Uptake and translocation of organophosphates and other emerging contaminants in food and forage crops

Abstract

Emerging contaminants in wastewater and sewage sludge spread on agricultural soil can be transferred to the human food web directly by uptake into food crops or indirectly following uptake into forage crops. This study determined uptake and translocation of the organophosphates tris(1-chloro-2-propyl) phosphate (TCPP) (log Kow 2.59), triethyl-chloro-phosphate (TCEP) (log Kow 1.44), tributyl phosphate (TBP) (log Kow 4.0), the insect repellent N,N-diethyl toluamide (DEET) (log Kow 2.18) and the plasticiser N-butyl benzenesulfonamide (NBBS) (log Kow 2.31) in barley, wheat, oilseed rape, meadow fescue and four cultivars of carrot. All species were grown in pots of agricultural soil, freshly amended contaminants in the range of 0.6–1.0 mg/kg dry weight, in the greenhouse. The bioconcentration factors for root (RCF), leaf (LCF) and seed (SCF) were calculated as plant concentration in root, leaf or seed over measured initial soil concentration, both in dry weight. The chlorinated flame retardants (TCEP and TCPP) displayed the highest bioconcentration factors for leaf and seed but did not show the same pattern for all crop species tested. For TCEP, which has been phased out due to toxicity but is still found in sewage sludge and wastewater, LCF was 3.9 in meadow fescue and 42.3 in carrot. For TCPP, which has replaced TCEP in many products and also occurs in higher residual levels in sewage sludge and wastewater, LCF was high for meadow fescue and carrot (25.9 and 17.5, respectively). For the four cultivars of carrot tested, the RCF range for TCPP and TCEP was 10–20 and 1.7–4.6, respectively. TCPP was detected in all three types of seeds tested (SCF, 0.015–0.110). Despite that DEET and NBBS have log Kow in same range as TCPP and TCEP, generally lower bioconcentration factors were measured. Based on the high translocation of TCPP and TCEP to leaves, especially TCPP, into meadow fescue (a forage crop for livestock animals), ongoing risk assessments should be conducted to investigate the potential effects of these compounds in the food web.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-012-1363-5) contains supplementary material, which is available to authorized users.

Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation

“…Salad Bowl, we found no significant difference in percent moisture content or dry weight between the two cultivars (data not shown). Several potential mechanisms described for sub-species variation in uptake of other organic contaminants include the quantity and quality of root exudates, plant composition, root structure, biomass, endophytes, and multi-species interaction (Eggen et al, 2013). Average plant biomass does not explain the differences observed in our study as the cultivar with greater average plant mass changed between harvests, but the higher uptake by cv.…”

“…Cultivar specific differences in uptake have been documented for organic pollutants such as chlordane in zucchinis and squash (Isleyen et al, 2013), organophosphate and DEET in carrots (Eggen et al, 2013); as well as nitrates in cabbage (Tang et al, 2013).…”

Organic Contaminant Content and Physico-Chemical Characteristics of Waste Materials Recycled in Agriculture

“…Additionally, the organophosphate flame-retardant, tris(2-chloroisopropyl) phosphate (TCCP), was detected in 8 of the samples (Biosolids1, CLO1, CLO2, PLA2, MBMA1, RWW1, RWW2, RWW4) and tris(2-chloroethyl)phosphate (TCEP) was found in PLA2 and Biosoids1. These compounds and their metabolites are of interest due to their toxicity, their translocation from soil to crops [55] and their potential bioconcentration through the food chain [56,57]. Therefore these chemicals will also be investigated further in the waste materials and the transfer investigations to crops and milk.…”

Substances of Very High Concern in Food Contact Materials: Migration and Regulatory Background

“…In our analysis, we found no data demonstrating the migration of TCEP from FCMs into food. Tris(2‐chloroethyl)phosphate was described as environmental contaminant that is commonly found in sewage sludge and wastewater, and it may be taken up by plants used as food or feed . Tris(2‐chloroethyl)phosphate has been found in certain foods, but it is unknown whether packaging or other FCMs contribute to this finding.…”