1 e-learning module introduction to pops. 2 e-learning module to pops module 1 – overview of pops...

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E-learning moduleE-learning module

Introduction to Introduction to POPPOPss

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E-learning module to POPsE-learning module to POPsModule 1 – Overview of POPsModule 1 – Overview of POPs

► Overview of the course Overview of the course This module introduces POPs, with their properties and impacts upon health.This module introduces POPs, with their properties and impacts upon health.

► ContentsContents

What are POPs?What are POPs?List of POPsList of POPsGroupings of POPsGroupings of POPs

Group AGroup APropertiesPropertiesSourcesSourcesPOPs in the environmentPOPs in the environmentExposure risksExposure risksHealth impactsHealth impacts

Group BGroup BPropertiesPropertiesSourcesSourcesPOPs in the environmentPOPs in the environmentExposure risksExposure risksHealth impactsHealth impacts

Group CGroup CPropertiesPropertiesSourcesSourcesPOPs in the environmentPOPs in the environmentExposure risksExposure risksHealth impactsHealth impacts

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E-learning module to POPsE-learning module to POPs► Learning outcomesLearning outcomes

Understand what POPs are.Understand what POPs are.Gain an appreciation for properties of POPs and how this may reach a population.Gain an appreciation for properties of POPs and how this may reach a population.Appreciate the health impacts associated with various POPs.Appreciate the health impacts associated with various POPs.

► Pre-requisitesPre-requisites

NoneNone

► Follow-on CourseFollow-on Course

Module 2 - Risk AssessmentModule 2 - Risk Assessment

► Download the course as a pdfDownload the course as a pdf

► Related informationRelated information

Chapter 1 of the ManualChapter 1 of the Manual

► Approximate time for this moduleApproximate time for this module

45 mins45 mins

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E-learning module to POPsE-learning module to POPsIntroductionIntroduction

Persistent Organic Pollutants (POPs) Persistent Organic Pollutants (POPs) are chemical substances that:are chemical substances that:

► persist in the environmentpersist in the environment

► biomagnifybiomagnify as they move up as they move up through the food chainthrough the food chain

► pose a risk causing adverse effects pose a risk causing adverse effects to human health and the to human health and the environmentenvironment

► may travel long distances to regions may travel long distances to regions where they have never been used or where they have never been used or producedproduced

Consequently POPs pose threats Consequently POPs pose threats to the global environment.to the global environment.

Industrial wasteland potentially contaminated with POPs

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E-learning module to POPsE-learning module to POPsWhat are POPs?What are POPs?

Persistent Organic Pollutants (POPs) Persistent Organic Pollutants (POPs) are a range of chemical compounds are a range of chemical compounds that have been used or created that have been used or created from a range of activities from a range of activities associated with industrial processes associated with industrial processes and chemical manufacturing.and chemical manufacturing.

The chemical composition of POPs The chemical composition of POPs are similar, they are hydrocarbons are similar, they are hydrocarbons containing one or more chlorine containing one or more chlorine atoms.atoms.

Where are they from?Where are they from?

Agricultural use – pesticidesAgricultural use – pesticidesElectrical component production - Electrical component production - oil additivesoil additivesCombustion productsCombustion products

Pesticides spraying in 1945 containing POPs

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E-learning module to POPsE-learning module to POPs

► Mirex has also been used as a Mirex has also been used as a fire retardant in plastics.fire retardant in plastics.

► Fungicide HCB is also Fungicide HCB is also unintentionally produced in unintentionally produced in various combustion processes. various combustion processes.

► Some of the POPs i.e. PCBs, Some of the POPs i.e. PCBs, are family of 209 chlorinated are family of 209 chlorinated compounds, called congeners.compounds, called congeners.

► Congeners are compounds Congeners are compounds which have same main which have same main structure, i.e. PCBs main structure, i.e. PCBs main structure is biphenyl, and structure is biphenyl, and different number of different number of substituents, i.e. chlorinesubstituents, i.e. chlorine

9 chlorinated 9 chlorinated

pesticidespesticides

Aldrin, Dieldrin, Chlordane, Aldrin, Dieldrin, Chlordane, Dichloro-Diphenyl-Dichloro-Diphenyl-Trichloroethane (DDT), Trichloroethane (DDT), Endrin, Heptachlor, Endrin, Heptachlor, Toxaphene, Mirex, Toxaphene, Mirex,

Hexachlorobenzene (HCB)Hexachlorobenzene (HCB)

Industrial Industrial

chemicalchemical

Polychlorinated Biphenyls Polychlorinated Biphenyls

(PCBs)(PCBs)

