by Jeffrey C. May — May Indoor Air
for Healthy Indoors Magazine Oct-Nov 2018 edition
Up until 1978, nearly all exterior paints and most interior wood-trim paints contained lead pigment. Of all the environmental hazards in homes, lead paint is one of the most serious.
Lead-poisoned children number in the tens of thousands and suffer from reduced learning skills, behavioral and nervous-system disorders, and in the worst cases of poisoning, mental retardation. Lead can also affect unborn children.
The Lead-Paint Myth
One of the most widely believed “myths” is that lead paint tastes sweet, and therefore children eat it and can become lead-poisoned.
In order for something to taste sweet, it must be soluble in water as well as in our saliva, which contains water. Sugar and all artificial sweeteners dissolve in water, so when added to foods (which contain varying amounts of water), they make the foods taste sweet or sweeter. If these chemicals did not dissolve in our saliva, they could not possibly produce the sensation of sweetness in our mouths.
Paints are primarily a mixture of pigment and a liquid vehicle that either dries or hardens, sticking to a surface. The purpose of the pigment is either to color the surface in the first place, or hide the color that the surface already has.
For centuries, white lead pigment was used in paint, because it had a strong hiding power. The most common white-colored lead pigment used was lead carbonate. This compound, no longer added to paint, is completely insoluble in water and therefore cannot possibly be sweet.
Another product that was phased out of use in the 1980s is paint containing lead chromate, which gives the paint a vivid yellow color. Like lead carbonate, lead chromate is insoluble in water and thus can’t taste sweet.
When paints were formulated with linseed oil and lead pigments, a very small amount of a chemical called “sugar of lead” was sometimes added to the paint to make it harden faster. The chemical name for sugar of lead is “lead acetate.”
Lead acetate forms when grape extracts are fermented in lead containers to make wine or vinegar. If the wine or vinegar is boiled out of the container, a thick syrupy liquid called
“sapa” is left. Sapa contains lead acetate and is sweet; it was used to sweeten foods and no doubt caused many cases of lead poisoning. But lead acetate is no longer added to paints (nor sapa to foods, for that matter).
Read the full article in the Oct-Nov issue of Healthy Indoors Magazine HERE