What is Ambient Air?

The air that makes up the typical outside environment is a mixture of gases, but it’s usually about 78% nitrogen and about 21% oxygen. The remaining 1% is a mixture of carbon dioxide, methane, hydrogen, argon, and helium. It has no smell, color, or taste, and most people don’t spend much time thinking about what exactly it is they’re breathing on a day-to-day basis. Ideally, and perhaps originally, the air composition was more or less the same everywhere on the planet. Oxygen levels tend to be more plentiful near sea level, so some changes are usually inevitable at high elevations, but in general ambient air should be about the same everywhere. It isn’t, but this is usually more the fault of humans and human-driven pollution than any sort of natural phenomenon.

Human activities, such as manufacturing and the burning of fossil fuels, cause changes in the chemical composition of the air through the release of chemical and industrial pollutants into the atmosphere. Air pollutants may include gases or particulate matter, which are small particles of dust, smoke, ash, pollen, and other substances. Many air pollutants have been found to be harmful to both the environment and human health. Pollutants known to have adverse health effects are called criteria pollutants. Criteria pollutants include ozone, lead, carbon monoxide, nitrogen dioxide, sulfur dioxide, and particulate matter.

Certain populations are most likely to be adversely affected by criteria pollutants. These include infants, children, the elderly, and people with cardiopulmonary conditions. In children, criteria pollutants have been shown to increase the risk of respiratory tract infections and worsen the severity of asthma attacks. In adults, exposure to particulate matter is associated with an increased risk of hospitalization and death due to cardiovascular disease. People who live in places with extreme pollution are often advised to wear protective masks on their faces during particularly bad days or, better yet, simply stay home.

Changes to air composition can cause problems for more than just people. Pollution and atmospheric shifts are one of the contributing factors many scholars point to when explaining the global warming phenomenon, for instance, and these shifts are often thought to undermine the ideal workings of the earth’s greenhouse effect. When the atmosphere gets heavy with smog or other pollutants, it can trap solar radiation in the lower atmosphere, which artificially boosts temperatures and can lead to any number of problems with plant and animal life, as well as things like tidal patterns, ocean depths and temperatures, and ice cap densities.

Air pollution also contributes to depletion of the ozone layer, the region of the atmosphere that protects the Earth from harmful types of ultraviolet radiation. Acid rain, which is basically rainfall that contains toxic chemicals along with ordinary water, is also a possible side effect of long-term changes in air composition.

There are a couple of things people can do to help prevent further damage to ambient air standards around the world. First, and most importantly, they can work to lessen emissions from cars and manufacturing facilities. Legislation and the force of national laws is one way to help encourage these sorts of changes. The United States, for instance, enacted the Clean Air Act in 1970 to set limits on emissions and penalties for violators. The act also set national standards for certain pollutants in order to safeguard the public health, ensure the welfare of animals and crops, and protect the health of the Earth’s ecosystems. Many other countries have similar regulations in place.