title: Accumulation of contaminants of emerging concern in food crops-part 2: Plant distribution.
abstract: Arid agricultural regions often turn to using treated wastewater (reclaimed water) to irrigate food crops. Concerns arise, however, when considering the potential for persistent contaminants of emerging concern to accumulate into plants intended for human consumption. The present study examined the accumulation of a suite of 9 contaminants of emerging concern into 2 representative food crops, lettuce and strawberry, following uptake via the roots and subsequent distribution to other plant tissues. Calculating accumulation metrics (concentration factors) allowed for comparison of the compartmental affinity of each chemical for each plant tissue compartment. The root concentration factor was found to exhibit a positive linear correlation with the pH-adjusted octanol-water partition coefficient (DOW ) for the target contaminants of emerging concern. Coupled with the concentration-dependent accumulation observed in the roots, this result implies that accumulation of these contaminants of emerging concern into plant roots is driven by passive partitioning. Of the contaminants of emerging concern examined, nonionizable contaminants, such as triclocarban, carbamazepine, and organophosphate flame retardants displayed the greatest potential for translocation from the roots to above-ground plant compartments. In particular, the organophosphate flame retardants displayed increasing affinity for shoots and fruits with decreasing size/octanol-water partition coefficient (KOW ). Cationic diphenhydramine and anionic sulfamethoxazole, once transported to the shoots of the strawberry plant, demonstrated the greatest potential of the contaminants examined to be then carried to the edible fruit portion.
authors.affiliation: Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA.
authors.forename: Katherine C
authors.initials: KC
authors.lastname: Hyland
authors.affiliation: Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Blaine
authors.affiliation: Civil and Environmental Engineering, Colorado School of Mines, Golden, Colorado, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Higgins
mesh_terms: D002851:Chromatography, High Pressure Liquid; D018556:Crops, Agricultural; D005411:Flame Retardants / Q000032:analysis; D031985:Fragaria / Q000737:chemistry* / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D018545:Lactuca / Q000737:chemistry* / Q000378:metabolism; D063148:Plant Dispersal; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D062065:Wastewater / Q000032:analysis*
chemical_list: D005411:Flame Retardants; D062065:Wastewater
keywords: Bioaccumulation; Biodistribution; Emerging contaminants; Reclaimed water