UnintentionallUnintentionally released y released

substancessubstances

Dioxins (polychlorinated Dioxins (polychlorinated dibenzo-p-dioxins, PCDDs) dibenzo-p-dioxins, PCDDs)

Furans (polychlorinated Furans (polychlorinated dibenzofurans, PCDFs)dibenzofurans, PCDFs)

UNEP and UNIDO have identified 12 POPs that are of particular interest and concern:

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E-learning module to POPsE-learning module to POPsGroupings of POPsGroupings of POPs

For the purpose of this e-learning course, POPs are considered in 3 groups For the purpose of this e-learning course, POPs are considered in 3 groups based on their application.based on their application.

GROUP AGROUP A

GROUP BGROUP B

GROUP CGROUP C

Note: these groups do not correlate exactly with Annexes A, B and C of the Stockholm Convention.

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Group AGroup A

PropertiesProperties

SourcesSources

POPs in the environmentPOPs in the environment

Exposure risksExposure risks

Health impactsHealth impacts

Aerial pesticide application (containing POPs)

Group APropertiesSourcesPOPs in the environmentExposure RisksHealth ImpactsGroup BGroup C

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E-learning module to POPsE-learning module to POPsGroup A: Properties Group A: Properties

Some of the chemical characteristics include:Some of the chemical characteristics include:

► very low water solubilityvery low water solubility► high lipid solubility (high solubility in oils)high lipid solubility (high solubility in oils)► semi-volatilitysemi-volatility► high molecular masseshigh molecular masses► resistance to chemical, biological resistance to chemical, biological and photolytic degradationand photolytic degradation

In pure form they mainly occur in powder or In pure form they mainly occur in powder or crystalline form with mild or no odour.crystalline form with mild or no odour.

Group A POPs were mainly used as:Group A POPs were mainly used as:

► organic solvent formulationsorganic solvent formulations► wettable powderswettable powders► granulesgranules► aerosolsaerosols

Commercial product containing 5% DDT

Group A

PropertiesSourcesPOPs in the environmentExposure RisksHealth ImpactsGroup BGroup C

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E-learning module to POPsE-learning module to POPsGroup A: SourcesGroup A: Sources

All chemicals in Group A were All chemicals in Group A were produced for the control of produced for the control of insects or as a fungicide.insects or as a fungicide.

DDT and Heptachlor are still DDT and Heptachlor are still produced in very limited produced in very limited quantities. quantities.

Some countries use DDT for the Some countries use DDT for the control of malaria carrying control of malaria carrying mosquitoes.mosquitoes.

Heptachlor is currently used to Heptachlor is currently used to control fire ants in power control fire ants in power transformers.transformers.

DDT spraying for insect vector control

Group AProperties

SourcesPOPs in the environmentExposure RisksHealth ImpactsGroup BGroup C

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E-learning module to POPsE-learning module to POPsGroup A: POPs in the environmentGroup A: POPs in the environment

► Group A POPs were applied mainly Group A POPs were applied mainly on ground and are expected to be on ground and are expected to be immobile in soil.immobile in soil.

► Volatilization from ground occurs Volatilization from ground occurs within first few weeks after within first few weeks after application.application.

► May exist as vapour or particulate May exist as vapour or particulate phases in the ambient atmosphere.phases in the ambient atmosphere.

► May be removed from air by wet May be removed from air by wet and dry deposition.and dry deposition.

► Do not dissolve in water and in Do not dissolve in water and in aquatic environment therefore aquatic environment therefore Group A POPs will be present in Group A POPs will be present in sediments.sediments.

Remediation of POPs contaminated site

Group APropertiesSources

POPs in the environmentExposure RisksHealth ImpactsGroup BGroup C

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E-learning module to POPsE-learning module to POPsGroup A: Exposure risksGroup A: Exposure risks

► Eating foods contaminated with this Eating foods contaminated with this chemicals.chemicals.

► Drinking contaminated water.Drinking contaminated water.

► Breathing air and dust with POPs Breathing air and dust with POPs particles.particles.

► Skin contact with contaminated soil Skin contact with contaminated soil at hazardous waste site.at hazardous waste site.

► Living at homes which has been Living at homes which has been treated for treated for insect or pest vector insect or pest vector controlcontrol (termites, mosquitoes). (termites, mosquitoes).

► Children may be exposed by Children may be exposed by drinking breast milk.drinking breast milk.

