Course Goals

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Introduction
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Course Goals

• To introduce the scope, concepts, and methods of
  the study of ecotoxicology
• To develop the principles in ecotoxicology
• To grasp recent environmental issues

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Expectations

• Be very quantitative
• Analytical
• Use of principles to address applied problems
• Broad views of environmental issues

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Contents

• Introduction, major classes of pollutants
• Entry and fates
• Bioaccumulation
• Biological monitoring, toxicity testing
• Biochemical, physiological effects

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Contents

• Population, community, ecosystem responses
• Biomarker study
• Water and sediment quality criteria
• Contaminated sediments

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Early ages of toxicology (I)

• Heavy metal poisoning in Japan
• Minamata disease in the 1950s (Minamata Bay)
• Itai-Itai disease in the 1940-1960 Cd in rice
  (ouch-ouch joint pain).

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W. Eugene SmithTomoko Uemura in Her
BathMinamata, 1972
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Early age of toxicology (II)

• Nuclear bomb and testing 1960s.
• Radionuclide discharge 137Cs, 131I
• Pesticides DDT, DDD, DDE (shell thinning of
  birds eggs). 

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More recent issues

• Chernobyl accident in 1986 301 million Ci
• Nuclear testing, weapons catch our news lines
  (middle east, Asia, Korea, etc).
• TBT antifouling agents
• Hg in fish and game
• Agricultural drainage of Se in California
• Pb in gasoline and household
• Exxon Valdez oil spill

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April 25th -26th, 1986

• Good evening, comrades, all of you know that
  there has been an incredible misfortunethe
  accident at the Chernobyl nuclear plant. It has
  painfully affected the Soviet people, and shocked
  the international community. For the first time
  we confront the real force of nuclear energy, out
  of control.
• Soviet President, Mikhail Gorbachev

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Exxon Valdez oil spill, 1989
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Consequences

• Legal
• 287 million for actual damages and 5 billion
  for punitive damages (single year's profit by
  Exxon)
• Environmental
• Thousands of animals died immediately the best
  estimates include 250,000 sea birds, 2,800 sea
  otters, 300 harbor seals, 250 bald eagles, up to
  22 orcas, and billions of salmon and herring
  eggs.
• Effects felt today. Reductions in population have
  been seen in various ocean animals.
• Some shoreline habitats could take up to 30 years
  to recover.

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Issues in Hong Kong (news line)

• Dioxins (Penny Bay-Disney Land).
• Land reclamation (dredging).
• Hg in fish
• Air Pollution
• Red tides
• Contaminated sediments
• East river (drinking waters)

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• 50 Mm3 of sediment unacceptable contaminated
• and require dredging (Dawes 2001)

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New chemicals

• Brominated fire retardants
• Synthetic estrogens
• Antimicrobial products
• Personal-care products

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Ecotoxicology

• Introduced in 1969, ecology and toxicology
• More environmentally relevant

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Definition of Ecotoxicology

• Ecotoxicology is the science of contaminants in
  the biosphere and their effects on constituents
  of the biosphere, including humans.
• the study of harmful effects of chemicals upon
  ecosystems.

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How is harm?

• harmful to one species may not be harmful to
  another
• different levels (biochemical, organismic,
  ecosystem) will have different harmful effects

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Status

• We are practically doing experiments using human
  as subject.
• Outcome remains to be seen (but probably not very
  promising).

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Different biological levels

• All relevant levels should be considered. This
  is one exciting feature of ecotoxicology.
• Caswell (1996) Processes at one level take their
  mechanisms from the level below and find their
  consequences at the level above.

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Blood
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Three aspects of study

• Scientific goals knowledge-based development,
  including observations and experiments
• Technological goals analytical techniques,
  biomarker, biomonitors, etc
• Practical goals management issues, water quality
  criteria, standards

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Recent development

• Move from analytical measurements (the
  concentrations) to the establishment of their
  effects at different biological levels.

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Environmental Contaminants

• Pollutants a substance in part as a result of
  mans activities, and which has a deleterious
  effect on living organisms.
• Contaminant a substance released by mans
  activity (not necessarily adverse effect).

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Environmental Contaminants

• Xenobiotics a foreign chemical not produced in
  nature and not a constitute component of a
  specified biological systemusually applied to a
  manufactured chemical.
• Stressor produce a stress, a response to a
  recent disorganizing or detrimental factor.

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Classes of Contaminants

• Metals and metalloids
• Nutrients
• Organic pollutants
• Organometals
• Radionuclides

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Metals/metalloids

• http//www.dartmouth.edu/toxmetal/RS.shtml
• Human activity contributes to metal
  input---anthropogenic enrichment factor (Table )
• Heavy metals density gt5, less often used
  nowadays.
• Trace metals in trace amount, ltppb levels.

