This document discusses air pollution and its impacts. It notes that air pollution is the introduction of harmful materials into the atmosphere, which can cause disease, death, and damage to living organisms and the environment. It states that indoor and urban air pollution are two of the worst pollution problems globally. According to the WHO, air pollution caused around 77 million deaths worldwide in 2012. Air pollution is linked to various health conditions like respiratory and heart disease. It also reduces crop yields and damages plants. The document discusses different types of air quality standards and indices used to regulate pollution levels and communicate risks to the public. While some pollution comes from natural sources, most is linked to human activities like burning fossil fuels.

1. Matac CristiMatac Cristi
Grupa: 8213Grupa: 8213

2. Air pollution is the
introduction of
particulates,
biological molecules, or
other harmful materials
into the
Earth's atmosphere,
possibly causing
disease, death to
humans, damage to
other living organisms
such as food crops, or
the natural or

3. Indoor air pollution and urban air quality are listed asIndoor air pollution and urban air quality are listed as
two of the world's worst toxic pollution problems in thetwo of the world's worst toxic pollution problems in the
20082008 Blacksmith InstituteBlacksmith Institute World's Worst PollutedWorld's Worst Polluted
Places report.Places report.[1][1]
According to the 2014According to the 2014 WHOWHO
report, air pollution in 2012report, air pollution in 2012
caused the deathscaused the deaths of aroundof around 77
millionmillion people worldwidepeople worldwide.

4. Air pollution is a significant risk factor for a number of
health conditions including respiratory infections, heart
disease, COPDCOPD, stroke and lung cancer.[2]

5. In India in 2014, it was reported that air pollution had cut crop yields in the most
affected areas by almost half in 2010 when compared to 1980 levels.[56] effect of
air pollution on plants Air pollution injury to plants can be evident in several ways.
Injury to foliage may be visible in a short time and appear as necrotic lesions
(dead tissue), or it can develop slowly as a yellowing or chlorosis of the leaf.
There may be a reduction in growth of various portions of a plant.
AgriculturalAgricultural effectseffects

6. In general, there are two types of air quality standards. The first class of
standards (such as the U.S. National Ambient Air Quality StandardsNational Ambient Air Quality Standards and E.U.
Air Quality DirectiveAir Quality Directive) set maximum atmospheric concentrations for specific
pollutants. Environmental agencies enact regulations which are intended to
result in attainment of these target levels. The second class (such as the
North American Air Quality IndexAir Quality Index) take the form of a scale with various
thresholds, which is used to communicate to the public the relative risk of
outdoor activity. The scale may or may not distinguish between different
pollutants

8. Some air pollution is not directly caused by humans: for example, animals
emit carbon dioxide when they breathe, and volcanoes release sulfur oxide.
However, most air pollution is linked directly or indirectly to human activity.
This means that air pollution can be best controlled by modifying human
activity to burn a smaller quantity of fossil fuels.