Transcript
ADVANCES IN
ENVIRONMENTAL
HYGIENEBy: Abdulrahman Mohammed
(L-2012-V-21-D)
School Of Public Health and Zoonoses, GADVASU, Ludhiana
DEFINITIONSEnvironmental Hygiene: is that branch of public health that is concerned with the control of all those factors in man’s surroundings or physical environment which may have deleterious effect on human health and wellbeing
Alternatively, it could be defined as all those aspects of public health that are determined by physical, chemical, biological, social and psychological factors in the environment.
It also includes theories and practices of assessing, correcting, controlling and preventing the factors present in the environment that can potentially affect the health of present and future generations.
Environmental sanitation: refers to interventions to reduce people’s and animals’ exposure to disease by providing a clean environment in which to live and these measures break the cycle of disease.
Objectives of Environmental
Hygiene
Prevention and control of:
Biological hazards
Chemical hazards
Physical hazards
Sociological hazards and psychological
hazards.
Scope of Environmental Hygiene
Water supply
Waste-water treatment and water pollution control
Solid waste management
Vector control
Prevention and control of soil pollution
Food hygiene
Air pollution control
Radiation pollution control
Noise pollution control
Occupational health
Scope of Environmental Hygiene
cont.…
Housing with particular reference to public health aspects
Urban and regional planning
Environmental health aspects of air, sea or land transport
Accident prevention
Public recreation and tourism
Sanitation measures during epidemics, emergencies, disaster and population migration
Wildlife and forest conservation
Preventive measures to ensure freedom from health risk of the general environment.
Advances in environmental hygiene
includes:
Carbon sequestration
Bioremediation
Rain water harvesting and artificial recharge
Echo-friendly technologies in India
Carbon sequestration
Also known as “carbon capture”
A geoengineering technique for the long-term storage of carbon
dioxide (or other forms of carbon) for the mitigation of global warming
More than 33 billion tons of carbon emissions (annual worldwide)
Ways that carbon can be stored (sequestered):
In plants and soil “terrestrial sequestration” (“carbon sinks”)
Underground “geological sequestration”
Deep in ocean “ocean sequestration”
As a solid material (still in development)
Terrestrial Carbon
Sequestration
Terrestrial Carbon Sequestration
The process through which Co2 from the atmosphere is absorbed naturally through photosynthesis & stored as carbon in biomass & soils.
Tropical deforestation is responsible for 20% of world’s annual Co2
emissions, though offset by uptake of atmospheric Co2 by forests and agriculture.
Ways to reduce greenhouse gases:
avoiding emissions by maintaining existing carbon storage in trees and soils
increasing carbon storage by tree planting or conversion from conventional to conservation tillage practices on agricultural lands
Terrestrial Carbon Sequestration
(continued)
Carbon seq. rates differ based on the species of tree, type of soil, regional climate, topography & management practice
Pine plantations in SE United States can accumulate almost 100 metric tons of carbon per acre after 90 years (~ 1 metric ton : 1 year)
Carbon accumulation eventually reaches saturation point where additional sequestration is no longer possible (when trees reach maturity, or when the organic matter in soils builds back up to original levels before losses occurred)
After saturation, the trees or agricultural practices still need to be sustained to maintain the accumulated carbon and prevent subsequent losses of carbon back to the atmosphere
Geological Sequestration
Storing of CO2
underground in rock
formations able to
retain large amounts of
CO2 over a long time
period
Held in small pore
spaces (have held oil
and nat. gas for millions
of years)
Layers shown: Coal, brine aquifer, gas bearing sandstone, gas bearing shale
Geological Sequestration
(case study)
Midwest Geological Sequestration Consortium (Illinois Basin)
assess geological carbon sequestration options in the 60,000 square mile Illinois Basin (Within the Basin are deep, noneconomic coal resources, numerous mature oil fields and deep saline rock formations with potential to store CO2)
Feb 2009: Successfully completed 8,000 ft deep injection well
By 2013, a total of one million metric tons of carbon dioxide (roughly the annual emissions of 220,000 automobiles) is expected to be stored within the formation.
Ocean Sequestration
Ocean Sequestration
Carbon is naturally stored in the ocean via two pumps, solubility
and biological, and there are analogous man-made methods,
direct injection and ocean fertilization, respectively.
