Biomagnification of Tantalum through Diverse ... - ACS Publications

Mar 9, 2018 - Department of Aquatic Systems, Faculty of Environmental Sciences and EULA-Chile Center, University of Concepción, Casilla. 160-C, Conce...
2 downloads 5 Views 937KB Size
Subscriber access provided by - Access paid by the | UCSB Libraries

Characterization of Natural and Affected Environments

Biomagnification of Tantalum through diverse aquatic food webs Winfred Espejo, Daiki Kitamura, Karen Kidd, Jose E Celis, Shosaku Kashiwada, Cristóbal Galbán-Malagón, Ricardo Barra, and Gustavo Chiang Environ. Sci. Technol. Lett., Just Accepted Manuscript • DOI: 10.1021/acs.estlett.8b00051 • Publication Date (Web): 09 Mar 2018 Downloaded from http://pubs.acs.org on March 9, 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 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 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.

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 15

Environmental Science & Technology Letters

1

Biomagnification of Tantalum through Diverse

2

Aquatic Food Webs

3 4

Winfred Espejoab, Daiki Kitamurac, Karen A. Kiddb‡, José E. Celisd, Shosaku Kashiwadac,

5

Cristóbal Galbán-Malagóne, Ricardo Barraa, Gustavo Chiangb†*

6 a

7

Center, University of Concepción, Casilla 160-C, Concepción, 4070386, Chile.

8 b

9

Canadian Rivers Institute and Biology, Department, University of New Brunswick, 100 Tucker Park Road, Saint John, NB E2L 4L5, Canada.

10 11

Department of Aquatic Systems, Faculty of Environmental Sciences and EULA-Chile

c

Research Center for Life and Environmental Sciences, Toyo University, Oura, 374-0193, Japan.

12 13

d

Department of Animal Science, Faculty of Veterinary Sciences, University of Concepción, Casilla 537, Chillán, 3812120, Chile.

14 e

Departmento de Ecologia y Biodiversidad, Facultad de Ecologia y Recursos Naturales,

15

Universidad Andres Bello, Santiago, 8370251, Chile.

16 17

Present address:

18 19 20 21



Department of Biology & School of Geography and Earth Sciences, McMaster University, 1280 Main Street W., Hamilton, ON, L8S 4K1, Canada. †

MERI Foundation, Santiago, 7650720, Chile.

22 23

*Corresponding author: Gustavo Chiang, [email protected]

24 25 26 27 28 29 30 31

ACS Paragon Plus Environment

1

Environmental Science & Technology Letters

Page 2 of 15

32 33

Abstract

34

Tantalum (Ta) is a Technology-Critical Element (TCE) that is growing in global

35

demand because of its use in electronic and medical devices, capacitors, aircraft, and hybrid

36

cars. Despite its economic relevance, little is known about its environmental concentrations

37

and the trophodynamics of Ta in aquatic food webs have not been studied. Invertebrates

38

and fishes from coastal marine food webs representing different climatic zones in

39

northwestern Chile, western Chilean Patagonia, and the Antarctic Peninsula were sampled

40

and analyzed for Ta. The trophic level (TL) of species was assessed with nitrogen stable

41

isotopes (δ15N), and carbon stable isotopes (δ13C) were used to trace energy flow in the

42

food webs. Levels of Ta varied among taxa and sites, with the highest values found in

43

fishes (0.53 – 44.48 ng g-1dry weight) and the lowest values found in invertebrates (0.11 –

44

7.80 n ng g-1dry weight). The values of δ13C ranged from -11.79 to -25.66 ‰. Ta

45

biomagnified in all four aquatic food webs, with slopes of log Ta versus TL ranging from

46

0.16 to 0.60. This has important implications as little is known about its potential toxicity

47

and there may be increased demand for TCEs such as Ta in the future.

48

Tantalum,

Biomagnification,

Trophic

Transfer,

49

Keywords

50

Technology-Critical Elements, Marine Organisms, Stable Isotopes.

Aquatic

Ecosystems,

51 52 53

Introduction

54

Tantalum (Ta) is a rare transition element that is highly corrosion-resistant and

55

stable at high temperatures,1, 2 and it is increasingly used in technology related to renewable

56

energies, electronics, the automotive and aerospace industries, and biomedicine.3, 4 World

57

production of Ta has increased over the last two decades, although its extraction remains

58

low (ca. 1000 metric tons per year) when compared to other elements.5 Although Australia,

59

Brazil, Canada, Ethiopia and Nigeria have produced Ta, countries such as Burundi, Congo

60

and Rwanda (65% of global production since 2014) have used it to finance illegal military

61

operations during civil wars, dubbing it a “conflict mineral”.5, 6 Nonetheless, it is estimated

ACS Paragon Plus Environment

2

Page 3 of 15

Environmental Science & Technology Letters

62

that new uses for Ta will increase global demand and production4 but its environmental

