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Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Finger and toe nails don't seem very interesting at the best of times, but did you know they carry a record of your exposure to metals like lead and arsenic? In this presentation I review how these materials can show if people are being exposed to trace metals and how they can be used to link exposure to possible early health effects. The talk includes work from 3 PhD projects that I have been involved in and show how a project can develop from a humble beginning to cutting edge research.
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1 1 RSC TOXICOLOGY GROUP and SOCIETY FOR BROWNFIELD RISK ASSESSMENT Current Issues in Contaminated Land Risk Assessment - 2013 Dr Chris Harrington Deputy Director SAS Trace Element Laboratory, Royal Surrey County Hospital Non-Invasive Methods for Biomonitoring Human Exposure to Trace Elements
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Page 1: Non-Invasive Methods for Biomonitoring Trace Element Exposure

11

RSC TOXICOLOGY GROUP and

SOCIETY FOR BROWNFIELD RISK ASSESSMENTCurrent Issues in Contaminated Land Risk Assessment - 2013

Dr Chris Harrington

Deputy Director

SAS Trace Element Laboratory,

Royal Surrey County Hospital

Non-Invasive Methods for

Biomonitoring Human Exposure to

Trace Elements

Page 2: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Human Health Effects

Page 3: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Biomonitoring Model

3

Two classes of biomarker can be measured:

Biomarkers of exposure and biomarkers of effect.

Page 5: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Biomarkers of Exposure

• Random urine: guidance values for occupational

exposure and defined species eg organic Pb.

Requires creatinine correction.

• Venous blood: guidance values for specific elements

(Ag, Cd, Hg, Mn and Pb).

• Hair: reference ranges available for some

populations. Provides a timeline of exposure.

Problems with surface contamination and cosmetic

treatments.

• Nails: similar to hair. Toe-nails better than finger-nails

as less affected by contamination.

• Zinc protoporphyrin in blood: blood drop from finger-

tip. Screening method for Pb and iron-deficiency

anaemia.

Page 7: Non-Invasive Methods for Biomonitoring Trace Element Exposure

77

Objectives

Small scale preliminary study looking at:

Control groups from Leicester.

As in hair, urine and nails.

Development of life-style questionnaire.

Methods for cleaning hair and nails

prior to analysis.

Total As and As speciation by ICP-MS

and HPLC-ICP-MS.

Page 8: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Results 1.

Total As concentration in

urine, hair and fingernail of

three ethnic groups:

Asian (n = 21), Somali (n =

22) and White (n = 20).

(A) Total As concentration

(μg/g creatinine) in urine.

(B) Total As concentration

(μg/kg) in hair and

fingernail.

E. I. Brima, P. I. Haris, R.O. Jenkins, A. G. Gault, D. A. Polya, C.

F. Harrington. Understanding arsenic metabolism through a

comparative study of arsenic levels in the urine, hair and

fingernails of healthy volunteers from three unexposed ethnic

groups in the United Kingdom. Toxicology and Applied

Pharmacology, Vol. 216, 122-130, (2006).

Page 9: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Results 2.

Proportions of As species in the

urine of three ethnic groups.

Differences are predominantly

related to dietary exposure: all

participants refrained from

seafood for 3 days prior to

sampling.

Higher proportion of DMA in

Somali urine could relate to

higher protein intake which

promotes methylation.

Page 11: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Objectives

Small scale preliminary study looking at:

Exposure to As from abandoned mine site.

As in human hair, urine and nails.

Use of worms as sentinel organisms.

Use of bioaccessible fraction.

Used preparation methods and

questionnaire from previous study.

Total As and As speciation by ICP-MS and

HPLC-ICP-MS.

Page 12: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Total As (mg/kg)

255 - 289

331- 439

913 - 1005

1564 - 2980

5141 - 12466 0 0.50.25 Kilometers'

Devon Great Consols, Cornwall

Devon Great Consuls

Bath

Exeter

Taunton

Swansea

Bristol

Weymouth

Plymouth

Penzance

CheltenhamCarmarthen

´0 25 50 75 10012.5Kilometers

Nottingham garden

used as control site.

•Total As in soil

determined via ICP-MS

following acid digestion.

