Transcript Ecotoxicology

Ecotoxicology
• Ecotoxicological study is a multi-step
process, involving:
– The entry, distribution and fate of
pollutants within the environment;
– The entry and fate of pollutants in living
(biota) organisms within an ecosystem;
and
– The harmful effects of the chemical
pollutants on the constituents (biotic &
abiotic) of ecosystems (which include
man).
Beyond our toxin trail
Is the grave deeper than we thought?
Transport
and fate
Toxin
emitted
Ecosystem
effects
Community
effects
Metabolized
and/or stored
Ingested
Contacts
human
Population
effects
Reaches
an organ
Physiological
chain of events
Toxicology and Ecotoxicology are
similar but not identical
•
•
•
•
Toxicology
Ecotoxicology
Absorption Release into environment
Distribution Fate and disposition
Metabolism Metabolism
Elimination No counterpart
There are also differences.
Toxicology
Ecotoxicology
• Host defense
mechanisms
• Individual
susceptibility states
• Single effects
• Cumulative
exposure
• Bioaccumulation
• Bioconcentration
(in water)
• Biomagnification
• Never single
effects
• Movement
between media (air,
water)
Ecological bases of Ecotoxicology
• The basis for determining the effects of
contaminants on ecosystem is at
organism level
• At organism level, response can be:
– Acute toxicity causing mortality
– Chronically accumulating damage ultimately
causing death
– Sublethal impairment of various aspects of
physiology and morphology
– Sublethal behavioral effects
– Measurable biochemical changes
•At population level, response can be:
–Size and dynamics (based on birth rates, death
rates, gains, from immigration and losses from
emigration)
–Cause a reduction or an increase in the natural
flowchart of numbers, in the biomass, sex ratio, etc.
•At community level, response can be:
–species diversity
–predator prey relationship, etc
•Change in ecosystem
–nutrient cycling rates, patterns of nutrient flow,
–physical-chemical conditions etc.
Understanding ecotoxicology
Assessment of Structural Changes
changes in species / population structure
- appearance/disappearance of an
indicator species
- number of individuals of a species
- biomass of a species
- presence or absence of a species
Biomass-a quantitative estimate of the total mass of
living plant or animal materials
changes in community/ecosystem structure
-
biomass
abundance
biotic indices (e.g. trophic types)
species richness / diversity
dominance
food chain length/complexity
Chemicals of Ecotoxicological interes
• They are toxic and in many cases their
metabolites are also harmful e.g. DDT & DDE
(metabolite of DDT)
• They are very stable both chemically and
environmentally
• Their stability has lead to their persistence and
ubiquitous nature in the environment
• Almost all chemicals of ecotoxicologigal interest
are bioavailable and in most cases undergo
bioaccumluation and biomagnification (food
chain)
Chemical behavior and Bioavailability
Bioconcentration (from external
environment)
Bioaccumulation (from external
environment/food )
Biomagnification (at higher tropic level)
Bioavailabiltiy The fraction of a chemical
that is in an available form to an organism
e.g. fish: food, absorption from water
Bioconcentration - where the chemical
concentration in an organism exceeds the
concentration in the surrounding media (i.e.
aquatic environment) as a result of exposure
through the respiratory surfaces (i.e. gills/dermal
surfaces) - not food!
Bioconcentration Factor =
conc. in organism
conc. in ambient medium (usually water)
Bioaccumulation - where the chemical
concentration in an organism achieves a level
that exceeds that in the water/media as a result
of chemical uptake through all routes of
exposure.
