Lead
Lead is a bluish-gray heavy metal that is naturally occurring in the earth's crust. It is often used in household plumbing materials and water service lines, batteries, and ammunition.[1] In the past, lead was commonly used in paints and gasoline. With its former and current widespread use as well as its natural distribution in the environment, lead has been found in sewage sludge, coal ash and coal waste.[2] The U.S. EPA does not allow any lead in drinking water.[3]. In sewage sludge applied to land, the U.S. EPA limits lead to a concentration of 840 parts per million.[4] In the Targeted National Sewage Sludge Survey, a 2009 test of 84 samples of sewage sludge from around the U.S., the EPA found lead in every sample in concentrations ranging from 5.81 to 450 parts per million.[5]
Lead and coal
Electrical utilities emit lead in flue gas from the burning of fuels, such as coal. A boiler burning a million pounds of lignite coal will release 420 pounds of lead into the atmosphere.[6] The constant leaching of heavy metals from coal mining and coal plants leads to bioaccumulation in plants and animals, creating the danger of toxicity.[7]
Reports filed with the EPA by the Tennessee Valley Authority show the 2008 TVA Kingston Fossil Plant coal ash spill resulted in heavy metal releases, including lead, higher than initially reported. According to the Environmental Integrity Project, "The new Toxics Release Inventory (TRI) data submitted to the EPA by TVA also show that the Kingston ash spill deposited nearly 320 tons of vanadium in the Emory River, or more than seven times the total discharge of this toxic pollutant from all power plants in 2007. The Kingston facility singlehandedly discharged more than of chromium, lead, manganese, and nickel into the Emory River last year than reported discharges of those pollutants from the entire U.S. power industry in 2007. The EIP analysis of the new TVA data finds a total of 2.66 million pounds of 10 toxic pollutants – arsenic, barium, chromium, copper, lead, manganese, mercury, nickel, vanadium and zinc. That compares to the much lower 2.04 million pounds of such discharges from all U.S. power plants into surface waters in 2007."[8]
The EPA Office of Air Quality Planning and Standards (OAQPS) has set National Ambient Air Quality Standards under the Clean Air Act for six principal pollutants, which are called "criteria" pollutants: sulfur dioxide, particulate matter, nitrogen oxides, ozone, lead, and carbon monoxide. After the EPA sets or revises each standard and a timeline for implementation, the responsibility for meeting the standard falls to the states. Each state must submit an EPA-approved plan that shows how it will meet the standards and deadlines. These state plans are known as State Implementation Plans (SIPs)." [9]
U.S. Laws Banning Lead
Because of lead's harmful neurological effects, the U.S. government has phased out many previous uses of lead.
Ban on Lead in Gasoline
As a gasoline additive, lead was phased out and ultimately banned in the United States as of January 1, 1996.[10]
Ban on Lead in Paint
The U.S. government banned use of lead paint in housing as of 1978, but homes built before then may still have lead paint.[11]
Ban on Lead in Plumbing Materials
As of June 19, 1986, the U.S. government banned the use of lead pipes or solder in the installation or repair of any public water system any plumbing in a facility providing water for human consumption.[12] However, the definition of "lead-free" in the law still permitted pipes of up to eight percent lead or solder or flux of up to 0.2 percent lead.
Health effects
The American Academy of Pediatrics has stated that there is no “safe level” of lead for children. In fact, acceptable lead exposure limits for all people have been repeatedly lowered over the years and current scientific understanding suggests that neurological damage can occur at blood lead levels much lower than previously believed. Exposure to small amounts of lead can be harmful. The body stores lead in bones, and small amounts of lead can build up in the body and cause lifelong learning and behavior problems. In particular, small amounts of lead in the body can make it difficult for children to learn, pay attention and succeed in school. Lead is released from a mother’s bones during pregnancy, enters the bloodstream, and crosses the placenta, resulting in harmful effects on the fetus.[6] Lead accounts for most of the cases of pediatric heavy metal poisoning.[13]
Because lead does not degrade, the burning of coal and former uses of lead leave their legacy as higher concentrations of lead in the environment. Levels of lead in the environment have increased more than 1,000-fold over the past three centuries as a result of human activity. The greatest increase occurred between the years 1950 and 2000, and reflects increasing worldwide use of leaded gasoline. In 1979, cars released 94.6 million kilograms (208.1 million pounds) of lead into the air in the United States. In 1989, when the use of lead was limited but not banned, cars still released 2.2 million kg (4.8 million pounds) to the air. The EPA did not ban the use of leaded gasoline for highway transportation until 1996. Leaded gasoline continues to be used throughout the globe, including countries from which the United States increasingly imports its food supply. Lead has also been introduced to our environment through coal burning by utilities, as well as mining activity, the use of lead-based paint, and the application of pesticides that contained metals, such as lead arsenate used in fruit orchards.[6]
Whatever its source, lead that falls onto soil sticks strongly to soil particles and remains in the upper layer of soil. Since it does not degrade over time, this contamination problem continues. It can be taken up by plants, and food processing can often introduce lead contamination through bronze plumbing parts, lead in water, or other sources. In 2010, the Environmental Law Foundation enlisted a U.S. Environmental Protection Agency lab to screen 400 samples from 150 branded food products marketed to children, including apple juice, grape juice, packaged pears and peaches (including baby food), and fruit cocktail mixes. The results: 125 out of 146 products tested, or 85 percent, contained alarming amounts of lead.[6]
Articles and resources
Related GEM.wiki articles
References
- ↑ Lead, Agency for Toxic Substances and Disease Registry website, Accessed August 17, 2010.
- ↑ Targeted National Sewage Sludge Survey Report, US EPA website, Accessed August 17, 2010.
- ↑ U.S. EPA, Lead in Drinking Water, Accessed August 4, 2010]
- ↑ Code of Federal Regulations, Title 40, Chapter 1, Subchapter O, PART 503—Standards for the Use or Disposal of Sewage Sludge, Subpart B—Land Application, Pollutant Limits
- ↑ Targeted National Sewage Sludge Survey Report, US EPA website, Accessed August 28, 2010.
- ↑ 6.0 6.1 6.2 6.3 "Lead in Children’s Foods: Frequently Asked Questions" The Environmental Law Foundation Report, accessed July 2010.
- ↑ Eilene Toppin Ording,"Heavy Metals and Coal: Carbon Footprint Aside, Coal is not Environmentally Friendly" Suite 101, accessed November 2009
- ↑ "EIP: Kingston coal plant released 2.6 million pounds of arsenic," Environmental Integrity Project press release, December 8, 2009
- ↑ "NAAQS" Sierra Club, accessed July 2010.
- ↑ U.S. EPA, Leaded Gasoline Phaseout, Accessed August 4, 2010
- ↑ U.S. EPA, Lead in Paint, Dust, and Soil, Accessed August 4, 2010
- ↑ U.S. Code, TITLE 42 > CHAPTER 6A > SUBCHAPTER XII > Part B > § 300g–6. Prohibition on use of lead pipes, solder, and flux, Accessed August 4, 2010
- ↑ "Heavy Metal Toxicity" Life Extension, accessed November 2009
