Organics Flashcards
What is different about Organic chemicals and metals?
- Non-radioactive metals
- Trace Metals
- Synthetic organic compounds
Non-radioactive metal traits
Can be transformed but not broken down to “inert substances” (not reactive)
Metabolic products of org. chemicals
- Mostly transformed to benign products
2. Rarely, more bio reactive and potentially toxic than parent compounds
Organic compounds
- Some are essential (AA, lipids, vitamins)
- Many metals have dissolved in seawater that are essential for some organisms
- Many are liphophilic
- End up in fatty tissue
Trace metals
Trace metals in ocean do not volatize from the ocean
- important process leading to transportation of POPs
- Exception- Hg and some metalloids
- high assimilation that gets built up food chain
What makes org contaminants marine pollutants?
- High bioaccumulation potential
- Low aqueous solubility (water dissolving)
- Small enough to pass membranes - High specificty or active sits of enzymes/receptors at membranes
POP’s are not drinking water pollutants
- Limited solubility
- water minor introduction - Absorb to soils, reducing concentration
- Want to stick to solids
- High Kd values
Biomagnification
- Increase in conc. of contaminant as you move up the food wed
- To biomagnify… org chemicals have to be hydrophobic and stable to transformations
- Chemical contaminant levels increase with age - Low excretion rates
Components of crude oil
Paraffins (alkanes) (least soluble)
Naphthenes (Cycloalkenes)
Mono-aromatic compounds and 2-ring naphthalene
Cyclic, often aromatic aromatic compounds that possess elements other than C and H are referred to as hetrocylci compounds
Halogens (I, Br, Cl, Fl)
Important in affecting likelihood org chemicals to be marine pollutants
Bonds are harder to break
Make more hydrophobic
Freons (Fluorines)
- C-Cl bond only broken in stratosphere
- Stable in the ocean
- Serves as oceanic water mass transport tracers
Modern pesticides
have H bonds with O,N,S
- Hydrogen bonding with water
- More soluble
- Less volatilization from water
- More persistent
Pyrethoids
-More hydrophobic
-More likely to accumulate in solid/sediment
Type 1— easily degradable
Type 2— Stable in env.
*Chrysanthemum
Brominated
Flame retardant
Persistent Organic Pollutants
- Stable molecules (persist for long)
- Transport via wind (long range)
- Can accumulate in organisms (biomag.)
- Pose risk to human health and env.
Stockholm Convention
Over 90 countries promise to reduce POP use
-info made to public, education, research, monitoring
Dirty dozen
Aldrin, Chlordane, DDT, Dieldrin, Endrin, Heptachlor,
Hexachlorobenzene, Mirex, Toxaphene, PCBs,Chlorinated dioxins and furans
**Polychlorinated hydrocarbons
-Stable
-Do not degrade to less toxic forms
-Low solubility in water
-Soluble in fats and lipid membranes
Octanol-water partition coefficient (Kow)
-Ratio of con. of chemical in octanol divided by conc in water
High Kow= higher bioaccumulation
Indicate how hydrophobic
*** Provide indication of tendency to accumulate in tissues
Fukushima
20k people died from explosion but none from radiation
Released 100 mill radioactivity
-Iodine
-Cesium (also naturally abundance in seawater)
Sampling radioactivity of fukushima
Used Zooplankton and anthropogenic radioisotopes
Iodine
I131- 8 day half life
1 year after- none left
I127- stable
present concentrations
Cesium
- Much longer halflife of 30 or 2.1
- Non-essential for all org.
- Higher uptake in freshwaters closer to land
- Modest mag in food chain (low in water high in food)
- Highly assimilated in fish (muscles)
Pesticides
Kill potential disease causing organisms and control insects, weeds, and other pests
- Enters surface waters through leakage, spills, runoff
- Highest concentrations at coast
DDT (pesticide) properties
Used for agriculture and mosquito control
- Stable and persistent
- —When sprayed, its there for decades
- Semi-volatile
- Low aqueous solubility
- —Soluble is oil and fat
- Bioaccumulates
POP Migration process
Sprayed at low lat areas and disperses to high lat areas cia wind
Effects of POP in animals
Effects on nervous system, and immune systems
Toxic to many aquatic invertebrates
Shell thinning
Competes with estrogen for binding at receptor leading to sexual impairments
DDT in mosquito control
- Long-acting
- Cost-effective
- Sprayed on walls
- Reduces survival if mosquitos come into contact
Nuclear energy
- Small waste generated
- Radioactive fuel source
- Generates almost no CO2
- Cleanest fuel
Alpha particle (He nuclei)
-Large and easily stopped
-Deadly if ingested
-Collides with DNA that can lead to mutations and cancer
Abundant in Polonium (found in soil by tobacco)
Beta rays
Travel faster, further, easily deflected (x-rays)
Primordial radionuclides
residues from big bang. Looong half lives 40K most important -Significant source of radioactivity - Essential for all living org -Common in oceans -Most radioactivity in seawater Uranium and Thorium (stable) U- heaviest naturally occurring ---Doesn't stick
Cosmic rays
High energy atomic nuclei
Produce radioactive nuclei- 3H and 14C
Transuranics in radioactive waste
Man-made elements released through nuclear weapons testing
Neptunium- just exist
Plutonium- BIG deal. Extremely toxic. 2nd most toxic substance, causes cancer.. Long half-life
Americium- Very toxic
How to get rid of waste
- Stick under land
- Under ocean floor
- Into space
- Convert to non-radioactive
Site of disposal
Isolated from living things Not near natural disaster areas Not near water Cannisters -- If escaped from cannister, would stick to sediment
Radioactivity input into oceans
All from nuclear testing. Small amount from dumping
Weapons testing
Input Uranium and Plutonium
- Entered as fallout
- Plutonium has a HL of 24.4k years
Petroleum hydrocarbons
Refined or crude oil
Has chemical, physical and biological properties
Aromatic Hydrocarbons
Fewer rings = lower weight = solubilize most in seawater- quickly volatilized- easily degraded = more toxic
PAH’s
More persistent
Very low water solubility
Linked out outbreaks of cancer in aquatic species
Oil spills
Sudden release of large volumes of oil
Persistent in sediments and shores
Process of break down
Enters water..
Evaporation - dispersion - dissolution - oxidation - emulsification - spreading
Tar balls
Form on beach
High mol. weight hydrocarbons- toxic
Form after oxidation by light
Mousse turns into tar balls after further photoxidation
Fate of oil spills
Contaminants will seep through beach
Not easily degraded/ cleaned
Acute Effects of oil
Accumulation in membranes affecting function
oiling on surfaces
death
narcosis
Chronic Effects of oil
reduced feeding, growth, reproduction
behavioral deficits
genetic damage and carcinogenesis
reduced immune function
Clean up efforts
Booms and skimmers to contain/ collect
Dispersants
Controlled fires
Dispersants
PRO
One end attracted to water, the other oil. Helps the oil break down
Minimize exposure of oil slicks to animals
CON
Negative affects to marine organisms
Bioaccumulation
Marine snow
Eutrophication
- Excess in nutrients (N ad P) from run off from agriculture/ industries.
- Increase in dense plant growth - no oxygen so death
- –See an increase in phytoplankton = strip oxygen = release bacteria that chews up organic matter.
- See altered trophic interactions, inc. mortality/growth of fish, toxic blooms.
Michaelis-Menten
predict the rate of product formation in enzymatic reactions for more than a century.
Water Treatment
Reduce O2 in water
Remove pathogens
Remove solids
Remove N and P
