POLLUTION BY XENOBIOTICS :BIOMARKERS FOR EARLY

DETECTION OF POLLUTION EFFECTS

Ibon Cancio

EUSKAL HERRIKO UNIBERTSITATEA

UNIVERSITY OF THE BASQUE COUNTRYeman ta zabal zazu

DEPARTMENT OF ZOOLOGY AND ANIMAL CELL DYNAMICS

POLLUTION

Nutrients

LightNoiseSmell

Toxic compounds

XENOBIOTICS

Alien species

CHEMICAL ANALYSIS OF THE WATER

- Knowledge of the chemical products in the environment

- Drawbacks:

* Requires selection of substances to be tested, it is difficult and expensive

* It has little biological meaning: toxic? Synergistic, antagonistic effects?

Legal action against polluting factory

BIOMONITORING

- Chemical analysis on biota * Mussel watch, slug watch... * Bioaccumulation: fraction of pollutants that is accumulated in biological tissues

- Drawbacks: * Still need to select substances * Pollutants may not accumulate (be metabolised) * Biological meaning? (does accumulation relate to a possible impairment of animal performance?)

Slug WatchSlug Watch

BIOMARKERS: LOOKING FOR BIOLOGICAL ANSWERS

- THE MAIN AIM OF ENVIRONMENTAL TOXICOLOGY IS TO KNOW THE EFFECT OF POLLUTANTS ON POPULATIONS AND ECOSYSTEMS:

Can we measure biologically exposure to chemicals and the effects caused by them?

* Noise* Ecological relevancePopulation

Organism

Physisological

Cellular

Molecular

Community

Ecosystem

* Specificity* Speed

Biomarkersat different levels of organization

BIOACCUMULATION: low water pollutant concentrations may be concentrated in biological structures

Cd

Cl

Biota

Cells

Cellular structures

MOLECULAR AND CELLULAR BIOMARKERS

- Quick responses that precede answers at higher levels of biological organization

- Quantitative and qualitative relationships between exposure and biomarker response

* DEFINITION: alterations at the molecular or cellular level that indicate exposure to

contaminants and/or injuries induced by them (McCarthy & Shugart, 1990)

BIOMARKERS ARE APPLIED ON SENTINEL SPECIES

CELLS AND TISSUES UNDER STUDYThose showing high exposure to pollutants, accumulation rates and responsiveness to

pollutants

LiverGillsDig. glandGonads

SAMPLING STRATEGIES

Shipyard

River coming from Gernika city

** *

*

* Sampling points

STRATEGIES: ANIMAL TRANSPLANT

ANALYSIS OF PROTEINS THAT SCAVENGE SPECIFIC POLLUTANTS OR THAT CHANGE

THEIR ACTIVITY UNDER EXPOSURE

* Organophosphorous pesticides inhibit brain Acetylcholinesterase

* Organic pollutants induce enzymes of the detoxification system (CYP450)

* Metals induce Metallothionein synthesis in cells to sequester them

ST MT 1 2 3 C 1h 1d 7d det Cod Cod Turbot

14.4 kDa

MT

-lev

el(a

.u.)

6

4

2

1 h 1 d 7 d Detox.

Control0.01 ppm Cd

0.1 ppm Cd

QUANTIFICATION OF METALOTHIONEIN LEVELS

* ORGANOTINS inhibit aromatase activity

IMPOSEX, INTERSEX

Aromatase

Testosterone Estradiol

Antifoulingpaints

TBT

IMPOSEX IN THE DOGWELK

Progression of vas deferens and penis growth in a female dogwelk

POLLUTANTS ACCUMULATE IN LYSOSOMES

* Induce changes in the structure of lysosomes

LSC - FIELD STUDY Aegean Sea / Biscay Gulf

LIMANI MUSKIZ

OLYMPIADA PLENTZIA

Polluted site

Reference site

PEROXISOME PROLIFERATION

Normal rat liver Treated with PP

PEROXISOME PROLIFERATORS

Hypolipidemic drugs and other therapeutic agents

Herbicides Plasticizers

Steroids Solvents and lubricants Food flavors

Natural products

Crude oils and petroleum

products

ENVIRONMENTAL ESTROGENSChemical substances that mimic female sexual hormones

* Alter sex ratios of wild populations* Impair reproductive performance

Normal testis Intersex testis

VITELLOGENIN IN FISH a biomarker of endocrine disruption

Male fish exposed to environmental estrogens express Vtg

LiverFemale gonadE2

Vtg2

1