Now You See It, Now You Don't!

TellZall's object for August is Lead Poisoning

Lead is a very useful material that people have used for thousands of years. Lead is a naturally occurring element that, in its basic form, is a heavy, soft, bluish-silver metal. It can be worked easily, melts at the relatively low temperature of 621ºF, resists corrosion, and is commonly found and easily refined. Since at least Roman times, lead has been made into pipe and used to transport drinking water and carry away sewage. The Romans called lead plumbum, which is the source of our word plumbing. Lead has been used to make bullets since the inception of firearms and has been used as a solder and to make containers and various types of weights.

In addition to its use in its elemental, metallic form, various lead compounds also have been used for centuries. Lead carbonate, also called white lead, has long been used as a pigment in paint and in glazes for ceramics. Lead tetraoxide, also called red lead, also has been used as a pigment, as have several other lead compounds. The development of the automobile led to another widespread use of a lead compound. In the early 1920s, Ohio inventor Charles Kettering discovered that tetraethyl lead, when added to gasoline, could prevent pre-ignition, a condition that had led to engine damage.

Unfortunately, lead also is very toxic and can cause considerable and permanent damage to humans. Lead poisoning, also called plumbism, can be contracted in many ways. Among the most common are breathing air and swallowing materials containing lead compounds. Lead poisoning is especially acute in children, whose bodies are damaged as they develop. Lead poisoning can cause brain damage, mental retardation, anemia, liver and kidney damage, hearing loss, hyperactivity, and developmental delays. At high concentrations, it can produce seizures, comas, and death.

Doctors can test for lead poisoning and treatments to remove it are available.

One of the common causes of lead poisoning, especially in children, is swallowing chips of paint containing lead pigment. For centuries, in fact, many paints consisted of little more than white or red lead (pigment) and linseed oil (vehicle), with perhaps the addition of something to make the paint dry more quickly and maybe some other coloring agents. Children, especially the very young, who put painted objects in their mouths were ingesting lead. Chipping or peeling paint produces lead dust that can be absorbed through the lungs or stomach. Because about 75 percent of the houses and apartments built in the United State before 1978 contain lead paint and because one square inch of lead-based paint contains enough lead to poison five hundred children, the health hazard is considerable.

Fortunately, we have recognized the dangers of lead and taken steps to reduce its presence in the environment. Gasoline no longer contain lead and neither, since 1978, do paints. Lead is no longer used to make water pipe or to solder other types of pipe. Removal of lead paint goes in daily and is handled by companies equipped to handle the dangers associated with removal and disposal.

Still, lead is with us and will be for years to come. All of us need to be watchful, especially where kids are concerned, to ensure that we do not consume lead. The Centers for Disease Control and Prevention recommend that all children receive testing at one year old and, if possible, at two. Everyone should learn about lead poisoning - the sources listed below are good places to start - and take steps to avoid exposure and seek treatment if necessary.

Lead in the environment is one thing from the "good old days" that we are better off without.

NOTE: The following links will load in new browser windows.

For more information on lead and lead poisoning, visit:

http://www.cdc.gov/nceh/lead/lead.htm

http://www.epa.gov/lead/nlic.htmm

http://www.nsc.org/ehc/lead.htm

http://www.afhh.org/