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HUMAN TOOTH INDICATE RURAL AND URBAN GRADIENT OF EXPOSURE TO

TRACE ELEMENTS

 

Dr. G. NAGARAJLab. Asst. in Zoology

  

    

 ZOOLOGY SECTIONREGIONAL INSTITUTE OF EDUCATION (NCERT)

MYSORE

e.mail: gnriem@gmail.com mobile: 9036865978

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Introduction

• Trace elements are dietary mineral needed in very minute quantities for the proper growth of organism.

• They are of two types: essential and non-essential/toxic.

• They prove to be hazardous even when the concentrations are slightly increased above the trace quantity needed.

• Human tissues (Blood, Hair, Nail, Tooth, Urine, etc) are analysed for element exposure levels (Biomonitoring).

• In addition to complete tooth, the dental enamel can also be used to measure the levels of other essential elements.

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Objectives of the study

To find out the differences / gradients of

element exposure between rural and urban

population in and around Mysore with the

use of five bio-samples.

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MATERIALS AND METHODS

1. Subjects: The residents of Mysore city & surrounding villages (R:68 & U:48)

2. Samples: Teeth, blood, scalp hair, fingernails and urine

3. Sampling places: Teeth: JSS dental college, Mysore Blood, scalp hair, fingernails and urine:

Kamakshi, Bassappa Memorial and Vickram Hospitals,

Mysore 4. Questionnaire: For personal and sample

characters

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5. Processing of samples:

Washing: T- DDW, H, N, - DDW & Acetone-

with magnetic stirrer

Drying: Hot air oven - 50C - 24hr

Digestion: HNO3 & HClO4 (4:1), Kjeldhal –

80’C - 8 hr

Make up to 10 ml with DDW and

Storage: in refrigerator at 4’C

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6. Element Analysis:

Sample Element Instrument Place

TeethCr, Cu, Fe, Ni, Pb, Zn

AAS 6 VARIO

AAS-GBC 902

CES- Anna Univ, Chennai.

SES-JNU- New Delhi.

Blood, urine, hair

& fingernail

Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn

ICP-AES - JY-IYON-2002–2

DEE - SJCE, Mysore

7. Quality control study: CRM- Human hair powder–NIES, Japan

8. Statistical analysis: Mean, SD, Student ‘t’ test.

Table 1. Comparison of element levels in five bio-samples between rural and urban subjects in and around Mysore

Result

BS SG Mean concentration of elements (ng/ml; µg/g; µg/l; µg/gcr ± SD)Cd Co Cr Cu Fe Mn Ni Pb Zn

BR 2.61±

13.30±1.3

5.44±5.3

130.0±125

3294.8±1 BDL 10.78±

1119.67±15

391.8±169

U 3.48±1 4.02±1 8.77±7

.5117.3±112

4003.9±1 BDL 12.69±

735.50±32

412.8±156

TR NA NA 15.49±

53.51±0.65

62.95±14 NA 19.21±

542.08±14

136.25±20

U NA NA 20.86±7

3.70±4.40

77.15±2 NA 27.89±

168.39±17

167.30±42

U

R0.12±0

0.17±0.0

0.17±0.0

0.10±0.04 0.16±0 0.07±0.

020.33±0.1

0.23±0.04

0.49±0.80

10.32±1

13.21±1

14.57±1

8.88±9.65

12.83±12

5.04±4.51

21.02±16

16.36±13

22.16±22.

U0.11±0

0.17±0.0

0.17±0.0

0.13±0.19 0.17±0 0.07±0.

02 0.38±0 0.23±0.08

0.38±0.24

5.74±6

7.08±8.0

7.90±8.5

6.00±7.36

8.08±10

3.06±3.09

14.26±10

10.28±11

13.90±14

HR BDL 3.89±1

.50.35±0.1

4.63±7.63

4.32±1.5

1.14±0.51

0.46±0.2

0.74±0.45

96.12±13

U BDL 4.02±3.0

0.51±0.2

3.88±4.92

4.78±3.9

1.83±1.72 0.74±0 1.10±0.

5108.43±30

NR 1.58±

1 6.17±3 1.51±1.5

8.24±7.79

23.42±1

5.07±4.90 2.14±2 1.01±0.

58140.32±88

U 1.21±1

2.76±2.3

1.10±1.0

6.16±7.83

13.21±8

3.84±4.23 2.19±1 2.96±1.

0114.72±10

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FINDINGS1. All the samples except urine indicated rural and

urban gradients of the element levels.

2. Variations of three elements in both blood (Cd, Co and Fe) and nails (Co, Fe and Pb) and two elements in hair (Ni and Pb) reflected the environmental influence.

3. Higher essential elements observed in urban subjects are ascribed to their intake of nutritionally rich food.

4. Higher levels of Cd, Pb and Ni are related to elevated sources from automobile exhaust, industrial emission, soil dust.

5. Out of six elements measured in teeth, five elements (Cr, Fe, Ni, Pb and Zn) differed in their concentrations due to environment.

6. Tooth samples may be the suitable indicator for monitoring environmental (rural & urban) element exposure.

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Acknowledgement

I sincerely thank

•Dr. A. Sukumar, Reader in Zoology, RIE,

Mysore,

•Prof. K.S. Lokesh, DEE, SJC, Mysore,

•The Principal, RIE, Mysore &

•NCERT, New Delhi

for providing me the guidance and support.

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THANK YOU