Most people rarely give a second thought to garbage. We throw away what we don't need, and it is "out of sight, out of mind." But were the waste-management industry to grind to a halt, Americans would quickly discover how much our way of life has come to depend on someone swiftly and safely removing the waste we produce.

Centuries ago, waste management wasn't much of an issue. Relatively few people inhabited the earth. Trees were cut for fuel and burned without too much adverse effect, and smoke from widely scattered fires dissipated in the atmosphere. Sewage and garbage could be disposed of by individuals on their own property. City efforts to deal with residents' waste go back to at least 500 B.C., when the first known dump was created outside of Athens. The ancient Romans created basic sewer systems. They also had trenches outside of cities where people threw trash, a practice that periodically led to epidemic diseases.

With the advent of the Industrial Revolution in England in the mid-1700s, the problems of managing wastes grew far more serious. City populations swelled as people were drawn from rural areas to work in factories. This generated unprecedented quantities of concentrated garbage, sewage, and other wastes. By the 1800s, smog engulfed London and all manner of wastes were dumped into the Thames River. Thousands of people became ill with typhoid fever when the drinking-water supply became contaminated.

The United States experienced the same types of problems as industrialization grew in the 1800s and early 1900s. By the early 1900s, there were about 300 incinerators in North America. Municipalities also created landfills, basically dumping the week's trash in a mound, compressing it, covering it with dirt, and repeating the process with the next week's load of trash. Early landfills were havens for rats and often leaked wastes into surrounding land and water, including groundwater used for drinking.

Alarm about municipal and industrial waste-handling practices climbed steadily in the early part of the 20th century. Scientists and other experts tried to warn others that poor waste management was a threat to human health and safety. It also was destroying the environment. Not until after World War II, however, did the general public begin to see the air, water, and land as deteriorating because of pollutants. Lakes, streams, and rivers were becoming choked with chemicals that were killing off fish and other wildlife. Burning of wastes containing toxic chemicals, such as mercury, was seriously contaminating the air, leading to an increase in respiratory problems and other ailments. Insecticides, toxic chemicals, and other lethal substances were finding their way into soil used for agriculture and water used for drinking.

Finally, in the mid-1960s, the federal government took action. Studies about industrial and municipal waste handling were conducted. Funds were made available to states to develop waste-handling strategies for their municipalities and industries. The first waste-management legislation was passed in 1965. The Environmental Protection Agency (EPA) was created in 1970 to implement waste handling and other environmental regulations. Laws, such as the Resource Conservation and Recovery Act of 1970 and its 1976 amendments, defined different types of wastes and described minimum actions for waste handling.

Today, waste management is a major U.S. industry, as well as the largest and fastest-growing part of the environmental industry. Waste primarily falls into two categories: hazardous and nonhazardous. Both include a wide variety of materials, but generally, hazardous waste falls under stricter regulations and covers a range of chemical and other wastes. Nonhazardous waste is known as municipal solid waste (MSW) and is what we think of as garbage, including household waste. A $55 billion dollar industry, waste management companies process more than 600 million tons of waste each year, about a third of which winds up recycled, according to Waste Business Journal.com.

Great strides have been made in waste management over the years. But hundreds of millions of tons of municipal and industrial solid and hazardous wastes continue to be generated every year. Properly handling all the waste is the job of the waste management industry.