Module 5: Fate and Transport of Toxic Materials

enters the system by inhalation of vapors or by absorption of compounds through the skin after prolonged contact (type of mercury) attacks the liver and kidneys, sometimes brain e.g, ? factory workers, lab techs, dentists can be exposed

*inorganic* *metallic* mercury 17th century France, *Mad Hatter's Disease*

____________ likely to happen if: substance is taken up and eliminated via passive transport processes substance is metabolized slowly substance has low water solubility (hydrophobic) substance has high lipid solubility (lipophilic)

Bioaccumulation

What greenhouse gases have shown exponential increase since the Industrial revolution? (3)

Carbon dioxide (CO2) methane (CH4) nitrous oxide (N20)

an organochloride used because of its insecticidal properties

DDT

chemically related to PCBs and other chlorinated hydrocarbons, large group of chemicals with varying levels of toxicity the most dangerous one with no industrial usefulness; formed as an unwanted by-product in the production of certain herbicides can escape into the atmosphere when it evaporates from soil and water or when chlorine compounds are burned

Dioxins TCDD

T/F. Effects of acid rain are always greatest near the source of pollution.

FALSE

T/F. Incineration will destroy heavy metals (inorganic) such as lead.

FALSE

energy can neither be created nor destroyed, only change from one form to another

First Law of Thermodynamics

What main sources do PCB loadings in Lake Michigan come from? What are the effects?

Kalamazoo River 40-50 kg/yr atmospheric loadings 1536 kg/yr Fish advisories

Why don't water and oil mix?

Oil is nonpolar

Monsanto terminated production of _____ in 1977, but effects are still seen today, mostly affecting workers in the *occupational setting*

PCBs

most widespread chemical contaminant in the world; contained in tissues of all types of animals (especially fish)

PCBs

group of man-made compounds that were widely used in the past, mainly in electrical equipment, but were banned at the end of the 1970s in many countries because of environmental concerns

PCBs (Polychlorinated biphenyls) can enter the environment through many processes

What is the primary cause of acid rain?

SO2 (sulfur dioxide) emissions Affects both plants and aquatic life human health effects has a LOW pH

with every energy transformation there is a loss of usable energy; all physical processes cause the availability of energy to decrease

Second Law of Thermodynamics

T/F. Elemental mercury can vaporize and become an airborne toxic at room temperatures.

TRUE

What is the problem with current insecticides?

They break down slowly, not water soluble, so they accumulate in fatty tissues

fine soil or sediment particles may have surface charges that strongly bind to some chemicals, slowing or preventing access by an organism

adsorb

In the 18th and 19th century, what caused an increased interest in pest control methods?

agricultural disasters

may be aerobic or anaerobic are frequently found in soils where these chemicals have existed for long periods of time are made up of diverse groups of bacteria NOT capable of destroying waste wherever it is found

bacterial communities that effectively degrade anthropogenic compounds in soil

accumulation of substances in an organism

bioaccumulation

_____________ reduced for substances with extremely low water solubility, that are bound to particulate matter, or dissolved in organic matter

bioavailability

amount of a substance in circulation; if it's high then it can be easily transferred to an organism

bioavailability

life is dependent on recycling of INORGANIC materials from the ABIOTIC environment to living things --> then back to the environment

biogeochemical cycling

bacteria looking for carbon and energy sources by breaking bonds and through co-metabolization causes the transformation of one compound into a different one

biological degradation

a chemical that is not metabolized and is readily stored in tissues is passed up in the food chain and is further concentrated at each trophic level; (increase in concentration of chemicals)

biomagnification

occurs when the concentration of a substance in an organism exceeds the background concentration of the substance in its diet How does this happen? What type of environment?

biomagnification introduction into the trophic chain (compresses substance into a smaller area) aquatic environments

treatment that uses naturally occurring organisms to break down hazardous substances into less toxic or non toxic substances Stimulates growth of microbes to clean up organic chemicals in soil and water waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site

bioremediation

How is acid rain produced?

caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere *to produce other contaminants* reactions in environment change pollutant into something worse

In Woburn, Massachusetts in the 1960s, new wells were created. There was something wrong with the taste and smell of water -->

childhood leukemia cases --> determined the wells had a high concentration of TCE (industrial solvent) 200 parts per billion, well above 5 parts per billion

What are some of the health effects from bioaccumulation of PCBs? (6)

chloracne, liver disorders, miscarriage, low birth weight, abnormal multiplication of cells

Why is pesticide residue found in basically all living organisms?

chlorinated hydrocarbons are persistent, so they circulate through the ecosystem and travel long distances

What health outcomes are seen from dioxin contamination? (9)

cloroacne, interference with immune system, fetal toxicity, cancer, disruption of hormonal systems some species exhibit species-specific effects so far only minor effects seen in humans (muscle aches, digestive problems, psychiatric effects)

How do humans normally accumulate dioxin?

consumption of meat, fish, dairy

chemical bond that involves the sharing of electrons; the more electrons shared the stronger the bond __________ gain energy from breaking these bonds to derive more carbon

covalent bonds bacteria

below the surface there is some source --> stimulates bacteria --> bacteria will break down toxic compounds into less toxic substances

dechlorination (transformation)

process that transforms compounds and can be biological, chemical, or photochemical

degradation

inorganic compounds can be transformed but NOT ______________ *This has very important environmental implications because they will accumulate in the environment* What kind of material can't be transformed?

