Download MBBS Biochemistry PPT 43 Environmental Biochemistry Lecture Notes

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Environmental Biochemistry

Health and Il -Health Effects Of

Unpol uted and Pol uted Environment

Do's and Don'ts To Maintain

Clean and Green Environment

Contents

? What is an Environment?

? Significance of an Environment on

Human Health

? Environmental Pol ution and Pol utants :

Types, Sources, Effects on human health

Control and Prevention


What Is An Environment ?
Features Of An Environment

? Next to Nutrition, Environment is most important

factor for human healthy life

? Environment is purely a natural entity where

human being in his living is surrounded with it.

? Environment of human being comprises of :

Atmosphere,air,water,soil,radiations,sound

,Temperature etc.

? Environment is directly and indirectly connected to

human body

? Natural environment is balanced and healthy

Environmental Entities

? Atmosphere

? Water

General

? physical structure

Oceans

? chemical composition

? composition, desalination

Outer Atmosphere

? ozone - photochem,

Fresh water

Troposphere

? Sulfur, acid rain

? Oxygen, water treatment

? CO

? NOx, smog

? "Green Chemistry"

? CO2, H2O

? Climate


Human Beings Leaders Of Universe

are Responsible For Maintaining State

Of An Environment


Significance Of An Environment On

Human Health


Close Relationship Of

Environment And Human Health


Environmental Pol utants




Environmental Pol utants Directly

Affect Human Health

Toxicity Of Pol utants Depends Upon

Amount,Duration,Potency

? Toxicity of pollutants is measured by dose and

response

? Dose: An amount that enters body of an exposed

organism

? Response: An amount of damage caused by a

specific dose

? LD50

? Lethal dose to 50% of test organisms
? Smaller LD50 more lethal is the chemical

? Determined for all new synthetic chemicals


Toxicity

? ED50

? Effective dose to 50% of test organisms
? ED50 causes 50% of population to exhibit whatever

effect is under study

? Dose-Response Curve

? Illustrates an effect of different doses on a

population

? Threshold Level

? Maximum dose with no measurable effects


Environmental Pol utants and Disease

? Often difficult to

link pollutants to

their effects on

people

? Persistence
? Bioaccumulation
? Biomagnification

Persistence

? A characteristic of certain chemicals that are

extremely stable and may take many years to

be broken down into simpler forms by natural

processes

? Synthetic chemicals (those not found in nature)
? Ex: DDT

? Natural decomposers (bacteria) have not

evolved a way to break it down


Bioaccumulation

? Buildup of a persistent toxic substance in an

organism's body, often in fatty tissues



? Synthetic chemical do not metabolize well

? They remain in body for extended periods of time

Biomagnification

? An increased

concentration of

toxic chemicals in

tissues of organisms

that are at higher

levels in food webs

? Diagram is example

of biomagnification

of DDT






Groupings of Chemical Pol utants:

Grouping

Grouped According to:

EDC (Endocrine Disrupting Chemical)

toxicological mode of action or

CMR (Carcinogenic, Mutagenic, toxic to

endpoint

Reproduction)

PBT (Persistent, Bioaccumulative Toxic)

environmental properties

vPvB (very Persistent, very Bioaccumulative)
POP (Persistent Organic Pollutant)

PPCPs

type of intended usage

priority pollutants and others

legislation

"emerging" contaminants/pollutants

novelty, fad, timeliness, or new

concern

PPCPs as Environmental Pol utants

? PPCPs are a diverse group of chemicals comprising all human and

veterinary drugs (available by prescription or over-the-counter;

including new genre of "biologics"

? Diagnostic agents (X-ray contrast media)

? Nutraceuticals (bioactive food supplements such as huperzine A)

? Fragrances,Perfumes,Deos Sprays (e.g., musks)

? Sun-screen agents (e.g., 4-methylbenzylidene camphor

octocrylene)

? Excipients (so called "inert" ingredients used in PPCP

manufacturing and formulation; e.g., parabens)


Mechanism of

Environmental Pol utants

? Environmental pol utant of physical, chemical or

biological origin

? Interacts with various biomolecules of human body

as per specific affinity

? Accumulate in cel s and tissues

? Disturb biomolecule structural features

? Distract biomolecules from true function

? Loads immune system, liver and kidneys

? Alter normal health

? Leads to il -effects/disorders- Anemia,Cancers



Endocrine Disrupters

? A chemical that mimics or interferes with the actions of

the endocrine system in humans and wildlife

? i.e. It effects the ability of the hormones in the organisms to

function properly

? Examples include:

