Environmental Problems And Health Risks

Environmental Problems and Health Risks

Ashok KumarSchool of Biotechnology

Banaras Hindu University

Man and Environment: DEPENDENCE and INTERACTIONS

Compounds Dependence Spill off

Air Oxygen Wastes

Water EnergyLife Support

Soil Raw materials PollutantsMinerals Soil, WaterHabitat

Light ? Energy ?

Environment in ActionEnvironment in Action

Environment in ActionEnvironment in Action

Environment

Processes (Biotic and Abiotic)

Transformation

New Products (Good and Bad)

Damage to Environment (By bad one)

Repair (up to a limit)

Regain the originality

End point of Repair: The origin of Problems

Major Environmental Problems(South East Asia)

• Industrial Effluents

• Man made chemicals

• Natural agents

Most Abundant and common

Arsenic

Nitrate

Uranium

Arsenic poisoning is thought to be responsible for the deaths of some well known historical figures such as:

– Claudius– Pope Pius III and

Clemente XIV – Charles Francis

Hall – Napoleon

As: A Global problem

• 200 million people worldwide are at risk to As exposure (NRC, 2001)

• Several regions in the World are above the WHO’s maximum permissible limit. These include:- Bangladesh - Cambodia- India - Vietnam- China - Thailand- Argentina - U.S.- Chile - Nepal- Mexico - Ghana- Taiwan

http://www.who.int/mediacentre/factsheets/fs210/en/index.html

Arsenic pollution in the world

• Several nations in the world such as Argentina, Australia, Bangladesh, Chile, China, Hungary, India, Mexico, Peru, Thailand, and the U.S. have shown concentrations higher than the guideline value of 10 ug/L of the WHO.

• Adverse health effects from arsenic exposure have been documented in China, Bangladesh, India (West Bengal), and the USA.

• Currently, the worst problem exists in Bangladesh and West Bengal (India) where millions are being exposed to unhealthy amounts of arsenic through drinking water.

Features of As

• More than 20 arsenic species are present in nature

• Various arsenic species can be metabolized

• Different arsenic species have dramatically different toxicities

Natural Arsenic Levels

Crystalline Rock

Soil

Ground Water

Surface Water

Avg. 2 ppm

1-40 ppm

0.01 – 800 ppbAs high as 40,000 in hot springs

2.38 – 65 ppbAs high as 22,000 in river water

Health Effects

• Keratosis

Cancers Associated with Exposure to Arsenic in Drinking Water

• Skin

• Bladder

• Lung

• Kidney

• Liver

• Prostate

Source of Energy

Solar radiation on the Earth’s surface

Good & Bad Effects of SunlightGood & Bad Effects of Sunlight

Photosynthesis

Vitamin Dsynthesis

Vision

Kills pathogens

Phototherapy

Warmth

Pre-Cancer

Phototosensitivity

Cataracts

Cancer

Sunburn

Premature Aging

Immune systemchanges

BADGOOD

What Prevents Bad Effects of Solar Radiation

Layers of the Atmosphere35

30

25

20

15

10

5

50 10 15 20 25

Stratospheric Ozone(The Ozone Layer)

Tropospheric Ozone

“Smog” Ozone

Ozone Amount

Alti

tude

(K

ilom

eter

s)

“Good Ozone”

“Bad Ozone”

“Good “ and “Bad” Ozone

• Stratospheric “Good” Ozone: absorbs incident UV radiation.

• Ground-level “Bad” Ozone: high levels toxic to living systems.

OZONE LAYER

Is UV Radiation on Increase?

Ozone Layer Depleting Chemicals

• chlorofluorocarbons (CFCs)

• carbon tetrachloride (CCl4)

• methyl chloroform (CH3CCl3)

• hydrochloric acid (HCl)

• methyl chloride (CH3Cl)

• methyl bromide(CH3Br)

Supersonic Jet & CFC Release

Global Ozone Field

Ozone Hole

Impacts of Ozone Depletion

• Increase in UV-B Radiation

• Global warming

Ultraviolet Radiation - UV

What is Ultraviolet Radiation?

