Vajad kellegagi rääkida?
Küsi julgelt abi LasteAbi
Logi sisse

Dioxins and furans in the atmosphere (0)

1 Hindamata
Punktid
Dioxins and furans in the 
atmosphere.
  T h e i r   i m p a c t   o n   h u m a n s   a n d   n a t u r e .   E m i s s i o n   s o u r c e s
What are dioxines and furans?
The  term  Dioxin is  commonly  used to  refer  to a family of  toxic  chemicals that 
all  share  a similar chemical structure and a common mechanism of toxic 
action . Most dioxins and furans are not man­made or produced intentionally, 
but are created when  other  chemicals or  products  are made.  
This family includes:
seven  of the polychlorinated dibenzo dioxins (PCDDs), 
ten of the polychlorinated dibenzo furans (PCDFs) and
twelve  of the polychlorinated biphenyls (PCBs).

PCDD

2,3,7,8­TCDD

PCDF

PCB
PCDDs and PCDFs are not commercial chemical products 
but are  trace  level unintentional byproducts of most forms of 
combustion  and  several   industrial  chemical processes. Of all 
of the dioxins and furans, one, 2,3,7,8­tetrachloro­p­dibenzo­
dioxin (2,3,7,8 TCDD) is considered the most toxic.

PCBs were produced commercially in large quantities  until  
production  was stopped in 1977. 

Emission   sources
Dioxins are mainly produced as unwanted by­products of industrial processes and  there  is no intentional 
production or use. They can also to a small extent be formed naturally in forest  fires  or volcanic  activity
Examples of  activities  resulting in dioxin  emissions  are 
waste  incineration,
burning  fuels ( woodcoal  or oil), 
chlorine bleaching of  pulp  and  paper  and 
chlorinated pesticides  manufacturing
Burning of many materials containing chlorine,  such  as plastics and wood treated with pentachlorophenol 
also produce dioxins. 
According to a  study  in the  context  of the  Stockholm  Convention, the main sources for emissions of 
dioxins to air in EU­25 are
Residential  combustion (~ 30%)
Open  burning of waste (backyard burning) (~15%)
Wood preservation (~15%)
Iron  and  steel  industry (~ 8%)
Power  production, non­ferrous metals, chemical industry (~ 5% each)
Emissions in estonia
Tabel 2.1.2.2. Dioksi nide heitkogused Eestis aastatel 2004–
2008 (g I­TEQ) (18).
Al ikad
2008 %
Põletamine energeetikas  (fossi lsel kütusel töötavad 
45
elektrijaamad  jm)
Mittetööstuslik põletamine
34
Põletamine töötlevas tööstuses
11
Maanteetransport
1
Teised li kuvad saasteal ikad
0
Haiglajäätmete põlemine
0,5
Tööstusjäätmete põletamine
8
Why are dioxins a problem?
Dioxins are widely encountered toxic substances. They are  found  in all 
environmental compartments, are  persistent  and, being fat  soluble , they  tend  to 
accumulate in  higher   animals  ­  including   humans
Their resistance to degradation and semi­volatility  means  that they may be 
transported over long distances and give  rise  to trans­national exchanges of 
pollutants. In addition, dioxins which were released into the environment many 
years  ago are  still  contributing to  current   exposure .
Even  very small dioxin  concentrations  can  cause  negative  effects  on the 
environment and on human health, in  particular  on the most vulnerable groups 
like  children . Human health effects  include   impairment  of the  immune  system, 
the nervous system, the hormonal system and the reproductive functions. 
Dioxins are also suspected of causing cancer.
How Are We Exposed to Dioxins?
Although  formation of dioxins is local, environmental distribution is  global
Dioxins are found throughout the world in the environment. The  highest  levels 
of  these  compounds are found in some soils, sediments and food, especially 
dairy  products,  meatfish  and  shellfish . Very low levels are found in plants, 
water and air.
Most of us receive  almost  all of our dioxin exposure from the food we eat
specifically from the  animal  fats associated with  eating  beef,  pork , poultry, fish, 
milk, dairy products.
How can you be exposed to dioxins and  furans? 
You can be exposed to dioxins and furans by  eating contaminated food.  
Dioxins and furans
typically  stay  and  build  up in the fatty tissues of animals.  This means that 
eating beef, pork, poultry, fish as well as dairy products can be a source of 
exposure.   There are several sources of exposure to dioxins and furans.  If you 
work  in or near a municipal  solid  waste incinerator,  copper   smelter,  cement  kiln 
or coal fired power plant you can be exposed to dioxins and furans.  Individuals 
who  burn  their household waste or burn wood can be exposed as well.  Even  
forest fires can contribute to the  creation  of small amounts of dioxins and 
furans.
Dioxins and furans have been found in the air,  soil , and food.  Dioxins and 
furans are mainly distributed  through  the air.   However , only a small percentage 
of exposure is from air. Eating contaminated food is the  primary  source of 
exposure.
Impact on Human
Dioxins have been characterized as likely to be human carcinogens and are 
anticipated to increase the risk of cancer at background levels of exposure.
At  body  burden levels 10  times  or less  above  those attributed to  average  
background exposure,  adverse  non­cancer health effects have been  observed  
both in animals and, to a more limited extent, in humans. In animals these 
effects include  changes  in hormone systems, alterations in fetal  development
reduced reproductive  capacity , and immunosuppression. Effects specifically 
observed in humans include changes in markers of  early  development and 
hormone levels. At much higher doses, dioxins can cause a serious  skin  
disease in humans called chloracne.
What are the health effects of exposure to dioxins and furans?
Dioxins and furans can cause a number of health effects.  The most well  known  
member  of the dioxins/furans family is 2,3,7,8 TCDD. 
The U.S.  Environmental  Protection   Agency (EPA) has said that it is likely to be 
a cancer causing substance to humans.  In addition, people exposed to dioxins 
and furans have  experienced  changes in hormone levels.  High  doses of dioxin 
have caused a skin diseased called chloracne.  Animal  studies  show that 
animals exposed to dioxins and furans experienced changes in their hormone 
systems, changes in the development of the  fetus, decreased  ability  to 
reproduce and suppressed immune system. 
Impact on human health
Short­term exposure of humans to high levels of dioxins may  result  in skin lesions, such as 
chloracne and patchy darkening of the skin, and altered liver  function
Long­term exposure is linked to impairment of the immune system, the  developing  nervous 
system, the endocrine system and reproductive functions. 
Due to the omnipresence of dioxins, all people have background exposure and a certain level of 
dioxins in the body, leading to the so­called body burden. Current normal background exposure 
is not  expected  to affect human health on average. However, due to the high toxic potential of 
this  class  of compounds, efforts need to be undertaken to reduce current background exposure.
Sensitive subgroups
The developing fetus is most sensitive to dioxin exposure. The newborn, with rapidly developing 
organ systems, may also be more vulnerable to certain effects. Some individuals or groups of 
individuals may be exposed to higher levels of dioxins because of their diets (e.g., high 
consumers of fish in certain parts of the world) or their occupations (e.g., workers in the pulp 
and paper industry, in incineration plants and at  hazardous  waste  sites , to name just a few).
References
http://www.epa.gov/osw/hazard/wastemin/minimize/factshts/dioxfura.pdf
http://www.epa.gov/ttnchie1/le/dioxin.pdf
http://ec.europa.eu/environment/dioxin/index.ht m
http://www2.dmu.dk/1_viden/2_publikationer/3_fagrapporter/rapporter/fr565.pdf
http://www.epa.gov/osw/hazard/wastemin/minimize/factshts/dioxfura.pdf
http://www.epa.gov/pbt/pubs/dioxins.ht m
http://www.who.int/mediacentre/factsheets/fs225/en/

