Glenn Ray, Attaway, Denise | 4/17/2009 9:10:22 PM
Lead is a naturally occurring blueish-gray metal. It also is considered one of the heavy metals, like mercury. Lead is very abundant and mined in numerous counties around the world including the United States. Because lead is soft, it is also very malleable which has contributed to a wide array of uses.
The use of lead dates back at least 5,000 years. Ancient Romans used lead to create Rome’s impressive plumbing system and aqueducts. In fact, the English word for plumbing comes from the Latin word “plumbus” which means “lead.”
Uses of Lead
Not only was lead used in plumbing, but both ancient and modern civilizations have found many additional uses for lead. Early uses of lead include building materials, pigments for glazing ceramics, and pipes. In the early 1900s, the major uses for lead in the United States were for ammunition, burial vault liners, glazes in ceramics, leaded crystal and windows, paints and coatings, and pipes. Modern uses of lead are lead acid batteries, solders, as an additive to paint for a mildewcide or pigment, and cable covering to name a few.
Lead is toxic. The human body has no use for lead, so even small amounts can be toxic. The most notable health effect of lead is in the mental development of young children. Some studies indicate that even a small amount of lead in the blood can cause loss of IQ points. Lead affects the nervous system in children and adults. Medical studies in Australia are examining a possible link between lead poisoning and dementia in older adults. Long term or chronic exposure to lead may cause damage to the blood-forming, nervous, urinary and reproductive systems.
How to Test for Lead Exposure
The only accurate way to test for lead poisoning is by doing a blood test. A level of 10 micrograms per deciliter of blood or greater is considered elevated. In Louisiana, all children under 6 years old are to be tested for lead.
In the past, children became contaminated with lead from either chewing on lead-based paint or from breathing lead fumes in the air. In 1978, Congress passed legislation prohibiting lead-based paints for residential use. Lead also has been removed lead from gasoline in automobiles to reduce the environmental risk factors. However, lead paint is still very common in older, pre-1978 homes, in soils, and in numerous imported items.
A major problem in recent years is children becoming lead poisoned from adults bringing home lead dust. Imagine dad is working on older homes in New Orleans damaged by Hurricane Katrina. Many of these older homes have lead-based paint under several coats of new paint. Dad, unknowingly, is exposed to and covered with dust, dust which contains lead from the paint, during the demolition of parts of the building. At the end of the work day, dad goes home and brings and hugs his children, still in the same dusty, lead covered clothing. The children inhale the dust from dad’s clothing and become contaminated. It’s innocent, tragic and played out too many times.
What can be done?
You should take steps to limit the amount of dust created on a particular project either by not using power equipment or using dust suppression methods. Workers who are possibly exposed to lead dust should shower and change clothing before going home. Don’t laundry these clothes with other clothing.
You may wish to have your home tested for lead-based paint. A list of trained inspectors certified by the State of Louisiana Department of Environmental Quality is available on the internet at www.deq.louisiana.gov.
The United States Department of Housing and Urban Development (HUD) and the United States Environmental Protection Agency (EPA) have created a program for Lead Safe Work Practices. All contractors working on property built prior to 1978 where children may be present will be required to have training in Lead Safe Work Practices by 2010. In addition, renovation contractors, and landlords are required to provide an Information Pamphlet, “Protect Your Family from Lead in Your Home,” available from the EPA.
Diffusion will allow moisture to enter but the quantity will be small. Instead of spending money to prevent diffusion, it is more cost effective to allow whatever is left to pass through and be removed by the home’s HVAC system. The key with diffusion is not to install a vapor retarder on the wrong side of the wall and stop it’s progress. What kind of vapor retarder would we install inside the home - vinyl wallpaper. In a hot humid climate it is preferred to finish the walls with a breathable coating such a latex paint.