Ultraviolet Radiation - UV

1.1. UV-A (320 400 nm)UV-A (320 400 nm)—causes skin aging & wrinkles. Used in tanning beds. Colors skin and gives false sense of protection from the sun. UVA rays pass effortlessly through the ozone layer.

Ultraviolet Radiation - UV

2.2. UV- B (280-320 nm)UV- B (280-320 nm)—causes sunburns, cataracts, immune system damage, skin cancer. Melanoma may be associated with severe UVB sunburns occurring before the age of 20. Most UVB rays are absorbed by the ozone layer.

Ultraviolet Radiation - UV

3.3. UV- C (200-280 nm)UV- C (200-280 nm)—these rays are the most dangerous. Fortunately, these rays are blocked by the ozone layer and don’t reach the Earth.

Another View of Sun

Ultraviolet Radiation - UV

Even on cloudy, cool, or overcast days, UV rays travel through the clouds and reflect off sand, water, snow, and even concrete.

Clouds and pollution don’t filter out UV rays, and can give a false sense of protection.

This “invisible sun” can cause unexpected sunburn and skin damage.

UV Exposure & Health

• Eye: Cataracts, universal problemEye: Cataracts, universal problem

• Even low amounts of sunlight can Even low amounts of sunlight can increase the risk of eye disorders.increase the risk of eye disorders.

• UVB damage to the eyes is cumulative, UVB damage to the eyes is cumulative, so it is never too late to start protecting so it is never too late to start protecting your eyes.your eyes.

Effects of UV Exposure

Skin Damage

Effects of UV Exposure

• There are about 1.3 million new There are about 1.3 million new cases of skin cancer in the U.S. cases of skin cancer in the U.S. each year, resulting in about 9,800 each year, resulting in about 9,800 deaths.deaths.

• Melanoma is one type of skin Melanoma is one type of skin cancer. It is the most common cancer. It is the most common cancer among women between the cancer among women between the ages of 25 and 29.ages of 25 and 29.

Effects of UV Exposure

• Scientists believe sunburns can alter Scientists believe sunburns can alter the body’s immune system for up to 24 the body’s immune system for up to 24 hours after exposure to the sun.hours after exposure to the sun.

• Repeated overexposure to UV radiation Repeated overexposure to UV radiation can cause more damage to the body’s can cause more damage to the body’s immune system, even in people with immune system, even in people with dark skin.dark skin.

UV Health Effects

• Short Term overexposure to UV-B:– UV-B causes sunburn (erythema)

– Sunburn can prevent your body from eliminating heat efficiently and can contribute to heat stress

• Long Term overexposure to UV-B:– Several severe sun burns linked to melanoma

– One person dies of skin cancer per hour in the U.S.

– Sustained exposure linked to squamous and basal skin cancers – non lethal

– Cataracts of eyes

• Long Term overexposure to UV-A:– Aging of skin

– Loss of elasticity (leathery look)

• Small amounts of UV radiation needed for Vitamin-D

Protection to UV-B Exposure

Guidelines for Protection

Eye Protection

Guidelines for Protection

Tanning Protection

Guidelines for Protection

Protective Clothing

Indirect Effects Having Effects on Human survival (Agricultural Productivity)

N fertilizer factory in Rice-field (cyanobacteria)

Rice-field

Rice-field

Anabaena

Calothrix

Scytonema

N. commune

UV-B effects on Ultrastructure of Cell

UV-B effects and loss of photosynthetic pigments

Effects of UV-B on total protein profile

Gene Expression with UV-B

• Gene expression in Synechocystis sp. PCC 6803 [----------------------------------------------]

3168 (ORFs)

DNA Microarray

UV-B Dose Transcript Response Induction Repression20 µE m-2 S-1 (120 min) 20 min 55 (2 fold) 44 (2 fold)120 min 21 4060 µE m-2 S-1 (120 min) 146 159

