(NaturalNews) Despite assurances of safe levels in water and only traces in cosmetics, most scientists agree that there are no safe levels of lead. Lead is toxic, period. It serves absolutely no useful function for the human or animal body. It can affect every organ of a body but most often adversely affects red blood cell production, protein metabolism, the kidneys and the nervous system. 
Lead is so toxic that it is no longer allowed in paints, and lead additives are banned from gasoline. But did you know that lead acetate is used in many red lipsticks and in hair dyes for women and men?  It often shows up in ceramics and eating utensils made outside the USA. And lead manages its way into tap water, not only in homes and areas with old pipes but in brass and copper fixtures that are soldered with lead.
Lead tends to affect children more than adults. The toxic effects on children often impede neurological development and IQ. Some toys may contain traces of lead. Lead acetate is the most common form of lead found in all the substances just mentioned. It's known as the "sugar of lead" because of its sweetness. So beware of sweet-tasting lipsticks and tap water.
The best, perhaps only, way to determine lead poisoning is by blood testing. Symptoms are often not present even when blood levels of lead are high. But here is a list of possible symptoms and effects from lead poisoning (http://www.atsdr.cdc.gov).
All the more reason to find natural antidotes
A 2010 study, "Protective effects of Spirulina maxima on hyperlipidemia and oxidative stress induced by lead acetate in the liver and kidney," was conducted at the National Autonomous University of Mexico and published in Lipids in Health and Disease. 
The study's background section explains that lead is foreign to the human body and is a persistent toxin. Although it has many uses externally, not one particle of it is useful for the body. Knowing the antioxidant characteristics of Spirulina maxima, which is cultivated in Mexico, the researchers embarked on an in vivo (animal) study to determine if spirulina protects against lead poisoning.
They used two-month-old Wistar rats and divided them into three groups. A control group was fed only standard Purina Mexico feed, another group was given feed with lead acetate added and the third group given feed with lead acetate and Spirulina maxima powder. Isotonic saline was used as a vehicle for lead acetate and spirulina but was used with the control group as well. 
After 30 days, ether gas was used to anesthetize the rats prior to killing them by cervical dislocation.  Their livers and kidneys were examined carefully for signs of lead acetate toxicity by determining lipid peroxidation, or oxidative degradation of lipids (fats), and the products of lipid peroxidation in serum as well as determining the health of free proteins. The spirulina had promoted general health benefits.
Here's their carefully worded conclusion: "[E]xposure to lead could have generated oxidative stress which resulted in the elevation of lipids both in plasma and liver, as well as lipid peroxidation in the liver and kidney associated with the reduction in the antioxidant status. Spirulina maxima co-treatment resulted in the prevention of the lead-induced damages. ... Consequently, Spirulina maxima could be useful in the preventive treatment of lead toxicity." 
Spirulina maxima is cultured in Mexico, but most types of spirulina should work as well. Many commercially sold spirulina products don't indicate source or type. But other types of spirulina have demonstrated the ability to neutralize heavy metal toxicity in several in vitro (lab culture) and in vivo (animal) studies.