CULPRITS IN THE AIR

We all know that the quality of our air is deteriorating. But what are the culprits that foul the air?

Their are seven major air pollutants. These are carbon monoxides, hydrocarbons, sulfur oxides, nitrogen oxides, particulate matter, ozone, and lead.

Carbon monoxide. Carbon monoxide is an invisible, odorless and tasteless gas that is formed when gasoline is burned in the presence of an inadequate supply of oxygen. The gas interferes with the ability of the blood to transport oxygen. Its binds with hemoglobin preventing it from picking up oxygen. Carbon monoxide poisoning results in dizziness and even heart attack because the heart has to pump harder in order to supply oxygen to different parts of the body. About 80 percent of carbon monoxide emissions come from motor vehicles.

Hydrocarbons. Hydrocarbons are organic compounds that contain only hydrogen and carbon. Motor vehicles and industries that use solvents account for about 40 percent of the hydrocarbons in the air. Hydrocarbons released by motor vehicles are actually unburned or partially burned gasoline that combines with oxygen and nitrogen oxide in a series of reactions to form peroxyacetyl nitrite (PAN). PAN is one of the substances associated with the formation of smog. Furthermore, hydrocarbons are narcotic at high concentrations and some are considered carcinogens.

Sulfur oxides. The world health organizations rates sulfur oxides as the worst pollutants. They are formed when sulfur-containing coal is burned. These oxides irritate the respiratory system and aggravate the condition of people who suffer from asthma, bronchitis, emphysema, and other lung ailments. They also damage plants whose leaves become bleached when exposed to sulfur oxides. Moreover, sulfur oxides help caused acid rain formation. They react with water vapor in the air to form acids that lower the pH of rain. More than 80 percent of sulfur oxides emission comes from power plants while the remainder comes from smelters and other industries.

NITROGEN OXIDES. Power plants that use fossil fuels, as well as motor vehicles, are the major sources of nitrogen oxides. Nitrogen oxides irritate the eyes and the respiratory system. They also produce brown haze or photochemical smog and contribute to acid rain formation. They cause fabrics to fade and discolor. They can also destroy crops. Motor vehicles account for more than 40 percent of nitrogen oxide emissions.
PARTICULATE MATTER. Composed of solid and liquid particles of greater than molecular size. Dust and smoke form particulate matter that is visible. Particles that are not visible are called aerosols. Various s,industries power plants, and dust from farms and construction sites are major sources of particulate matter. The particulate matter released by coal plants is actually composed of soot or unburned carbon and unburned mineral matter. particulate matter irritates the respiratory system. They also contain adsorbed toxic metals and carcinogens.
OZONE. We always think of ozone as a good substance because it protects us from harmful ultraviolet rays. However, in the lower portion of the atmosphere, ozone is a pollutant. It can irritate the eyes even at low concentration. At high concentrations, ozone can cause pulmonary edema, hemorrhage, and even death. Ozone is also a constituent of photochemical smog. Moreover, it can cause extensive crop damage, especially to tobacco and tomatoes. It also shortens the life span of automobile tires and other rubber products because it causes rubber to harden and crack. Most of the ozone in the lower troposphere are formed during the formation of photochemical smog from nitrogen oxides.
LEAD. Lead is a heavy metal poison that effects the blood, liver,kidneys, and brain. Most of the lead in the atmosphere comes from the used of tetraethyllead which improves the antiknock qualities of gasoline. Many countries have already replaced leaded gasoline with unleaded gasoline but some countries, including the Philippines, continue to make leaded gasoline available to consumers. The major air pollutants come from motor vehicles. In fact, about one-half of the mass of air pollutants can be traced to motor vehicles.