Bioaccumulation factor = Conc. in organism
Conc. in food
(or ingested water)
•Bio-accumulation of Cd is higher than most
metals as it is assimilated rapidly and
excreted slowly
•depends on the rate of excretion
Biomagnification - where the chemical
concentration in an organism achieves a
level that exceeds that in the organism’s diet
due to dietary absorption. i.e. higher trophic
levels accumulate more chemical
Biomagnification Factor =
Conc. in predator
Conc. in prey
Factors that influence bioaccumulation
•Environmental persistence
•Lipophilicity
•Biotransformation
ECOSYSTEMS: Fate of Metals
• The ultimate compartment is the whole
planet but compartment can be
– individual organism or
– as small as single cells
– Or even organelles within a cell
• Metals are non-biodegradable
• However there is the formation and
degradation of organometallic
compounds e.g. MeHg,
Fate of Metals
• Certain metals are assimilated by
organisms to a greater extent than others
• Bio-accumulation of Cd is higher than most
metals as it is assimilated rapidly and
excreted slowly
• Bio-availability is another reason for a high
bio-concentration factor in that the
chemical in question may be more bioavailable
Fate of Metals
• pH is very important when it comes
to metal bio-availability
• Some metals e.g. Al is insoluble at
normal to slightly acidic pH but
below pH 4.5 its solubility increases
dramatically and becomes most
important responsible for fish kills
in acidified lakes
ECOSYSTEMS: Terrestrial
• Soils are contaminated
– by metals and radioactive isotopes
resulting from
• industrial, mining or other activity or
deposition from agricultural practices such
as application of
– metal-containing pesticides or
– metal-contaminated sewage sludge
– or wet or dry deposition from smelting
activity, lead-containing car exhaust,
atmospheric nuclear weapon testing or
accidents such as Chernobyl.
ECOSYSTEMS: Terrestrial
• Mobility of metals in soils is dictated
largely by
– clay content
– amount of organic matter
– pH
• In general the higher the clay and/or
organic matter content and pH, the more
firmly bound are the metals and the longer
is their residence time in soil
• Acid rain helps in leaching nutrient
(magnesium in European soil) from top to
lower soil (inaccessible to root system)
ECOSYSTEMS: Terrestrial
• Contamination of soils by radioactive
materials is largely due to nuclear
weapon testing (Australian and
Nevada deserts)
• Accident has also contributed to that
e.g. Chernobyl fallout outside the
former Soviet Union.
• When soils are contaminated
organisms living in soils are affected
ECOSYSTEMS: Aquatic
• The ultimate “sink” for metal is the ocean
but difficult to estimate effect on biota due to
massive dilution
• Effect of metals on biota is much felt in
estuaries especially those receiving water
from contaminated sites
• In estuaries the flow rate diminishes,
suspended sediments settled and dissolved
metals precipitated
• Contaminated water affect organisms living
in it
Biomarkers
A xenobiotically induced alteration in
cellular or biochemical components or
processes, structures, or functions that is
measurable in a biological system or
sample.
Types of Biomarkers
Biomarkers of exposure
Biomarkers of effect
Biomarkers of susceptibility
1. Biomarkers of exposure
Biomarkers of exposure include exogenous
chemicals, metabolites, or products of
interactions between environmental toxicants
and target molecules or cells that are measured
in a compartment within an organism (Travis,
1993).
Internal dosimeters1. measure the amount of a toxicant or its metabolite
present in cells, tissues, or body fluids. Ex.
urinary nitrophenol concentration used as a
marker for methyl parathion exposure.
2. account for individual differences in absorption
and bioaccumulation of the xenobiotic and are
relatively easy to measure.
The biologically effective dose is the amount of the
internal dose necessary to elicit a response or
health effect.
2. Biomarkers of Effect
Biomarkers of effect are measurable alterations
of an organism that can indicate a potential or
established health impairment or disease (Travis,
1993). These can include an alteration in a tissue or
organ, an early event in a biologic process that is
predictive of disease, a health impairment or clinical
disease, or a response parallel to the disease
process, but correlated with it, and able to predict
health impairment. Ex. the change in blood
cholinesterase activity after exposure to anticholinesterase organophosphorous pesticides.
Nonspecific
The induction of mixed function oxidase
The formation of DNA adducts
Sister chromatid exchange
Strand breakage
Porphyrin profile alteration
Induction of vitellogenin in oviparous vertebrates
Immunochanges (immunosupression,
hypersensitivity)
Biomarkers in order of decreasing specificity
Source: Walker et al. Principles of Ecotoxicology (2001) 2nd Edition [DUHS-P]
3. Biomarkers of Susceptibility
Biomarkers of susceptibility indicate individual factors
that can affect response to an environmental toxicant
(Bearer, 1998). They are indicators of inherent or
acquired properties of an organism that may lead to an
increase or decrease in the internal dose of the
xenobiotic or an increased or decreased level of the
response resulting from the exposure.
