chemical hazards

1. Chemical HazardsChemical Hazards

2. CHEMICAL HAZARDSCHEMICAL HAZARDS
 Toxic chemicalsToxic chemicals – element or compound– element or compound
that can cause temporary or permanent harmthat can cause temporary or permanent harm
or death to humans and animalsor death to humans and animals

MutagensMutagens – chemicals or forms of radiation that– chemicals or forms of radiation that
cause or increase frequency of mutations in DNAcause or increase frequency of mutations in DNA
(ex: radiation, nitrous acid from nitrites & nitrates)(ex: radiation, nitrous acid from nitrites & nitrates)

TeratogensTeratogens – are chemicals that cause harm or– are chemicals that cause harm or
birth defects to a fetus or embryo (ex: alcohol,birth defects to a fetus or embryo (ex: alcohol,
chlorine, DDT, PCBs, mercury, lead, arsenicchlorine, DDT, PCBs, mercury, lead, arsenic

CarcinogensCarcinogens – are chemicals or types of– are chemicals or types of
radiation that can cause or promote cancer (ex:radiation that can cause or promote cancer (ex:
PCBs, chemicals in tobacco smoke, benzene)PCBs, chemicals in tobacco smoke, benzene)

3. CHEMICAL HAZARDSCHEMICAL HAZARDS
 A hazardous chemical can harm humans orA hazardous chemical can harm humans or
other animals because it:other animals because it:

Is flammableIs flammable

Is explosiveIs explosive

An irritantAn irritant

Interferes with oxygen uptakeInterferes with oxygen uptake

Induce allergic reactionsInduce allergic reactions

4. The Story of Cosmetics

5. CASE STUDY: PCBsCASE STUDY: PCBs
 PCBs – polychlorinated biphenylsPCBs – polychlorinated biphenyls
 Class of chlorine-containing compoundsClass of chlorine-containing compounds

Lubricants, insulators in electrical transformers, etc.Lubricants, insulators in electrical transformers, etc.

Carcinogen, neurological damage, growth problemsCarcinogen, neurological damage, growth problems

Very stable – 70% still in environmentVery stable – 70% still in environment

NonflammableNonflammable

Break down slowly in the environmentBreak down slowly in the environment

Travel long distances in the airTravel long distances in the air

Fat soluble – biomagnify in food chains and websFat soluble – biomagnify in food chains and webs
 Banned (1977 in U.S.), but found everywhereBanned (1977 in U.S.), but found everywhere

6. CASE STUDY: PCBsCASE STUDY: PCBs

7. Effects of Chemicals on the Immune,Effects of Chemicals on the Immune,
Nervous, and Endocrine SystemsNervous, and Endocrine Systems
 Long-term exposure to some chemicals atLong-term exposure to some chemicals at
low doses may disrupt the body’s:low doses may disrupt the body’s:

Immune systemImmune system – specialized cells and tissues– specialized cells and tissues
that protect the body against disease and harmfulthat protect the body against disease and harmful
substances – some chemicals weaken immunesubstances – some chemicals weaken immune
system – ex: arsenic, dioxin, methylmercurysystem – ex: arsenic, dioxin, methylmercury

Nervous systemNervous system – brain, spinal cord, and– brain, spinal cord, and
peripheral nerves – neurotoxins – ex: PCBs,peripheral nerves – neurotoxins – ex: PCBs,
methylmercury, arsenic, lead, some pesticidesmethylmercury, arsenic, lead, some pesticides

Endocrine systemEndocrine system – glands releasing hormones– glands releasing hormones
into blood – controls reproduction, growth,into blood – controls reproduction, growth,
development, learning ability, behaviordevelopment, learning ability, behavior

8. Endocrine DisruptorsEndocrine Disruptors
 Endocrine disruptorsEndocrine disruptors – chemicals that may– chemicals that may
interfere with body’s endocrine system andinterfere with body’s endocrine system and
produce adverse developmental,produce adverse developmental,
reproductive, neurological and immunereproductive, neurological and immune
effects in both humans and wildlifeeffects in both humans and wildlife

Hormonally active agents (HAAs)Hormonally active agents (HAAs)

Endocrine-disrupting chemicals (EDCs)Endocrine-disrupting chemicals (EDCs)
 Include pharmaceuticals, dioxin and dioxin-Include pharmaceuticals, dioxin and dioxin-
like compounds, polychlorinated biphenyls,like compounds, polychlorinated biphenyls,
DDT and other pesticides, and plasticizersDDT and other pesticides, and plasticizers
(ex: bisphenol A)(ex: bisphenol A)

9. Endocrine DisruptorsEndocrine Disruptors
 Molecules of certain synthetic chemicalsMolecules of certain synthetic chemicals
have shapes similar to those of naturalhave shapes similar to those of natural
hormones and can adversely affect thehormones and can adversely affect the
endocrine systemendocrine system

10. Endocrine DisruptorsEndocrine Disruptors
 AtrazineAtrazine – commonly used herbicide– commonly used herbicide

Effects on frogsEffects on frogs

11. Endocrine DisruptorsEndocrine Disruptors
 Bisphenol-A (BPA)Bisphenol-A (BPA) – estrogen mimic in– estrogen mimic in
many plasticsmany plastics

Used in water bottles, baby bottles, foodUsed in water bottles, baby bottles, food
containers, cans, receipts, etc.containers, cans, receipts, etc.

My leach into food and waterMy leach into food and water

May be adverse effects from low doses – brainMay be adverse effects from low doses – brain
damage, prostate and breast cancer, impaireddamage, prostate and breast cancer, impaired
immune function, hyperactivity, decreased seximmune function, hyperactivity, decreased sex
drive, obesitydrive, obesity

12. Endocrine DisruptorsEndocrine Disruptors
 PhthalatesPhthalates – softeners– softeners
in polyvinyl chloridein polyvinyl chloride
(PVC) products(PVC) products

Found in cosmetics, hairFound in cosmetics, hair
sprays, deodorants, babysprays, deodorants, baby
toys, food packaging,toys, food packaging,
some foods, etc.some foods, etc.

May be adverse effects –May be adverse effects –
birth defects, liver cancer,birth defects, liver cancer,
kidney and liver damage,kidney and liver damage,
immune suppression,immune suppression,
premature breastpremature breast
development,development,
feminization of malesfeminization of males

13. NBC: Hormones in Water
Turn Male Fish Into Females
Toxic Hot Seat Trailer

14. Case Study:Case Study:
A Black Day in Bhopal, IndiaA Black Day in Bhopal, India
 Bhopal, India – Union CarbideBhopal, India – Union Carbide pesticide plantpesticide plant

World’s worst industrial accident – 1984World’s worst industrial accident – 1984

Explosion released highly toxic methyl isocyanateExplosion released highly toxic methyl isocyanate
(MIC) gas – converted to hydrogen cyanide cloud(MIC) gas – converted to hydrogen cyanide cloud

15,000-22,000 people15,000-22,000 people
died, 600,000 exposeddied, 600,000 exposed

Simple upgrades toSimple upgrades to
plant could haveplant could have
preventedprevented

15. Bhopal Disaster