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Projected Dietary Intake of Zinc, Copper, and Cerium from Consumption of Carrot (Daucus carota) Exposed to Metal Oxide Nanoparticles or Metal Ions.

Ebbs SD, Bradfield SJ, Kumar P, White JC, Ma X - Front Plant Sci (2016)

Bottom Line: The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots.Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake.The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how peeling mitigated that dietary intake.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Biology and Center for Ecology, Southern Illinois University, Carbondale IL, USA.

ABSTRACT
The expanding production and use of engineered nanomaterials (ENMs) have raised concerns about the potential risk of those materials to food safety and human health. In a prior study, the accumulation of Zn, Cu, and Ce from ZnO, CuO, or CeO2, respectively, was examined in carrot (Daucus carota L.) grown in sand culture in comparison to accumulation from exposure to equivalent concentrations of ionic Zn(2+), Cu(2+), or Ce(4+). The fresh weight concentration data for peeled and unpeeled carrots were used to project dietary intake of each metal by seven age-mass classes from child to adult based on consumption of a single serving of carrot. Dietary intake was compared to the oral reference dose (oral RfD) for chronic toxicity for Zn or Cu and estimated mean and median oral RfD values for Ce based on nine other rare earth elements. Reverse dietary intake calculations were also conducted to estimate the number of servings of carrot, the mass of carrot consumed, or the tissue concentration of Zn, Cu, or Ce that would cause the oral RfD to be exceeded upon consumption. The projections indicated for Zn and Cu, the oral RfD would be exceeded in only a few highly unrealistic scenarios of exceedingly high Zn or Cu concentrations in the substrate from ZnO or CuO or consumption of excessive amounts of unpeeled carrot. The implications associated with the presence of Ce in the carrot tissues depended upon whether the mean or median oral RfD value from the rare earth elements was used as a basis for comparison. The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots. Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake. The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how peeling mitigated that dietary intake. The results also demonstrate the potential utility of dietary intake projections for examining potential risks of NM exposure from agricultural foods.

No MeSH data available.


Related in: MedlinePlus

Dietary intake models for Zn based on consumption of a single serving of unpeeled (A,B) or peeled carrot (C,D) grown in sand culture in the presence of four final concentrations of Zn (0.5, 5, 50, or 500 mg kg DW-1) as nanomaterial (NM) ZnO (A,C) or ionic Zn2+(B,D). Intake for each scenario is modeled for seven age-mass classes ranging from child to adult females and males. The dashed line represents the chronic oral RfD value for Zn. Data represent the mean and standard error (n = 4–5).
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Figure 1: Dietary intake models for Zn based on consumption of a single serving of unpeeled (A,B) or peeled carrot (C,D) grown in sand culture in the presence of four final concentrations of Zn (0.5, 5, 50, or 500 mg kg DW-1) as nanomaterial (NM) ZnO (A,C) or ionic Zn2+(B,D). Intake for each scenario is modeled for seven age-mass classes ranging from child to adult females and males. The dashed line represents the chronic oral RfD value for Zn. Data represent the mean and standard error (n = 4–5).

Mentions: The projected dietary intake of each element for the seven age-mass classes was estimated for a single serving of peeled or unpeeled carrots grown in the presence of the ENM or ionic form of the element (Figures 1–3). For unpeeled carrots (Figures 1A,B), the projected dietary intake for both forms for the two lower treatment concentrations and the control fell far below the oral RfD for Zn. The dietary intake from unpeeled carrots grown in the two highest concentrations of ionic Zn exceeded the oral RfD for some age-mass categories. For the 50 mg kg DW-1 ionic Zn treatment, the oral RfD was exceeded only for the smallest age-mass class (children 1–3 years) while for the 500 mg kg DW-1 ionic Zn treatment exceeded the oral RfD for all child age-mass classes from age 1 to 13 years. By comparison, the 50 mg kg DW-1 ENM Zn treatment fell below the Zn oral RfD and the 500 mg kg DW-1 ENM Zn treatment was similar to the corresponding ionic treatment. The projected dietary intake values calculated for the peeled carrots (Figures 1C,D) were >100-fold lower than the oral RfD and were considerably lower than the corresponding values for the unpeeled carrots. Projected dietary intake from peeled carrots treated with ionic Zn were consistently higher than the corresponding carrots from the ENM treatment.