Genetic polymorphisms fall into this category of
biomarkers.
P450 1A1 induction
Decreases in conjugated enzymes
Inhibit the activity of immune system
Biomarker interpretation
 Species different-ex.P450 induction
 to integrate multiple chemical exposure across
an area with a variety of chemical contaminants
Relationship between biomarker and disease
pathology
To predict disease
To predict environmental and genetic risk
Toxic Effects
• The biochemical (molecular in nature) or
physiological (observed at organ and whole
organism levels) changes which adversely
affect individual organisms’ birth, growth
or mortality rates.
• Both biochemical and physiological
changes could lead to behavioral (whole
organism level) changes
Example
• The pollutant binding to a receptor
• Followed by biochemical response at
both cellular and organ levels
• Leading to physiological responses
• Finally, behavioral changes on the
individual leading to effects on the
population, community and the
ecosystem.
BEHAVIORAL EFFECTS:
– Migration,
– intraspecific attraction,
– aggregation,
– aggression,
– predation,
– vulnerability,
– mating
• Binding:
– Reversible vs. Irreversible binding
• Irreversible binding (covalent) causes harmful
effects.
• Types of bonding:
– Covalent > ionic > Hydrogen binding > Vanderwaals >
hydrophilic
• Biochemical responses:
– Biochemical response could be protective or nonprotective (may or may not cause harmful effect).
• Non-protective biochemical responses have
Carcinogenic, Mutagenic, Teratogenic and
Neurotoxic potentials.
• Protective biochemical responses:
– Monoxygenase (OCs and PAHs)
– Induction and binding to metalothionein (Cu,
Cd, Zn and Hg)
– Binding to blood plasma, bones and hair
(Metals and xenobiotics)
– Dissolving in fat (organics- e.g. OCs)
– Mineralization ( e.g. MeHg to Hg 2+)
– Demineralization (As to MeAs)
Protective biochemical response
• Heavy metals for example can be stored and
detoxified by organisms either by binding to
specific proteins e.g. metallothioneins (-SH
proteins)
• In some cases it is mineralized to inorganic
form, which is less toxic: e.g. Hg bound to Se
is a mineralized Hg (detoxified Hg: MeHg to
Hg). On the other hand, the inorganic form,
which is more toxic can be methylated to a
less toxic form e.g. As.
Protective biochemical response
PHASE 1 REACTION.
• Organic pollutants could also be metabolized and
detoxified by Cytochrome P450 enzymes
(Microsomal Monoxygenase; MMO).
PHASE 2 REACTION
• The metabolites undergo conjugation with
endogenous molecules e.g. GSH.
• For some chemicals the metabolites/conjugated
form are more toxic than the parent compound and
can lead to cancer formation.
Non-protective response
– Binding to DNA (DNA adduct)
– DNA Structural damage (strands break)
induced by genotoxic compounds
– Binding to SH-Protein (Protein adduct);
enzymes and proteins
– Nerotoxicity: prolongation of K and Na flow
and inhibition of AChE activity in the brain
Non-protective response
– Mitochondrial Poison (lost of proton
gradient)
– Inhibition of vitamin K cycle (competition
with vit K binding site)
– Inhibition of Thyroxine (competition with
thyrosine binding site)
– Inhibition of ATPase (enzymes for transport
of ions e.g. K, Na, Ca)
Non-protective response
• Environmental Estrogens (eg DDT) and
androgens (tributhyl Tin)
• Endocrine disrupters (binding to endocrine
receptors)
• Photosystems of Plants (interruption of
electron flow)
• Plant growth regulation
Physiological changes
Non-protective biochemical responses lead to
Physiological changes which could be
observed at organ and organism levels
• Organ level:
– accumulation of Cd in kidney, which could cause
cell death (cytotoxicity), resulting in dysfunction of
the kidney
– PAHs and Lung cancer
• Organism level:
– decrease in production (growth and reproduction)
– changes in gene frequency
– decrease in resources acquisition and uptake
Behavioral Changes
– Either or both physiological and biochemical
effects could lead to behavioral effects at
organism level– e.g. caring for young ones and avoidance of
predator.
