An Effective Approach to Maintain Homogeneity of Test Item in Soil - - PowerPoint PPT Presentation

▶
an effective approach to maintain homogeneity of test
SMART_READER_LITE
LIVE PREVIEW

An Effective Approach to Maintain Homogeneity of Test Item in Soil - - PowerPoint PPT Presentation

Feb 12, 2024 280 likes •449 views

An Effective Approach to Maintain Homogeneity of Test Item in Soil for Earthworm ( Eisenia fetida) Toxicity Test Jigar R. Rana Ecotoxicology Introduction Guideline suggests analysis for volatile, unstable, and readily degradable

slide-1
SLIDE 1

An Effective Approach to Maintain Homogeneity of Test Item in Soil for Earthworm (Eisenia fetida) Toxicity Test

Jigar R. Rana Ecotoxicology

slide-2
SLIDE 2

2

Introduction

  • Guideline suggests analysis for volatile, unstable, and

readily degradable substances

  • Q1. How about insoluble and soluble compounds?
  • Q2. How to maintain homogeneity in the absence of

analysis?

slide-3
SLIDE 3

3

Introduction (Continued)

  • Carbendazim
  • Solubility in water is 8 mg/L
slide-4
SLIDE 4

4

Introduction (Continued)

  • Eisenia fetida has been extensively used as a standard test
  • rganism for the risk assessment of pesticides and is widely

used to assess its sensitivity to chemical pollution Life Cycle of Earthworm

Cocoon Production Cocoon Hatchling Juvenile Adult Reproduction

slide-5
SLIDE 5

5

Experimental Design

Acclimatisation Artificial soil preparation Mixing and Exposure of Test Item Distribution in test vessels Addition of water to achieve moisture content Observation

slide-6
SLIDE 6

6

Experimental Design (Continued)

Conventional Method

Mixing of Test Item Mixing in artificial soil in bulk Distributed in replicates

Individual Replicate Exposure Method

Mixing of Test Item Mixing with sand Mixing in artificial soil in replicate Transfer into test vessels

slide-7
SLIDE 7

7

Results

200 250 300 350 400 450 500 0.7 1.3 2.4 4.2 7.6 13.7 24.7 44.4 80 Body Weight (mg) Concentration (mg/kg A. soil)

Body Weight (mg) - Day 0

200 250 300 350 400 450 500 0.1 0.2 0.4 0.8 1.4 2.6 4.6 8.3 15.0 Body Weight (mg) Concentration (mg/kg A. soil)

Body Weight (mg) - Day 0

200 250 300 350 400 450 500 0.1 0.2 0.4 0.8 1.4 2.6 Body Weight (mg) Concentration (mg/kg A. soil)

Body Weight (mg) - Day 28

200 250 300 350 400 450 500 0.7 1.3 2.4 4.2 7.6 13.7 Body Weight (mg) Concentration (mg/kg A. soil)

Body Weight (mg) -Day 28

Conventional Method Individual Replicate Exposure Method

slide-8
SLIDE 8

8

Results (Continued)

Conventional Method Individual Replicate Exposure Method

Concentrations (mg/kg A. soil) Sign of Toxicity 4.2 Sluggish, Shrunk 7.6 Sluggish, Shrunk 13.7 Sluggish, Shrunk 24.7 Shrunk 44.4

  • 80.0
  • Concentrations

(mg/kg A. soil) Sign of Toxicity 1.4 Sluggish 2.6 Sluggish, Shrunk 4.6 Shrunk 8.3

  • 15.0
  • 0.0

0.0 0.0 2.5 17.5 50.0 65.0 97.5 100.0 100.0

0.0 20.0 40.0 60.0 80.0 100.0 0.7 1.3 2.4 4.2 7.6 13.7 24.7 44.4 80 % Mortality Concentration (mg/kg A. soil)

2.5 17.5 97.5 100 100

20 40 60 80 100 0.1 0.2 0.4 0.8 1.4 2.6 4.6 8.3 15.0 % Mortality Concentration (mg/kg A. soil)

slide-9
SLIDE 9

9

Results (Continued)

Conventional Method Individual Replicate Exposure Method

0.00 20.00 40.00 60.00 0.7 1.3 2.4 4.2 Mean N° of Juveniles Concentration (mg/kg A. soil)