Eventually equilibrium between the ocean and the atmosphere
will be reached with or without human intervention and 80% of
the carbon will remain in the ocean.
The same equilibrium will be reached whether the carbon is
injected into the atmosphere or the ocean. The rational behind
ocean sequestration is simply to speed up the natural process.
Ocean Sequestration
Carbon sequestration by direct injection into the deep ocean involves the capture, separation, transport, and injection of CO2 from land or tankers
1/3 of CO2 emitted a year already enters the ocean
Ocean has 50 times more carbon than the atmosphere
Current Status Carbon
Sequestration
At the global level, the IPCC Third Assessment Report estimates that
~100 billion metric tons of carbon over the next 50 years could be
sequestered through forest preservation, tree planting and improved
agricultural management.
Offset 10-20% of estimated fossil fuel emissions
Carbon Sequestration is not yet viable at a commercial level
Small scale projects demonstrated (lab experiments) but CS is still a
developing technology
Concern with injecting carbon dioxide into ground or ocean
because fear of leaks into water table or escape of CO2 into a massive bubble that can potentially suffocate humans and animals
Bioremediation
Biodegradation - the use of living organisms such as bacteria, fungi, and
plants to degrade chemical compounds
Bioremediation – process of cleaning up environmental sites
contaminated with chemical pollutants by using living organisms to
degrade hazardous materials into less toxic substances
Bioremediation: Purpose
Initiative of the U.S. Environmental Protection Agency (EPA)
To counteract careless and even negligent practices of chemical dumping and storage, as well as concern over how these pollutants might affect human health and the environment
To locate and clean up hazardous waste sites
Bioremediation
Environmental Genome Project
Purpose is to study and understand the impacts of
environmental chemicals on human disease
Why use bioremediation?
Most approaches convert harmful pollutants into
relatively harmless materials such as carbon dioxide,
chloride, water, and simple organic molecules
Processes are generally cleaner
Biotechnological approaches
Biotechnological approaches are essential for
Detecting pollutants
Restoring ecosystems
Learning about conditions that can result in human
diseases
Converting waste products into valuable energy
Bioremediation Basics
What needs to be cleaned up?
Soil, water, air, and sediment
Pollutants enter environment in many different ways
Tanker spill, truck accident, ruptured chemical tank at industrial site, release of pollutants into air
Location of accident, the amount of chemicals released, and the duration of the spill impacts the parts of the environment affected
Bioremediation Basics
9.2 Bioremediation Basics
Chemicals in the Environment
Carcinogens
Mutagens
Cause skin rashes, birth defects
Poison plant and animal life
Fundamentals of Cleanup
Reactions
Microbes convert chemicals into harmless substances
by either
Aerobic metabolism (require oxygen) or anaerobic metabolism (do not require oxygen)
Fundamentals of Cleanup Reactions
Aerobic and
Anaerobic
Biodegradation
Stimulating Bioremediation
Nutrient enrichment (fertilization) – fertilizers are added
to a contaminated environment to stimulate the
growth of indigenous microorganisms that can
degrade pollutants
Bioaugmentation (seeding) –bacteria are added to the
contaminated environment to assist indigenous
microbes with biodegradative processes
Cleanup Sites and Strategies
Soil Cleanup
Ex situ bioremediation
Slurry phase bioremediation
Solid phase bioremediation
Composting
Land farming
Biopiles
In situ bioremediation
Bioventing – pumping either air or hydrogen peroxide into the contaminated soil
Cleanup Sites and Strategies
Cleanup Sites and Strategies
Bioremediation of Water
Wastewater treatment
Groundwater cleanup
Cleanup Sites and Strategies
Cleanup Sites and Strategies
Applying Genetically Engineered Strains to Clean Up the
Environment
Petroleum-Eating Bacteria
Created in 1970s
Isolated strains of pseudomonas from contaminated
soils
Contained plasmids that encoded genes for breaking
down the pollutants
Applying Genetically Engineered Strains to Clean Up the
Environment
E. coli to clean up heavy metals
Copper, lead, cadmium, chromium, and mercury
Biosensors – bacteria capable of detecting a variety of environmental
pollutants
Genetically Modified Plants and Phytoremediation
Plants that can remove RDX (Research Department Explosive) and TNT
(Trinitrotoluene)
Shrishti Eco-Research Institute, Pune, INDIA
Develops eco-friendly technologies to control pollution of water, air and soil.
