Lead is a naturally occurring element found in nature in the form of ores; it is a heavy, soft, malleable bluish metal. The history of it's use traces back many centuries. The oldest known lead object was a statue excavated in Turkey and dated somewhere around 6500 B.C. During the Roman Empire, lead was used extensively in many aspects of life; to line vessels that stored water and wine, in utensils, and, in combined form, as a glaze on pottery.
In more recent years lead was widely used to extend the protective properties of paints, helped automobiles attain better fuel efficiency, protected occupation ally exposed workers from harmful radiation and provided a suitably dense material for ammunition and fishing weights. Even though it is no longer used in many of these applications, millions of homes remain painted with lead paint. It's been estimated that approximately 94% of the residential housing in San Francisco was built prior to 1978 and probably has lead-based paint.
HUD estimates that 1 in 11 American children have elevated blood lead level, and that 57 million homes and apartments have lead-based paint. Lead-based paint chips, as well as soil and household dust contaminated with lead are the primary sources of childhood lead poisoning, typically from hand-to-mouth contact with lead contaminated dust, soil and water. We often talk about "chewable surfaces" such as window sills that a toddler might chew on, however a primary source comes from children touching old painted surfaces and then hand to mouth contact either directly or through food consumption.
- Lead carbonate ("white lead") - white pigment most commonly used in house paint.
- Lead Acetate - commonly used in paint, varnish and other coatings.
- Lead oxide ("red lead") - commonly used as primer on steel to prevent corrosion.
- Gray or Blue Lead - commonly used on ships for corrosion control.
- Lead chromate - commonly used on highways, parking structures, etc..
In the late 1950′s, Paint manufacuters voluntarily reduced lead content of most paint for residential use. In 1978 the Consumer Product Safety Commission limited paint for residential use to 600 parts per million (600 ppm). Lead paint for non-residential use is still manufacured and sold.
There are numerous federal, state and local regulations that relate to lead and lead exposures. Three of the major federal regulations are:
- OSHA – 29 CFR part 1926.62 which regulates occupational exposure in the construction industry and applies to employees of employers.
- HUD – Dept. of Housing and Urban Development developed "Guidelines for the Evaluation and Control of Lead-Based Paint hazards in Housing".
- EPA - the "Real Estate Notification and Disclosure Rule". Copies of the EPA pamphlets and other information can be obtained by calling the national lead "hot line" at +1 (800) 424-LEAD.