Yasen Nikolov, Duc Do

&Petar Mitev

That’s the accumulation of a toxin, or organic compound in organism over time period.

could enter the body through inhalation, food intake, skin etc.

-bioconcentration – specific case of bioaccumulation – through (in a) water

-can be the accumulation of a substance that is not toxic, but the body is taking more of it than it can use up

Accumulation of a substance only through contact with water

Example:

Fish living in a river

fish cannot express the hormones

Pharmaceutical wastes contamination

(such as human hormones)

the body of the fish contains more

hormones than the surrounding water

the increase of the concentration/accumulation of a substance in the body of an organism

the concentration increases as large animals eat many small animals that have that substance (little by little = BIG)

this results a larger concentration of that substance in the body of the larger animal

the substance is often absorbed by the tissue of the organism

Concerns substances that can not be naturally degraded

Usually about substance that are toxic or harmful (Not always)

Difficult to be thrown out of the organism due to weak water-solubility

2,3,7,8-Tetrachlorodibenzodioxin It is herbecide used in the Vietnam War It indirectly afects theDNA It is anti-estrogenic to women and

estrogenic to men It could couse oxidative stress and

endocrine disruption. It was found in Victor Yushchenko who

had 50, 000 times the amount usualy found in human beings.

colorless chemical pesticide, used to eradicate disease-carrying and crop-eating insects

1874 – first isolated in Germany 1939 – first recognized as a potent nerve

poison on insects used heavily in World War II for preinvasion

spraying

In India – reduced malaria from 75 million cases to fewer than 5 million cases in a decade

Crops and livestock sprayed with DDT sometimes as much as doubled their yields

1962 – started growing suspicions that it causes reproductive disfunctions

Some insect pests also gradually developed DDT-resistant strains

1973 – banned in the U.S. except for use in extreme health emergencies

Chemical Properties: Organochloride  highly hydrophobic,

colorless, crystalline solid with a weak, chemical odor

nearly insoluble in water but has a good solubility in most organic solvents, fats, and oils

Effects Persistent organic pollutant Strongly absorbed by the soil Quickly absorbed by organisms in aquatic ecosystem Its breakdown products and metabolites, DDE and

DDD, are also highly persistent and have similar chemical and physical properties

DDT, DDE, and DDD magnify through the food chain, with apex predators such as raptor birds concentrating more chemicals than other animals in the same environment

Stored mainly in body fat very resistant to metabolism

Man-made organic compound – chlorinated hydrocarbon

Used in many industrial and commercial application

Toxic to living organisms Specific qualities of the compound made

it very useful in the industry

High thermal and chemical resistance Can’t be broken down through natural

conditions – heating and chemical reactions

The chemical remains in the environment Travel large distances Slightly dissolves in water and be stored

into the sediment Stays in the soil where it can be

consumed by worms

Worms => Small fish => Large fish => Mammals/ Birds

This causes the amount of PCB in the fat of the different organisms to increase

Can cause – aches, rashes, liver damage, anemia, stomach/thyroid glands injury

Weaker immune system and behavioral alternations, reproduction system weakened

Most feared damage – can cause cancer in human beings

October 1968 Epidemic of a disease similar to

chloracne Fukuoka-Ken, Japan Soon after the outbreak – a team

assembled to investigate Cause of the epidemic – contaminated

rice oil Poison = PCB, Disease = Yusho (“Oil

disease”)

Used to extinguish forest fires In production of textile and electronic

devices. In 1999 North American industry used

around 34,000 metric tons of PBDEs. IT is harmful to humans It was found in people all over the world. In 2008 polybrominated diphenyl ethers

were banned because it was found to be bioaccumulated in breast milk. Almost every human on the planet have consumed flame retardants

Radioactive materials

Mercury

Humanity and the top of the food chain.

Trough the food chain bioconcentration rises.

When eating a predator human can consume bioconcentration of 100kg of plankton in one meal and even more. http://www.cartoonstock.com/lowres/

sea0179l.jpg

That means that the biggest victim of the pollution is us.

Barbalace, Roberta C. “The Chemistry of Polychlorinated Biphenyls.” &#1045;nvironmental &#1062;hemistry. J.K. Barbalace, inc., 2010. Web. 14 June 2010. <http://environmentalchemistry.com/// pcb.html>.

Masanori Kuratsune, et al. “Epidemiologic Study on Yusho, a Poisoning Caused by Ingestion of Rice Oil Contaminated with a Commercial Brand of Polychlorinated Biphenyls*.” National Center for Biotechnology Information . N.p., Apr. 1972. Web. 14 June 2010. <http://www.ncbi.nlm.nih.gov/// PMC1474867//-0115.pdf>.

Polychlorinated Biphenyl Chemical Structure. N.d. Science Leadership Academy. N.p., n.d. Web. 14 June 2010. <https://sci10bestq3bm.wikispaces.com/silver+class+%2709>.

Polychlorinated Biphenyls (PCBs). Environmental Protection Agency, 7 Apr. 2010. Web. 14 June 2010. <http://www.epa.gov/////.htm>.

"DDT." Microsoft® Student 2009 [DVD]. Redmond, WA: Microsoft Corporation, 2008.