**3. Occurrence in the environment**

#### **3.1. Surface water, groundwater, and sediment**

As described previously, veterinary ATBs may contaminate the environment after their use, principally soil and water matrices, and also aquatic nontargeted organisms and sediments.

The first reported case of antibiotic contamination in surface waters happened in England more than two decades ago, when Watts et al. [27] found at least one compound belonging to the group of macrolides, tetracyclines, and sulfonamides in river water, in 1 µg L-1 concentrations. Subsequently, other studies, such as those of Richardson and Bowron [28], Pearson and Inglis [29], Ternes [30], and Hirsch et al. [31], have been developed, enabling the detection of other ATBs groups. Although the study of pharmaceutical residues in the environment is relatively a new topic, a lot of papers have already been published from the 1990s to the present day, as can be seen in Tables 3, 4, and 5, which describe ATBs and their reported concentrations in different environmental matrices in several parts of the world.



Generally, pharmaceutical products are compounds characterized by a complex chemical structure that have very variable molar masses (172 at 916 g mol-1), low volatilization potential, several ionizable functional groups (amphoteric molecules), different p*K*a values, and low octanol–water partition coefficient values (log Kow), which indicates low bioaccumulation potential [25]. The log Kow indicates the tendency of an organic chemical product to partition into lipids or fats and adsorb to particles of soils, sediments, biomasses, and muds [23]. Table

As described previously, veterinary ATBs may contaminate the environment after their use, principally soil and water matrices, and also aquatic nontargeted organisms and sediments.

The first reported case of antibiotic contamination in surface waters happened in England more than two decades ago, when Watts et al. [27] found at least one compound belonging to the group of macrolides, tetracyclines, and sulfonamides in river water, in 1 µg L-1 concentrations. Subsequently, other studies, such as those of Richardson and Bowron [28], Pearson and Inglis [29], Ternes [30], and Hirsch et al. [31], have been developed, enabling the detection of other ATBs groups. Although the study of pharmaceutical residues in the environment is relatively a new topic, a lot of papers have already been published from the 1990s to the present day, as can be seen in Tables 3, 4, and 5, which describe ATBs and their reported concentrations in

**Antibiotics Concentration (ng L-1) Location Reference**

Amoxillin 200 River water, Australia [32] Cefaclor 200 River water, Australia [32] Penicillin G 250 River water, Australia [32] Penicillin V 10 River water, Australia [32]

Danofloxacin 19 Seine River, France [34] Enoxacin 11 Seine River, France [34] Enrofloxacin 300 River water, Australia [32]

1300 River water, Australia [32] 17.4–588.5 Po, Olona, and Lambro Rivers, Italy [33] <10 Seine River, France [34] 370–9660 Arc River, France [34] 14.4–26.2 Po and Lambro Rivers, Italy [35]

2 shows some of these characteristics described above for some ATBs.

different environmental matrices in several parts of the world.

**3. Occurrence in the environment**

**β-Lactams**

**Fluoroquinolones**

Ciprofloxacin

**3.1. Surface water, groundwater, and sediment**

112 Emerging Pollutants in the Environment - Current and Further Implications



**Antibiotics Concentration (ng L-1) Location Reference**

Demeclocycline 120–440 Cache La Poudre, USA [42]

**Tetracyclines**

114 Emerging Pollutants in the Environment - Current and Further Implications

Chlortetracycline

Doxycycline

Oxytetracycline

Tetracycline

**Sulfonamides**

Sulfadiazine

Sulfadimethoxine

60 River water, Australia [32]

600 River water, Australia [32] 160 Cache La Poudre, USA [42] 1–180 Choptank watershed, USA [43] <0.17–22.13 Panjiakou Reservoir, China [36]

50–80 Cache La Poudre, USA [42] 13–146 Choptank watershed, USA [43] 400 River water, Australia [32] 0.19–13.69 Panjiakou Reservoir, China [36]

100 River water, Australia [32] 7.7–105.1 Po, Olona, and Lambro Rivers, Italy [33] 80–130 Cache La Poudre, USA [42] 1–388 Choptank watershed, USA [43] 110–680 Arc River, France [34] 2–7 Mess and Alzette Rivers, Luxembourg [44] 68000 River water, Japan [45] 0.20–19.93 Panjiakou Reservoir, China [36] 14–7993 Ilha Solteira Reservoir, Brazil [46]

80 River water, Australia [32] 60–140 River water, USA [42] 1–5 Choptank watershed, USA [43] 7–8 Mess abd Alzette, Luxembourg [44] 0.14–14.05 Panjiakou Reservoir, China [36]

336 Pearl River, Guangzhou, China [37] 0.35–10.86 Panjiakou Reservoir, China [36]

50–90 Cache La Poudre, USA [42] 1–9 Choptank watershed, USA [43] 3.0 Mess and Alzette Rivers, Luxembourg [44]

0.95–3.56 Panjiakou Reservoir, China [36]

Spain [47]

Spain [47]

1.9–2312 Segre, Llobregat, and Anoia Rivers,

1.5–182.4 Segre, Llobregat, and Anoia Rivers,

**Table 3.** Antibiotic concentrations reported in surface water in several regions of the world. Adapted from Fata-Kassinos et al. [24].



**Table 4.** Antibiotic concentrations reported in groundwater in several regions of the world. Adapted from Fata-Kassinos et al. [24].

**Antibiotics Concentration (ng L-1) Location Reference**

Lincomycin 320 18 States, USA [49]

Sulfadimethoxine 0.2 Barcelona, Espain [47]

Sulfabenzamide 0.09–10.32 Plana de Vic and La Selva,

116 Emerging Pollutants in the Environment - Current and Further Implications

Sulfacetamide 1.77–3461 Plana de Vic and La Selva,

Sulfadoxine 0.02–53.63 Plana de Vic and La Selva,

Sulfaguanidine 3.3–91.78 Plana de Vic and La Selva,

Sulfamiderazine 0.11–744.7 Plana de Vic and La Selva,

Sulfamethizole 0.22–9.29 Plana de Vic and La Selva,

Sulfametoxipiridazina 0.02–68.70 Plana de Vic and La Selva,

Sulfanitran 0.04–568.8 Plana de Vic and La Selva,

Sulfapyridine 0.07–72.45 Plana de Vic and La Selva,

Sulfaquinoxaline 0.01–112.1 Plana de Vic and La Selva,

Sulfathiazole 0.01–16.78 Plana de Vic and La Selva,

Sulfisomidine 0.01–64.40 Plana de Vic and La Selva,

Sulfisoxazole 0.21–4.43 Plana de Vic and La Selva,

0.02–56.95 Plana de Vic and La Selva,

0.03–106.8 Plana de Vic and La Selva,

0.08–312.2 Plana de Vic and La Selva,

2.7 Barcelona, Espain [47]

360 18 States, USA [49]

>160 Agricultural areas, Germany [31]

9.9 Barcelona, Espain [47] 1110 18 States, USA [49]

>410 Baden*-*Württemberg, Germany [51] >470 Áreas agrícolas, Alemanha [31]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

Catalonia, Spain [50]

**Lincosamides**

**Sulfonamides**

N4-acetil sulfamethazine

Sulfamethazine

Sulfamethoxazole



**Table 5.** Antibiotic concentrations reported in sediments of aquatic environments in several regions of the world. Adapted from Fata-Kassinos et al. (2011).