Biochemical, Physiological and Behavioral
effects on the individual organism culminate
effects observed at the Population,
Community and Ecosystem levels.
Population Changes
• Changes in population may come about as a
result of direct changes in numbers of
individual organism and gene frequency
(resistance)
• By indirect means (decrease in
population of predators due to toxic
chemicals could lead to increase in
numbers of its prey).
Diclofenac residues as the cause of
vulture population decline in Pakistan.
Nature. 2004 Feb 12;427(6975):630-3.
• Diclofenac
causes kidney
damage,
increased serum
uric acid
concentrations,
visceral gout, and
death.
• Changes in community structure
– change in pyhtoplankton assemblage due to
eutrophication
– acid rain affecting microorganisms in the soil,
aquatic life
• Changes in Ecosystem level (earth as
an ecosystem)
– carbon dioxide increase
– ozone depletion
Some General effects of pollution on an
Ecosystem
• Decrease in the suitability of the abiotic
component as a habitat for the biotic
components of the ecosystem, which have
been naturally established and adapted to
that ecosystem
• Detrimental impact on part of the biotic
component (vulnerable species) as related to
the intensity and type of pollution
• Alteration to the community structure and in
most cases, there is a declined in the number
of species present
Some General effects of pollution
on an Ecosystem
• Matter and Energy flow within the
ecosystem changes
• Removal of larger organisms with longer
life spans
• The appearance of opportunistic species
with short life spans exhibiting large
population fluctuations in time and
space
What is an Endocrine
Disruptor ?
“An exogenous agent that interferes
with the synthesis, secretion,
transport, binding, action, or
elimination of natural hormones in
the body that are responsible for the
maintenance of homeostasis,
reproduction, development and/or
behavior. “
Mechanisms of endocrine disrupting
compounds
1) Binding and activating the estrogen receptor
2) Binding but not activating the estrogen
receptor (therefore acting as an anti-estrogen)
3) Binding other receptors
4) Modifying the metabolism of natural
hormones
5) Modifying the number of hormone receptors
in a cell
6) Modifying the production of natural hormones
Hormone regulation and feedback control
Estrogen levels depend on
Estrodiol serum-binding proteins
-fetoprotein (AFP)
Testosterone-estradiol binding globulin
Xenoestrogens (ex. DES)
100-fold lower affinity than E2 to these binding
protein
Bioavailability increased
Non-genomic mechanisms of ED
action
• Compounds of the azole type, such as
ketoconazole and the fungicide fenarimol,
inhibit these CYP isoforms and
consequently can also affect steroid
synthesis while the now-banned anti-fouling
agent tributyltin and its metabolites, which
have strong ED potential, are thought to act
by the same mechanism, probably by
inhibition of aromatase.
Genomic mechanisms of ED action
• bind to oestrogen receptors and so act as
pseudoestrogens in vivo, giving feminising effects
• tamoxifen and diethylstilbestrol) and industrial
chemicals (e.g. octylphenol and bisphenol-A
• fungicide vinclozolin binds competitively to the
androgen receptor (Shono et al., 2004), blocking
the cellular actions of testosterone on androgendependent tissue growth and behaviour patterns
• chlordecone, inhibit binding to the oestrogen and
progesterone receptors (Guzelia, 1982), whereas
bisphenol-A can block ligand binding to the thyroid
receptor
Timing, duration, and amount of exposure.
Organization vs. activation
Timing, duration, and amount of exposure are each
important determinants of the outcome. There are
windows of vulnerability during fetal development in
which small exposures to endocrine disruptors may
have profound effects not observed in adults.
Studies of the intrauterine position of mice during
fetal development show that slight fluctuations of
steroid hormone levels influence genital morphology,
timing of puberty, sexual attractiveness, sexual
behavior, aggressiveness, and activity level of
offspring.