Obsolete pesticide packagings

Group APropertiesSourcesPOPs in the environment

Exposure RisksHealth ImpactsGroup BGroup C

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E-learning module to POPsE-learning module to POPsGroup A: Health impactsGroup A: Health impacts

► All Group A POPs have health risks All Group A POPs have health risks from acute and chronic exposure.from acute and chronic exposure.

► Health risks can be assessed only Health risks can be assessed only in conjunction with toxicological in conjunction with toxicological data.data.

► Toxicity of substance is Toxicity of substance is represented by dose (in mg of represented by dose (in mg of substance per kg of body weight) substance per kg of body weight) at which adverse health effects at which adverse health effects occur.occur.

► The The US EPAUS EPA and and WHOWHO categorized categorized Group A POPs as moderately or Group A POPs as moderately or highly toxic substances. highly toxic substances.

► IRACIRAC and US EPA classified Group and US EPA classified Group A substances as possible or A substances as possible or probable carcinogens.probable carcinogens.

► The carcinogenic classification The carcinogenic classification reflects reflects weight of available weight of available evidenceevidence..

DDT was used in many countries for insect vector control

Group APropertiesSourcesPOPs in the environmentExposure Risks

Health ImpactsGroup BGroup C

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Group BGroup B


SourcesSources




Collection and labelling of PCBs containing equipment

Group APropertiesSourcesPOPs in the environmentExposure RisksHealth Impacts

Group BGroup C

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E-learning module to POPsE-learning module to POPsGroup B: Properties Group B: Properties Polychlorinated biphenyls (PCBs):Polychlorinated biphenyls (PCBs):

► are a class of 209 individual are a class of 209 individual chlorinated compounds known as chlorinated compounds known as congenerscongeners

► do not occur in naturedo not occur in nature► are highly stable and heat resistant are highly stable and heat resistant

properties to breakdownproperties to breakdown► are either oily liquids or solidsare either oily liquids or solids► either colourless or light yelloweither colourless or light yellow► have no smell or tastehave no smell or taste► were used in a variety of primarily were used in a variety of primarily

coolant, lubricant and hydraulic coolant, lubricant and hydraulic applicationsapplications

Group AGroup B

PropertiesSourcesPOPs in the environmentExposure RisksHealth ImpactsGroup C

PCB chemical formula

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E-learning module to POPsE-learning module to POPsGroup B: SourcesGroup B: Sources

PCBs have been released to the PCBs have been released to the environment solely by human environment solely by human activity.activity.

PCBs can enter the soil, water PCBs can enter the soil, water and air environments:and air environments:

► by accidental leaks and spills by accidental leaks and spills from older electrical equipmentfrom older electrical equipment

► deposition of vehicular deposition of vehicular emissionsemissions

► incineration of PCB-containing incineration of PCB-containing wasteswastes

Old PCBs containing transformer

Group AGroup BProperties

SourcesPOPs in the environmentExposure RisksHealth ImpactsGroup C

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E-learning module to POPsE-learning module to POPsGroup B: POPs in the Group B: POPs in the

environmentenvironment

► PCBs are highly persistent in the PCBs are highly persistent in the environment and, as other POPs, environment and, as other POPs, can bio-accumulate.can bio-accumulate.

► In water, PCB congeners with less In water, PCB congeners with less chlorine atoms dissolve, but chlorine atoms dissolve, but mostly PCBs bind to soils within mostly PCBs bind to soils within the upper layers of the sediment the upper layers of the sediment load. load.

► In the atmosphere, PCBs are In the atmosphere, PCBs are present both in the vapour phase present both in the vapour phase and sorbed to particles.and sorbed to particles.

► PCBs are removed from the PCBs are removed from the atmosphere by wet and dry atmosphere by wet and dry deposition.deposition.

PCB-contaminated creek

Group AGroup BPropertiesSources

POPs in the environmentExposure RisksHealth ImpactsGroup C

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E-learning module to POPsE-learning module to POPsGroup B: Exposure risksGroup B: Exposure risks

The main exposure to humans is from:The main exposure to humans is from:

► eating fish, meat or dairy products eating fish, meat or dairy products contaminated with PCBscontaminated with PCBs

► drinking water from a drinking water from a contaminated sourcecontaminated source

► inhalation of dust or dermal contact inhalation of dust or dermal contact from sites near waste sitesfrom sites near waste sites

► from exposure to vapours in the from exposure to vapours in the use and repair of old electrical use and repair of old electrical equipment or florescent lightequipment or florescent light

► in the disposal of PCB in the disposal of PCB contaminated materials and oilscontaminated materials and oils

PCB warning sign near the Housatonic River, USA

Group AGroup BPropertiesSourcesPOPs in the environment

Exposure RisksHealth ImpactsGroup C

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E-learning module to POPsE-learning module to POPsGroup B: Health impactsGroup B: Health impacts

– Different PCB Different PCB congenerscongeners have have varying harmful effects.varying harmful effects.

