Uptake and Accumulation of Pharmaceuticals in Overhead- and

Jan 2, 2018 - Petrie , B.; Barden , R.; Kasprzyk-Hordern , B. A review on emerging contaminants in wastewaters and the environment: Current knowledge,...
0 downloads 25 Views 950KB Size
Subscriber access provided by READING UNIV

Article

Uptake and Accumulation of Pharmaceuticals in Overhead- and Surface-Irrigated Greenhouse Lettuce Gemini D Bhalsod, Ya-Hui Chuang, Sangho Jeon, Wenjun Gui, Hui Li, Elliot T Ryser, Andrey K Guber, and Wei Zhang J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.7b04355 • Publication Date (Web): 02 Jan 2018 Downloaded from http://pubs.acs.org on January 3, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Journal of Agricultural and Food Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 29

Journal of Agricultural and Food Chemistry

1

Uptake and Accumulation of Pharmaceuticals in Overhead- and Surface-Irrigated

2

Greenhouse Lettuce

3

Gemini D. Bhalsod,†,¶ Ya-Hui Chuang,† Sangho Jeon,†,▲ Wenjun Gui,†,ǁ Hui Li,† Elliot T. Ryser,‡

4

Andrey K. Guber,† and Wei Zhang*,†,§

5



Department of Plant, Soil and Microbial Sciences, ‡Department of Food Science and Human

6

Nutrition, and §Environmental Science and Policy Program, Michigan State University, East

7

Lansing, MI 48824, United States

8

ǁ

9

China

Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058,

10



11



12

Republic of Korea

13

*Corresponding author. Dr. Wei Zhang, Address: 1066 Bogue ST RM A516, East Lansing, MI

14

48824, United States; Tel: 517-353-0471; Fax: 517-355-0270; Email: [email protected].

Cook County Unit, University of Illinois Extension, Arlington Heights, IL 60004, United States National Institute of Agricultural Sciences, Rural Development Administration, Wanju 54875,

15

1 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

16

ABSTRACT: Understanding the uptake and accumulation of pharmaceuticals in vegetables

17

under typical irrigation practices is critical to risk assessment of crop irrigation with reclaimed

18

water. This study investigated the pharmaceutical residues in greenhouse lettuce under overhead

19

and soil-surface irrigations using pharmaceutical-contaminated water. Compared to soil-surface

20

irrigation, overhead irrigation substantially increased the pharmaceutical residues in lettuce

21

shoots. The increased residue levels persisted even after washing for trimethoprim, monensin

22

sodium, and tylosin, indicating their strong sorption to the shoots. The post-washing

23

concentrations in fresh shoots varied from 0.05 ± 0.04 µg/kg for sulfadiazine to 345 ± 139 µg/kg

24

for carbamazepine. Root concentration factors ranged from 0.04 ± 0.14 for tylosin to 19.2 ± 15.7

25

for sulfamethoxazole. Translocation factors in surface-irrigated lettuce were low for

26

sulfamethoxalzole, trimethoprim, monensin sodium and tylosin (0.07–0.15), but high for caffeine

27

(4.28 ± 3.01) and carbamazepine (8.15 ± 2.87). Carbamazepine was persistent in soil and

28

hyperaccumulated in shoots.

29

KEYWORDS: pharmaceuticals, uptake, lettuce, Lactuca sativa, irrigation

30

2 ACS Paragon Plus Environment

Page 2 of 29

Page 3 of 29

Journal of Agricultural and Food Chemistry

31

INTRODUCTION

32

Pharmaceuticals are considered contaminants of emerging concern, because they are widely

33

detected in the environment, are not routinely monitored or regulated, and could pose potential

34

risks to human and ecosystem health.1, 2 The ubiquitous presence of pharmaceuticals in the

35

environment results from their large use in healthcare and animal agriculture.3 For instance, as an

36

important group of pharmaceuticals, antibiotics are commonly used in livestock production for

37

growth promotion, and disease prevention and treatment.3, 4 Like many other pharmaceuticals, a

38

significant portion of the administered antibiotics is released to agroecosystems via sewage

39

sludge, wastewater effluents, animal manure, and agricultural wastewater, due to incomplete

40

drug metabolism or insufficient removal during wastewater treatment.3, 5-7 The anthropogenic

41

loading of antibiotics to agroecosystems has been linked to the proliferation of antibiotic

42

resistance in bacteria populations.4, 8, 9 Antibiotic resistance is an eminent global health threat,10

43

thus demanding more research in both clinical and agricultural settings. When contaminated soil

44

and water are used for agricultural production, potential risks of pharmaceuticals to food safety

45

and human health need to be examined in terms of chronic low-level exposure and the

46

proliferation of antibiotic resistant bacteria and genes.9, 11, 12

47

Currently over 70% of the world’s freshwater is used for crop irrigation.13, 14 Due to

48

increasing water shortage, alternative irrigation water sources (often of lower water quality) must

49

be considered.15 Treated municipal or agricultural wastewaters are increasingly being reclaimed

50

for crop irrigation,13, 15-17 particularly in water-stressed regions. However, many pharmaceuticals

51

have been detected in wastewater effluents at ng/L to µg/L levels.7 For instance, acetaminophen,

52

caffeine, carbamazepine, sulfamethoxazole and trimethoprim was found up to 11.7, 15.2, 3.1,

53

22.0, and 2.5 µ/L in the wastewater effluents, respectively.6, 7, 18 Thus, concerns have been raised

3 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

54

regarding potential risks of crop irrigation with reclaimed water to food safety and human

55

health.11, 16, 18, 19 In the US, 52 million acres of cropland are irrigated,20 and about 51% of

56

irrigation is performed by overhead sprinkler systems, 42% by surface flood irrigation, and 7%

57

by micro-irrigation.21 Irrigation practices with reclaimed water (e.g., overhead spray irrigation

58

and soil surface irrigation) vary substantially across the world, depending on source and quality

59

of reclaimed water, crop types (nonfood and food crops), and adequacy of reuse infrastructure

60

and management.13, 16, 22 For wheat crop spray-irrigated with wastewater effluent,

61

sulfamethoxazole, trimethoprim, olfoxacin and carbamazepine were detected at 0.1–5.2 µg/kg on

62

wheat grain surface and 0.6–2.3 µg/kg in wheat grains, respectively.18 Therefore, understanding

63

the transfer of pharmaceuticals from contaminated soil and water to and their residue levels in

64

crops under typical irrigation practices is critical to informed assessment of exposure level and

65

health risks. It is particularly important to evaluate the effect of irrigation methods on

66

pharmaceutical uptake by vegetables such as lettuce (Lactuca sativa), because vegetables are

67

often consumed with minimal processing.

68

A number of recent studies have examined the uptake and accumulation of pharmaceuticals

69

in plants including vegetable crops.23-26 These previous studies often examined the

70

pharmaceutical uptake through plant roots,27-30 whereas little work has been directed to foliar

71

uptake of pharmaceuticals. Two recent studies reported that foliar uptake most likely occurs for

72

lipophilic compounds.31, 32 Lu et al.31 observed greater accumulation of relatively lipophilic

73

bisphenol A (log Kow = 3.40) and nonylphenol (log Kow = 4.48) in lettuce and tomato through the

74

foliar exposure rather than the subsurface root exposure. Similarly, Calderón-Preciado et al.32

75

found greater retention of lipophilic contaminants in leaves with closed stomata in the dark.