PsaA & PsaB - about 20 fold repression after 2 h(for PS I)D1 processing protease (ctpA) - 2 to 3 fold increasePBS-apcA, B, C, E,

cpcA, B, C, D, G - Down regulation

Scytonemin as a photoprotective compound

0 min 5 min 10 min 15 min 20 min 25 min

Water Blooms

Concern for Human Health

1- Lakshmikund 2- Durgakund 3- Kandawa pond4- Laat Bhairov pond5- Pishach Mochan Kund

1

2

3

4

5

Polluted Pond

Why Concern for Human Health?

Presence of Toxic Cyanobacterium • Over growth of Microcystis aeruginosa bloom• Shows allelopathic effects• Appears due to eutrophication

Health Concern• Produces hepatotoxin• Microcystin a heptapeptide having MW of 909 to 1067 dalton• Very stable and not easily biodegradable• Dose more lethal than cobra toxin• Released in pond water• Killings of human, pets, fishes etc. reported

ColonyMorphology

BIOASSAYS

Survival (LD50)

Circulatory complications

Liver morphology

Peripheral Blood Supply

Peripheral Blood Supply

IP

100 μl Cell freecrude extract (1.5 mg mcyt)

Loss of blood Supply

Control

Treated

Normal blood supply

Control

10.31% increasein %L/B ratio

Blood pooling andleakage of blood

capillaries

100 μl Cell freecrude extract(1.5 mg mcyt)

IP

Remedial Approach- 1

RawMaterials

Process Waste RECOVERYOf valuable compounds

Water EnergyRECYCLING

New Products

The Five R Policies:

• Process modifications aimed at the reduction of waste• Feedstock substitutions seeking the replacement of toxic or hazardous raw materials for more environment-friendly inputs 3. Efficient use of water, energy or inputs by means of reuse and/or recovery practices4. Good housekeeping and management practices, applying the reuse and/or recovery practices

Remedial Approach-II : Biotechnological Tools

Microbes: The Real Player• Natural selection• Genomic Modifications

Approaches• Isolate mutants • Modify cell functions/metabolism• Develop super strains by Rec-DNA Technology (GEM/GMO)

Purpose

• Use in Bioremediation• process development

Transposon

Genome

Plasmids

OCT

CAM - Camphor

OCT - Octane

XYL - Xylene

NAH - Naphthalene

DEVELOPMENT OF BACTERIAL STRAIN FOR DEGRADATION OF VARIOUS ORGANIC POLLUTANTS

Biotechnological Approach

Biotechnological Tools

CAM

C + T

XYL NAH

Biotechnological Approaches:

A. Bioremediation

• Can be done on site• Keeps site disruption to a minimum• Eliminates transportation costs and liabilities• Eliminates long-term liability• Uses biological systems, often less expensive• Can be coupled with other treatment techniques into a treatment train

B. Bioremediation Types;

1. Phytoremediation2. Microbial Systems: single strain/Microbial consortiums

For remediation of various pollutants/xenobionts such as industrial wastes,pesticides, heavy metals etc. Commercially available metal biosorbents BIOCLAM: Bacillus AlgaSORB: AlgaeBIO-FIX: Ulva sp., Spirulina, Saccharomyces cerevisiae, Lemna sp.

Commonly Used Genetically Engineered Microbes

Name Altered Trait Genets Transferred

Pseudomonas Altered pathway regula- Tol plasimid catabolic enzymestion

E. coli Metal removal from waste Metallothionein (human) waterE. Coli Polychlorinated biphenyl Entire pathway (Pseudomonas sp.)

metabolism

In-vivo Engineering of Bacteria for the Degradation of Xenobiotics and Toxic Wastes

Bacterium Substrate

Pseudomonas cepacia 2,4,5-trichlorophenylacetic acidP. Putida ChlorobenzenesAlcaligenes sp. Dechlorophenoxyacetic acid

mixed chlorophenols

Thanks