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Classification of metals

• Based on chemistry (Nieboer and Richardson 1980).
• Affinity
• Class A like to bind with O-
• Class B like to bind with S-
• Borderline in-between

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Essentiality vs. non-essentiality

• Essential Fe, I, Cu, Mn, Zn, Co, Mo, Se, Cr, Ni,
  Si, As.
• Non-essential Cd, Hg

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Metals in proteins
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Metal production in the US
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Metals in sediments Hong Kong
LCEL 65 mg kg-1
UCEL 110 mg kg-1
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Metals in contaminated bay
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Different metals (I)

• Al Second most abundant metal in Earth crust.
• As metal alloys, pesticides, wood preservative,
  plant desiccants, herbicides.
• Cd alloy product, electroplating, galvanizing,
  batteries, Zn by-product.
• Cr alloys, pigments, catalyst, wood
  preservatives, product tanning.
• Cu wiring, electronics, plumbing.

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Different metals (II)

• Pb gasolines, batteries, solders, pigments,
  piping, ammunition, paints, ceramics.
• Hg electronics, dental amalgam, chlorine-alkali
  product, gold mining, paints.
• Ni stainless steel, plating, battery.
• Se electronics, glass, pigments, alloys, mining
  by-product.
• Zn coating, galvanizing.

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Nutrients N, P.

• N fertilizer, P fertilizer. Eutrophication

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Organic compoundscontaining carbon

• Oils
• PAHs
• PCBs
• Organochlorines
• gt200,000 xenobiotics

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Oils

• Gas, liquid, or solids.
• Low water solubility, high in organic solvents.
• Sources deposits of petroleum and natural gas
  (fossil fuel), oil spillage.

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Oils

• Alkane (saturated) stable, unreactive, CnH2n2,
  nlt4 as gas, n5-17 as liquid, ngt18 as solid
• alkenes (unsaturated, double bond), alkynes
  (unsaturated triple bond) more reactive, lower
  members as gases, higher as liquid and solid.
• Aromatic hydrocarbon more reactive, susceptible
  to transformation

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Polycyclic aromatic compounds (PAH)

• Incomplete combustion (burning), 2-6 rings
• From human activity or natural conditions

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Polychlorinated biphenyls (PCB)

• A total of 209 congeners, Cl content.
• Synthetic compounds, very stable, high molecular
  weight, low vapor pressure, low water solubility,
  and high stability
• Used for dielectric fluids, heat transformer
  fluid, lubricants, vacuum pump fluids, etc. Now
  banned in most countries.

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Chlorinated phenols

• Wood preservatives (TCP) and fungicides (PCP).

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Organochlorine pesticides/insecticide

• DDT, DDD, DDE (now dominated by DDD, DDE due to
  the bans of DDT and the metabolism/degradation of
  DDT).
• Stable solids, limited vapor pressure, low water
  solubility, high lipophilicity.
• DDT World War II as vector control, then as
  disease and insecticide. Causing egg shell
  thinning.

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Chlorinated cyclodiene insecticides

• aldrin, dieldrin, heptachlor after DDT, high
  toxicity, persistence.
• 1990 mostly banned for DDT and cyclodiene, but
  they are still detected in the environment due to
  their persistence.

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Dioxins

• Polychlorinated dibenzodioxins (PCDD) and
  dibenzofurans (PCDF) dioxins.
• 75 possible congeners of PCDD
• by products from synthesis of other compounds, or
  combustion of PCBs /bleaching, or interaction of
  chlorophenols during disposal of industrial
  wastes.
• Chemical stable with low water solubilities (lt1
  ?g/l).

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Organophosphate (OP) insecticides

• Derivatives of orthophosphoric acids, inhibit
  acetylcholine esterase activity (nerve function)
  as a neurotoxin.
• Parathion, High water solubility. Less stable
  than organochlorine insecticides. Toxicity is
  thus short term acute toxicity.
• OPs are still applied to crops as sprays,
  granules, seed dressing and root dips to control
  parasites, and pests.

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Polybrominated biphenyls (PBB)

• Bromine atoms replace the Cl
• Similar property as PCBs, as fire retardants and
  added to hard plastics/TV/electronic plastics

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Detergents

• Both polar and non-polar characteristics.
• Anionic permanent negative charge
• Cationic permanent positive charge
• Non-ionic no permanent charge, weakly
  electropositive and electronegative. 
• Domestic and industrial uses.

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farmed
supermarket
Hites et al. 2004, Science
wild
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wild
supermarket
farmed
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Organometallic compounds

• Organolead antiknok additives to gasolines
• Organomercury
• Organotins (TBT)

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Radioisotopes

• Background radiation (natural).
• Human made for nuclear weapons, power stations,
  etc.
• Half-lives of radioisotopes
• Closely related to the biochemistry 137Cs
  follows K behavior, 90Sr follows Ca behavior,
  131I concentrated in thyroid gland and may lead
  to thyroid cancer.

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Emerging contaminants of concerns (COC)

• Newly released/discovered by advanced analytical
  technique, or transformed chemicals
• brominated diphenyl ether (PBDE) as flame
  retardants (foams)
• perfluorooctane sulfonates (PFOS) refrigerants,
  surfactants, paper coating 

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