76

Therefore, foliar uptake of pharmaceuticals in vegetables under overhead sprinkler irrigation

4 ACS Paragon Plus Environment

Page 4 of 29

Page 5 of 29

77

Journal of Agricultural and Food Chemistry

deserves further study.

78

This study aimed to compare the uptake and accumulation of pharmaceuticals in greenhouse

79

lettuce irrigated with pharmaceutical-contaminated water via overhead or soil-surface irrigation.

80

We selected eleven commonly used pharmaceuticals, including a fever reducer and pain reliever

81

(acetaminophen), a stimulant (caffeine), an anticonvulsant (carbamazepine), and 8 antibiotics

82

(sulfadiazine, sulfamethoxazole, carbadox, trimethoprim, lincomycin, oxytetracycline, monensin

83

sodium, and tylosin), based on their large use in humans and animals, and their varying

84

physicochemical properties such as molecular weight, water solubility, charge behaviors (pKa),

85

and hydrophobicity (log Dow, the pH-adjusted log Kow by accounting for neutral species) (Table

86

S1). This study was conducted in a controlled greenhouse setting so that the pharmaceutical

87

residues in lettuce shoots, roots, and soils under two irrigation treatments could be compared to

88

infer major uptake pathways.

89

MATERIALS AND METHODS

90

Chemicals and Materials. Eleven pharmaceuticals (acetaminophen, caffeine,

91

carbamazepine, sulfadiazine, sulfamethoxazole, carbadox, trimethoprim, lincomycin,

92

oxytetracycline, monensin sodium, and tylosin) were purchased from Sigma-Aldrich (St. Louis,

93

MO, USA). Their detailed physicochemical properties are provided in Table S1 in Supporting

94

Information. These pharmaceuticals were dissolved in HPLC-grade methanol to prepare stock

95

solutions at concentrations ranging from 10 to 1000 mg/L. Acetonitrile and anhydrous sodium

96

sulfate (Na2SO4) were purchased from EMD Chemicals (Gibbstown, NJ, USA), ceramic

97

homogenizers, C18 and primary-secondary amine (PSA) from Agilent Technologies (Santa

98

Clara, CA, USA), and disodium ethylenediaminetetraacetate (Na2EDTA), formic acid, and

99

sodium chloride (NaCl) from J.T. Baker (Phillipsburg, NJ, USA). All chemicals used were of 5 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

®

100

analytical grade or better. Oasis hydrophilic-lipophilic balance (HLB) extraction cartridges

101

(6cc) were purchased from Waters Corporation (Milford, MA, USA).

102

A soil sample was collected at Charlotte, MI, and was air-dried, passed through a 2-mm

103

sieve, and stored in a covered plastic container before use. The soil was tested at the Soil and

104

Plant Nutrient Laboratory of Michigan State University (East Lansing, MI) according to the

105

standard methods. The soil had 81.3% of sand, 10.5% of silt, and 8.2% of clay, and was

106

classified as a loamy sand as per the USDA classification. Soil pH was 7.4 measured in a 1:1

107

soil:water mixture. Organic matter content was 2.5% measured by loss-on-ignition at 360 °C.

108

Bray P1 extractable phosphorus concentration was 71 mg/kg. Potassium, magnesium, and

109

calcium concentrations in 1-mol/L ammonium acetate extractant were 71, 50, 126, and 1298

110

mg/kg, respectively. Cation exchange capacity was 7.0 meq/100 g as measured by the

111

ammonium saturation method. The soil was found free of the selected pharmaceuticals. The

112

loamy sand was used because it is a common soil type in many areas where lettuce is produced

113

(particularly in California). Also, coarse-textured soils typically demand higher amount of

114

irrigation water, which may necessitate the use of reclaimed water and represent a “worse-case”

115

scenario. Similar loamy sand soils were also used in previous studies on the uptake of

116

pharmaceuticals by lettuce and other vegetables.23, 24, 33, 34

117

Greenhouse Growth Experiments. This study was conducted in a greenhouse under

118

controlled condition with a 16-h photoperiod, air temperature of 24 ± 10 °C, and relative

119

humidity of 43 ± 17%. To prepare free-draining nursery pots for growing lettuce, approximately

120

1455 g of soil sample were uniformly packed into each nursery pot (14.6 cm in diameter at top

121

and 10.8 cm in height) to a depth of 9 cm, resulting in a bulk density of 1.35 g/cm3.

122

Concurrently, 4–6 seeds of Burpee Black Seeded Simpson Lettuce (Burpee, Warminster, PA,

®

6 ACS Paragon Plus Environment

Page 6 of 29

Page 7 of 29

Journal of Agricultural and Food Chemistry

123

USA) were planted in a sterile potting mix for approximately three weeks to produce transplant

124

seedlings for the subsequent irrigation experiments. The selected lettuce is a commonly grown

125

lettuce type. The potting mix was watered with deionized (DI) water and applied with a fertilizer

126

solution with a nitrogen concentration of 125 mg/L (Peters Professional water soluble 20-20-20

127

general purpose fertilizer, Scotts, Marysville, OH, USA) as needed. Seedlings were thinned and

128

transplanted into individual soil pots. Before transplanting, excess potting mix was removed

129

from the transplants, and the soil pots were watered with DI water and then free-drained for 10–

130

15 mins. After the transplanting, the pots were watered again, and the lettuce plants were left to

131

acclimate for about 2 days before beginning the irrigation experiments.

132

®

Thirty-six lettuce plants were planted (i.e., 36 soil pots), and placed randomly in a custom-

133

built automatic irrigation system, as described in Supporting Information S1. The automatic

134

irrigation system was able to accurately control water volume and timing during the overhead

135

and soil-surface irrigations. As illustrated in Figure S1, fifteen lettuce plants were placed under

136

either the overhead or surface irrigation line fed with an opaque pharmaceutical water tank,

137

whereas three lettuce plants were irrigated with the pharmaceutical-free water for overhead or

138

surface irrigation, respectively. The pharmaceutical water tank was filled with prepared irrigation

139

water containing the eleven pharmaceuticals and covered to avoid exposure to light. Detailed

140

procedure on irrigation water preparation is described in Supporting Information S1. Two trials

141

were performed at two varying pharmaceutical concentrations of 50 (Trial 1) and 30 µg/L (Trial

142

2). These concentrations were on the high end of pharmaceutical concentrations observed in

143

wastewater effluents and other environmental waters,6, 7 but were needed to allow for the

144

detection of pharmaceutical residues in lettuce so that the effect of irrigation methods could be

145

compared. Because stunt and major necrosis were observed on the lettuce plants in Trial 1, the 7 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

146

irrigation water in Trial 2 was fertilized with the 20-20-20 general purpose fertilizer to a final

147

nitrogen concentration of 125 mg/L. A lower pharmaceutical level of 30 µg/L was also selected.

148

No fertilizer was added in the irrigation water in Trial 1, and the fertilizer solution (125 mg N/L)

149

was applied to the pots periodically. In Trial 1 each lettuce plant received about 0.27 L of the

150

fertilizer solution (or 34 mg nitrogen), whereas in Trial 2 each lettuce plant received

151

approximately 3.78 L of the fertilizer solution (i.e., 472 mg nitrogen). The pharmaceutical-free

152

controls were included to examine if there was any phytotoxicity of pharmaceuticals to the

153

lettuce. It was also used to obtain background matching matrices for the water, lettuce, and soil

154

samples in the LC/MS-MS analysis. The irrigation water in both water tanks was used to irrigate

155

lettuce plants until the water level reached the tank outlet, after which the tanks were cleaned out

156

and refilled twice during the trials.