Document Outline

  • Slide 1
  • What are dioxines and furans?
  • Slide 3
  • Slide 4
  • Emission sources
  • Emissions in estonia
  • Why are dioxins a problem?
  • How Are We Exposed to Dioxins?
  • Slide 9
  • Impact on Human
  • What are the health effects of exposure to dioxins and furans?
  • Impact on human health
  • References
Vasakule Paremale
Dioxins and furans in the atmosphere #1 Dioxins and furans in the atmosphere #2 Dioxins and furans in the atmosphere #3 Dioxins and furans in the atmosphere #4 Dioxins and furans in the atmosphere #5 Dioxins and furans in the atmosphere #6 Dioxins and furans in the atmosphere #7 Dioxins and furans in the atmosphere #8 Dioxins and furans in the atmosphere #9 Dioxins and furans in the atmosphere #10 Dioxins and furans in the atmosphere #11 Dioxins and furans in the atmosphere #12 Dioxins and furans in the atmosphere #13
Punktid 5 punkti Autor soovib selle materjali allalaadimise eest saada 5 punkti.
Leheküljed ~ 13 lehte Lehekülgede arv dokumendis
Aeg2013-10-11 Kuupäev, millal dokument üles laeti
Allalaadimisi 4 laadimist Kokku alla laetud
Kommentaarid 0 arvamust Teiste kasutajate poolt lisatud kommentaarid
Autor mitokonder1 Õppematerjali autor
Their impact on humans and nature. Emission sources

Kasutatud allikad

Sarnased õppematerjalid

Formaldehyde
11
doc

Formaldehyde

alcohol) and carbon monoxide at very high temperatures. Formaldehyde is naturally produced in very small amounts in our bodies as a part of our normal, everyday metabolism and causes us no harm. It can also be found in the air that we breathe at home and at work, in the food we eat, and in some products that we put on our skin. A major source of formaldehyde that we breathe every day is found in smog in the lower atmosphere. Automobile exhaust from cars without catalytic converters or those using oxygenated gasoline also contain formaldehyde. At home, formaldehyde is produced by cigarettes and other tobacco products, gas cookers, and open fireplaces. It is also used as a preservative in some foods, such as some types of Italian cheeses, dried foods, and fish. Formaldehyde is found in many products used every day around the house, such as antiseptics, medicines, cosmetics, dish-washing liquids, fabric softeners,

Inglise keel
Aniliini riskianalüüs-eng
7
docx

Aniliini riskianalüüs (eng)

