Human Health and Human Health and Environmental Environmental ToxicologyToxicology

Human HealthHuman Health

2 indicators of human health2 indicators of human health Life expectancyLife expectancy - how long people are - how long people are

expected to liveexpected to live Infant mortalityInfant mortality - how many children die - how many children die

before age of 1 yearbefore age of 1 year

Highly Developed CountriesHighly Developed Countries

Average life expectancyAverage life expectancy Men = 76 yearsMen = 76 years Women = 81 yearsWomen = 81 years

Leading causes of death in USLeading causes of death in US Cardiovascular disease, Cancer, Lung Cardiovascular disease, Cancer, Lung

DiseaseDisease Premature deaths caused by lifestylePremature deaths caused by lifestyle

Poor diet, Lack of exercise, Smoking, Poor diet, Lack of exercise, Smoking, ObesityObesity

Developing CountriesDeveloping Countries

Biggest problemsBiggest problems Malnutrition, unsafe water, poor Malnutrition, unsafe water, poor

sanitationsanitation Life ExpectancyLife Expectancy

~65 years, can be 45yrs ~65 years, can be 45yrs Childhood mortality is highChildhood mortality is high

Diarrheal diseasesDiarrheal diseases MalnutritionMalnutrition MalariaMalaria AIDS/HIVAIDS/HIV

Emerging and Reemerging Emerging and Reemerging DiseasesDiseases

Emerging DiseaseEmerging Disease - not - notpreviously observed inpreviously observed inhumanshumans Ex: AIDS, lime disease,Ex: AIDS, lime disease,

West Nile VirusWest Nile Virus

Reemerging Disease -Reemerging Disease - existed in the existed in the past and are recently increasing in past and are recently increasing in incidenceincidence Ex: tuberculosis, yellow fever, malariaEx: tuberculosis, yellow fever, malaria

Reasons for Reasons for Emergence/ReemergenceEmergence/Reemergence Evolution of disease so it transitions to human Evolution of disease so it transitions to human

hosthost Evolution of antibiotic resistance in diseaseEvolution of antibiotic resistance in disease Urbanization and overcrowdingUrbanization and overcrowding Increased pop. of elderly - susceptible to Increased pop. of elderly - susceptible to

diseasedisease Pollution and environmental degradationPollution and environmental degradation International travel and commerceInternational travel and commerce Poverty and social inequalityPoverty and social inequality

Environmental Pollution and Environmental Pollution and Disease Disease

PersistencePersistence

Chemicals that are extremely stable Chemicals that are extremely stable and may take many years to be and may take many years to be broken down by natural processes broken down by natural processes Synthetic chemicalsSynthetic chemicals Ex: DDTEx: DDT

BioaccumulationBioaccumulation

The buildup of a persistent toxic The buildup of a persistent toxic substance substance in an organism’s bodyin an organism’s body, , often in fatty tissues often in fatty tissues

BiomagnificationBiomagnification

The The increased increased concentration concentration of of toxic chemicals in toxic chemicals in tissues of tissues of organisms organisms at at higher levels in higher levels in food webs food webs

Endocrine DisruptersEndocrine Disrupters

A chemical that mimics or interferes with A chemical that mimics or interferes with the actions of the endocrine systemthe actions of the endocrine system

Ex:Ex: PCBs, DioxinsPCBs, Dioxins Heavy metals - lead and mercuryHeavy metals - lead and mercury DDTDDT BPABPA ParabensParabens Phthalates?Phthalates?

Endocrine DisruptersEndocrine Disrupters Case Study: 1980 chemical spill into Case Study: 1980 chemical spill into

Lake Apopka, FLLake Apopka, FL

http://www.youtube.com/watch?v=0hP6eu-87Wk

ToxicologyToxicology

Acute toxicityAcute toxicity Adverse effects occur within a short Adverse effects occur within a short

period after exposure to toxinperiod after exposure to toxin Chronic toxicityChronic toxicity

Adverse effects occur some time after Adverse effects occur some time after exposure, or after prolonged exposure exposure, or after prolonged exposure to toxinto toxin

ToxicityToxicity

LD50LD50 Lethal doseLethal dose to to

50% of the test 50% of the test organismsorganisms

ToxicityToxicity

ED50ED50 Effective doseEffective dose causes 50% of the pop. to causes 50% of the pop. to

exhibit whatever effect is under studyexhibit whatever effect is under study

Children more susceptible to chemicalsChildren more susceptible to chemicals Weigh less than adultsWeigh less than adults Bodies are still developingBodies are still developing Play on floors and lawnsPlay on floors and lawns Put things into theirPut things into their

mouthsmouths

http://www.youtube.com/watch?v=Kpwu8DOmzoUhttp://www.youtube.com/watch?v=Kpwu8DOmzoU http://www.youtube.com/watch?v=ognIAmUu-HU&feature=relatedhttp://www.youtube.com/watch?v=ognIAmUu-HU&feature=related

Children and Chemical Children and Chemical ExposureExposure

Chemical MixturesChemical Mixtures

Chemical Mixtures interact by:Chemical Mixtures interact by: AdditivityAdditivity SynergySynergy AntagonismAntagonism

Dilution Paradigm is not validDilution Paradigm is not valid ““Dilution is the solution to pollution”Dilution is the solution to pollution”

Boomerang Paradigm is acceptedBoomerang Paradigm is accepted ““What you throw away can come back What you throw away can come back

and hurt you”and hurt you”

Case Study: The OceanCase Study: The Ocean

Land based nutrient Land based nutrient and pollution runoff and pollution runoff into ocean is into ocean is affecting affecting microorganismsmicroorganisms

Ex: Red TideEx: Red Tide

Risk AssessmentRisk Assessment