157

The lettuce plants in Trial 1 and Trial 2 were irrigated with about 25–125 mL of irrigation

158

water daily (equivalent to an irrigation depth of 1.5–7.5 mm), depending on the water demand of

159

lettuce at various growth stages. The irrigation amounts were in the typical range of average

160

daily irrigation for lettuce in the field.35 The irrigation water amounts were recorded for

161

calculating total amount of each pharmaceutical applied to lettuce plants, totaling 2.58 L in Trial

162

1 and 3.78 L in Trial 2. In the overhead-irrigated pots, a perforated transparent screen was placed

163

around each lettuce plant to minimize water loss from the overhead spray while allowing for air

164

exchange. In the Trial 2, surface-irrigated pots also had a screen placed around the lettuce plant.

165

Volumetric soil water content in the soil pots was measured in situ using 5TE sensors and EM 50

166

data loggers (Decagon® Devices, Pullman, WA). Average volumetric soil water contents in the

167

overhead- and surface-irrigated pots were 0.20 ± 0.05 and 0.16 ± 0.04 in Trial 1, and 0.15 ± 0.04

8 ACS Paragon Plus Environment

Page 8 of 29

Page 9 of 29

Journal of Agricultural and Food Chemistry

168

and 0.13 ± 0.05 in Trial 2, respectively, which were much lower than the saturation level. No

169

free drainage occurred at the bottom of the soil pots.

170

Sampling and Extraction of Lettuce and Soil Samples. The lettuce plants irrigated with

171

the pharmaceutical-containing water were randomly harvested weekly in triplicates, whereas the

172

pharmaceutical-free control plants were harvested at the end of Week 2, 4 and 5. The lettuce

173

shoots were washed in 200 mL DI water, and the wash water in Trial 1 was saved for later

174

analysis. The washing was to simulate the possible wash-off of pharmaceutical residues by post-

175

harvest washing typically performed by vegetable producers or consumers prior to consumption.

176

Soil samples at the top (0-3 cm), middle (3-6 cm), and bottom (6-9 cm) layers of the pots were

177

also collected. Detailed procedures on sampling of the lettuce shoots, roots, and soils could be

178

found in Supporting Information S1. The lettuce shoot, root and soil samples were freeze-dried

179

and ground before extraction and analyses for the pharmaceutical residues.

180

The pharmaceutical residues in the lettuce shoots and roots were extracted following a quick,

181

easy, cheap, effective, rugged, and safe (QuEChERS) method.36 The pharmaceutical recovery in

182

vegetable samples by this method was about 72–96%.36 Detailed extraction and clean-up

183

procedure is provided in Supporting Information S1. This QuEChERS method was also adapted

184

for extracting the pharmaceutical residues from the soil samples. In general, the extraction with

185

the Na2EDTA concentration of 150 mg/L produced better results than the Na2EDTA level of 300

186

mg/L (Table S2).

187

Sampling and Extraction of Water Samples. Water samples of 20 mL were collected from

188

both water tanks daily in Trial 1 and 2–3 times a week in Trial 2. The collected water samples

189

were stored in amber glass vials with polyurethane caps. Using the HLB cartridges, the

190

extraction and clean-up of water samples was adopted from Chuang et al.36 and described in

9 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

191

detail in Supporting Information S1 (Table S3). The extracts were stored in the −20 °C freezer

192

for later analysis.

193

LC-MS/MS Analysis. The extracts were analyzed for the pharmaceutical concentrations

194

using a Shimadzu Prominence high performance liquid chromatograph (Colombia, MD, USA)

195

coupled with an Applied Biosystems Sciex 4500 QTrap mass spectrometer (Foster City, CA,

196

USA). An Agilent Eclipse Plus C18 Column (2.1 mm × 50 mm, particle size of 5 µm) was used

197

for separation. The mobile phase consisted of phase A (0.3% formic acid in DI water) and phase

198

B, i.e., acetonitrile/methanol mixture (1/1 by volume) with 0.3% formic acid. The flow rate was

199

0.35 mL/min, and the sample injection volume was 10 µL. Pharmaceutical concentrations were

200

quantified using a matrix-matched calibration curve. Precursor ions and product ions for

201

qualification and quantification, along with mass spectrometer parameters, can be found in Table

202

S4.

203

Calculations and Statistical Analyses. The pharmaceutical concentrations measured in the

204

freeze-dried shoot and root samples were converted to their concentrations based on the fresh

205

weight of lettuce shoots and roots (i.e., Cshoot and Croot), according to the measured fresh and dry

206

weights of the shoots and roots. We selected to calculate the pharmaceutical concentrations in

207

lettuce by fresh weight27 because lettuce is often consumed in fresh. The gravimetric water

208

content was 0.92 ± 0.03 in the fresh shoots and 0.92 ± 0.02 in the fresh roots, respectively. Thus,

209

the pharmaceutical concentrations by dry weight in the lettuce was on average 12.5 times of the

210

concentrations by fresh weight.

211 212 213

To elucidate the uptake pathways of pharmaceuticals in lettuce, bioconcentration factors including root concentration factors (RCF) and translocation factors (TF) were calculated via:

RCF =

Croot Csoil

(1) 10 ACS Paragon Plus Environment

Page 10 of 29

Page 11 of 29

Journal of Agricultural and Food Chemistry

TF =

214

Cshoot Croot

(2)

215

where Croot and Cshoot are the pharmaceutical concentrations by fresh weight of lettuce. Thus, the

216

calculated RCF would be on average 12.5 times less than the RCF by dry weight. The TF by

217

fresh weight would be similar to its values by dry weight due to similar water content in the

218

lettuce shoots and roots. RCF and TF were calculated weekly, allowing for assessing their

219

changes throughout the growth stages of the lettuce.

220

Total mass balance of applied pharmaceuticals in the soil-lettuce system was calculated as

221

described in Supporting Information S1. The unrecovered fraction might be dissipated through

222

transformation and degradation in soils and within plants.3, 19, 24, 37 Or a fraction of certain

223

pharmaceuticals may be irreversibly bound with soil matrices, and thus could not be extracted,38,

224

39

225

which is often considered not bioavailable to plants.5 All statistical analyses were conducted using GraphPad PRISM 7. Lettuce biomass

226

comparisons by trials were analyzed as grouped unpaired t-tests. Statistical significance was

227

determined using the Holm-Sidak method. Lettuce biomass at each week was analyzed

228

individually, without assuming a consistent variance. Lettuce biomass comparisons between

229

irrigation methods within trials were analyzed in the same manner.

