The use of lead goes back thousands of years for building and plumbing materials, containers, and machine parts. Its soft and malleable nature made it ideal for many of these uses, but it has since been realized over time that its toxic nature is not worth the trouble it has caused in human environments.
This article will highlight the use of lead in older buildings, and its proper removal or reduction, referred to as lead abatement. If done improperly however, lead abatement may lead to a more hazardous situation. Licensed professional contractors should be used.
The most common issue in older homes is lead paint, but in rural areas lead can also be found concentrated in the soil, due to runoff from the pesticides and gasoline products in which it was once found. Lead pigments were eliminated from common paint in 1978, so the concern is with homes built before that year. The paint on windows and walls chips over time, eventually forming dust which is easily breathed in or consumed by children putting their fingers in their mouth. As a toxin, lead affects the nervous system, kidneys, and brain; symptoms include learning difficulties and erratic behavior.
Abatement usually begins with an inspection if a building is under suspicion. The local health department can help find a contractor for examination and removal. If the building is occupied, all residents should be tested for lead poisoning. Relocation may be necessary until the work is finished.
Windows are a strong focus during lead abatement, and it is often recommended that they be replaced entirely if possible, as well as outside porches and steps. Removal of lead paint will involve completely scraping it from the wood or sheet-rock. Dry scraping or sanding is not advised, and chemicals such as methylene chloride must be handled with extreme caution. Dust will be created to a certain degree, and untreated areas should be effectively sealed off with thick plastic sheeting. Disposable coveralls containing a HEPA (High Efficiency Particulate Air) respirator must be worn in the work environment. In some cases certain structures can be removed from the building and treated off-site. Areas being decontaminated should be emptied of all furnishings, carpets, curtains, etc.
In cases where the paint surface is flat and generally undisturbed, enclosure or encapsulation can be applied. This involves the use of flexible coverings, panels, gypsum board, or a special coating to cover the lead paint or seal it in place. Large, flat areas not subject to friction can be easily treated with these methods.