Comparing injury statistics with environmental disease for the US (population 260 million): each year people die from

• 720,862 heart attacks• 514,657 cancer (150,000 lung cancer, 85% related to

smoking)• 500,000 (estimated) strokes• 390,000 estimated diseases related to smoking

(approximately one in every six deaths)• 100,000 (estimated) alcohol• 43,536 motor vehicle accidents - 17,900 vehicle-vehicle - 11,900 vehicle-fixed o bject - 6200 vehicle-pedestrian - 2394 motorcycles - 800 vehicle-bicycle - 600 vehicle-train• 30,810 suicides (~18,526 from firearms)• 29,555 AIDS• 9100 work, nonmotor vehicle, and 22,500 accidents in

the home - 12,662 falls (7000 at home) - 4120 fires (3200 at home) - 2900 suffocation-ingestion (1900 at home) - 4621 drowning (800 at home, 312 in bathtub)• 26513 homocides, 5000 unsolved murders• 1833 carbon monoxide (suspected suicide, 50%)• 93 lightning• 90 vernomous animals and plants

• Death estimated due to environmental causes such as

- radon or secondary smoke ~ 3500 people

one-half of people die from fall at home

Table 1-1 shows the number of deaths and disabling injuries from several industries

Environmental illness is difficult to define for three reasons

•Many environmental diseases are indistinguishable from diseases generally•The relationship between a disease and the environment is not always recognized•Many diseases have long latency periods and occur after exposure has ceased or the person has removed to another part of the country

Two notorious air pollution episodes resulting in the loss of life

• Donora, Pennsylvania in 1948: 20 people dies when SO2 and other particle emissions accumulated during a 5-day period

• The London fog of 1952: several thousands people are believed to have died from large concentrations of SO2 that accumulated over a period of approximately a week

- SO2 as high as 1.3 ppm

- total particles of 4.5 mg m-3 = 4500 ug m-3

were recorded.

- the conditions during these episodes were characterised by

- heavy fogs

- low inversion levels

- the inversion heights so low that occasionally the tops of the

stack of a power station (~337 feet) were above the fog

- in some locations, inversion heights as low as 150 feet occured

Anderson, 1999

Air pollution and death•Air pollution is one of many factors involved in the death of older people (infant, etc) suffering from

- chronic bronchitis: inflammation of the bronchi, or air passages of the lung

- heart disease

- emphysema: a lung condition in which the air spaces in the lungs are enlarge

- asthma

- bronchopneumonia: infection extend from the air passage between the windpipe and the lungs to the lungs

Air pollution often is not the immediate cause of death as in the case of industrial accidents

Why air pollution are importance•Risks associated with the air we breath comprise the ultimate involuntary risk

•Risk of unwanted climate change are involuntary risks for which remedy take decades to implement

•Risks to Earth’s forests and waters require decades to correct

The exponential growth of population and its related exponential increase in pollutant production represents a clear and present danger that must be addressed while we have time to do so

Summary

•Pollution is the unwanted consequence of deliberate decisions about industrial activity and the allocation of financial resources.

•Political institution have it within their power to make rational decisions and reduce the emission of pollutants to the atmosphere

Future?

• In year 2050 the Earth is dying (too polluted for homo sapiens (human) to live on, and too crowded (~ 10 billions), colonization on other planet such as Mars is the only hope…

-- the Red Planet (2000)

• Many episodes in Star Treks where planets are too polluted to survive

1.3 Risk management and assessment

• Risk management is the goal of personal and government policy• Risk assessment is an activity that estimates the spectrum and

frequency of accidents and negative events• Public acceptance of risk depends more on public confidence in risk

management than on informed use of the quantitative estimates of the consequences, probabilities, and magnitudes on undesirable consequences.

• The nation’s future economy depends on sustaining preeminent role in the development of new products and maintaining or reassuming a position of leadership in process technology.

• The building blocks of advanced products are metals, polymers, ceramics, semiconductors, and composites that are assembled sometimes molecule by molecule.

• Some steps in the process involve exotic hazardous materials such as carcinogenic organics, highly toxic gases, and submicron particles to whose surface highly active organics have been added.

PAHs + PM10/PM2.5

Figure 1.3 Percent of materials for which health hazards are known

Assessing risk requires:

•Knowledge of the actual amount of the materials used

•The percent of amounts of the materials discharged to the environment

•Working Steps

1. To identify the amounts of materials used over a period of time

2. Estimate the amount remaining in the products

3. The amounts removed as waste

4. The amounts that escape to the environment

1.5 Pollution control system: Grouping according to the physical processes used to separate

pollutants from their carrier gas

•Particle control system

- Settling chambers (gravity)

- Cyclones (inertial separation)

- Filtration (inertial separation and diffusion)

- Electrostatic precipitators (electrostatic forces)

- Wet scrubbers (inertial separation and diffusion)

•Gas vapor control systems

- Wet scrubber (absorption)

- Activated charcoal (absorption)

- Thermal destruction (chemical oxidation): direct flame or catalytic

- Biological oxidation (biofiltration and bioscrubber)

- Advanced oxidation (chemical reactions initiated by ultraviolet light (UV) augmented by ozone and hydrogen peroxide

Figure 1-4 Gravimetric settling devices: element devices that remove large particles

Settling chambers and cyclones are often used upstream of high-efficiency devices to remove large particles, allowing high-efficiency devices to remove the smaller particles

Figure 1-7 Particle collectors using filters (baghouse)

Mechanical shaking

Reverse-flow cleaning

Pulse-jet cleaning

Figure 1.8 Electrostatic precipitators (EPS)These areHigh-efficiencyParticleCollectors thatRemove smallParticles fromAn airstream

Principle of Electrostatic Precipitators (ESPs)

• A ESP consists of

- dozens of large vertically mounted plates

- hundreds of vertically mounted small-diameter wires

1. High-voltage applied to the wire produces a corona that

generates electrons these electrons transferred to airborne particles

2. The electrically charged wire and plates also establish an electric field.

3. This electric field causes the charged particles (1) to migrate laterally and attach themselves to the plates.

4. The plates are rapped mechanically to let large fragments of the deposited dust to slack off and fall to hoppers below

Sensitivity and Use of ESPs

• ESPs is very sensitive to

- variations in the gas volumetric flow rate

- the electric resistance of the collected dust

• ESPs are commonly used to clean large steady volumetric flow rates of gases, such as in

- coal-fire electric utility boilers

- lime kilns

- cement kilns

A Real-World Example:Wheelabrator Air Pollution Control, Inc

Pulp and Paper

Wood-waste-firedcogeneration

Oil refinery

Figure 1-9 Scrubber

The packingCreates a Large surface Area ---------------

Figure 1-12 Bubblecap scrubbers

Figure 1-12ABubblecapScrubber: UsingNumerous trays Through which The gas is bubbledTo achieve the Gas-liquid Interaction to Remove particleAnd gaseous pollutants