Download - Environmental Pollutants
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
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.
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