Various Classes of EDCs
Flame Retardants
Fungicides
Herbicides
Insecticides
Metals
Pharmaceuticals
Phenols
Plasticizers
Polyaromatic
Hydrocarbons
Soy Products
Surfactants
Polybrominated diphenyl ether
Vinclozolin
Atrazine
Methoxychlor
Tributyltin
Ethynyl Estradiol
Bisphenol A
Phthalates
PCBs, dioxins
Genistein
Alkylphenol
Ethoxylates
PBDEs（多溴二苯基醚）
• Polybrominated diphenyl ethers (PBDEs)
are a class of recalcitrant and
bioaccumulative halogenated
compounds that have emerged as a
major environmental pollutant. PBDEs
are used as a flame-retardant and are
found in consumer goods such as
electrical equipment, construction
materials, coatings, textiles and
polyurethane foam (furniture padding).
Bioavailability of PBDEs
Found in animals
Increase in fish
Increase in whales
Sewage sludge
PCBs Found in Lake Washington
Fish (PBDEs next?)
Found in human (breast milk)
PBDEs Breast Milk - Sweden
(Norén and Mieronyté, 1998)
Health Effects of PBDEs
Similar to PCBs (Polychlorinated biphenyls)
PBT (Persistent Bioaccumulative Toxicant)
No human data
Animals studies indicate
Effects thyroid hormone levels
Neurobehavioral toxicity
Effects development - alters Behavior
Impairs memory and learning
Delays sexual development
Vinclozolin
• Vinclozolin is a fungicide that has been
shown to cause Leydig cell tumors and
atrophy of the accessory sex glands in
adult rodents. In addition, exposure of
rats during pregnancy causes a pattern
of malformations in the male urogenital
tract .
• Androgen receptor antagonist
Atrazine
• A chlorotriazine herbicide, is used to control
annual grasses and broadleaf weeds.
• suppression of the luteinizing hormone surge
during the estrus cycle by atrazine leads to the
maintenance of elevated blood levels of 17betaestradiol (E2) and prolactin.
• The mechanism for tumor development may
include one or more of the following: the induction
of aromatase (CYP19) and/or other P450
oxygenases, an antagonist action at the estrogen
feedback receptor in the hypothalamus, an
agonist action at the mammary gland estrogen
receptor or an effect on adrenergic neurons in the
hypothalamic-pituitary pathway.
雙酚Ａ
Bisphenol-A
BPA is used in the manufacture of
polycarbonate plastics and epoxy resins from
which food and beverage containers and dental
materials are made. Perinatal exposure to
environmentally relevant BPA doses results in
morphological and functional alterations of the
male and female genital tract and mammary
glands that may predispose the tissue to earlier
onset of disease, reduced fertility and mammary
and prostate cancer
聚氯乙烯（PVC）製的嬰兒固齒器、玩具
讓長牙的嬰兒咬玩的固齒器、洗澡玩的軟性玩具、價格不貴的流
行卡通玩具常常是PVC製品，在使用中可能釋出鄰苯二甲酸
（phthalates）這類有致癌性的環境荷爾蒙。
【安全替代品】仔細查看成分標示，凡是嬰幼兒可能放到口中把
玩的玩具一定選購PE（聚乙烯）製品。
苯乙烯 alkylphenol（烷基酚）
攤販、自助餐店、速食店的熱飲杯（裝湯、茶、咖啡）、泡麵的
碗麵及杯麵絕大多數都使用聚苯乙烯（polystyren）的塑膠容器，
簡稱為PS，被國人稱為保麗龍。保麗龍是全球環保界的頭痛產品。
其原料單体叫苯乙烯，是已知致癌物，且製造過程所添加的塑化
劑alkylphenol（烷基酚）也是會干擾內分泌的環境荷爾蒙，二
者在使用過程很容易溶出到食物中。
化妝品中的環境荷爾蒙
多數的化妝品、卸妝用清潔用品含有幾類的環境
荷爾蒙：
•壬基苯酚乙烯（一種非離子界面活性劑）
•鄰苯二甲酸（phthalates）
•烷基酚（alkylphenol）
Tributyltin (TBT)
三丁基錫是一種有機錫化合物，常被
添加於船舶油漆中，以防止貝類及藻
類附著於船身，由於具有殺菌效果，
所以也可以作為殺菌劑使用
受到三丁基錫或三苯基錫污染的雌岩螺，因生殖孔阻塞受