Soil Scape Filter
Stream Ecosystem
Hydrasch Succession Pond
Phytofiltration and Biox Process
Green lake technologies
Green bridge technologies
Some of the Ecotechnological installations afre described below
It is the simulation of natural filtration of water or wastewater through the
well developed soils and fragmented rock materials below which give
purified water in the form of groundwater. Soil filter contains layers of bio-
active (i.e. biologically activated) soil.
Soil Scape Filter
It involves the use of the natural slopes of the polluted drains, beds, banks
of streams or ponds to enhance the aerobic activity in water by
generating turbulence and providing shallow depths to allow sun– light to
reach the bottom
Stream Ecosystem
It is an application of ecological succession of aquatic plants depending on characteristics of incoming effluents. Various green plants including invasive species are successfully employed in these phytofiltration and phytoremediation processes with ecoremediation to treat organic and inorganic pollution.
Hydrasch Succession Pond
It involves the use of plant fibres, roots to remove suspended solids from
wastewater effectively in well designed tank.
Some of the installations are solids by biosorption methods
Phytofiltration and Biox Process
uses floating, submerged or food web help in the
purification process. These can be termed as
macrophyte ponds also .
Macrophytes are capable to absorb large amounts
of inorganic nutrients such as N and P, and heavy
metals such as Cd, Cu, Hg Zn etc and to engineer the
growth of microbes to facilitate the degradation of
organic matter and toxicants.
Green lake technologies
Green bridge technologies
uses filtration power of biologically originated cellulosic / fibrous material in combination with sand and gravels and root systems of green plants.
Ecotechnological Applications for the Control of Pollution in India
Efficacy of Green Bridge and Green
Lake treatment systems
RAIN WATER HARVESTING (RWH)
RWH refers to collection and storage of rainwater and also other activity such as harvesting surface water extracting ground water , prevention of loss through evaporation and seepage.
PURPOSES OF RWH
Stored for ready use in containersground or below ground
Charged into the ground for withdrawal later
BENEFITS OF RWH
Rainwater harvesting prevents flooding of lowlying areas
Rain water harvesting replenishes the ground water table and enables our dug wells and bore wells to yield in a sustained manner
It helps in the availability of clean water by reducing the salinity and the presence of iron salts.
RHH TECHNIQUES
STORAGE OF RAINWATER ON SURFACE FOR FUTURE USE
RECHARGE TO GROUND WATER
1. SUBSURFACE DAMS
2. CHECK DAMS
3. ROOF TOP CATCHMENTS
4. FARM PONDS
RECHARGE TO GROUND WATER
Recharge bore pit
Recharge well
Spreading basins
Ditches
Hand pumps
RECHARGE BORE PIT
RECHARGE WELL
DITCHES
HAND PUMPS
SPREADING BASINS
References
Sengupta, M. and Dalwani, R. (Editors). 2008. Ecotechnological Applications for the Control of Lake Pollution. Proceedings of Taal 2007: The 12th World Lake Conference: 864-867
Sherikar A.T, Bachhil V.N and Thaplyal D.C. 2001.Textbook of elements of veterinary public health. ICAR, New Delhi.
Chu,S.C and Liaw,C.H 1995-1997 study of industrial rainwater catchment systems(I)-(III). Final Report of Indus. Tech.Res.Inst
Liaw,S.C and Tsai,Y.L.2002. Application of rainwater retardation and retention for a healthy water envirnoment in urban areas.Journal of water resources management
Liaw,C.H., Chen,H.K, Chang, K.c. and Tsai, Y.l. 2000. Feasibility analysis of rainwater catchment systems in taiwan,proc. East Asia 2000 Rainwater utilization symposium:131-144, oct.1,2000,Taipei,Taiwan.
http://en.wikipedia.org/wiki/Carbon_sequestration
http://www.netl.doe.gov/technologies/carbon_seq/index.html
http://www.princeton.edu/~chm333/2002/fall/co_two/oceans/
THINK GREENTHANK YOU FOR LISTENING
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