Accumulation of Weathered Pesticides in Four Agricultural Plants

Accumulation of Weathered Pesticides in Four Agricultural Plants

The effect of multiwalled carbon nanotubes (MWCNT) or C₆₀ fullerenes on the uptake of weathered chlordane or DDx (DDT + metabolites) by Cucurbita pepo (zucchini), Zea mays (corn), Solanum lycopersicum (tomato), and Glycine max (soybean) was investigated. The plants were grown in 50 g of soil with weathered chlordane (2150 ng/g) and DDx (118 ng/g) that was amended with 0, 500, 1000, or 5000 mg/kg MWCNT or C₆₀. After 28 d, the root and shoot content of chlordane components and DDx was determined by GC-MS. Zucchini and tomato growth were unaffected by carbon nanomaterial coexposure, although C₆₀ at 500 mg/kg reduced corn and soybean biomass by 36.5–45.0%. Total chlordane content ranged from 1490 (tomato) to 4780 (zucchini) ng; DDx amounts ranged from 77.8 (corn) to 395 ng (zucchini). MWCNT coexposure decreased chlordane and DDx accumulation 21–80% across all crops, depending on species and nanotube concentration. Conversely, C₆₀ had species- and contaminant-specific effects on pesticide uptake, ranging from complete suppression of DDx uptake (corn/tomato) to 34.9% increases in chlordane accumulation (tomato/soybean). The data show that pesticide accumulation varies greatly with crop species and carbon nanomaterial type/concentration. These findings have implications for food safety and for the use of engineered nanomaterials in agriculture. More at:  https://pubs.acs.org/doi/abs/10.1021/es4034809?src=recsys