精卵無法排出，堆積在生殖管道內變紅變黑形成壞死組織，
此時長出陰莖的雄化作用也同時被引發
許多生物對有機錫的代謝能力低，在低濃度長
時間的污染下，負面效果即能呈現，有機錫累
積在食物階層頂端的鯨豚肝臟也普遍存在 (up
to 10 mg/kg) ，累積濃度在開發國家及近岸
種類較高，物種間因代謝能力的差異受有機錫
污染影響也不同，鑒於有機錫污染對海域生態
的威脅，全世界預計在2008年禁止三丁機錫做
為油漆添加物。
有機錫也是致畸胎劑，在北海核電廠附近
的畸形魚
核電廠為了保持進、出水口的暢通，避免
藻類或貝類攀附縮短壽命，所以在進、出
水口處塗抹劇毒「有機錫」，毒殺了近海
生態。
Phthalates鄰苯二甲酸酯
• 軟化劑，廣泛存在於化粧品、兒童玩具、
食品包裝中 。
• 聚氯乙烯PVC製品，在使用中可能釋出
鄰苯二甲酸
• male infertility
• Interfere with cholesterol uptake and
androgen biosynthesis
Alkylphenol（烷基酚）
• 保麗龍製造過程所添加的塑化劑alkylphenol
（烷基酚）也是會干擾內分泌的環境荷爾蒙
• disrupted reproduction in pikeperch
• In juvenile fish a decrease in the percentage
of males and an increase of intersex fish was
observed in relation to dose of NP and time of
exposure to this alkylphenol.
• Exposure of adult males to the NP led to the
reduction in fecundity, milt quality and fertility.
EDSTAC Tier 1 Assays
Concerned with detecting
•
•
•
•
•
•
•
Receptor binding assays (ER and AhR)
Uterotrophic
Hershberger
Pubertal female
Steroidogenesis
Frog metamorphosis
Fish reproductive screen
EDSTAC Tier 2
dose-response relationship
• Mammal development and
reproduction
• Bird development and reproduction
• Mysid shrimp life cycle
• Fish reproduction and development
• Amphibian development and
reproduction
Species-dependent sex determination
Mammal XY/XX
synthesis of testosterone/functional androgen receptors
estrogen receptor in the brain
Birds WZ/WW
The ability to synthesize and recognize 17-estradiol is
necessary for female CNS and gonadal sexual
development to occur
Reptile
temperature-dependent sex determination (aromatase
related)
Temperature-dependent sex determination
thermosensitive period (TSP)
Temperature
determines their
sex. A nest
temperature of
73.5 degrees
would develop
males. If it heats
up to 83.5,
hormones would
trigger changes
causing the
embryonic cells
to differentiate
as females.
III. Field studies
Manipulative
Observational (biomonitoring)
This sections looks briefly at the field of microcosm
and mesocosm toxicity testing.
Microcosms - laboratory systems that are
intended to physically simulate an ecosystem or a
major subsystem of an ecosystem. They are an
attempt to create systems that display ecosystem
properties while permitting control of conditions and
replication of treatments at reasonable cost.
There are two types of microcosms, assembled and
excised.
One of the more common assembled type is the aqutic
microcosm developed by Taub (see Suter, 1993). This
system consists of ten species of algae, five
zooplankters (cladoceran, amphipod, ostracod,
protozoan, and rotifer), and a bacterium in a defined
aqueous medium with serile sand sediment all contained
in gallon jar under fluorescent lights. The advantage of
the system is that it is standardized, similar results can
be achieved from different labs, researchers can
compare results with different chemicals, and the limited
and constant array of species makes it more likely that
the cause of observed responses can be determined
making it possible to model the ecosystem level
interactions for extrapolation to the field. However, they
are very much oversimplified.
