Environmental Pollutants

Dr.Rathnakar U.P.MD.DIH.PGDHM

K.M.C. Mangalore

Polluted environment

•We live in a chemical environment•We inhale, ingest, or absorb from

the skin many of these chemicals.• Toxicology is concerned with the

deleterious effects of these chemical agents on all living systems.

•?????Humans

Toxicology

•Occupational Toxicology

•Environmental Toxicology

•Ecotoxicology

Occupational Toxicology

• Chemicals found in the workplace

• Identifies, defines safety [threshold limit values (TLVs)] limits and lays down guidelines to minimize absorption

Ecotoxicology

•Traditional toxicology is concerned with toxic effects on individual organisms

•Ecotoxicology is concerned with the impact on populations of living organisms or on ecosystems

Environmental Toxicology

•Environmental toxicology deals with the deleterious impact of chemicals, present as pollutants of the environment, on living organisms.

•The term environment includes all the surroundings of an individual organism, but particularly the AIR, SOIL, AND WATER.

Pollution And pollutants•PollutionIntroduction of contaminants Into an environment [Which] Causes instability, disorder, harm or discomfort

To the ecosystem i.e. physical systems or living organisms .

Pollution and pollutants

Pollution And pollutants

•Pollutants-• A pollutant is a waste

material that pollutes air, water or soil.

Elements of pollution, Can be foreign substances Or energies, Or naturally occurring-

when they exceed natural levels

History

•Undesired spin-off of Human activity

•Discovery fire-Paleolithic era

•Discovery of tools- Iron Age

•Industrial revolution-Modern era

Water Pollution•Uncontaminated water does not occur in nature

•Less serious→Natural-N2, Co2, H2S ←Rain fall

•Serious →Sewage, Industrial waste, Agricultural waste, radioactive sub. ←Urbanization & industrialization

Land pollution•Main causesIndiscriminate dumping of Industrial, muncipal solid hazardous waste.

Industrial effluents and domestic sewage

Mining and mineral processing

Other Pollutions•Noise pollution•Light pollution•Visual pollution•Thermal pollution•Misc.•Pesticides, Natural [Dust,

Fungi, Noise, Light] •Tobacco smoke

"The smoke of chimneys is the breath of Soviet Russia"

Sources-Air Pollution

1. Automobiles-Major urban

HC, CO, Pb, N.oxides, Particulate matter

Strong sun light→HC & N.Oxides →Oxidizing photochemical pollutants

Disel engines →Smoke, Fumes

2. Industries Smoke, So2,

N.Oxides, Fly ash, H.Fluoride, HCL, CO, Ozone, H2S, SO2.

3. Domestic Burning-Coal, wood,

Oil. →So2, No2.

London Disaster-1952

Great Smog of 1952- LondonMore than 4000 people died

Routes• Inhalation • Atmospheric

pollutants , Industry

• Transdermal• Oral • Pollutants of

water and soil

Duration

•Acute exposure• Single or multiple

for 2-3 daysIndustry,

occupational• Chronic exposure• Occupational or

atmospheric

Exposure

BIOACCUMULATION

• Intake of a contaminant by an organism

• Exceeds the latter's ability to metabolize or excrete the substance

• Chemical accumulates within the tissues of the organism.

• Bioaccumulation.

BIOMAGNIFICATION• Concentration of a

contaminant may be virtually undetectable in water

• Magnified thousands of time as the contaminant passes up the food chain

• Biomagnification

Phytoplankton

Zooplankton

Rainbow smelt

Lake trout

Herring Gull

Fish Fry

Polychlorinated biphenyls (PCBs)

undetectable in water

BiomagnificationIn food chain

X 1

X 49.2

X 416

X 1932

X 49,600

?????

Air pollutants [Inhalation]Size• 5µ -Deposited

upper airway• 1µ-5µ-terminal

airway• <1µ deposited in

alveoli –absorbedLarger surface

areaProximity to

circulationHigh blood flow

Removal1.Wiping,

blowing, sneezing

2.Ciliary movement

3.From alveoliAbsorbrdPhagocytosedLymphatic

system

Types & SourcesAir pollution

Sulfur oxides

CO

Volatile organic

compounds

Particulate matter

Nitrogen oxides

5 pollutants-98% of Air Pollution

Others•Lead

•Hydrocarbons•Cadmium

•H2S•Ozone

•Polynuclear aromatic

hydrocarbon•Indoor air pollution

http://upload.wikimedia.org/wikipedia/commons/d/df/Health_effects_of_pollution.png

Toxicology –Carbon Monoxide• Colorless, tasteless, odorless, and

nonirritating gas• Incomplete combustion• CO +Hemoglobin=

Carboxyhemoglobin.Cannot transport oxygenInterferes with the dissociation of

oxygen from the remaining oxyhemoglobin

Brain and the heart most affected

Carbon MonoxideClinical Effects:Psychomotor impairment.Headache.Loss of visual acuity.Tachycardia,Tachypnea,Syncope

&Coma.Convulsions, Shock and

Respiratory failure.Treatment:Administration of Oxygen.

