duplicate plants were analyzed over the 6 weeks of the study using the silver diethyldithiocarbamate (SDDC) procedure. Rates of uptake, partitioning of the herbicide in roots, stems and leaves and bioaccumulation ratios were determined for each plant species.