Excised microcosms are segments of ecosystems that
have been removed from the environment as a unit or a
few units and placed in containers in the laboratory.
They contain natural assemblages of biota, natural
median and are more realistic. The are also less
amenable to quality control and to comparisons.
Examples include:
•Mixed flask culture - mixed culture of microbes and
microinvertebrates derived from one or more natural
communities and held in the lab.
•Pond microcosm - water, sediment, macrophytes, and
associated biota obtained from a shallow pond or the
littoral zone of a lake or slow-moving river
•Site-specific aquatic microcosm - large tank of
ambient water, a sediment core suspended in the water,
and associated biota
Mesocosms - outdoor experimental systems that are
delimited and to some extent enclosed.
These systems offer more realism than microcosms due
to their larger size and more natural physical conditions
but can still provide replication, control of chemical
exposure, and some control of biotic components.
Mesocosm studies are currently a requirement for
pesticide registration in the U.S. Mesocosms are also
either assembled such as artificial ponds and streams or
delimited such as limnocorrals and other enclosures of
portions of an ecosystem.
Biomonitoring
生物監測（Biomonitoring）在歐洲國家於20世紀
初首先使用藻類腐水指標系統監測水質，其後陸續
建立底棲生物及魚類指標監測方法。一般河川水質
監測只有分析水中理化參數，而忽略水中生物之存
在與否。Loeb及Spacie（1994）指出，水中生物
因長期生活棲息之水中環境，任何外來物質刺激
（Stress），他們首當其衝，故他們才是最佳環境
監測器。他們身體健康情況或存在與否，即是反映
水質好壞。
河川生物監測
藻類評估水質使用之方法為藻屬指數
底棲水生昆蟲使用之方法為科級生物指標及快速生
物評估法
魚類評估方法有魚類生物整合性指標法及魚類指標
法
An Index of Biotic Integrity (IBI) is a tool (index) which
we use to determine the health (integrity) of the fish
community (biotic) in a given river. Webster's defines
an index as "a ratio or other number derived from a
series of observations and used as an indicator or
measure". Biotic is defined as "of or relating to
life". And integrity is defined as "the quality or state of
completeness".
The IBI examines three components of the fish
community to determine its health. By knowing the
abundance (total number of fish), the diversity
(number of different species), and trophic (food chain)
interactions, we get an idea of how healthy the fish
community is in a given area.
Indicator species
A species whose status provides information
on the overall condition of the ecosystem and
of other species in that ecosystem.
Particular tolerant or sensitive to
environmental contamination.
Ex. Ephemeroptera, Plecoptera, and
Trichoptera
Biomarker responses to specific chemical
are well characterized
Accumulated environmental contaminants
未受污染水體中生存之生物指標
石蠅
扁蜉蝣
高身鏟頷魚
長鬚石蠶
流石蠶
網蚊
台灣鏟頷魚
錐螺
澤蟹
台灣間爬岩鰍
香魚
輕度污染水體中生存之生物指標
縞石蠶
雙尾小蜉蝣
台灣石
網石蠶
石蛉
水蠆
脂鮠
台灣纓口鰍
小裳蜉蝣
台灣馬口魚
中度污染水體中生存之生物指標
水蛭
平頷
大口螺類
大眼華
短吻鐮柄魚
姬蜉蝣
粗首
褐吻
虎
極樂吻 虎
嚴重污染水體中生存之生物指標
紅蟲
顫蚓
泥鰍
大眼海鰱
水蟲
大肚魚
吳郭魚
鱧魚
Example 1
• What will happen When Raw Domestic
Sewage from a Sewered Community of
40,000 people flows into a stream?
Ecological Risk Assessment
has three primary phases
Problem formulation
Analysis
Risk characterization
•Data required to conduct an ecological risk
assessment include the following:
•Toxicity to wildlife, aquatic organisms, plants, an
nontarget insects
•Environmental fate
•Environmental transport
•Estimated environmental concentrations
•Where and how the pesticide will be used
•What animals and plants will be exposed
•Climatologic, meterologic, and soil information