  • 1.6

2.49 23.22 74.02 90.95 91.83

  • 20

20 40 60 80 100 0.1 0.2 0.4 0.8 1.4 2.6 Percent Reduction Concentration (mg/kg A. soil) 8.58 49.10 93.25 98.96 0.00 20.00 40.00 60.00 80.00 100.00 0.7 1.3 2.4 4.2 Percent Reduction Concentration (mg/kg A. soil) 20 40 60 80 100 0.1 0.2 0.4 0.8 1.4 2.6 Mean N° of Juveniles Concentration (mg/kg A. soil)

slide-10
SLIDE 10

10

Results (Continued)

End points Conventional Method Individual Replicate Exposure Method Comparison mg/artificial soil LC50 for adult mortality (28 day) 8.26 2.81 2.9 times EC50 for reproduction 1.32 0.68 1.9 times NOEC 0.7 0.4 1.8 times LOEC 1.3 0.8 1.6 times

slide-11
SLIDE 11

11

Published results

End points Garcia, 2004 Sian R Ellis et al., 2007

  • R. Shanmuga-

sundaram et al., 2013 Mcshane et

  • al. 2012

Method 1 Method 2 LC50

  • 8.03

6.33

  • 8.26

2.81 EC50 2.7

  • 2.45

3.3 1.32 0.68 NOEC 0.1

  • 1.14
  • 0.7

0.4 LOEC

  • 2.06
  • 1.3

0.8

slide-12
SLIDE 12

12

Summary

  • Individual replicate exposure method leads to deduction of

the end points: survival, growth, and reproduction to higher level of accuracy, with compressed range of concentrations.

  • While the LC50, EC50, and LOEC results of our study are

substantially lower than the published data.

slide-13
SLIDE 13

13

Conclusion

The Individual Replicate Exposure Method:

  • Helps in maintaining the homogeneity of the test item in

soil

  • Fulfills the objective of test to get enhanced accuracy for

the end points.

slide-14
SLIDE 14

14

References

  • Allen, H.E., 2002. Bioavailability of Metalsin Terrestrial Ecosystems:

Importance of Partitioning for Bioavailability to Invertebrates, Microbes, and Plants. SETAC, NewYork.

  • Boudina, C. E., Baaliauamer, A., Grenier-Loustalot, M.F., Choven, J.M., 2003.

Photochemical behaviour of carbendazim in aquatic solution. Chemosphere. 50, 649-655.

  • Edwards, C.A., 1998. Earthworm Ecology. St. Lucie Press, New York.
  • Edwards, C.A., Bohlen, P.J., 1992. The effects of toxic chemicals on
  • earthworms. Rev. Environ. Contam. Toxicol. 125, 23–99.
  • Ellis, S.R., Hodson, M.E., Wege, P., 2007. The influence of different artificial

soil types on the acute toxicity of carbendazim to the earthworm Eisenia fetida in laboratory toxicity tests. Eur. J. Soil Biol. 43, 239-245.

  • Garcia, M., Römbke, J., de Brito, M.T., Scheffczyk, A., 2008. Effects of three

pesticides on the avoidance behavior of earthworms in laboratory tests performed under temperate and tropical conditions. Environ. Pollut.153(2), 450-456.

slide-15
SLIDE 15

15

References (Continued)

  • Holmstrup, M., 2000. Field assessment of toxic affects on reproduction in the

earthworm Aporrectodea longa and Aporrectodea rosea. Environmental toxicology and chemistry.19,1781-1787.

  • ISO, 1998. Soil quality Effects of Pollutants on Earthworms (Eisenia fetida). Part2:

Determination of Effects on Reproduction. ISO - The International Organization for Standardization, Genève, Switzerland.

  • Landrum, M., Cañas, J.E., Coimbatore, G., Cobb, G.P., Jackson, W.A., Zhang, B., derson,

T.A., 2006. Effects of perchlorate on earthworm (Eisenia fetida) survival and reproductive success. Sci. Total Environ. 363, 237–244.

  • OECD, 1984. Guidelines for Testing of Chemicals. Test 207: Earthworm Acute

Toxicity Tests. Organization for Economic Co-operation and Development (OECD).

  • OECD, 2016. Guidelines for Testing of Chemicals. Test 222: Earthworm Reproduction

Test (Eisenia fetida/ Eisenia andrei). Organization for Economic Co-operation and Development (OECD).

  • Reinecke, S.A., Reinecke, A.J., 2007. The impact of organophosphate pesticides in
  • rchards on earthworms in the Western Cape, South Africa. Ecotoxicol. Environ. Saf.

66(2), 244–251.

  • Römbke, J., Jänsch, S., Didden, W., 2005. The use of earthworms in ecological soil

classification and assessment concepts. Ecotoxicol. Environ. Saf. 62, 249–265.

slide-16
SLIDE 16

Thank You