According to the World Health Organization (WHO) the worst air pollution is undoubtedly in Asia. More than 1.5 million Asians die each year for the effects of air pollution alone, and another half million die from water pollution.

High levels in China and India

Anything over 100 micrograms of particles per cubic meter of air is considered dangerous. But in cities like Taiyuan, China and Delhi, India the levels routinely top 500 micrograms.

The danger is compounded by the fact that so many people in these areas cook indoors with coal briquettes. Particles in the air are a major cause of respiratory ailments in Asia; such ailments are a leading cause of death in China.

Not local but widespread

Although we tend to think of air pollution as a local problem, studies reported in 1995 demonstrate that there are widespread effects. It is reported that air pollution is so pervasive in industrial regions of northeastern North America, Central Europe and eastern Asia that it partly blocks sunlight, counteracting global warming with regional cooling.

Deadly pollutants

The basic law dealing with air pollution is the Clean air Act of 1990, which orders the US Environmental Protection Agency (EPA) to set standards for air quality. EPA monitors air quality at about 3,000 sites for six air pollutants: (1) particular matter — soot and dust (2) sulfur dioxide (3) carbon monoxide (mostly from automobiles (4) nitrogen oxides (5)lead and 6) ozone.

Particulate matter (PM) is measured with an aerodynamic diameter smaller than 10 micrometers down to 2.5 micrometers. This includes dust, dirt, soot, smoke and liquid droplets directly emitted into the air from factories, power plant, cars, construction sites, fires, and natural erosion, as well as particles formed in the atmosphere by condensation or transformation of emitted gases such as sulfur dioxide and volatile organic compounds.

PM is responsible for most health problems like COPD, influenza, asthma and adverse effects in the lower regions of the respiratory tract.

Colorless, odorless, but…

Sulfur dioxide (SO) comes mostly from stationary – source coal and oil combustion, refineries, pulp/paper mills and smelters. Health hazards associated with SO: Impaired breathing, respiratory illness, lung and cardiovascular diseases.

Carbon monoxide (CO) is odorless, colorless and poisonous gas produced by incomplete burning of carbon in fuels. It enters the bloodstream and disrupts delivery of oxygen to the body’s organs and tissues.

Protect your lungs

Nitrogen oxides (NO) can irritate the lungs and lower resistance to respiratory infections. Many urban areas violate the EPA standards on occasional hot summer days when the sun cooks hydrocarbons and nitrogen oxides, thus producing smog.

Ozone (O3) is a colorless gas that affects people with impaired respiratory systems, such as asthmatics and can significantly reduce lung function.

And your kidneys too.

Lead (Pb) can affect us via air, diet, and ingestion of lead in soil and dust. It accumulates in the body in blood, bone and soft tissue. It is not easily excreted and affects the kidneys, nervous system and blood – forming organs. It can cause seizures, mental retardation and/or behavioral disorders. At low doses it is harmful to infants. Today more than 99.8 percent of the lead once added to gasoline in the US has been removed.

Watch the numbers

To measure air quality in urban areas EPA has developed an indicator called Air Quality Index (AQI), formerly the Pollutant Standard Index (PSI). The AQI integrates into a single number emission levels of five major pollutants: Particulate matter, sulfur dioxide, carbon monoxide, ground-level ozone and nitrogen oxide.

AQI measure in numbers: 0-50, good air; 51 to 100, moderate air and over 100 is classified as unhealthy; 201 – 300, very unhealthy, and 301 – 500, hazardous. (Summary from the US Environmental Protection Agency)

(Comments are welcome at roming@pefianco.com)