230

RESULTS AND DISCUSSION

231

Lettuce Shoot Biomass. In the pharmaceutical-free control, the overhead-irrigated lettuce

232

shoots harvested on Week 2, 4, and 5 consistently had greater fresh and dry weight than the

233

surface-irrigated shoots in both trials (Figure 1a and b). Thus, the overhead-irrigated lettuce grew

234

better than the surface-irrigated lettuce. Upon exposure to the pharmaceuticals, there was no

235

significant difference in the shoot biomass between two irrigation methods, and the fresh weight

236

in Week 2 and dry weight in Week 3 were even lower under overhead irrigation than under 11 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

237

surface irrigation. Thus, the pharmaceuticals in the irrigation water negated the positive effect of

238

the overhead irrigation on the lettuce shoot growth. The lettuce shoot weights in Trial 2 were

239

significantly greater than Trial 1, probably due to increased fertilizer input and reduced

240

phytotoxicity with the lower pharmaceutical concentrations in Trial 2. The difference in fertilizer

241

application cannot be solely responsible for the observed difference in the lettuce growth,

242

because the difference of shoot weight between Trial 1 and Trial 2 was in general much greater

243

with the pharmaceutical exposure than that without the pharmaceutical exposure. For example,

244

on Week 4 the fresh weight of shoots between Trial 1 and Trial 2 differed by a factor of 6.2–10.6

245

in the presence of pharmaceuticals, and only by a factor of 3.0–4.5 in the absence of

246

pharmaceuticals. The similar trends were observed for the dry weight of the shoots.

247

The lettuce plants also showed stunt and major necrosis under a higher pharmaceutical

248

exposure in Trial 1, but appeared much healthier in Trial 2 (Figure S3). Boxall et al.23 reported

249

that lettuce growth was significantly reduced upon exposure to oxytetracycline, but not to

250

sulfadiazine, trimethoprim, and tylosin at the pharmaceutical concentration of 1 mg/kg in a

251

loamy sand. The phytotoxicity of pharmaceuticals to plants varies with pharmaceutical type,

252

plant species, and exposure level.5 For example, the reported median effective concentrations

253

(EC50) of the pharmaceuticals ranged between 0.1 to 5 mg L−1 for duckweed.2 Liu et al.40 found

254

that the lowest concentrations of chlortetracycline, tetracycline, tylosin, sulfamethoxazole,

255

sulfamethazine, and trimethoprim to negatively affect the seeding height and root length of rice

256

and cucumber were all above 10 mg/kg in a silt loam soil. In our study, the cumulative

257

concentrations of pharmaceuticals applied to the soil were less than 0.12 mg/kg individually.

258

Nonetheless, a significant negative impact on the lettuce growth was observed. Thus, the lettuce

259

might access the pharmaceuticals in irrigation water more easily than the soil-sorbed

12 ACS Paragon Plus Environment

Page 12 of 29

Page 13 of 29

Journal of Agricultural and Food Chemistry

260

pharmaceuticals in the previous studies.23, 40 Also, the bioavailability of the pharmaceuticals in

261

the loamy sand soil might be higher than other fine-textured soils.23 Finally, there might be an

262

additive and/or synergistic toxicity of a pharmaceutical mixture as already demonstrated for

263

algae and duckweed,41, 42 which should be explored in future studies.

264

Pharmaceutical Residues in Lettuce Shoots. During harvest in both trials, the lettuce

265

shoots were washed in DI water to remove any weakly sorbed pharmaceuticals on the shoots.

266

The concentrations of washable pharmaceutical residues were higher in the overhead-irrigated

267

shoots than in the surface-irrigated shoots (Figure S4), with the exception of carbadox and

268

oxytetracycline (Figures S4f and i). In fact, the washable pharmaceutical residues was essentially

269

nonexistent in the surface-irrigated shoots (Figure S4). The negligible levels of washable

270

carbadox and oxytetracycline residues in the shoots likely resulted from photodegradation43 or

271

strong foliar sorption. Clearly, the direct exposure of pharmaceuticals to the lettuce with

272

overhead irrigation could substantially increase their residues in the shoots. This effect was

273

particularly pronounced during the early stage of lettuce growth when the shoot biomass was

274

lower, except for lincomycin and tylosin. As lettuce is often washed either by producers or

275

consumers prior to consumption, the washable fraction of pharmaceutical residues in the lettuce

276

shoots might be effectively removed during washing, and are of less concern. Thus, they were

277

only measured in Trial 1. Rather, the remaining pharmaceutical residues after washing would

278

represent a higher exposure risk to consumers, and were thus focused in this study.

279

The post-washing concentrations of each pharmaceutical in the lettuce shoots in both trials

280

are shown in Figures 2 and S5, respectively. In contrast to the concentrations of washable

281

pharmaceutical residues, only trimethoprim, monensin sodium and tylosin consistently showed

282

greater post-washing concentrations in the shoots under overhead irrigation than under surface

13 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

283

irrigations (Figure 2g, 2j and 2k; Figure S5g, 5j and 5k). For other pharmaceuticals such as

284

acetaminophen, caffeine, carbamazepine, sulfadiazine, sulfamethoxazole, carbadox, and

285

oxytetracycline, no conclusive difference in their concentrations in the shoots between overhead

286

and surface irrigations was observed over time (Figure 2 and S5). The post-washing

287

pharmaceutical residues in the lettuce shoots could originate directly from the irrigation water

288

under overhead irrigation, or be translocated from the roots. Thus, they could be collectively

289

controlled by exposure route (i.e., foliar vs root exposure), in-plant metabolism, and root-to-

290

shoot translocation, which would vary with individual pharmaceuticals. Thus, a large variation in

291

the post-washing pharmaceutical concentrations in the shoots was expected, e.g., ranging from

292

1.4 ± 0.1 µg/kg of tylosin to 327 ± 99 of carbamazepine in the overhead-irrigated mature lettuce

293

shoot on Week 5 (Figure 2). While the post-washing concentrations of most pharmaceuticals in

294

the shoots did not increase with time, the concentrations of carbamazepine, trimethoprim, and

295

lincomycin in Trial 2 clearly demonstrated an increasing trend over time (Figure 2). The increase

296

of trimethoprim concentration was only observed for the overhead-irrigated shoot (Figure 2g and

297

Figure S5g), and thus most likely resulted from the accumulation of trimethoprim directly

298

received from the irrigation water. However, for carbamazepine and lincomycin, the surface-

299

irrigated shoots also showed an increasing concentration over time, suggesting the translocation

300

from the roots. In particular, the concentration of carbamazepine was very high (Figure 2c and

301

Figure S5c), and was hyperaccumulated in the lettuce shoot, similar to its hyperaccumulation in

302

radish leaf, ryegrass,33 cucumber leaf, and tomato leaf.24

303

Pharmaceutical Residues in Lettuce Root. The concentrations of each pharmaceutical in

304

the lettuce roots in Trail 1 and Trial 2 are shown in Figures S6 and S7, respectively. In Trial 2,

305

there was no statistically significant difference in the pharmaceutical concentrations in the roots

14 ACS Paragon Plus Environment

Page 14 of 29

Page 15 of 29

Journal of Agricultural and Food Chemistry

306

with regard to the irrigation method, indicating that irrigation methods do not play a large role in

307

the root accumulation of pharmaceuticals in lettuce (Figure S7). This observation was expected,

308

because all the applied pharmaceuticals in both overhead and surface irrigations eventually

309

drained to the soils, and became accessible by the roots. In Trial 1, due to the low root biomass

310

(Figure 1), all of the roots collected from the three pots at each harvest were combined, and

311

therefore no statistical significance could be inferred. Closer examination of the results from

312

Trial 2 revealed that the concentration in the roots increased over time for carbamazepine,

313

carbadox, trimethoprim and lincomycin (Figure S7c, f, g and h), suggesting the effective root

314

accumulation of these pharmaceuticals, despite their disparate log Dow values (−1.22–2.45, Table

315

S1). Interestingly, there was a decrease in the concentration of acetaminophen in the root over

316

time (Figure S7a). This observation is supported by a hydroponic study,37 in which the

317

concentrations of acetaminophen in the Indian mustard shoots and roots sharply decreased in

318

only one week. The concentrations of caffeine, sulfadiazine, sulfamethoxazole, monensin

319

sodium, and tylosin were relatively stable with time, implying either ineffective root uptake or

320

equilibrium between root uptake, translocation and dissipation.

