First introduced in U.S. grocery stores in 1977, over 380 billion plastic shopping bags are used in the U.S. annually, according to the EPA. By 1996 four out of five grocery bags were plastic. Only a fraction of the plastic bags are recycled (0.6 percent), but about 100 billion plastic bags are thrown away by Americans. It takes a 1,000 years for plastic bags to degrade.

It is estimated that 500 trillion to 1 trillion plastic bags are used globally, or one million bags per minute. Almost 80 percent of plastic bag use is by North American and Western Europe. Asian countries produce a quarter of the plastic bags used in Western countries.

Plastic bags contain chemical additives which can be harmful to human health and the environment. Among the chemicals contained in plastic bags are lead, cadmium, mercury, and the carcinogen diethylhexyl phthalate.

Producing plastic bags requires petroleum and sometimes natural gas. The environmental organization, Californians Against Waste says that if the state of California alone cut out half of the plastic bag use over 2,000 barrels of oil would be saved, and 73,000 tons of garbage would be eliminated from landfills. According to the Worldwatch Institute, it takes 430,000 gallons of oil to produce 100 million plastic bags.

The World Watch Institute estimates that plastic bags cost U.S. retailers $4 billion annually. Retailers in turn pass the cost of the �free� plastic bags on to consumers in the form of higher product prices. WSJ Target, the second largest retailer in the U.S., purchases 1.8 billion bags per year.

Plastic bags are toxic to animals. An estimated 100,000 birds, marine mammals, whales, and sea turtles die from eating plastic bags every year. The animals either choke on the bags or suffer from intestinal blockages.

The world cracks down

The Republic of Ireland enacted a 15 cents tax on plastic shopping bags in 2002. The tax curbed the use of plastic bags by 90 percent. An estimated 1.2 billion plastic shopping bags were handed out every year prior to the tax in the Republic, according to the environment ministry. During the three-month period after the tax about 277 million fewer bags were handed out.

Bangladesh banned plastic shopping bags in 2002. During the 1988 and 1998 floods, it was discovered that the bags blocked drainage systems, and were one of the main causes of the floods. Taiwan, Singapore, South Africa, and a number of East African countries also banned plastic shopping bags.

San Francisco became the first city in North America to ban the plastic bags from supermarkets and chain pharmacies this spring. Sponsored by Ross Mirkarimi, member of the city�s Board of Supervisors, the ban will take place in about six months in supermarkets and a year in chain pharmacies.

The Swedish housewares chain IKEA began to charge five cents per plastic bag March 15. Up to $1.75 million of the proceeds from the bags will be donated to the conservation group American Forests. IKEA will sell reusable blue bags for 59 cents, previously 99 cents. IKEA estimates that the amount of plastic bags used in their U.S. stores will be reduced by 50 percent. The program first began in IKEA�s British stores in 2006.