Impact of non-functionalized and amino-functionalized multiwall carbon nanotubes on pesticide uptake by lettuce (Lactuca sativaL.)

Abstract

The effect of non-functionalized and amino-functionalized multiwall carbon nanotube (CNT) exposure, as well as the impact of CNT presence on coexistent pesticide accumulation, was investigated in lettuce (Lactuca sativa L.). Lettuce seeds were sown directly into CNT-amended vermiculite (1000 mg L(-1)) to monitor phytotoxicity during germination and growth. During growth, lettuce seedlings were subsequently exposed to chlordane (cis-chlordane [CS], trans-chlordane [TC] and trans-nonachlor [TN]) and p,p'-DDE (all at 100 ng/L) in the irrigation solution for a 19-d growth period. CNT exposure did not significantly influence seed germination (82-96%) or plant growth. Similarly, pesticide exposure had no impact on plant growth, total pigment production or tissue lipid peroxidation. After 19 d, the root content of total chlordane and p,p'-DDE was 390 and 73.8 µg g(-1), respectively; in plants not exposed to CNTs, the shoot levels were 1.58 and 0.40 µg g(-1), respectively. The presence and type of CNT significantly influenced pesticide availability to lettuce seedlings. Non-functionalized CNT decreased the root and shoot pesticide content by 88% and 78%, respectively, but amino-functionalized CNT effects were significantly more modest, with decreases of 57% in the roots and 23% in the shoots, respectively. The presence of humic acid completely reversed the reduced accumulation of pesticides induced by amino-functionalized CNT, likely due to strong competition over adsorption sites on the nanomaterial (NM). These findings have implications for food safety and for the use of engineered NMs in agriculture, especially with leafy vegetables.

Quantitative evaluation of multi-wall carbon nanotube uptake by terrestrial plants

“…However, little is known about the effect of SPAOMs on CNTs fate in planted systems. There are limited but related studies focusing on accumulation of pesticides by plants in the presence of CNTs [33][34][35]. The results showed that pesticide uptake was generally reduced by CNTs [33][34][35].…”

Nanoparticle silver coexposure reduces the accumulation of weathered persistent pesticides by earthworms

“…With plants, De La Torre‐Roche et al reported that coexposure to NP, bulk, or ionic Ag reduced the accumulation of freshly added DDE, although the magnitude of the effect was dependent on plant species as well as Ag type and concentration. Similarly, a 78% to 88% reduction in the accumulation of freshly added chlordane and DDE by lettuce ( Lactuca sativa L.) was reported on exposure to functionalized and bare carbon nanotubes . Conversely, De La Torre‐Roche et al reported that exposure to carbon nanomaterials could either increase or decrease pesticide uptake, depending on both the nanomaterial and the plant species.…”

“…Of specific concern are agricultural soils that receive or have received long‐term amendments in the form of organic chemicals (pesticides) and elements, including some heavy metals (pesticides, biosolids). Given the high surface area and reactivity of nanomaterials, the potential for cocontaminant interactions is high and could be complicated, with concerns ranging from food safety (increased pesticide/contaminant accumulation in the presence of nanomaterial) to food security (reduced yield from loss of pesticide/fertilizer efficacy or activity) . For example, accumulation of the solvent trichloroethylene by Populus deltoides (cottonwood) was increased by 82% on coexposure to C 60 fullerenes under hydroponic growth .…”

Carbon nanotubes: Impacts and behaviour in the terrestrial ecosystem - A review

“…For example, Hamdi et al [111] found no effect of MWCNTs functionalized and non-functionalized on seed germination of lettuce (Lactuca sativa). Lin and Xing [112] evidenced no effect of MWCNTs on seed germination and root length of several plants (radish, rape, ryegrass, lettuce, corn, and cucumber) like Larue et al [20] in wheat and rapeseed.…”