321

Pharmaceutical Residues in Soils. The pharmaceutical residue levels in the soils were

322

similar regardless of irrigation methods (Figure S8 and S9). This was expected because the soils

323

in both trials received about similar amount of pharmaceuticals as the soil surface was not

324

covered, despite minor interception of pharmaceuticals by lettuce shoots under overhead

325

irrigation. Most pharmaceuticals were accumulated in the soils to a varying degree, except for

326

acetaminophen and sulfadiazine that were quickly dissipated in both trials (Figure S8 and S9).

327

Compared to Trial 1, oxytetracycline also diminished in the soils in Trial 2 (Figure S9i). The

328

dissipation of pharmaceuticals in the soils could result from either degradation/transformation or

15 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

329

irreversible sorption to soil matrix.38, 39 For example, about 73–93% of acetaminophen and 64%

330

of sulfadiazine initially applied to soils became non-extractable fraction.38, 39 Sulfadiazine has

331

been reported to degrade in soils with half-lives ranging from 12–18 days in aerobic soils to 57–

332

237 days in anoxic soils.44 In loamy sand soils, the dissipation of sulfadiazine in our study

333

appeared to be much faster (a half-life < 45 days) than the reported half-life < 103 days,23 likely

334

because a greater organic content of the soil in our study promoting greater microbial activities

335

or stronger sorption of sulfadiazine to the soil.

336

The concentrations of acetaminophen, caffeine, sulfamethoxazole, lincomycin,

337

oxytetracycline and monensin sodium showed no patterns with the soil depth, likely resulted

338

from either their high mobility or quick dissipation.45-48 For instance, caffeine has been reported

339

to have a high desorption capacity (>15%), especially in sandy loam soils,48 which likely resulted

340

in its leaching downwards. Sulfonamides such as sulfamethoxazole often has lower sorption and

341

higher mobility in soils at neutral and basic pH.46, 49 The trend for sulfadiazine in Trial 2 could

342

not be assured due to its low concentrations. Monensin has a half-life of less than 4 days in

343

soils.47 Conversely, the concentrations of carbamazepine, carbadox, trimethoprim, and tylosin in

344

the top soil layer was greater than the lower layers and increased with time, probably due to their

345

lower mobility or dissipation in soils.46, 50-54 For instance, carbamazepine has low leaching

346

potential and high persistence in soils, with the half-lives greater than 40 days.33, 52, 54

347

Bioconcentration Factors of Pharmaceuticals in Lettuce. Bioconcentration factors

348

including RCF and TF were calculated weekly for 5 weeks in Trial 2 (Table S5), but not for Trial

349

1 due to unhealthy lettuce plants and low plant growth (Figure 1 and S3). RCFs and TFs were

350

not significantly different throughout the lettuce growth stages, except for the TFs of

351

carbamazepine in the surface-irrigated lettuce that increased with mature plants. Thus, the RCFs

16 ACS Paragon Plus Environment

Page 16 of 29

Page 17 of 29

Journal of Agricultural and Food Chemistry

352

and TFs for the 5 weeks were averaged and reported in Table 1. RCFs were similar for both

353

overhead- and surface-irrigated lettuce, which was again expected due to similar pharmaceutical

354

concentrations in the soils. Comparing with other pharmaceuticals, sulfamethoxazole, carbadox,

355

trimethoprim, and oxytetracycline had greater RCF values, suggesting that they tend to

356

accumulate in the roots.

357

As the overhead-irrigated lettuce shoots also received the pharmaceuticals directly from the

358

irrigation water, the calculated TF values do not truly represent the root-to-shoot translocation of

359

a pharmaceutical. Thus, only the TF values of the surface-irrigated lettuce was examined closely.

360

In general, a pharmaceutical with a TF below 1 is not readily transported from roots to shoots in

361

plants, whereas a pharmaceutical with a TF above 1 suggests a readily root-to-shoot translocation

362

and accumulation in the shoots.28 Caffeine and carbamazepine had a TF of 4.28 ± 3.01 and 8.15

363

± 2.87 in the surface-irrigated lettuce, respectively. Thus, caffeine and carbamazepine tend to be

364

translocated up and accumulated in the lettuce shoots. The uptake factors were calculated as the

365

product of RCF and TF, and were about 6.4 and 81.5 for caffeine and carbamazepine (dry

366

weight), respectively. These values, while on the high end, were consistent with the previously

367

reported values, e.g., 2 for caffeine and 47 for carbamazepine in tomato and cucumber leaves,

368

and 59 for carbamazepine in rye grass grown in sandy soils.24, 34 The TF of carbamazepine

369

observed in this study (8.15 ± 2.87) was very similar to the calculated TF of 7.88 in the radish

370

leaf grown in a loamy sand.33 Since carbamazepine has a log Dow of 2.45 and is neutral over a

371

wide pH range (Table S1), it tends to be taken up by the plant roots, but not bind with the

372

function groups in the root tissues. Thus, carbamazepine can be freely transported by the

373

transpiration stream.

17 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

374

Other pharmaceuticals all had a TF value less than 1. In particular, sulfamethoxazole,

375

trimethoprim, monensin sodium, and tylosin had a TF value less than 0.15, indicating a very

376

limited root-to-shoot translocation. Insignificant root-to-shoot translocation of these

377

pharmaceuticals have been reported previously for cabbage, corn, cucumber, and onion, possibly

378

due to either their quick degradation in soils, their strong accumulation in roots, or their large

379

molecular sizes.19, 24, 25, 30

380

Acetaminophen, sulfadiazine, carbadox, lincomycin, and oxytetracycline had moderate TF

381

values ranging from 0.47 to 0.98, suggesting that they could be moderately transported by the

382

transpiration stream. Additionally, the TF values of trimethoprim, monensin sodium and tylosin

383

for the overhead-irrigated lettuce were much greater than the ones for the surface-irrigated

384

lettuce (Table 1). This obviously resulted from the foliar exposure of these pharmaceuticals from

385

the irrigation water, despite the shoots were washed in DI water. Trimethoprim is predominantly

386

cationic and neutral with a low log Dow (0.54) (Table S1). Therefore, it could either bind with

387

negatively charged surface function groups or diffuse into the waxy cuticle layer on the lettuce

388

leaves.32 Monensin sodium and tylosin had relatively large log Dow (Table S1), thus being sorbed

389

to the lettuce leaves through hydrophobic interaction. Additionally, tylosin is mainly positively

390

charged (Table S1), which further promotes its binding with the negatively charged surface

391

function groups in the shoots. Due to the stronger interactions of trimethoprim, monensin sodium

392

and tylosin with the lettuce shoots, their increased foliar accumulation, as a result of overhead

393

irrigation, persisted even after the washing in DI water (Figure 2).

