Lead Exposure in Infants: The Role of Breastfeeding
By Roberta Attanasio
Lead, a toxic heavy metal, is the well-known cause of a global epidemic. It has acute and chronic effects on human health, causing neurological, cardiovascular, renal, gastrointestinal, haematological and reproductive effects. Children under the age of 6 are especially vulnerable to lead poisoning, which can severely and adversely influence mental and physical development.
In the U.S., lead poisoning has been called the “silent epidemic” — children are exposed mostly because of the remodeling of old houses painted before lead paint was banned in 1978. Indeed, lead paint is one of the most common health hazards. Children exposed to lead experience brain damage, behavioral problems and developmental delays.
Recently (December 2013), a study found that high levels of lead in Washington D.C. water coincided with increased numbers of miscarriages in the early 2000s (Fetal Death and Reduced Birth Rates Associated with Exposure to Lead-Contaminated Drinking Water). In this case, exposure to lead in pregnant mothers was caused by a change in the drinking water disinfectant — the new chemical made the water more corrosive for lead pipes and plumbing, resulting in unintended release and transfer of lead to drinking water.
Human milk is a well-known source of lead exposure in infants. Lead is transported from the mother’s blood to breast milk — however, the mechanisms of this transport are not clear.
To better understand the role that breast milk plays in infant exposure to lead, Adrienne Ettinger (School of Public Health, Yale University) and her collaborators measured the concentrations of lead present in maternal blood, plasma, and breast milk samples at 1 month postpartum. They also measured the concentrations of lead present in infant blood samples at 3 months of age. The samples were collected during a study of lactating women in Mexico City, Mexico.
The results of the study (Maternal blood, plasma, and breast milk lead: lactational transfer and contribution to infant exposure) are published in the scientific journal Environmental Health Perspectives (January 2014). The scientists found that the concentrations of lead varied in all samples tested, and that lead may sometime concentrate in breast milk — in other words, the concentration of lead in breast milk may be higher than the concentration of lead in maternal plasma.
The scientists suggest that breast milk is a significant and important source of infant lead exposure. Testing the mothers’ blood for lead concentrations mat not give a reliable estimate of lead concentrations in their breast milk. Therefore, early testing of babies for lead levels may be important to avoid potential lead poisoning through breastfeeding.
Even most toxicologists are not aware of research, since 1994, that demonstrates lead transfer through the skin does take place, but the blood lead test does not elevate much since lead that passes through skin does not retain the characteristic affinity for erythrocytes that other routes of exposure demonstrate. Skin surface is remarkably lower pH than one would think pH 4 to 5.5 often, which can dissolve particulate and cause higher uptake. Skin abrasions and cuts can greatly increase rate of uptake as well, and a real kicker is that washing exposed skin with soap and water often results in substantial uptake, some soaps being more problematic than others. Breastmilk Pb content may increase without much evidence seen via blood lead assessment.
There are many sources of lead that we are still exposed to and are unregulated, though great strides have made in cleaning gasoline and house paint up.
Lead poison is serious problem especially in women who are nursing their children. Lead can be found in the paint that is used in houses, breast milk and the toys that children play with. Even if a woman is very healthy they can still have lead elements in breast milk that will cause a lot of diseases to children. Breast milk is supposed to have nourishment elements for the baby especially IgG. Children who are exposed to lead elements have lots of complications in the nervous systems, cardiovascular systems, renal system etc. Lead poising can cause miscarriages for women that are exposed to lead during pregnancies.
There are people who have allergic reactions metals like copper. These individuals have devices that can detect the amounts of copper in clothes for example. My question is there devices that can trace the amount of lead in the toys that children use and also the breast milk? IF devices can be made this can save lots of children.
Lead leach test kits are common, fairly inexpensive, and give reliable results for many surfaces. Any level of lead in the body does cause damage but society has placed regulatory levels as guidelines for levels that are generally thought to be relatively ‘safe’. Lead affects so very many physiologic pathways, and our body burdens in bones are 100 to 1000 times what is contained in prehistoric bones, that we are all contaminated with more lead than our body defense mechanisms were adapted to deal effectively with. The body burden of lead can mobilize and move into some tissues preferentially depending on the current needs of our bodies for calcium, lead follows calcium around where it can substitute for calcium in physiologically active molecules and often result in dysfunction that the body thought it had dealt with. One of those tissues that calcium and associated lead move into preferentially is breast tissue.When the Blood Brain Barrier gets compromised in some way, lead can more readily enter into the brain and cause many sorts of damage. Young children are most at risk, but anyone with reduced function of the bbb is also at higher risk.
Do all mothers have lead in their blood?
No, only mothers that are exposed to lead during pregnancy and/or lactation or have been exposed to lead before becoming pregnant have lead in their blood. During pregnancy and lactation there is increased bone turnover. Because lead is stored primarily in bone, the increased bone turnover leads to release of the previously stored lead. Therefore, levels rise during pregnancy and lactation even if the mother has been exposed to lead before she got pregnant.
Does everyone have lead in the body but at very low amounts that will not cause lead poisoning?
Everyone has lead in the body, and everyone is harmed by that level of lead, the more lead the more harm accumulates. There is no known level that prevents all harm, but modern bones have hundreds to a thousand times the lead that accumulated into prehistoric bones, we all have anthropogenic lead levels that make us less healthy than we would have been without lead pollution.