63

concentrations and fate are poorly characterized.7

64 65

Published data on Ta levels in the environment are scarce, focusing mainly on

66

mineralogical analysis and then abiotic matrices,7 with only a few reports on Ta in aquatic

67

animals. Ascidians (Styela plicata) from Japanese waters had 100-410 µg g-1 dw Ta8

68

whereas marine organisms from coastal areas of southern England ranged from 0.009 in

69

mollusks to 2.3 µg g-1 dw in crustaceans.9 Chebotina et al. 10 reported the bioconcentration

70

of Ta from water to phytoplankton (>101) and zooplankton (>107). Despite evidence of Ta

71

bioaccumulation in aquatic organisms, the factors affecting its concentrations in different

72

species have not been examined.

73 74

Metals such as mercury, persistent organic pollutants and organotin compounds are

75

known to biomagnify in diverse aquatic food webs to levels in upper-trophic-level fish that

76

may pose a risk to fish consumers and the fish themselves.11-13 The trophic level (TL) of

77

species is estimated from δ15N and frequently used to provide a measure of the relative

78

trophic position of organisms within food webs.11 Levels of contaminants are regressed

79

against TL to understand whether they biomagnify and these relationships can be compared

80

among ecosystems differing in species composition, physical and chemical characteristics,

81

and climatic zones.11, 12

82 83

There is a lack of knowledge on the concentrations of Ta in biota and whether this

84

element biomagnifies through aquatic food webs.7 This is important to address because of

85

the likely increased use of Ta and the potential risk it may pose from dietary exposures.13

86

The objectives of the present study were to determine the concentrations of Ta and the

87

relative trophic level of aquatic organisms from marine coastal food webs across three

88

climatic zones in Antarctica and Chile. The results show for the first time that there is an

89

increase in Ta concentrations with increasing trophic level, and that its biomagnification

90

occurred at sites differing in their physical and biological characteristics.

91 92

Material and methods

ACS Paragon Plus Environment

3

Environmental Science & Technology Letters

93

Page 4 of 15

Field collections

94

During the austral summer of 2015, four marine ecosystems with different climatic

95

conditions were sampled in the following regions of the southern hemisphere (Figure 1):

96

northwestern coast of Chile (Sector A), with a tropical hyper-desertic climate;14 western

97

Chilean Patagonia (Sector B) with a climate classified as template hyper-oceanic;14 and the

98

Antarctic Peninsula area (Sector C), which is classified as a cold desert.15 In northwestern

99

Chile, samples were obtained from Pan de Azúcar Bay (26°09´S, 70°40´W). In Chilean

100

Patagonia, samples were obtained from two sites: the first was off of La Leona Island

101

(44°1´58ʺW, 73°7´56ʺW) and the second was at the mouth of the Marchant River

102

(44°5´15ʺS, 73°5´6ʺW). In Antarctica, samples were obtained from Fildes Bay (62°12´S,

103

58°58´W).

104 105

Fishes and invertebrates were collected from each of the locations by SCUBA to

106

ensure the collection of the selected species, as well as to minimize any impacts of

107

sampling. At Pan de Azúcar Bay in northwestern Chile, 8 species of macroinvertebrates

108

and 6 species of fishes were collected (N = 61; Supporting Table S1). In Chilean Patagonia,

109

4 species of macroinvertebrates and 3 species of fishes were collected at the mouth of the

110

Marchant River (N = 31), and 4 species of macroinvertebrates and 3 species of fishes were

111

sampled at La Leona Island (N = 28; Supporting Table S2). At Fildes Bay in Antarctica, 9

112

of both macroinvertebrate and fish species were sampled (N = 55; Supporting Table S3).

113

Fish were anaesthetized with BZ-20 (Veterquimica), sacrificed by severing the spinal cord,

114

and sampled for muscle tissues. Soft tissues of mollusks were collected and whole bodies

115

of other macroinvertebrates were retained. All specimens were stored at -20°C until

116

processed in the laboratory.

117 118

Laboratory analyses

119

Individual fish muscle and soft invertebrate tissues were freeze-dried until dry

120

masses were constant and then were homogenized into a fine powder using a glass mortar

121

and pestle pre-cleaned with 2% Conrad solution (Merck) for 24 h, washed with deionized

122

water and HCl 1M and rinsed with distilled water.16 Sub-samples (0.2 g) were placed into

123

50 mL Teflon beaker with 5 mL of ultrapure nitric acid and heated (at 110oC) until almost

ACS Paragon Plus Environment

4

Page 5 of 15

Environmental Science & Technology Letters

124

dry (about 3 h). Then 5 mL of ultrapure nitric acid and 1 mL of hydrogen peroxide were

125

added and the mixture was heated again to near dryness (about 3 h). The residue was

126

dissolved in 5 mL of 1% ultrapure nitric acid, filtered with glass fiber filter® (