The toy company Mattel recalled nearly 800,000 more Mattel and Fisher-Price toys due to lead paint just last month. Barbie Accessories were among the Mattel, Fisher-Price Toys.

The Campaign for Safe Cosmetics in the US said one-third of the 33 red lipsticks examined by an independent lab contained a level of lead exceeding 0.1 parts per million (ppm). None listed lead as an ingredient.

Lead poisoning usually does not cause symptoms until the level of lead in your blood is very high. Most lead poisoning comes from low levels of exposure over a long period of time. The major organ systems affected are the central nervous system, gastrointestinal tract, and the renal system.

The human body needs a diet enriched with many ingredients from the periodic table that sound less like food than like machine parts or spare change. We must have iron to capture oxygen, copper and chromium to absorb energy, cobalt to sheathe our nerves and zinc to help finger our genes.

Other creatures demand the occasional sprinkling of tin, nickel, platinum, tungsten and even strontium.
But when it comes to lead, the 82nd item on Mendeleev's menu of the elements, the universal minimum daily requirement is zero. As far as we know, neither we nor any known life form needs the slightest amount of lead to survive. And for humans, especially infants and young children, consumption of even moderate amounts of the metal can have serious consequences.

Developing brains seem to be extremely sensitive to the effects of the metal, which is why many scientists who study lead were distraught by the latest news of lead paint's being used on children's toys.
"I'm not normally a rabble rouser, but I'm disturbed by the potential enormity of this problem," said Jeremy R. Knowles, a professor of chemistry and biochemistry at Harvard. "We're talking about millions of toys, and the possibility of an entire generation of children being exposed to gratuitous constraints on their neurological development."

Yet even as Knowles and others urged that much more rigorous inspection procedures be adopted to guard against lead finding its way into children's mouths, the experts conceded that the toy recall fiasco felt like another case of Et tu, deja vu?

Humans have a long, tangled relationship with lead, now celebrating its pliant versatility, now fearing its orotund power, and who knows if we can ever put our saturnine genie back in the bottle we've been mining for at least 5,000 years.

As one of the 100-plus elements of which the Earth is built, lead is certainly "natural." But it is relatively uncommon, and only became a ubiquitous feature of our everyday human landscape because we pulled it up from the ground and put it there.

Like any element, lead is a substance that cannot be broken down by chemical means, an aggregate of large numbers of the same type of atom, in this case very heavy atoms. The dense core of a lead atom bulges with more than 200 nuclear particles, nearly four times the number in an iron nucleus.

Lead is considered the heaviest of the so-called stable elements, meaning atoms that are not radioactive and don't tend to spit out nuclear particles periodically the way uranium does. But stable does not mean inert, and lead interacts readily with other elements, particularly sulfur, an association that makes lead easy to find and mine, but also makes it a particularly inhospitable bully.

Lead was indeed one of the first metals mined, for it doesn't take much to convert raw lead ore into a usable commodity. Lead is easily purified away from the odiferous sulfur, and it has such a low melting point that a hunk of it can be softened in a campfire and shaped into a wondrous variety of objects -- pots, pans and water pipes, all displaying lead's trademark resistance to corrosion and discoloration.

"Lead was a civilizing metal, there were so many things it could do," said John Emsley, a chemist and author of "The Elements of Murder: A History of Poison."

The ancient Romans mined lead on a huge scale, mostly from deposits in England and Spain, spinning it into vast subterranean waterworks, hammering it into pewter tableware, cheaply doping their silver coins, kohl-lining their eyes.

A bad harvest year? Boil the sour grapes in lead vessels, and the release of lead acetate would sweeten the wine. (In fact, the sweet flavor of some lead compounds is thought to aggravate the danger of lead-painted toys, adding the temptation of sweetness to young children.)

Time and again lead proved its versatile mettle. Paint pigment made from white lead was said to have an exceptional brightness and unequaled "covering power," and well into the 20th century, old-school housepainters insisted that nothing clung to wood as faithfully as lead paint.

The refractive index of lead made it the ideal element to stir moltenly with glass to form crystal, and the finest facets on the most luxurious chandeliers owe their diamond spangle to a recipe that may be 30 percent lead. With the advent of automobiles and inefficient engines that rattled and balked, engineers solved the problem by adding lead to gasoline, lowering the combustion point and silencing "knock."

Yet practically from the start there were signs of trouble. The Greek physician Hippocrates described circa 400 B.C. a severe case of "colic" in a lead miner, and the Roman engineer Vitruvius noted that men who worked in lead smelters had disturbingly wan complexions.

Over the centuries, doctors described disorders like "wrist drop," in which housepainters using leaded paint would suddenly lose control of their wrist musculature.

Not until the 20th century were epidemiological studies carried out that showed the particular dangers that lead posed to children, evidence that helped usher in bans in many countries against lead paint, leaded gasoline, lead-glazed pottery and the like.

Titanium has replaced lead as the gold-standard white pigment in paint, and, apart from its superior safety profile, is considered more than a match for lead in brilliance and opacity, if not low price. With the introduction of cleaner additives in the 1970s, lead-laden fuels were phased out in the United States, though leaded gasoline is used in developing countries.

Scientists, too, have made great strides in mapping lead's impact on the body. They have shown that after it infiltrates a cell, lead seeks out those regions of proteins where sulfur abounds and pushes aside smaller characters that stand in its way. But being bulkier than whatever it displaces, and chemically inappropriate besides, lead twists the entire protein into a sad, worthless shape. As it turns out, this distorting effect has a particularly severe effect on so-called transcription factors, proteins that control when genes flick on and flick off. In gestation, genetic timing is critical. This could help explain why even modest exposure to our old "civilizing" friend might corrupt the whole script of a developing brain.

New York Times News Service