394

Mass Balance of Pharmaceuticals. The distribution of recovered pharmaceutical residues in

395

the shoots, roots, and soils on Week 5 is shown in Figure 3 and S10. Detailed mass distribution

396

and total recovered percentage over the initially applied amount of each pharmaceutical are

18 ACS Paragon Plus Environment

Page 18 of 29

Page 19 of 29

Journal of Agricultural and Food Chemistry

397

provided in Table S6 and S7. The pharmaceutical residues were predominantly distributed in the

398

soils, and the uptake and accumulation of the pharmaceuticals (except for carbamazepine in Trial

399

2) in the lettuce might be minor (Figure 2). In the case of carbamazepine, it was likely that in

400

Trial 2 the better lettuce growth allowed the hyperaccumulation of carbamazepine in the shoots

401

to the level comparable to its mass in the soil. The mass recoveries of the pharmaceuticals were

402

much lower in Trial 2 than in Trial 1 (Figure 3 and S10), likely because the biodegradation and

403

metabolism of pharmaceuticals were enhanced by greater microbial activities and lettuce growth

404

in Trial 2 due to higher fertilizer application. The biodegradation in soils and in-plant

405

metabolism played an important role in the fate of pharmaceuticals in the soil-lettuce systems, in

406

addition to abiotic sorption and degradation.3, 19, 24, 29, 37 For example, Bartha et al.37 proposed

407

acetaminophen could be degraded through both a plant-dependent pathway and a plant-

408

independent pathway. About 50% of total carbamazepine mass in tomato and cucumber leaves

409

were metabolized to two main metabolites (10,11-epoxide-carbamazepine and 10,11-dihydro-

410

10,11-dihydroxy-carbamazepine).24 Some pharmaceuticals, such as caffeine and acetaminophen,

411

have been shown to degrade through photolysis.55, 56

412

Overall, our findings may have interesting implications on utilizing reclaimed water to

413

irrigate vegetable crops. Despite the wide use of overhead sprinkler systems, their use in

414

vegetable production needs to be carefully assessed when using reclaimed water for irrigation

415

due to greater concentration and mass of some pharmaceuticals (specifically trimethoprim,

416

monensin sodium and tylosin) in overhead- as opposed to surface-irrigated lettuce shoots. Most

417

applied pharmaceuticals from irrigation water were quickly dissipated in soils, thus suggesting

418

reduced exposure risks over time. However, carbamazepine was very persistent in soil, and was

419

hyperaccumulated in the lettuce shoots, thus posing a particular concern to food safety and

19 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

420

human health. This study used the pharmaceutical-containing irrigation waters that were

421

prepared in DI water, which differed from actual reclaimed waters in terms of water chemistry

422

such as dissolved organic matter (DOM), metal cations, and solution pH.22 As some

423

pharmaceuticals (e.g., tetracyclines) complex with DOM and metal cations, and solution pH

424

determines species distribution of ionizable pharmaceuticals,3 it is expected that water chemistry

425

of reclaimed water could influence the pharmaceutical residues in lettuce, specifically for the

426

overhead-irrigated shoots. Future study should examine the uptake and accumulation of

427

pharmaceuticals under diverse chemical conditions of reclaimed water. Finally, our study

428

showed the ubiquitous accumulation of pharmaceuticals in the lettuce upon exposure from

429

irrigation water, demonstrating the need for further assessing the environmental and food safety

430

risks associated with using pharmaceutical-contaminated water for irrigation.

431

ABBREVIATIONS USED: RCF, root concentration factors; TF, translocation factors.

432

ASSOCIATED CONTENT

433

Supporting Information

434

Supplemental Materials and Methods, and Supplemental Results. The Supporting Information is

435

available free of charge on the ACS Publications website at DOI:

436

ACKNOWLEDGMENT

437

This research was supported by Agriculture and Food Research Initiative Competitive Grant No.

438

2016-67017-24514 from the USDA National Institute of Food and Agriculture and the Project

439

GREEEN from Michigan State University AgBioResearch.

440

REFERENCES

441 442 443

(1) Snow, D. D.; Bartelt-Hunt, S. L.; Saunders, S. E.; Cassada, D. A. Detection, occurrence, and fate of emerging contaminants in agricultural environments. Water Environ. Res. 2007, 79, 1061-1084.

20 ACS Paragon Plus Environment

Page 20 of 29

Page 21 of 29

444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487

Journal of Agricultural and Food Chemistry

(2) Li, S.; Shi, W.; Liu, W.; Li, H.; Zhang, W.; Hu, J.; Ke, Y.; Sun, W.; Ni, J. A duodecennial national synthesis of antibiotics in China's major rivers and seas (2005–2016). Sci. Total Environ. 2018, 615, 906-917. (3) Kumar, K.; C. Gupta, S.; Chander, Y.; Singh, A. K. Antibiotic use in agriculture and its impact on the terrestrial environment. In Advances in Agronomy, Donald, L. S., Ed. Academic Press: San Diego, CA, 2005; Vol. 87, pp 1-54. (4) Zhang, Q.-Q.; Ying, G.-G.; Pan, C.-G.; Liu, Y.-S.; Zhao, J.-L. Comprehensive evaluation of antibiotics emission and fate in the river basins of China: Source analysis, multimedia modeling, and linkage to bacterial resistance. Environ. Sci. Technol. 2015, 49, 6772-6782. (5) Jjemba, P. K. The potential impact of veterinary and human therapeutic agents in manure and biosolids on plants grown on arable land: a review. Agric., Ecosyst. Environ. 2002, 93, 267278. (6) Petrie, B.; Barden, R.; Kasprzyk-Hordern, B. A review on emerging contaminants in wastewaters and the environment: Current knowledge, understudied areas and recommendations for future monitoring. Water Res. 2015, 72, 3-27. (7) Oulton, R. L.; Kohn, T.; Cwiertny, D. M. Pharmaceuticals and personal care products in effluent matrices: A survey of transformation and removal during wastewater treatment and implications for wastewater management. J. Environ. Monit. 2010, 12, 1956-1978. (8) Zhu, Y.-G.; Zhao, Y.; Li, B.; Huang, C.-L.; Zhang, S.-Y.; Yu, S.; Chen, Y.-S.; Zhang, T.; Gillings, M. R.; Su, J.-Q. Continental-scale pollution of estuaries with antibiotic resistance genes. Nature Microbiology 2017, 2, 16270. (9) Williams-Nguyen, J.; Sallach, J. B.; Bartelt-Hunt, S.; Boxall, A. B.; Durso, L. M.; McLain, J. E.; Singer, R. S.; Snow, D. D.; Zilles, J. L. Antibiotics and antibiotic resistance in agroecosystems: State of the science. J. Environ. Qual. 2016, 45, 394-406. (10) Laxminarayan, R.; Duse, A.; Wattal, C.; Zaidi, A. K. M.; Wertheim, H. F. L.; Sumpradit, N.; Vlieghe, E.; Hara, G. L.; Gould, I. M.; Goossens, H.; Greko, C.; So, A. D.; Bigdeli, M.; Tomson, G.; Woodhouse, W.; Ombaka, E.; Peralta, A. Q.; Qamar, F. N.; Mir, F.; Kariuki, S.; Bhutta, Z. A.; Coates, A.; Bergstrom, R.; Wright, G. D.; Brown, E. D.; Cars, O. Antibiotic resistance—the need for global solutions. The Lancet Infectious Diseases 2013, 13, 1057-1098. (11) Prosser, R. S.; Sibley, P. K. Human health risk assessment of pharmaceuticals and personal care products in plant tissue due to biosolids and manure amendments, and wastewater irrigation. Environ. Int. 2015, 75, 223-233. (12) Greenlees, K. J.; Friedlander, L. G.; Boxall, A. Antibiotic residues in food and drinking water, and food safety regulations. In Chemical Analysis of Antibiotic Residues in Food, Wang, J.; MacNeil, J. D.; Kay, J. F., Eds. John Wiley & Sons, Inc.: Hoboken, NJ, 2011; pp 111-123. (13) Pedrero, F.; Kalavrouziotis, I.; Alarcón, J. J.; Koukoulakis, P.; Asano, T. Use of treated municipal wastewater in irrigated agriculture—Review of some practices in Spain and Greece. Agric. Water Manage. 2010, 97, 1233-1241. (14) Zimmerman, J. B.; Mihelcic, J. R.; Smith; James. Global stressors on water quality and quantity. Environ. Sci. Technol. 2008, 42, 4247-4254. (15) Bouwer, H. Integrated water management: Emerging issues and challenges. Agric. Water Manage. 2000, 45, 217-228. (16) Yi, L.; Jiao, W.; Chen, X.; Chen, W. An overview of reclaimed water reuse in China. Journal of Environmental Sciences 2011, 23, 1585-1593.

