Modeling Uptake of Selected Pharmaceuticals and Personal Care Products into Food Crops from Biosolids-Amended Soil

Biosolids contain a variety of pharmaceuticals and personal care products (PPCPs). Studies have observed the uptake of PPCPs into plants grown in biosolids-amended soils. This study examined the ability of Dynamic Plant Uptake (DPU) model and Biosolids-amended Soil Level IV (BASL4) model to predict the concentration of eight PPCPs in the tissue of plants grown in biosolids-amended soil under a number of exposure scenarios. Concentrations in edible tissue predicted by the models were compared to concentrations reported in the literature by calculating estimated human daily intake values for both sets of data and comparing them to an acceptable daily intake value. The equilibrium partitioning (EqP) portion of BASL4 overpredicted the concentrations of triclosan, triclocarban, and miconazole in root and shoot tissue by two to three orders of magnitude, while the dynamic carrot root (DCR) portion overpredicted by a single order of magnitude. DPU predicted concentrations of triclosan, triclocarban, miconazole, carbamazepine, and diphenhydramine in plant tissues that were within an order of magnitude of concentrations reported in the literature. The study also found that more empirical data are needed on the uptake of cimetidine, fluoxetine, and gemfibrozil, and other ionizable PPCPs, to confirm the utility of both models. All hazard quotient values calculated from literature data were below 1, with 95.7% of hazard quotient values being below 0.1, indicating that consumption of the chosen PPCPs in plant tissue poses de minimus risk to human health

Least-squares means of the instantaneous rate of increase (<i>r_i</i>) and total number of aphids per plant after 21 days following infestation of <i>M. persicae</i> on to potato plants treated with sublethal concentrations of imidacloprid in a greenhouse.

a<p>Data were square root transformed before analysis. Backtransformed means are presented. Values followed by different letters are significantly different (LSD, α = 0.05). SEM values are not backtransformed.</p

Regression parameters of model-fitting hormetic responses (G₀, G₁ fecundity and <i>r_i</i>) in <i>M. persicae</i> exposed to sublethal concentrations of imidacloprid.

a<p><i>b,</i> steepness of the curve after the maximal hormetic effect; <i>d</i>, untreated control; <i>e,</i> lower bound on the ED50 level; <i>f,</i> rate of stimulation; RSE, residual standard error; <i>df,</i> degrees of freedom. In the model, <i>c</i> was set to zero and α set at 0.25 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074532#pone.0074532-Cedergreen1" target="_blank">[32]</a>.</p>b<p>denotes fecundity of <i>M. persicae</i> adults continuously exposed to sublethal concentrations of imidacloprid. G₀ is initial generation, G₁ is progeny of G₀.</p>c<p>data were square-root transformed before analysis.</p>d<p><i>r_i</i> is the instantaneous rate of increase of a <i>M. persicae</i> population exposed to low-dose imidacloprid treated potato plants.</p

Least-squares means of multigenerational fecundity^a following two-day exposure of <i>M. persicae</i> to sublethal concentrations of imidacloprid.

a<p>24 h old nymphs were placed on treated potato leaf discs and fecundity of each resulting adult was recorded every 2 days until it died. In the succeeding generation, 5 randomly selected 24 h old nymphs were tracked and fecundity of the resulting adults was recorded every 2 days until they died. G₀ is initial generation, G₁ is progeny of G₀, G₂ is progeny of G₁, and G₃ is progeny of G₂. G₀ nymphs were exposed to treated discs for two days and all aphids were thereafter exposed to untreated leaf discs.</p>b<p>Progeny per adult data were log transformed before analysis. Backtransformed means are presented. Values followed by different letters are significantly different (LSD, α = 0.05). SEM values are not backtransformed.</p>c<p>Mean total number of nymphs produced over four generations.</p>d<p>G₀ nymphs did not survive to adulthood when treated with 25 µg L⁻¹. This concentration was not included in the analysis.</p

Multigenerational effects of low doses of imidacloprid on aphids.

<p>Multigenerational effects of continuous exposure to sublethal concentration of imidacloprid on the (A) longevity and (B) length of adult <i>M. persicae.</i></p

Least-squares means of multigenerational fecundity^a following continuous exposure of <i>M. persicae</i> to sublethal concentrations of imidacloprid.

a<p>24 h old nymphs were placed on treated potato leaf discs and fecundity of each resulting adult was recorded every 2 days until it died. In the succeeding generation, 5 randomly selected 24 h old nymphs were tracked and fecundity of the resulting adults was recorded every 2 days until they died. G₀ is initial generation, G₁ is progeny of G₀, G₂ is progeny of G₁, and G₃ is progeny of G₂. Leaf discs were replaced every two days over all generations.</p>b<p>Progeny per adult data were log transformed before analysis. Backtransformed means are presented. Values followed by different letters are significantly different (LSD, α = 0.05). SEM values are not backtransformed.</p>c<p>Mean total number of nymphs produced over four generations.</p

Least-squares means of two-generational fecundity^a following topical exposure of <i>M. persicae</i> to sublethal concentrations of imidacloprid.

a<p>24 h old nymphs were topically treated and thereafter reared on untreated potato leaf discs. Fecundity of each resulting adult was recorded every 2 days until it died. In the succeeding generation, 5 randomly selected 24 h old nymphs were tracked and fecundity of the resulting adults was recorded every 2 days until they died. G₀ is initial generation, G₁ is progeny of G₀.</p>b<p>Progeny per adult data were log transformed before analysis. Backtransformed means are presented. Values followed by different letters are significantly different (LSD, α = 0.05). SEM values are not backtransformed.</p>c<p>Mean total number of nymphs produced over four generations.</p

Hormesis model-fitting of low doses of imidacloprid on fecundity and <i>r_i</i> of aphids.

<p>Four-parameter biphasic model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0074532#pone.0074532-Cedergreen1" target="_blank">[32]</a> for reproductive hormetic responses of <i>M. persicae</i> in an initial (A) and second (B) generation when continuously exposed to sublethal concentrations of imidacloprid on potato leaf discs, and (C) the instantaneous rate of increase (<i>r_i</i>) of <i>M. persicae</i> populations developing on whole potato plants treated with sublethal concentrations of imidacloprid. * indicates data were square-root transformed before analysis.</p