Tallinna tehnikaülikool Riski- ja ohutusõpetus keemiatööstuses Referaat: Kemikaali riskianalüüs Aniliin Õppejõud: Karin Reinhold Üliõpilane: Kood: 000000 Tallinn 2012 1. Introduction Aniline (also known as phenylamine or aminobenzene) is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. The largest application of aniline is for the preparation of methylene diphenyl diisocyanate. The majority of aniline serves this marke

Riski- ja ohuõpetus
Alcohol
5
doc

Alcohol

ALCOHOL Alcohol is a widely used substance for both science and in technology. Its name comes from an Arabic word al-kuhl meaning " a powder for painting the eyes". The term was later applied to all compounds that contain alcoholic spirits. To most people alcohol is considerd a downer that reduces activity in the nervous system. Some of the things alcohol effects you is, the alcohol intoxicated person exhibits lose muscle tone, loss of fine moter coordination,and often has a staggering "drunken" gait. The eyes may appear somewhat "glossy" and pupils may be slow to respond to stimulus. At high doses pupils may become constricted. At intoxing doses, alcohol can decrease heart rate, lower blood pressure and respiration rate, and result in decreased reflex and slower reaction times. Skin may be cool to touch but to the user may feel warm or normal, profuse sweating may accompany alcohol use. Loose muscle tone, lose of fine motor coordination,odor of alcohol on the breath,a

Inglise keel
Thoughts on Air Pollution Essay
6
docx

Thoughts on Air Pollution Essay

Air pollution Every day, the average person inhales about 20,000 liters of air. Every time we breathe, we risk inhaling dangerous chemicals that have found their way into the air. Air pollution includes all contaminants found in the atmosphere. These dangerous substances can be either in the form of gases or particles. Air pollution can be found both outdoors and indoors. Pollutants can be trapped inside buildings, causing indoor pollution that lasts for a long time. The sources of air pollution are both natural and human-based. As one might expect, humans have been producing increasing amounts of pollution as time has progressed, and they now account for the majority of pollutants released into the air.

Inglise keel
Caffeine
3
docx

Caffeine

1 Caffeine 2 3 Caffeine (C8H10N4O2) is the common name for trimethylxanthine (systematic name is 1,3,7- 4 trimethylxanthine or 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione). The chemical is also 5 known as coffeine, theine, mateine, guaranine, or methyltheobromine. Caffeine is naturally 6 produced by several plants, including coffee beans, guarana, yerba maté, cacao beans, and tea. 7 For the plants, caffeine acts as a natural pesticide. It paralyzes and kills insects that attempt to 8 feed on the plants. The molecule was first isolated by the German chemist Friedrich Ferdinand 9 Runge in 1819. 10 When purified, caffeine is an intensely bitter white powder. It is added to colas and other soft 11 drinks to impart a pleasing bitter note. However, caffeine is also an addictive stimulant. In 12 humans, it stimulates the central nervous system, heart rate, and respiration, has psychotropic 13 (mood altering) p

Inglise keel
Biogas – The source of future energy
26
docx

Biogas – The source of future energy

outhouses. Spontaneous fires and explosions caused by build-ups of gas have been recorded in many regions of the world, illustrating a major problem which needs to be confronted by waste management companies. When this gas is trapped, however, it can be made useful, instead of just being a nuisance. Trapped biogas can be used to power stoves for cooking and heating, in addition to other applications. By trapping the gases, people can prevent methane from reaching the atmosphere, thereby reducing degradation caused by methane gas. The ability to turn waste products into something which can be utilized is also rather convenient, especially in developing countries, where available resources may be limited. Furthermore, by turning biomass into biogas, people can address issues like sewage treatment, ensuring that raw sewage is not released into the natural environment. Producing process

Inglise keel
A short overview of veganism
18
pptx

A short overview of veganism

A short overview of veganism Veganism is both the practice of abstaining from What is the use of animal products, particularly in diet, and an associated philosophy that rejects the veganism? commodity status of animals. Eating vegan has a number of benifits that include: Why do Improving one`s health people go Helping the environment vegan? Saving the animals Our planeet is tumoil, humans are ailing in health, and animals are suffering everyday, but that can be fixed by simply going vegan, if you should be interested in contrbuting. So what? A vegan diet benifits everything and everyone on ? our planeet Simple changes in your diet and lifestyle can make a huge impact for yourself and the planeet we live on. Processed meat was rightfully demonized as contributing to rising cancer rates by the world

Inglise keel
Liha töötlemine
1168
pdf

Liha töötlemine

Handbook of Meat Processing Handbook of Meat Processing Fidel Toldrá EDITOR A John Wiley & Sons, Inc., Publication Edition first published 2010 © 2010 Blackwell Publishing Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Editorial Office 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book, please see our website at www.wiley.com/ wiley-blackwell. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. F

Inglise keel




Meedia

Kommentaarid (0)

Kommentaarid sellele materjalile puuduvad. Ole esimene ja kommenteeri



Sellel veebilehel kasutatakse küpsiseid. Kasutamist jätkates nõustute küpsiste ja veebilehe üldtingimustega Nõustun