Projected Dietary Intake of Zinc, Copper, and Cerium from Consumption of Carrot (Daucus carota) Exposed to Metal Oxide Nanoparticles or Metal Ions.

Ebbs SD, Bradfield SJ, Kumar P, White JC, Ma X - Front Plant Sci (2016)

Dietary intake models for Zn based on consumption of a single serving of unpeeled (A,B) or peeled carrot (C,D) grown in sand culture in the presence of four final concentrations of Zn (0.5, 5, 50, or 500 mg kg DW-1) as nanomaterial (NM) ZnO (A,C) or ionic Zn2+(B,D). Intake for each scenario is modeled for seven age-mass classes ranging from child to adult females and males. The dashed line represents the chronic oral RfD value for Zn. Data represent the mean and standard error (n = 4–5).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4764699&req=5

Figure 1: Dietary intake models for Zn based on consumption of a single serving of unpeeled (A,B) or peeled carrot (C,D) grown in sand culture in the presence of four final concentrations of Zn (0.5, 5, 50, or 500 mg kg DW-1) as nanomaterial (NM) ZnO (A,C) or ionic Zn2+(B,D). Intake for each scenario is modeled for seven age-mass classes ranging from child to adult females and males. The dashed line represents the chronic oral RfD value for Zn. Data represent the mean and standard error (n = 4–5).
Mentions: The projected dietary intake of each element for the seven age-mass classes was estimated for a single serving of peeled or unpeeled carrots grown in the presence of the ENM or ionic form of the element (Figures 1–3). For unpeeled carrots (Figures 1A,B), the projected dietary intake for both forms for the two lower treatment concentrations and the control fell far below the oral RfD for Zn. The dietary intake from unpeeled carrots grown in the two highest concentrations of ionic Zn exceeded the oral RfD for some age-mass categories. For the 50 mg kg DW-1 ionic Zn treatment, the oral RfD was exceeded only for the smallest age-mass class (children 1–3 years) while for the 500 mg kg DW-1 ionic Zn treatment exceeded the oral RfD for all child age-mass classes from age 1 to 13 years. By comparison, the 50 mg kg DW-1 ENM Zn treatment fell below the Zn oral RfD and the 500 mg kg DW-1 ENM Zn treatment was similar to the corresponding ionic treatment. The projected dietary intake values calculated for the peeled carrots (Figures 1C,D) were >100-fold lower than the oral RfD and were considerably lower than the corresponding values for the unpeeled carrots. Projected dietary intake from peeled carrots treated with ionic Zn were consistently higher than the corresponding carrots from the ENM treatment.

Bottom Line: The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots.Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake.The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how peeling mitigated that dietary intake.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Biology and Center for Ecology, Southern Illinois University, Carbondale IL, USA.

ABSTRACT
The expanding production and use of engineered nanomaterials (ENMs) have raised concerns about the potential risk of those materials to food safety and human health. In a prior study, the accumulation of Zn, Cu, and Ce from ZnO, CuO, or CeO2, respectively, was examined in carrot (Daucus carota L.) grown in sand culture in comparison to accumulation from exposure to equivalent concentrations of ionic Zn(2+), Cu(2+), or Ce(4+). The fresh weight concentration data for peeled and unpeeled carrots were used to project dietary intake of each metal by seven age-mass classes from child to adult based on consumption of a single serving of carrot. Dietary intake was compared to the oral reference dose (oral RfD) for chronic toxicity for Zn or Cu and estimated mean and median oral RfD values for Ce based on nine other rare earth elements. Reverse dietary intake calculations were also conducted to estimate the number of servings of carrot, the mass of carrot consumed, or the tissue concentration of Zn, Cu, or Ce that would cause the oral RfD to be exceeded upon consumption. The projections indicated for Zn and Cu, the oral RfD would be exceeded in only a few highly unrealistic scenarios of exceedingly high Zn or Cu concentrations in the substrate from ZnO or CuO or consumption of excessive amounts of unpeeled carrot. The implications associated with the presence of Ce in the carrot tissues depended upon whether the mean or median oral RfD value from the rare earth elements was used as a basis for comparison. The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots. Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake. The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how peeling mitigated that dietary intake. The results also demonstrate the potential utility of dietary intake projections for examining potential risks of NM exposure from agricultural foods.

No MeSH data available.


Related in: MedlinePlus