21 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532

(17) Bradford, S. A.; Segal, E.; Zheng, W.; Wang, Q.; Hutchins, S. R. Reuse of concentrated animal feeding operation wastewater on agricultural lands. J. Environ. Qual. 2008, 37, S97S115. (18) Franklin, A. M.; Williams, C. F.; Andrews, D. M.; Woodward, E. E.; Watson, J. E. Uptake of three antibiotics and an antiepileptic drug by wheat crops spray irrigated with wastewater treatment plant effluent. J. Environ. Qual. 2016, 45, 546-554. (19) Tanoue, R.; Sato, Y.; Motoyama, M.; Nakagawa, S.; Shinohara, R.; Nomiyama, K. Plant uptake of pharmaceutical chemicals detected in recycled organic manure and reclaimed wastewater. J. Agric. Food Chem. 2012, 60, 10203-10211. (20) USDA. 2013 Farm and Ranch Irrigation Survey. https://www.agcensus.usda.gov/Publications/2012/Online_Resources/Farm_and_Ranch_Irrigatio n_Survey/ (21) USGS. Irrigation water use. https://water.usgs.gov/watuse/wuir.html (22) USEPA. 2012 Guidelines for water reuse; EPA/625/R-04/108; US Environmental Protection Agency Washington, D.C., 2012. (23) Boxall, A. B. A.; Johnson, P.; Smith, E. J.; Sinclair, C. J.; Stutt, E.; Levy, L. S. Uptake of veterinary medicines from soils into plants. J. Agric. Food Chem. 2006, 54, 2288-2297. (24) Goldstein, M.; Shenker, M.; Chefetz, B. Insights into the uptake processes of wastewaterborne pharmaceuticals by vegetables. Environ. Sci. Technol. 2014, 48, 5593-5600. (25) Kang, D. H.; Gupta, S.; Rosen, C.; Fritz, V.; Singh, A.; Chander, Y.; Murray, H.; Rohwer, C. Antibiotic uptake by vegetable crops from manure-applied soils. J. Agric. Food Chem. 2013, 61, 9992-10001. (26) Jones-Lepp, T. L.; Sanchez, C. A.; Moy, T.; Kazemi, R. Method Development and Application To Determine Potential Plant Uptake of Antibiotics and Other Drugs in Irrigated Crop Production Systems. J. Agric. Food Chem. 2010, 58, 11568-11573. (27) Sallach, J. B.; Zhang, Y.; Hodges, L.; Snow, D.; Li, X.; Bartelt-Hunt, S. Concomitant uptake of antimicrobials and Salmonella in soil and into lettuce following wastewater irrigation. Environ. Pollut. 2015, 197, 269-277. (28) Eggen, T.; Lillo, C. Antidiabetic II drug metformin in plants: Uptake and translocation to edible parts of cereals, oily seeds, beans, tomato, squash, carrots, and potatoes. J. Agric. Food Chem. 2012, 60, 6929-6935. (29) Macherius, A.; Eggen, T.; Lorenz, W. G.; Reemtsma, T.; Winkler, U.; Moeder, M. Uptake of galaxolide, tonalide, and triclosan by carrot, barley, and meadow fescue plants. J. Agric. Food Chem. 2012, 60, 7785-7791. (30) Malchi, T.; Maor, Y.; Tadmor, G.; Shenker, M.; Chefetz, B. Irrigation of root vegetables with treated wastewater: Evaluating uptake of pharmaceuticals and the associated human health risks. Environ. Sci. Technol. 2014, 48, 9325-9333. (31) Lu, J.; Wu, J.; Stoffella, P. J.; Wilson, P. C. Uptake and distribution of bisphenol A and nonylphenol in vegetable crops irrigated with reclaimed water. J. Hazard. Mater. 2015, 283, 865-870. (32) Calderón-Preciado, D.; Matamoros, V.; Biel, C.; Save, R.; Bayona, J. M. Foliar sorption of emerging and priority contaminants under controlled conditions. J. Hazard. Mater. 2013, 260, 176-182. (33) Carter, L. J.; Harris, E.; Williams, M.; Ryan, J. J.; Kookana, R. S.; Boxall, A. B. A. Fate and uptake of pharmaceuticals in soil–plant systems. J. Agric. Food Chem. 2014, 62, 816-825.