? PCBs, Dioxins
? Heavy metals ? lead and mercury
? DDT

? Animals exposed to these chemicals have altered

reproductive development and are often sterile

Endocrine Disrupters and Humans

? Infertility and hormonally related cancers are

increasing

? Breast cancer and testicular cancer

? Phthalates have been implicated as potential

endocrine disrupters

? Common ingredient in: cosmetics, fragrances, nail

polish, medication, toys, food packaging

? Cannot make a link between endocrine

disrupters and human illness

? Too few studies have been performed
Determining Health Effects of Pol utants

? Toxicants to human body

? Toxicant- chemical with adverse human health

effects

? Acute toxicity

? Adverse effects occur within a short period after

exposure to toxin

? Chronic toxicity

? Adverse effects occur some time after exposure,

or after prolonged exposure to toxin

? Symptoms often mimic other diseases- hard to

assess source

Children and Chemical Exposure

? Children are more susceptible to chemicals

? Weigh less than adults

? Bodies are stil developing

? Play on floors and lawns

? Exposed to cleaning products and pesticides

? Put things into their mouths
Exposure Of Chemical Mixtures

? Generally humans body is exposed to chemical

mixtures

? Ex: automobile exhaust

? Chemical Mixtures interact by

? Additivity

? Synergy

? Antagonism

Risk Assessment

? Risk- probability that a particular adverse effect wil

result from some exposure or condition

? We assess risk daily with four steps:

1. Hazard identification

2. Dose response assessment

3. Exposure assessment

4. Risk characterization


Environmental Hazards











Composition of Atmosphere

? Composition of gases in

an atmosphere is not

uniform.

? Lighter gases tend to rise

to top.

Gases are measured in ppm volume (?L/L), which is

directly proportional to mole fraction.
Outer Atmosphere

? Sun emits radiation

across an

electromagnetic

o
f

p
h
o
t
o
n
s

spectrum.

umber

? Light in an ultraviolet

N

region has enough

energy to break

chemical bonds.

Wavelength, m

Energy

Ozone

? Ozone absorbs much of radiation between 240 and 310

nm.

? It forms from reaction of molecular oxygen with an oxygen

atoms produced in upper atmosphere by

photodissociation (< 242 nm).

O + O2 O3
Ozone Depletion

In 1974 Rowland and Molina (Nobel Prize, 1995)

discovered that chlorine from chlorofluorocarbons

(CFCs) may be depleting the supply of ozone in the

upper atmosphere.

Troposphere

Although Troposphere is made up almost entirely of

nitrogen and oxygen, other gases present in relatively small

amounts still have a profound effect on troposphere.
Radiation

Aurora

Formed {Atmosphere is first

here

line of defense against

radiation from Sun.

Chlorofluorocarbons

CFCs were used for years as aerosol

propellants and refrigerants.

Mostly = CFCl3, CF2Cl2.

They are not water soluble (so they do not

get washed out of the atmosphere by rain)

and are quite unreactive (so they are not

degraded naturally).
Water Vapor and Carbon Dioxide

? Gases in an atmosphere form an insulating blanket that

causes the Earth's thermal consistency.

? Two of the most important such gases are carbon

dioxide and water vapor.

Water Vapor and Carbon Dioxide

? This blanketing effect is

known as the "greenhouse

effect."

? Water vapor, with its high

specific heat, is a major

factor in this moderating

effect.

? But increasing levels of CO2

in an atmosphere is causing

an increase in global

temperatures.


Sulfur

? Sulfur dioxide is a by-product of burning of coal or oil.

? It reacts with moisture in air to form sulfuric acid.

? It is primarily responsible for acid rain.

Carbon Monoxide

? Carbon monoxide binds

preferentially to the iron

in red blood cells.

? Exposure to CO can

lower O2 levels to the

point of causing loss of

consciousness and death.


Nitrogen Oxides

? What we recognize as

smog, that brownish gas

that hangs above large

cities like Los Angeles, is

primarily nitrogen

dioxide, NO2.

? It forms from the

oxidation of nitric oxide,

NO, a component of car

exhaust.


Photochemical Smog

Smog also contains ozone, carbon monoxide,

hydrocarbons, and particles.


Effect of Photochemical Smog on

Human Health

















































Effects Of Water Pol ution

























Shocking side effects of Earphones

To Brain and Ears!

? TINNITUS. [Noise in ear]. . .

? HYPERACUSIS. This is an increased sensitivity to

normal environment sounds.

? SEVERE EAR INFECTION. It is usual y unavoidable

that people share earphones. . .

? LOSS OF HEARING. . .

? AFFECTS YOUR BRAIN. . .

? EAR PAIN. . .

? LOSS OF CONNECTION WITH REALITY. . .

? LEARNING DISABILITIES.

Research findings

Sound's volume by 6 to 9 decibels

? Loud music played on earphones causes hearing

loss by having a similar effect on nerves as

multiple sclerosis,

? Research shows noise levels above 110 decibels

strip insulation from nerve fibers carrying signals

from the ear to the brain.

























Human Responsibilities To Maintain

Healthy Environment

? Use Sense, time and Energy for Significance and

Health

? Be Monitor,maintainer,Constructor

? Never be Destructor

? Do sensible environmental friendly acts which

control and prevent pollution



Factors For Quality Of Health

? Intentions and Actions= Behavior (Sleep Cycle)

? Nutrition (Food Cycle)

? Environment

This post was last modified on 05 April 2022