•Bioaccessible fraction

by PBET.

•SGV 32 – 640 mg/kg

*

Page 13: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Devon Great Consols: Sampling

Page 14: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Pathways of Exposure to Contaminated Soil

1. Inhalation

2. Dermal uptake

3. Ingestion- Soil particles adhere to

vegetables

- Geophagia

- Hand-to-mouth activities

(‘Pica’ Children)

Page 15: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Unified Bioaccessibility Method

Stomach

Phase

Stomach + Intestine

Phase

Bioaccessible = Maximum concentration of arsenic available

for gastro-intestinal absorption.

(Bioavailable – Contaminant fraction that reaches the systemic

circulation).

Page 16: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Results: Stomach vs. Intestine

Sample site Total As (mg/kg-1)

Stomach Only

Stomach + Intestine

Bioaccessible As (%)

1 2 3 5 6 7 9

10 11 12 13 15

Control

3058 1564 996 238

11939 313 272 452 282 5232 2870 876 15.4

578 298 308 44.2 340 94.8 60.9 43.8 36.5 1595 848 158 4.6

588 303 329 36.8 1603 73.0 72.2 40.5 35.3 1116 690 113 6.7

19.2 19.4 33.1 18.5 13.4 30.3 26.6 9.68 12.9 30.5 29.6 18.1 43.4

Page 17: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Toe-Nail Levels: DGC

Exposed Group Control Group

Mean±SD min max Mean±SD min max

Age 46 ± 26 11 67 41 ± 13 25 55

Male/Female (n) 5/3 6/3

Time outdoors (hr/wk) 11 ± 7 3 21 5 ± 2 2 10

Toenail As (ug/kg) 5406 858 25981 122 73 273

Exogen. TN As (ug/kg) 506 102 3784 4.0 2.1 13

Total conc. As in toe-nail as a biomarker of exposure.

Levels much higher in participants living near to DGC.

Small cohort sizes.

Page 18: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Publications From this Project

M.J. Watts, M. Button, T.S Brewer, G.R.T. Jenkin and C. F. Harrington. The speciation of arsenic in two species of

earthworms from a former mine site. Journal of Environmental Monitoring, Vol 10, 753-759, (2008).

M.J. Watts, M. Button, T.S Brewer, C. F. Harrington and G.R.T. Jenkin. Toenails as a biomarker of exposure to

elevated environmental arsenic levels in residents of an abandoned mine site, Devon, UK. Journal of Environmental

Monitoring. Vol. 11, 610-617. (2009).

Mark Button, Mark Cave, Chris F. Harrington, Michael J. Watts. Earthworms and in vitro physiologically based

extraction tests: complimentary tools in a holistic approach towards understanding risk at arsenic contaminated sites.

Environmental Geochemistry and Health, 31, 273-282, (2009).

Button M, Jenkin GRT, Bowman, KJ, Brewer TS, Harrington CF, Jones GDD and Watts MJ (2008). Assessment of

resistance to arsenic in earthworms from genotoxic contaminated soils using the Comet assay. Mutation Research:

Genetic Toxicology and Environmental Mutagenesis, 696, 95-100, (2010).

Page 19: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Study Three: MultielementalPanasqueira Mine, Portugal

Panasquei

ra Mine

Castelo

dam

Page 20: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Objectives

Investigate the effects on population health caused by mine

waste contamination

using a multistage approach

integrate different biomarkers

a better characterization of the risk

Three groups: control (n = 35); occup. exp. (n = 34); environ. exp (n = 33).

Page 21: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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São Francisco de

Assis village

Geochemical sampling

campaign undertaken

in the vicinity of São

Francisco de Assis

village

Soil samples (when compared to local

background)

As - 36x

Cd - 4x

Stream sediments (when compared to

local background)

As – 117x

Cd – 23x

Mining

site

Village

Page 22: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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- Genotoxicity:

- T-cell receptor (TCR) mutation assay

- Micronucleus (MN)

- Chromosomal Aberrations (CA)

- Comet Assay

- Immunotoxicity-> Lymphocyte subset frequency

- Susceptibility-> genetic polymorphisms (enzymes

involved in the metabolism of metal(loid)s and

DNA repair)

Biomarkers of Effect

Page 23: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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COLLECTED SAMPLES / METHODS

Blood

Urine

Nails

Hair

Digestion in

microwave

vessels with

HNO3 (conc.)