– People exposed to high levels are People exposed to high levels are likely to have suffered liver disease, likely to have suffered liver disease, changes to the blood and skin changes to the blood and skin complaints, in particular Chloracne. complaints, in particular Chloracne.

– The The DHHSDHHS, US EPA and IARC have , US EPA and IARC have determined that PCBs are a determined that PCBs are a probableprobable carcinogen to humans. carcinogen to humans.

– Studies of pregnant women and Studies of pregnant women and nursing mothers exposed to high nursing mothers exposed to high levels of PCBs in foods, revealed levels of PCBs in foods, revealed children born with:children born with:• decreased average birth weightsdecreased average birth weights• decreased motor skillsdecreased motor skills• decreased short-term memory decreased short-term memory • a reduced immune systema reduced immune system

Labelling of electrical goods containing PCB oils

Group AGroup BPropertiesSourcesPOPs in the environmentExposure Risks

Health ImpactsGroup C

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Group CGroup C


SourcesSources




Group AGroup B

Group C

Possible unintentional emission of POPs

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E-learning module to POPsE-learning module to POPsGroup C: Properties Group C: Properties

Dioxins formally known as Dioxins formally known as polychlorinated dibenzo-p-dioxins polychlorinated dibenzo-p-dioxins (PCDDs) (PCDDs)


► in pure form they are a colourless in pure form they are a colourless crystal or solid crystal or solid

► 2,3,7,8-tetrachloro dibenzo-p-dioxin 2,3,7,8-tetrachloro dibenzo-p-dioxin (2,3,7,8-TCDD), one of the most (2,3,7,8-TCDD), one of the most toxic dioxins, is odourlesstoxic dioxins, is odourless

► the odour of other dioxins is not the odour of other dioxins is not knownknown

► in the environment dioxins occur as in the environment dioxins occur as a mixture of different congeners a mixture of different congeners together with furanstogether with furans

Group AGroup BGroup C

PropertiesSourcesPOPs in the environmentExposure RisksHealth Impacts

2,3,7,8-TCDD chemical formula

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E-learning module to POPsE-learning module to POPsGroup C: Properties Group C: Properties

Furans formally known as Furans formally known as polychlorinated dibenzofurans polychlorinated dibenzofurans (PCDFs) (PCDFs)


► in pure form they are a colourless in pure form they are a colourless solidsolid

► do not readily dissolve in waterdo not readily dissolve in water

► in the environment furans occur as a in the environment furans occur as a mixture of different congeners mixture of different congeners together with dioxinstogether with dioxins

Note: Not all Furans have been studiedNote: Not all Furans have been studied

PCDFs chemical formula

Group AGroup BGroup C

PropertiesSourcesPOPs in the environmentExposure RisksHealth Impacts

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E-learning module to POPsE-learning module to POPsGroup C: SourcesGroup C: Sources

Dioxins and Furans are Dioxins and Furans are substances produced un-substances produced un-intentionally from the combustion intentionally from the combustion of organic compounds and of organic compounds and materials containing chlorine.materials containing chlorine.

Some examples:Some examples:

► combustion of fossil fuelscombustion of fossil fuels► waste incineratorswaste incinerators► bleaching in paper millsbleaching in paper mills► volcanic activities and forest firesvolcanic activities and forest fires► home heatinghome heating► even home frying and barbeque even home frying and barbeque

(salt contains chlorine)(salt contains chlorine)

A fossil fuel power station

Group AGroup BGroup CProperties

SourcesPOPs in the environmentExposure RisksHealth Impacts

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E-learning module to POPsE-learning module to POPsGroup C: POPs in the Group C: POPs in the

environmentenvironment

► Dioxins and furans enter the Dioxins and furans enter the environment as mixtures environment as mixtures containing a variety of individual containing a variety of individual components and impurities.components and impurities.

► PCDDs along with PCDFs are PCDDs along with PCDFs are known to occur naturally.known to occur naturally.

► These substances are removed These substances are removed from the atmosphere to earth as from the atmosphere to earth as fine particles in rain and/or snow. fine particles in rain and/or snow.

► In waste water they mainly In waste water they mainly attach to sediments in the water attach to sediments in the water environment and settle out, or environment and settle out, or are either broken down by are either broken down by sunlight or evaporated to air.sunlight or evaporated to air.

