Last year, a study in Lancet Public Health found a link between lead exposure and a higher risk of death from cardiovascular disease. The data came from a nationally representative sample of more than 14,000 people in the United States who were adults in the late 1980s.
The association persisted after researchers controlled for many confounding factors and was evident even among people with blood lead levels of less than 5 micrograms per deciliter (mcg/dL). Until 2013, only levels higher than 10 mcg/dL were considered worrisome, and mainly for children.
“Today, average blood lead levels are just over 1 mcg/dL, down from an average of 10 mcg/dL in the 1980s,” says Dr. Rose Goldman, associate professor of medicine at Harvard Medical School. But there is no safe blood level of lead, according to the CDC.
And even though about half the lead in the blood leaves the body in urine within a month or two, a portion of it goes into the bones, where it can stay for decades, she says.
Bone tissue constantly remodels itself, and that stored lead can be released back into the bloodstream in response to different conditions, including pregnancy, breastfeeding, hyperthyroidism, and aging.
Lead’s legacy
Studies that measure bone lead levels in the tibia (shin bone) with a noninvasive test called x-ray fluorescence have found that increases in blood pressure are associated with higher bone lead levels.
Not only does lead have detrimental effects on blood vessels, it may also raise harmful LDL cholesterol levels and promote blood clots, all of which can contribute to cardiovascular problems.
Another clue pointing to lead’s toxic legacy comes from a 2017 study in the International Journal of Epidemiology. As the authors noted, deaths from cardiovascular disease dropped by 43% between the mid-1980s and the early 2000s.
Where lead still lurks
Although lead was banned from paint decades ago, it’s still found in homes and other structures built before 1978. To avoid inhaling lead dust, don’t scrape or sand your older home; hire an EPA-certified lead abatement professional.
Lead can also contaminate drinking water through erosion from lead pipes, mainly in homes built before 1986. Consider testing your water, especially if young children live in your home.
Here are some other possible sources of lead exposure:
Cosmetics. The FDA’s recommended limit for lead in lipstick (which you may ingest when you lick your lips) is 10 parts per billion, but some brands contain much higher amounts. Consider seeking out lead-free brands.
Hair dyes.In October 2018, the FDA banned lead acetate from hair coloring products. But companies still have a year to comply with the ruling, so check labels if you use these products, which are mainly drugstore brands that gradually cover grays.
Bullets.Indoor and outdoor firing ranges can expose people to dust from lead bullets. Wild game shot with leaded bullets may also be contaminated with lead.
Herbal remedies and supplements.Both Ayurvedic remedies and traditional Chinese medicinal herbs may be contaminated with lead, as evidenced by high blood levels seen in some users.
Cookware and tableware.Cooking or eating off lead-glazed ceramics (usually decorative traditional pottery, not commercially made products) has caused lead poisoning. Hardware stores carry lead testing kits you can use to check such products.
Get the lead out
Despite those successes, lead remains an insidious presence in daily life (see “Where lead still lurks”). Because even low levels of lead can cause harm, people should take steps to minimize their lead exposure throughout life, says Dr. Goldman.