22 ACS Paragon Plus Environment

Page 22 of 29

Page 23 of 29

533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576

Journal of Agricultural and Food Chemistry

(34) Williams, M.; Martin, S.; Kookana, R. Sorption and plant uptake of pharmaceuticals from an artificially contaminated soil amended with biochars. Plant Soil 2015, 395, 75-86. (35) Johnson, L. F.; Cahn, M.; Martin, F.; Melton, F.; Benzen, S.; Farrara, B.; Post, K. Evapotranspiration-based irrigation scheduling of head lettuce and broccoli. HortScience 2016, 51, 935-940. (36) Chuang, Y.-H.; Zhang, Y.; Zhang, W.; Boyd, S. A.; Li, H. Comparison of accelerated solvent extraction and quick, easy, cheap, effective, rugged and safe method for extraction and determination of pharmaceuticals in vegetables. J. Chromatogr. 2015, 1404, 1-9. (37) Bartha, B.; Huber, C.; Harpaintner, R.; Schröder, P. Effects of acetaminophen in Brassica juncea L. Czern.: Investigation of uptake, translocation, detoxification, and the induced defense pathways. Environ Sci Pollut Res 2010, 17, 1553-1562. (38) Kreuzig, R.; Höltge, S. Investigations on the fate of sulfadiazine in manured soil: Laboratory experiments and test plot studies. Environ. Toxicol. Chem. 2005, 24, 771-776. (39) Li, J.; Ye, Q.; Gan, J. Degradation and transformation products of acetaminophen in soil. Water Res. 2014, 49, 44-52. (40) Liu, F.; Ying, G.-G.; Tao, R.; Zhao, J.-L.; Yang, J.-F.; Zhao, L.-F. Effects of six selected antibiotics on plant growth and soil microbial and enzymatic activities. Environ. Pollut. 2009, 157, 1636-1642. (41) Eguchi, K.; Nagase, H.; Ozawa, M.; Endoh, Y. S.; Goto, K.; Hirata, K.; Miyamoto, K.; Yoshimura, H. Evaluation of antimicrobial agents for veterinary use in the ecotoxicity test using microalgae. Chemosphere 2004, 57, 1733-1738. (42) Białk-Bielińska, A.; Caban, M.; Pieczyńska, A.; Stepnowski, P.; Stolte, S. Mixture toxicity of six sulfonamides and their two transformation products to green algae Scenedesmus vacuolatus and duckweed Lemna minor. Chemosphere 2017, 173, 542-550. (43) Doi, A. M.; Stoskopf, M. K. The kinetics of oxytetracycline degradation in deionized water under varying temperature, pH, light, substrate, and organic matter. J. Aquat. Anim. Health 2000, 12, 246-253. (44) Yang, J.-F.; Ying, G.-G.; Yang, L.-H.; Zhao, J.-L.; Liu, F.; Tao, R.; Yu, Z.-Q.; Peng, P. A. Degradation behavior of sulfadiazine in soils under different conditions. Journal of Environmental Science and Health, Part B 2009, 44, 241-248. (45) Unold, M.; Kasteel, R.; Groeneweg, J.; Vereecken, H. Transport and transformation of sulfadiazine in soil columns packed with a silty loam and a loamy sand. J. Contam. Hydrol. 2009, 103, 38-47. (46) Tolls, J. Sorption of veterinary pharmaceuticals in soils:  A review. Environ. Sci. Technol. 2001, 35, 3397-3406. (47) Sassman, S. A.; Lee, L. S. Sorption and degradation in soils of veterinary ionophore antibiotics: Monensin and lasalocid. Environ. Toxicol. Chem. 2007, 26, 1614-1621. (48) Karnjanapiboonwong, A.; Morse, A. N.; Maul, J. D.; Anderson, T. A. Sorption of estrogens, triclosan, and caffeine in a sandy loam and a silt loam soil. J. Soils Sed. 2010, 10, 1300-1307. (49) Kurwadkar, S. T.; Adams, C. D.; Meyer, M. T.; Kolpin, D. W. Comparative mobility of sulfonamides and bromide tracer in three soils. J. Environ. Manage. 2011, 92, 1874-1881. (50) Rabølle, M.; Spliid, N. H. Sorption and mobility of metronidazole, olaquindox, oxytetracycline and tylosin in soil. Chemosphere 2000, 40, 715-722.

23 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592

(51) Strock, T. J.; Sassman, S. A.; Lee, L. S. Sorption and related properties of the swine antibiotic carbadox and associated N-oxide reduced metabolites. Environ. Sci. Technol. 2005, 39, 3134-3142. (52) Williams, C. F.; Williams, C. F.; Adamsen, F. J. Sorption–desorption of carbamazepine from irrigated soils. J. Environ. Qual. 2006, 35, 1779-1783. (53) Lin, K.; Gan, J. Sorption and degradation of wastewater-associated non-steroidal antiinflammatory drugs and antibiotics in soils. Chemosphere 2011, 83, 240-246. (54) Li, J.; Dodgen, L.; Ye, Q.; Gan, J. Degradation kinetics and metabolites of carbamazepine in soil. Environ. Sci. Technol. 2013, 47, 3678-3684. (55) De Laurentiis, E.; Prasse, C.; Ternes, T. A.; Minella, M.; Maurino, V.; Minero, C.; Sarakha, M.; Brigante, M.; Vione, D. Assessing the photochemical transformation pathways of acetaminophen relevant to surface waters: Transformation kinetics, intermediates, and modelling. Water Res. 2014, 53, 235-248. (56) Bruton, T.; Alboloushi, A.; De La Garza, B.; Kim, B. O.; Halden, R. U. In Fate of caffeine in the environment and ecotoxicological considerations, ACS Symp. Ser., 2010; American Chemical Society: 2010; pp 257-273.

593 594

24 ACS Paragon Plus Environment

Page 24 of 29

Page 25 of 29

595

596 597 598 599

Journal of Agricultural and Food Chemistry

Table 1. Root concentration factors and translocation factors of pharmaceuticals in Trial 2. a Overhead Irrigation Surface Irrigation Pharmaceutical RCF TF RCF TF Acetaminophen na 0.17 (0.14) na 0.51 (0.71) Caffeine 0.13 (0.12) 28.1 (27.2) 0.12 (0.09) 4.28 (3.01) Carbamazepine 0.73 (0.22) 10.1 (1.84) 0.80 (0.37) 8.15 (2.87) Sulfadiazine 0.69 (0.19) 0.18 (0.08) 0.95 (0.18) 0.47 (0.84) Sulfamethoxazole 19.2 (15.7) 0.07 (0.14) 7.80 (5.72) 0.07 (0.13) Carbadox 2.51 (0.91) 0.41 (0.13) 2.45 (1.95) 0.51 (0.23) Trimethoprim 5.20 (5.90) 1.41 (0.31) 2.39 (1.30) 0.15 (0.13) Lincomycin 1.29 (0.40) 1.18 (0.28) 0.93 (0.34) 0.98 (0.62) Oxytetracycline 1.15 (0.27) 1.02 (0.46) 1.41 (0.69) 0.70 (0.34) Monensin Sodium 0.17 (0.09) 9.29 (2.88) 0.20 (0.12) 0.11 (0.25) Tylosin 0.09 (0.02) 3.07 (1.14) 0.04 (0.14) 0.14 (0.05) a RCF = root concentration factor, and TF = root-to-shoot translocation factor. The values are the mean with standard deviation in parentheses for the RCF and TF in 5 weeks as provided in Table S7. “na” means that RCF was not available due to zero concentrations of acetaminophen in the soil.

600

25 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

601

602 603 604 605 606 607

Figure 1. Fresh (a) and dry (b) weight of lettuce shoots in Trial 1 and Trial 2. Holm-Sidak twotailed unpaired t-test showed a significant difference in mean weight of lettuce shoots (p < 0.016) between Trial 1 and Trial 2. No significant difference in mean weight of lettuce shoots between overhead and surface irrigation unless noted the figure (p = 0.051–0.97). Error bar is the standard deviation of triplicates (n = 3).

26 ACS Paragon Plus Environment

Page 26 of 29

Page 27 of 29

Journal of Agricultural and Food Chemistry

608

609

610

611 612 613 614 615 616 617 618

Figure 2. Post-washing pharmaceutical concentrations in overhead- or surface-irrigated lettuce shoots (fresh weight) in Trial 2 (nominal concentration of each pharmaceutical in irrigation water = 30 µg/L). (a) Acetaminophen, (b) Caffeine, (c) Carbamazepine, (d) Sulfadiazine, (e) Sulfamethoxazole, (f) Carbadox, (g) Trimethoprim, (h) Lincomycin, (i) Oxytetracycline, (j) Monensin Sodium, and (k) Tylosin. Error bar is the standard deviation of triplicates (n = 3).

27 ACS Paragon Plus Environment

Journal of Agricultural and Food Chemistry

619 620 621

Figure 3. Recovered percentages of applied pharmaceuticals in shoots, roots, and soils with overhead (a) or surface (b) irrigation at Week 5 in Trial 2.

622

28 ACS Paragon Plus Environment

Page 28 of 29

Page 29 of 29

623

Journal of Agricultural and Food Chemistry

TOC Graphic

624

29 ACS Paragon Plus Environment