micro and macro pollution

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MICRO AND MACRO POLLUTION Air pollution problems may occur on three scales: micro, meso, and macro. MICROSCALE problems range from those covering less than a centimeter to those the size of a house or slightly larger. MESOSCALE air pollution problems are those of a few hectares up to the size of a city or country. MACROSCALE problems extend from counties to states, nations, and in the broadest sense, the globe. Indoor Air Pollution People who live in cold climates may spend more than 90% of their time indoors (Lewis, 2001). In the last 3 decades, researchers have identified sources, concentrations, and effects of air pollutants that arise in conventional domestic residences. The startling results indicate that, in certain instances, indoor air may be substantially more polluted than the outdoor air. Indoor tobacco smoking is of particular concern because of the carcinogenic properties of the smoke. While mainstream smoking (taking a puff) exposes the smoker to large quantities of toxic compounds, the smoldering cigarette in the ashtray (sidestream smoke) adds a considerable burden to the environment. Bacteria, viruses, fungi, mites, and pollen are collectively referred to as bioaerosols. They are require a reservoir (for shortage), an amplifier (for reproduction), and a means of dispersal. Most bacteria and viruses in indoor air come from humans and pets. Other microorganisms and pollen are introduced from the ambient air through either natural ventilation or through the intakes of building air – handling systems. Humidifiers, air – conditioning systems, and other places where water accumulates are potential reservoirs for bioaerosols. ACID RAIN Unpolluted rain is naturally acidic because CO2 from the atmosphere dissolves to sufficient extent to form carbonic acid.

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Page 1: Micro and Macro Pollution

MICRO AND MACRO POLLUTION

Air pollution problems may occur on three scales: micro, meso, and macro.

MICROSCALE problems range from those covering less than a centimeter to those the size of a house or slightly larger.

MESOSCALE air pollution problems are those of a few hectares up to the size of a city or country.

MACROSCALE problems extend from counties to states, nations, and in the broadest sense, the globe.

Indoor Air Pollution

People who live in cold climates may spend more than 90% of their time indoors (Lewis, 2001). In the last 3 decades, researchers have identified sources, concentrations, and effects of air pollutants that arise in conventional domestic residences. The startling results indicate that, in certain instances, indoor air may be substantially more polluted than the outdoor air.

Indoor tobacco smoking is of particular concern because of the carcinogenic properties of the smoke. While mainstream smoking (taking a puff) exposes the smoker to large quantities of toxic compounds, the smoldering cigarette in the ashtray (sidestream smoke) adds a considerable burden to the environment.

Bacteria, viruses, fungi, mites, and pollen are collectively referred to as bioaerosols. They are require a reservoir (for shortage), an amplifier (for reproduction), and a means of dispersal. Most bacteria and viruses in indoor air come from humans and pets. Other microorganisms and pollen are introduced from the ambient air through either natural ventilation or through the intakes of building air – handling systems. Humidifiers, air – conditioning systems, and other places where water accumulates are potential reservoirs for bioaerosols.

ACID RAIN

Unpolluted rain is naturally acidic because CO2 from the atmosphere dissolves to sufficient extent to form carbonic acid.

OZONE DEPLETION

Without ozone, every living thing on the Earth’s surface would be incinerated. (On the other hand, as we have already noted, ozone can be lethal). The presence of ozone in the upper atmosphere (20-40km and up) provides a barrier to ultraviolet (UV) radiation. The small amounts of UV rays that do seep through provide you with your summer tan. Too much UV, however, will cause skin cancer.

Page 2: Micro and Macro Pollution

GLOBAL WARMING

To understand the physics of global warming, we will use the simplest model of energy balance. It does not take into account location on the planet, time, precipitation, wind, ocean currents, soil moistures, or any of a number of other variables.

SOLAR CONSTANT

The solar constant is the average annual intensity of the radiation that is intercepted by the cross section of a sphere equivalent to the Earth’s diameter, normal to the incident radiation just outside of Earth’s atmosphere.

A fraction of the radiation that reaches the Earth is reflected back into space. The ratio of the radiation reflected by an object to that absorbed by it is called the albedo.

The actual temperature differs from the blackbody temperature because of the greenhouse effect.

GREENHOUSE GASES

At the other end of spectrum, radioactively active gases that absorb at wavelengths greater that 4 micrometer are the greenhouse gases (GHCs). This absorption heats the atmosphere, which radiates energy back to the Earth as well as into space.

KYOTO PROTOCOL

The framework convention for the protocol was signed in 1992. In 1997, the protocol targets for industrialized countries to reduce their GHG emission were finalized. To become legally binding two conditions had to be fulfilled:

• Ratification by 55 countries.

• Ratification by nations accounting for at least 55% of emissions from 38 industrialized countries plus Belarus, Turkey, and Kazakhstan.