GFAAS and ICP-MS analysis

ICP-MS analysis

ICP-MS and

ICP-OES

analysis

Page 24: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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RESULTS – ICP-MS

Confounding factors

Gender

- Cd in WB (↑ in males - E.E.)

- Pb in WB (↑ in males - C. and E.E.)

Age

- As in U

- Hg in U

- Se in U

- Se in FN - ↑ younger individuals

Smoking Habits

- Cd in WB (↑ in males - E.E.)

↑ older individuals

Page 25: Non-Invasive Methods for Biomonitoring Trace Element Exposure

RESULTS – ICP-MS

C. vs. E.E. E.E. vs. O.E. C. vs. O.E.

As↑ WB*, FN* &

TN* - ↑ FN*

Cd ↑ FN* ↓ FN*,↑ H* ↑ H*

Cr ↑ WB** ↓ WB** -

Hg ↓ TN** & H* ↑ TN* & H* ↑ H*

Mn - ↓ U*, ↑ H* ↑ H*

Ni - - -

Pb - ↑ WB* & H** ↑ WB*

Se - ↓ FN* -

* p<0,05 * *p<0,001

C. – Contol Group

E.E. – Environmental Exposed Group

O.E. – Occupational Exposed Group

WB – Whole Blood

FN – Fingernails

TN – Toenails

H – Hair

U – Urine

Page 26: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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RESULTS – ICP-MS

Correlations between elements & matrices

Significant correlations between:

• different elements / same matrix

• same element / different matrices

• different elements / different matrices were found for

the majority of the elements showing a good synergy

between these biomarkers.

Elements concentrations vs. Reference/Published ranges

Several elements exceed the reference ranges for

WB and U samples, and for FN, TN and H the

published ranges for non-exposed populations.

Page 27: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Initial Conclusions

Preliminary results for the biomarkers of effect:

• Increased MN frequency -> genotoxicity

• Elevated TCR mutation frequency -> mutagenicity

• Alterations in the percentages of lymphocytes subsets ->

immunotoxicity

Related to the metal(loid) contamination

from Panasqueira mine activities

FURTHER DATA ANALYSIS IS

UNDERWAY

Increased risk of effects on health

Page 28: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Publications From this Project

Patrícia Clara dos Santos Coelho, Solange Costa, Susana Silva, Alan Walter, James Ranville, Ana Sousa, Carla da

Costa, Marta Isabel Correia Coelho, Julia García-Lestón, M. Ramiro Pastorinho, Blanca Laffon, Eduardo Pásaro

Mendez, Chris Harrington, Andrew Taylor and João Paulo Teixeira. Metal(loid) levels in biological matrices from

human populations exposed to mining contamination - Panasqueira Mine (Portugal). Journal of Toxicology and

Environmental Health, Part A. 2012, 75(13-15), 893-908.

P. Coelho, S. Costa, C. Costa, S. Silva, A. Walter, J. Ranville, M.R. Pastorinho, C. Harrington, A. Taylor, V. Dall'Armi,

R. Zoffoli, C. Candeias, E. Ferreira da Silva, S. Bonassi, B. Laffon J.P. Teixeira. Impact of Panasqueira mine

activities on populations environmentally and occupationally exposed – quantification of several metal(loid)s in

different biological matrices. Environmental Geochemistry and Health, published on-line.

All publications relating to this work are available to download from Research Gate :

www.researchgate.net/profile/Chris_Harrington/?ev=hdr_xprf

Page 30: Non-Invasive Methods for Biomonitoring Trace Element Exposure

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Acknowledgements

All colleagues and collaborators who helped with the

different studies:

Study One: De Montfort University Studentship

(Dr Eid Brima).

Study Two: British Geological Survey, NERC

Award (Dr Mark Button).

Study Three: FCT Portugal (Dr Patricia Coelho).

Current work: NHS for on-going instrument time.

All publications relating to this work are available to

download from Research Gate : www.researchgate.net/profile/Chris_Harrington/?ev=hdr_xprf


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