Pollution, Air

Outdoor Air Pollution

Outdoor air pollution in urban environments is fast becoming a grave threat to urban residents as levels of toxicity increase beyond safe limits. This is especially true in countries where urban centers are rapidly growing and becoming extremely dense, such as India. While developed countries such as the United States, Canada, Australia, and most European countries have government-controlled air quality monitoring apparatuses, the major problem with developing countries is a lack of any urban air quality data collection infrastructure. When real-time pollutant levels in the air remain unknown, it becomes much harder to manage air pollution or to promote public understanding of the subject and its severity.

Whether one lives in a high-income, middle-income, or low-income country, air is regularly contaminated with varying levels of several pollutants. The fundamental pollutants include sulfur oxides (a group of chemical compounds containing sulfur and oxygen), carbon monoxide (a colorless, odorless, and tasteless gas extremely toxic in high levels), nitrogen oxides (a group of chemical compounds containing nitrogen and oxygen), lead (a heavy metal with various industrial uses), ground-level ozone (visualized as smog in high concentrations), and particulate matter (particle pollution). These pollutants were identified as the six most common air pollutants by the Environmental Protection Agency (EPA) and are also referred to as criteria pollutants. According to the EPA, particulate matter and ground-level ozone pollution are currently the most widespread health threats around the world.

Particulate matter is a mixture of microscopic solids and liquid drops suspended in the air and is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, soil or dust particles, and allergens (such as fragments of pollen or mold spores). The larger the particles are, the more hazardous for public health they become.

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