degraded metals

removes compounds from media; contaminant sticks to something or isn't stable in the solution so it is deposited

deposition depending on the medium: sedimentation atmospheric (wet or dry)

molecules spread out from each other as a function of temperature and time; relatively small in effects

diffusion

spreading and mixing caused by molecular diffusion and velocity of a moving fluid; causes lots of movement

dispersion

inorganic compounds containing metals and arsenic that had to be ingested; toxic to humans

early insecticides

all energy is moving toward an ever less available and more dispersed state

entropy energy transfer not 100% efficient

can evaluate at the global, continental, national, urban scale; soil, water, air

environmental compartments

How do fish become contaminated with mercury?

fallout from atmospheric mercury

Where might you expect to find a non-volatile, high molecular weight, organic (nonpolar) compound that a nearby factory is releasing into the water?

fish tissues

What are some health/land impacts due to climate changes from increased greenhouse gases? (8)

health- weather related mortality, infectious diseases, air quality illnesses agriculture- crop yields, irrigation demands, forest composition, health and productivity water supply, quality, competition for water coastal areas- erosion of beaches, species and natural areas- loss of habitat and species diminishing glaciers

Carnivores are more likely than plants to have ________ levels of mercury in their tissues

higher

compound that DOESN'T have carbon/carbon bonds; can't be changed as much

inorganic compounds

an atom in which the total number of electrons is not equal to the total number of protons giving the atom either a positive or negative charge

ion

a type of chemical bond that involves the electrostatic attraction between oppositely charged ions. These ions represent atoms that have lost one or more electrons and atoms that have gained one or more electrons

ionic bond

organic insecticides that act as contact poisons, broad spectrum killing anything they touch; leave a residue that causes them to break down slowly

later insecticides

Hg (mercury) to water: NOx (nitrogen oxides) emitted to air: Hg (mercury) to air: CFCs (Chlorfluorocarbons, industrial chemicals) to air:

local regional regional global

What types of molecules have higher volatility?

lower molecular weight, smaller, less inter-molecular bonding under HIGH vapor pressure

valuable constituent of many industrial processes and products; not harmful at low levels of exposure enters environment by coal combustion, mining and smelting of__________-containing ores, incineration of wastes, textile manufacturing, pharmaceutical production

mercury

In Minimata Bay in Japan, inorganic mercury waste was being dumped into waters where many earned their living fishing. What happened? *What type of poisoning did people get?

mercury converted to an even more toxic bacterium --> readily soluble and moved through the food chain --> increasingly concentrated at higher trophic levels --> towns people got METHYL poisoning from consuming lots of fish

Mercury poisoning of indigenous tribes in Peru occurred because _____________________

mercury poisoning from gold mining (utilize mercury to separate gold from mud)--> toxic levels of mercury dumped in Amazon rivers --> gets into food chain via fish --> serious health risk to children, neurological damage

Large quantities of chemical wastes are released into the air, water, and soil, but what prevents them from being toxic? (3)

most chemicals are diluted or decomposed, not persistent, not toxic at low levels

In dispersion modeling, what causes a fluid to take different paths? (3)

moving through different types of sediments/media, volume, area amount of mixing and where its transported depends on lots of factors

neutrally charged all around; non-volatile, high molecular weight

nonpolar compounds

compound that HAS carbon/carbon bonds; you can break them apart and turn them into new compounds

organic compounds

a lot more toxic than the inorganic kind; very soluble, penetrate membranes, circulate in the blood stream bound to red blood cells and gradually diffuses in the brain and destroys cells that control coordination

organic mercury

bioconcentrate in the kidneys --> biomagnify when consumed by a predator

organic mercury and cadmium

chemical compounds consisting of rings/chains of carbon atoms attached to chlorine, bromine, fluorine, etc.; includes many industrial chemicals and pesticides

organohalides, have a tendency to bioaccumulate can persist for decades because they don't break down

degree to which a compound will associate itself with different kinds of materials (salt into water nicely, it will avoid the oil) distribution of compounds based on polarity

partitioning

convert SOLAR energy into chemical bonds --> release oxygen during energy conversion making life possible

plants, photosynthesis

electrons distributed unevenly throughout compound structure --> they have positive and negative sides related to what other process?

polar compounds solubility- e.g., salt dissolves in water because H2O takes a positive sodium atom and will orient around it with negative side

difference in electrical charge between two ends of a compound

polarity

trace metal that occurs in some soils, becomes concentrated in the environment, and is a teratogen for birds

selenium

Why did an entire town have to evacuate Missouri in 1983 due to contamination from oiling roads for dust control in the 1970s?

soil analyses revealed high levels of *dioxin* contamination

What is the Agent Orange Exposure?

soldiers in Vietnam War exposed to herbicide (TCDD) used in clearing jungle vegetation

depends on how compounds interact at the surface

sorption (ad or ab)

What properties do PCBs have that make them useful in a variety of industrial settings, but also cause them to accumulate in the environment? (5)

stable substance with high boiling point high solubility in fat low solubility in water low electrical conductivity high resistance to heat

What types of insecticides are there? (3)

stomach poisons, contact poisons, fumigants (respiratory)

2 metals that are treated like calcium and bioaccumulate in the bones?

strontium and lead(don't magnify, but accumulate)

What potential climate changes can result from increased greenhouse gases? (3)

temperature increase sea level rise precipitation increase

In Minimata Bay in Japan, what health effects were seen from the inorganic mercury waste infiltrating fishing waters? (4)

teratogenic effects, neurological damage, some death, strange cat behavior

Why do many man-made ORGANIC chemicals accumulate in the environment?

they can't be broken down by biotic or abiotic processes

What is the quantity problem?

too many chemicals, too little data (at what conditions do wastes become a health/environmental problem)

involves mixing of compounds in environmental media

transport

when a molecule leaves a liquid phase and into a gas phase (vaporize)

volatilization

chemical compounds that are foreign to living systems

xenobiotics