Carbon MonoxideDon’t be cozy in a closed car!!!

Sulfur Dioxide (SO2) • Colorless, irritant gas• Combustion of sulfur-

containing fossil fuels

• Moist membranes+ SO2 → sulfurous acid, → severe irritation of the eyes, mucous membranes, skin.

• Bronchoconstriction & P.Edema• No specific tt

Nitrogen Dioxide•Brownish irritant gas•Fire and fresh silage-Silo filler’s disease in farmers

•Lung irritant -pulmonary edema

•Treatment-Preventive and symptomatic

Ozone• Bluish irritant gas - occurs normally in

the earth's atmosphere• Source:• Workplace→Around high-voltage

electrical equipment and around ozone-producing devices used for air and water purification.

• Important oxidant found in polluted urban air.

• Important absorbent of ultraviolet light.

Ozone-Clinical Effects & Treatment• Irritant of mucous membranes.• Mild exposure →Upper respiratory tract

irritation. • Severe → Deep lung irritation → pulmonary

edema • Ozone penetration in the lung depends on

tidal volume → exercise increases the amount reaching the distal lung.

• Some effects of O3 resemble→ radiation effects← formation of reactive free radicals.

Ozone….• Causes shallow, rapid breathing and

a decrease in pulmonary compliance.• Enhanced sensitivity of the lung to

bronchoconstrictors • Irritation and dryness of the throat; • Changes in visual acuity, substernal

pain, and dyspnea.• Airway hyperresponsiveness and

airway inflammation

• NO specific treatment for acute O3 intoxication

SOLVENTS1.Halogenated Aliphatic Hydrocarbons

• CCl4,

• Chloroform,• Methyl chloroform.• Trichloroethylene, • Tetrachloroethylene,• Uses -Industrial solvents,

degreasing agents, cleaning agents• Occupational hazard

Solvents-MOA & Clinical Effects•CNS depression,•Liver injury, kidney injury,&

cardiotoxicity•Tetrachloroethylene can →

impaired memory and peripheral neuropathy

•Carcinogenic effect-Safety margin is large

•No specific treatment

SOLVENTS2. Aromatic Hydrocarbons

Benzene• Solvent and in the synthesis of

other chemicals• Acute effect• Depression of CNS• Euphoria, nausea, locomotor

problems, and coma; vertigo, drowsiness, headache, and nausea.

• No specific treatment

Benzene• Chronic exposure →very serious

toxic effects, • Injury to the bone marrow; aplastic

anemia, leukopenia, pancytopenia, or thrombocytopenia

• Increased incidence of leukemia• TOLUENE (METHYLBENZENE):• NO myelotoxic properties nor

associated with leukemia. • But a CNS depressant

INSECTICIDES

•Organophosphorus Insecticides.

•Carbamate Insecticides.

•Organochlorine Insecticides.

•Botanical Insecticides

Organochlorine Insecticides• Eg. DDT , Benzene hexachlorides,

cyclodienes, toxaphenes • They can be absorbed through the

skin[Not DDT] as well as by inhalation or oral ingestion

• Interfere with inactivation of the sodium channel →rapid repetitive firing in most neurons.

• Effect is CNS stimulation.• Tremor and convulsions, • There is no specific treatment

Organochlorine insecticides…• Envn. Toxicology• Persistent chemicals.• Degradation is slow and

bioaccumulation, particularly in aquatic ecosystems, is well documented.

• Once adsorbed in soil, they do not readily desorb.

Botanical Insecticides:

• Nicotine – Convulsions, respiratory paralysis, hypertension and cardiac arrhythmias.

• Rotenone – Pharyngitis, GI irritation, Conjunctivitis and Dermatitis.

• Pyrethrum – CNS excitation,Convulsions,

and tetanic paralysis.

Endocrine Disruptors

• Chemicals mimic, enhance, or inhibit a hormonal action

• Estrogen-like or antiandrogenic properties

• Eg.Phytoestrogens ,Mycoestrogens, Persistent organochlorine agents such as DDT.

Lead free toys

The Indian Vultures'God’s own incinerators’ - Dr. Salim Ali

•The White backed vulture population 30 million birds in 1992. •Today, it is a mere 11,000 birds and falling.•Diclofenac poisonong

Kerala is called "God's own country." Its beauty is unsurpassed.

Only ENDOSULFAN marred that beauty

Summary• Occupational, Envn,

Ecotoxicology• Definitions-Pollution

and pollutants• Air, Land, Water

pollution• Other pollutants• Sources-Auto,

Industry, Domestic• Exposure-Route and

Duration• Bioaccumulation ,

Biomagnification

• Air pollutants size and removal

• Imp 5 pollutants-Sulfur dioxide, nitrogen dioxide, CO, volatile organic chemicals, Particulate matter

• Affect on health• Individual pollutants• Solvents-Aliphatic and

Aromatic• Insecticides-Carbamates

Organophos, OrganoCl, Botanical

PleaseKeep theWorldClean

Thank You

W

Future of our planet lies in our hands