New environmental biomarkers. Mari Murtomaa Centre for Arctic medicine / Thule Institute University of Oulu

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1 New environmental biomarkers Mari Murtomaa Centre for Arctic medicine / Thule Institute University of Oulu

2 New environmental biomarkers Biomarkers theory and practice Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers?

3 New environmental biomarkers Traditional contaminant monitoring Measurements of chemicals in water, soil, sediment and air Determination of contaminant levels in biota great benefit of quantifying the fraction which is bioavailable BUT they do not provide information about the effects on living organisms

4 Environmental biomarkers A biomarker is a xenobiotically-induced variation in cellular or biochemical components or processes, structures, or functions that is measurable in a biological system or sample (NRC, 1987) molecular cellular tissue individual population community

5 1. repeatability Environmental biomarkers 3Rs 2. reliability 3. relevance Often: repeatability + reliability relevance

6 Environmental biomarkers Relationships between biomarker responses and the impact on the organisms, population and ecosystem are rarely sufficiently demonstrated So what? The important consideration is what we are using the biomarkers for

7 Environmental biomarkers Should.. be sensitive enough be easily and rapidly assayed respond in a dose-dependent manner be valid for the species in question be evaluated for possible influences by other endogenous and exogenous factors

8 Environmental biomarkers Molecular Gene expression Up- and down regulations of specific genes e.g. expression of a certain calcium-binding protein gene in zebrafish(danio rerio) and rainbow trout (Oncorhynchus mykiss) exposed to TCDD [Cao et al. 2003] Changes in expression patterns of the entire genome DNA integrity

9 Biochemical Enzymatic Environmental biomarkers e.g. mixed function oxygenase (MFO) system receptor-mediated induction of cytochrome P450- dependant monooxygenases Specific proteins changes in the levels of key molecular components of the cell e.g. metallothioneins trace metal exposure stress proteins (hsp70 and hsp60) persistant organic pollutant exposure

10 Environmental biomarkers Histo-cytopathological Changes in the structure of cells, tissues, organs or individual organisms e.g. development of imposex in molluscs such as the dog whelk (Nucella lapillus) as a response to the presence of butylin compounds Physiological basic functions such as respiration, changes in growth rate, feeding, excretion etc. e.g. growth as an indicator of pollution stress in marine invertebrates

11 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? The chlorophenol based wood preservative Ky-5 to protect timber against blue staining contamination of soil by polychlorinated bibenzo-p-dioxins and furans (PCDD/Fs)

12 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Effects of in utero and lactational 2,3,7,8- TCDD exposure on rat molar development [Kattainen et al. 2001] The size of molars decreased in TCDD-treated groups Effects of 2,3,7,8-TCDD on bone [Miettinen et al. 2005] The three-point bending breaking force of the tibia and femur reduced in TCDD-treated groups

13 Suitable for monitoring? Matti Laine Bank vole Clethrionomys glareolus Field vole Microtus agrestis

14 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Biota Grey alder (Alnus incana) Common tansy (Tamacetum vulgare) Concentration in biota (pg WHO-TEQ/g dw) 20 0,01 Concentration in soil (pg WHO-TEQ/g dw) Common earthworm (Lumbricus terrestris) Bank vole (C.glareolus) liver 11600(134000pg WHO-TEQ/g fat) 3110 (31300pg WHO- TEQ/g fat Pöyry Environment Ltd National Public Health Institute, Kuopio

15 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Bone quality peripheral quantitative computed tomography (pqct) bone density Three-point bending strength of tibia, femur and femoral neck

16 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Adult bank vole males: 40 * F Bending strength (N) of femur neck Pateniemi (N=11) Control (N=9)

17 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Sawmill area: 23.6% Control area: 23.9% Sawmill area: 24.4% Control area: 25.8%.

18 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Size of 3rd molar (% of all three molars) Sawmill N=17 *** Control N=17 Sawmill N=22 Control N=14 20 Clethrionomys glareolus Microtus agrestis

19 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Saw mill Control 150 pg I-TEQ/g ,9 Clethrionomys glareolus 26,4 10,3 Microtus agrestis

20 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Conclusions and further studies (1) Impossible to demostrate a clear causeeffect relationship between detected effects and the exposure Nevertheless, impaired tooth development proved to be sensitive endpoint of dioxininduced toxicity Size of molar teeth as a sensitive and robust biomarker for PCDD/Fs exposure worth of further studies

21 Case study: Old sawmill area contaminated by dioxins use of small mammals as biomarkers? Conclusions and further studies (2) Two relatively similar species may have considerable differences in PCDD/F concentrations and related effects depending on diet and ecology in general challenge for reseacrh of biomarkers The reason for such a great difference? study of metabolism of PCDD/F by the liver of bank and field vole

22 Thank you for your attention