Indonesia volcano emitting hot ashes and gases containing dioxins and furans into the atmosphere

Group AGroup BGroup CPropertiesSources

POPs in the environmentExposure RisksHealth Impacts

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E-learning module to POPsE-learning module to POPsGroup C: Exposure risksGroup C: Exposure risks

Dioxins and furans:Dioxins and furans:

► Bio-accumulate in the food chain Bio-accumulate in the food chain (meat, dairy products and fish).(meat, dairy products and fish).

► Inhalation of dust.Inhalation of dust.

► Drinking low levels in water.Drinking low levels in water.

► Skin contact with certain Skin contact with certain herbicides and pesticides herbicides and pesticides contaminated by PCDDs.contaminated by PCDDs.

► Living near/ working at a Living near/ working at a incinerator or Hazardous waste incinerator or Hazardous waste sitesite

► Working at a paper mill or water Working at a paper mill or water treatment plant.treatment plant.

Eating contaminated foods is most important pathway of POPs exposure

Group AGroup BGroup CPropertiesSourcesPOPs in the environment

Exposure RisksHealth Impacts

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E-learning module to POPsE-learning module to POPsGroup C: Health impactsGroup C: Health impacts

► Acute and chronic toxicity varies for Acute and chronic toxicity varies for diferent dioxin and furan diferent dioxin and furan congeners.congeners.

► The most toxic dioxin is 2,3,7,8-The most toxic dioxin is 2,3,7,8-TCDD (2,3,7,8-tetrachlorodibenzo-TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin).p-dioxin).

► The most toxic furan is 2,3,7,8-The most toxic furan is 2,3,7,8-TCDF (2,3,7,8-TCDF (2,3,7,8-tetrachlorodibenzofuran).tetrachlorodibenzofuran).

Group AGroup BGroup CPropertiesSourcesPOPs in the environmentExposure Risks

Health ImpactsDioxins

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E-learning module to POPsE-learning module to POPsGroup C: Health ImpactsGroup C: Health Impacts

Health effects of exposure to dioxins Health effects of exposure to dioxins include:include:

► severe Chloracne, particularly the upper severe Chloracne, particularly the upper body and facebody and face

► skin rashesskin rashes► excessive and discoloured body hairexcessive and discoloured body hair► possible liver damagepossible liver damage► changes in glucose metabolism and changes in glucose metabolism and

hormone levelshormone levels

Long term exposure to dioxins may cause Long term exposure to dioxins may cause birth defects.birth defects.

Animal studies on the exposure to 2,3,7,8-Animal studies on the exposure to 2,3,7,8-TCDD revealed that acute exposure can TCDD revealed that acute exposure can cause death. cause death.

The WHO and DHHS have concluded that The WHO and DHHS have concluded that 2,3,7,8-TCDD is a 2,3,7,8-TCDD is a probableprobable carcinogen. carcinogen.


Health ImpactsDioxinsFurans

Severe chloracne

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E-learning module to POPsE-learning module to POPsGroup C: Health ImpactsGroup C: Health Impacts

Human acute exposure to furans Human acute exposure to furans showed:showed:

► skin and eye irritationskin and eye irritation► severe acnesevere acne► darkening skin colourdarkening skin colour► swelling eyelids and eye swelling eyelids and eye

dischargesdischarges

Children exposed in the womb have Children exposed in the womb have had skin irritation and increased had skin irritation and increased learning difficulties.learning difficulties.

Animal studies showed much the Animal studies showed much the same effects as those in humans same effects as those in humans only often more severe. only often more severe. The DHHS, IARC and US EPA do not The DHHS, IARC and US EPA do not classify furans as a carcinogen.classify furans as a carcinogen.


Health ImpactsDioxinsFurans

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E-learning module to POPsE-learning module to POPsConclusionsConclusions

► POPs are very stable, and exhibit POPs are very stable, and exhibit only very slow decay in the only very slow decay in the environment.environment.

► The main mechanisms of exposure The main mechanisms of exposure are bio-accumulation, inhalation and are bio-accumulation, inhalation and dermal contact.dermal contact.

► POPs are considered to be of low POPs are considered to be of low solubility in water.solubility in water.

► All POPs are probable or possible All POPs are probable or possible carcinogens. carcinogens.

► Their mobility and bioaccumulation Their mobility and bioaccumulation properties have the most influence properties have the most influence upon the choice of mitigation and upon the choice of mitigation and remedial measures, rather than remedial measures, rather than their toxicity.their toxicity.

1 e-learning module introduction to pops. 2 e-learning module to pops module 1 – overview of pops...

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