• Phasing out lead in gasoline had dramatic impact — The study found that hair lead levels in older samples often ranged between 28 and 100 parts per million (ppm), a level that reflects extremely high environmental contamination. Those numbers remained common throughout the 1960s, meaning anyone born in that era lived in a world where the air, dust, soil, and household environments were consistently enriched with lead.

Measurements fell sharply in the 1970s, dropping to around 50 ppm in that decade, then to about 10 ppm in the 1990s, and eventually falling below 1 ppm in samples collected after 2020.

While the U.S. Centers for Disease Control and Prevention (CDC) has set an upper blood lead level (BLL) limit of 3.5 micrograms per deciliter (mcg/dL) — above which immediate action should be taken to lower it — they also note that there is NO safe BLL.⁹

• Regulatory action drove a 100-fold drop in lead exposure — The study directly ties the decline in hair lead to regulatory action, noting that exposure "declined by about 2 orders of magnitude since the establishment of EPA." In other words, it signified a 100-fold reduction. Before this shift, gasoline alone contained about 2.2 grams of lead per gallon (0.6 grams per liter).

• Lead still lingers in the environment — Although modern hair samples show far lower levels than in past decades, the study cautions that old lead has not vanished. Lead that settled into soil years ago does not break down. During dry weather, construction, yard work or shifting winds, that contaminated soil and dust can rise into the air again, which creates new exposure long after the original source disappeared.

• The protections in place could change any moment — The researchers noted that lead exposure could rise again if environmental regulations change. They pointed to a March 12, 2025, announcement from the EPA describing plans to reconsider or roll back certain regulatory provisions related to its environmental mission.

The authors also referenced broader discussions about how revisions to long-standing environmental policies could affect public health, health care costs and the economy. While no direct deregulation of lead exposure has occurred, they highlighted proposals under consideration that could introduce greater flexibility in how the 2024 Lead and Copper Rule is enforced, which may influence future exposure levels.¹⁰

• Generational divide in lead exposure and childhood BLLs — Younger cohorts, especially those born after 1990, lived in environments with drastically lower exposure. Meanwhile, older cohorts (those born between 1951 and 1980) experienced the peak period of contamination.

Overall, the researchers found that over 170 million people had childhood BLLs above 5 mcg/dL, with more than 54 million exceeding 15 mcg/dL during early childhood.

• A staggering number of children have been exposed to lead — BLLs above 5 mcg/dL were nearly universal — over 90% — among people born between 1951 and 1980. That means if you were born during that period, your brain development occurred under the influence of lead during your most vulnerable years.

The authors also found that more than 4.5 million Americans had childhood BLLs exceeding 30 mcg/dL, which represents extremely heavy exposure and aligns with levels documented to produce major cognitive and behavioral harm.

• The cumulative neurological cost of lead exposure — The researchers estimated that as of 2015, an average of 2.6 IQ points per person across the entire U.S. population had been lost, adding up to 824,097,690 IQ points across the population, due to early-life exposure.

Note that the loss is not spread evenly across age groups. People born during the peak era of leaded gasoline lost far more cognitive capacity compared to those born later, simply because their exposure was higher, more frequent, and began earlier in life.

• Effect of gasoline on total lead exposure levels — Similar to the previous study, this one also highlights the impact of leaded gasoline on public health, specifically children. When stricter regulations emerged in the 1970s and leaded gasoline was gradually phased out, BLLs in young children dropped nearly as fast as gasoline-related emissions declined.

• Lead exposure also affects behavior, heart health and brain aging — Aside from IQ, the researchers hinted at other ways exposure can eventually affect the human body. These include "criminal behavior, personality, psychopathology, social mobility, cardiovascular disease, kidney function, and pathological brain aging." Having emphasized this, they noted that future studies can follow this path and paint a more complete picture of lead's true impact on public health.

• Generations that saw the greatest impact — The researchers noted that those born during the 1950s, 1960s, and 1970s were exposed to the highest levels of lead in air, dust, and soil because leaded gasoline emissions were at their peak. Since cognitive development is rapid during early childhood, this exposure window produced the greatest harm.

The authors describe lead as a "developmental neurotoxicant," meaning it directly harms the growing brain by interfering with fundamental neurological processes. As noted in a different study, lead exposure can also cause stunted growth, which not only affects cognitive development, but also physical, emotional, and social development.¹³

• The impact of leaded gasoline outweighed other known sources — Gasoline-derived lead was overwhelmingly the strongest predictor of population-wide exposure throughout the entire study period. While other sources existed, such as paint, plumbing, and industrial emissions, none matched the widespread distribution and daily inhalation risk created by combusting leaded gasoline.

1. Inspect your home and address hazards promptly — Homes built before 1978 are more likely to contain lead-based paint or contaminated soil. If any of these criteria apply to your home, arrange for professional testing and, if lead is detected, work with contractors certified by the EPA to safely remediate the problem.

Areas with flaking or deteriorating paint deserve special attention, as the dust created from chipping paint is particularly dangerous. Keep children away from these spaces until they are properly treated.

2. Check your water quality — Many older municipal water systems still rely on lead service lines, which can leach lead into household tap water. Installing a high-quality filtration system certified for lead removal is one of the most reliable and cost-effective protective measures. Use filtered water for drinking and food preparation and avoid using hot tap water — especially unfiltered — for cooking or mixing infant formula.

3. Strengthen your defenses with proper nutrition — Adequate calcium intake from sources such as grass fed dairy and bone broth can help limit lead absorption because calcium competes with lead in the body. A diet rich in iron, vitamin C, and B vitamins also supports healthy blood production and helps reduce the risk of lead-related anemia.

As for pregnant women, ensure sufficient folate intake to help protect developing babies from lead's harmful effects on the nervous system.

4. Monitor BLLs regularly — Testing is the only way to know how much lead exposure you've accumulated. So, it would be wise for families living in older homes or high-risk areas to undertake routine screening.

Children under age 5 are especially vulnerable and need to be tested at regular intervals, while adults should ideally strive to keep blood lead concentrations below 3.5 mcg/dL. Early detection allows for timely intervention before serious health consequences develop.

5. Explore safe detoxification methods — Lowering elevated lead levels is a gradual process that takes time. To help you with this, consider chelation therapy with edetate disodium (EDTA). It has been shown to reduce certain cardiovascular risks, but it also carries side effects.

A more accessible option is N-acetylcysteine (NAC), which helps replenish glutathione — one of the body's primary detoxifying compounds — and supports the safe removal of heavy metals.

Another strategy I recommend is sweating regularly, either through sauna or exercise. As I explained in a previous article, both of these activities induce sweating that helps remove toxic heavy metals from your system. Exercise was shown to be superior at detoxing compared to a sauna, but combining both methods produced synergistic effects.