Non-invasive biomonitoring of metals using hair

Transcription

1 Non-invasive biomonitoring of metals using hair Workshop on non-invasive human biomonitoring 10 December 2010, Brussels Marta Esteban J. Antonio Jiménez Guerrero Argelia Castaño Environmental Toxicology National Centre for Environmental Health Institute of Health Carlos III Majadahonda, Madrid (Spain)

2 OUTLINE General considerations of hair: anatomy, structure, growth, etc. Applications, advantages and limitations. Hair samples in HBM. Analysis of trace metals in hair. Mercury.

3 HAIR ANATOMY AND COMPOSITION Tightly compacted cells Diameter: µm Sulfur rich proteins KERATIN S-S bounds Cross linking with other proteins

4 HAIR SHAFT STRUCTURE

5 ENDOGENOUS SOURCES OF XENOBIOTICS Epidermis

6 RATE OF GROWTH 1 cm/month Main factors affecting hair growth: - Type - Body location - Age - Sex - Race Growth in cycles of growing and quiescence

7 APLICATIONS OF HUMAN HAIR ANALYSIS Forensic toxicology Clinical toxicology Occupational medicine Doping control Human biomonitoring ADVANTAGES Non- invasive Easy collect/transport Stable Historical exposure LIMITATIONS External contamination Source identification Interpretation

8 HUMAN HAIR IN HBM ATSDR 2001, Hair Analysis Panel Discussion Exposure and time period Type of substance and metabolism Clinical relevance

9 HUMAN HAIR IN HBM ATSDR 2001, Hair Analysis Panel Discussion CONCLUSIONS: 1. Recent exposure, > 1 year NOT USEFUL 2. SOPs 3. Supportive tool EXCEPTIONS: 1. Arsenic 2. Mercury

10 HUMAN HAIR IN HBM TECHNOLOGY SAMPLING VARIATIONS SAMPLE PREPARATION VARIATIONS ANALYTIC METHODS VARIATIONS RELIABLE AND COMPARABLE RESULTS? HARMONIZATION SOPs

11 MERCURY IN HUMAN HAIR

12 MERCURY IN ENVIRONMENT Persistent global cycle Long range transport local liberation, global effects Microbial mercury methylation More toxic forms Bioconcentration Biomagnification

13 MERCURY BIOMARKERS Hair Blood Cord blod Cord tissue Urine Nails Breast milk Non-invasive Easy to collect Low cost Easy transport and storage Stable Long-term exposure High concentration Certified reference material

14 EPIDEMIOLOGICAL STUDIES WITH HUMAN HAIR HIGH PRESENCE IN DIET: Neurodevelopmental toxicity in children. Faroe Islands Seychelles Islands ACCIDENTS: Severe health effects in general population. Minamata, Japan Iraq

15 HAIR MERCURY AND FISH CONSUMPTION Fish: 75-95% of Hg is MeHg Absorption: 95 % of MeHg Hair: Hg and MeHg levels linearly correlated; 70-80% of Hg is MeHg Global Mercury Assessment, 2002

16 HAIR MERCURY ANALYSIS Techniques: Atomic Absortion Spectrometry (AAS) Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) Neutron Activation Analysis (NAA) X-Ray Fluorescence Proton Induced X-Ray Emission Spectrometry (PIXE)

17 HAIR MERCURY ANALYSIS Thermal decomposition-gold amalgamation-atomic Absorption Spectroscopy (AAS) No sample digestion Small amount Number of samples Low cost / time Wide concentration range

18 SAMPLING MATERIALS Scissors, alcohol, cotton cloth, identification labels, paper envelopes, adhesive tape and gloves Grasp the hair from the middle of the back of the head to the top. Take several strands of hair horizontally and roll it up to form a lock. Fasten the lock with adhesive tape at 5-6 cm from the root of the hair. Cut the sample with the scissors as close to the scalp as possible.

19 SAMPLING Seal the end of the adhesive tape and label it with an arrow indicating the extreme closet to the scalp. Put the hair sample into a paper envelop and label it. Put the envelop into a ziplock plastic bag.

20 SAMPLE PREPARATION Cut the first 3 cm from the extreme closest to the scalp. Put the sample in a PP vessel and grind it, 1-3 mm Store it at room temperature until analysis.

21 ANALYSIS Weigh 3 mg of grinded hair for triplicate. PARAMETERS Drying time: 60 s Drying temp: 200ºC Decomp time: 150 s Decomp temp: 650ºC Purge time: 60 s λ: 254 nm ANALYSIS TIME: 5-6 min VALIDATION Two Certified Reference Materials NIES-13: 4,42±0,20 ppm IAEA-086: 0,573±0,039 ppm

22 SOME RESULTS FROM SPAIN

23 FISH COMSUMPTION IN SPAIN EPIC STUDY (European Investigation into Cancer and Nutrition) WOMEN MEN Welch et al Public Health Nutrition: 5(6B),

24 National Centre for Environmental Health ENVIRONMENTAL TOXICOLOGY

25 BIOAMBIENT.ES MULTIDISCIPLINARY RESEARCH GROUP Environmental Toxicology - ISCIII Environmental and Cancer Epidemiology - ISCIII Department of Sanitary Projects of Ibermutuamur Age range: % men; 56% women

26 BIOAMBIENT.ES SAMPLES COLLECTED 1936 Urine 1936 Blood 1936 Serum 604 Hair Total Hg: GM =1.86 ng/mg CI95% = MATRIX HAIR URINE BLOOD SERUM BIOMARKERS Hg Metil-Hg Cd, Pb and Hg Cotinine Hydroxylated metabolites of PAHs Cd, Pb and Hg PCBs non coplanar: PCB28, PCB52, PCB101, PCB135, PCB152, PCB180 PBDEs: PBDE47, PBDE85, PBDE99, PBDE100, PBDE119, PBDE126, PBDE153, PBDE154, PBDE183, PBDE196, PBDE197 Organochlorine compounds: 2,4 -DDT, 2,4 -DDE, 4,4 -DDT, 2,4 -DDE, Aldrin, Dieldrin, Endrin, Heptachlor, Heptachlor epoxide, HCB, HCH

27 ISCIII PILOT STUDY Four campaigns: 2007, 2008, 2009, % women, 21% men Age mean ± SD = 43 ± 11 YEAR BIOLOGICAL MATRIX PARTICIPANTS URINE HAIR 2007 X X X X X X X 105 (IN PROGRESS)

28 ISCIII PILOT STUDY 2007 Total Hg (ng/mg) N 268 <LQ 0% GM (CI95%) 2.2 ( ) ( ) ( ) ( ) Percentile ( ) (CI95%) ( ) ( ) ( ) SIGNIFICANT DIFFERENCES AGE, GENDER, FISH CONSUMPTION 2008 Total Hg (ng/mg) N 259 <LQ 0% GM(CI95%) 2.2 ( ) ( ) ( ) ( ) Percentile ( ) (CI95%) ( ) ( ) ( )

29 FINAL REMARKS Hair is a useful matrix in HBM, specially in large population studies. It is a suitable matrix only for specific biomarkers such as mercury and arsenic. Further research is needed in order to achieve consistent results in hair analysis for other contaminants. It is essential to develop SOPs in order to achieve reliable and comparable results.

30 THANKS FOR YOUR ATTENTION!!! Funded by the Spanish Ministry of the Environment and the ISCIII projects number EG and SEG 1251/07 and by COPHES.