Lead poisoning in America is usually told as a water story - Flint, lead service lines, the tap. But for most exposed children, the bigger source is older: paint. Lead-based paint was not banned for residential use until 1978, and it did not disappear when the ban took effect. It is still on the walls, window frames, and porches of tens of millions of American homes, and the dust it sheds as it ages is the leading route of childhood lead exposure in the country.
You cannot test a whole nation's paint. But you can measure the thing that predicts it: the age of the housing. A home built before 1978 may contain lead paint; a home built before 1950 very likely does, because the paint of that era was far leadier. So we mapped the US housing stock by age, county by county, using Census data, to show where the risk is concentrated. Here is what it looks like.
Across US counties, the median county has about 53% of its homes built before 1980 - the lead-paint era. The oldest housing, and therefore the highest lead-paint risk, clusters in the Northeast and the Plains: Nebraska, Iowa, Kansas, Rhode Island, New York, Pennsylvania, and Massachusetts lead the state rankings. The newest housing - and lowest risk - is in the Sun Belt: Florida, Arizona, and Nevada. And the pattern is starkest in old industrial cities: in St. Louis, 87% of homes predate 1980 and 67% predate 1950; Philadelphia, Baltimore, Cleveland, and Milwaukee are close behind. This is a housing-age map, not a paint test - but it is the best nationwide picture of where lead paint most likely lives.
The EPA is direct about it: homes built before 1978 are likely to contain lead-based paint, and the older the home, the higher the odds and the higher the lead content. The federal ban on lead in residential paint took effect in 1978; before 1955, much of the white house paint sold was about 50% lead, per the ATSDR.
That makes the age of a home a strong, if imperfect, predictor of lead-paint risk - and unlike a paint inspection, it exists for every county in the country. The Census Bureau's American Community Survey reports when the homes in each area were built. We used two thresholds:
This is a statistic about a county's housing stock, not a claim about your specific home. A pre-1980 house that has been fully repainted and maintained can be low-risk; a newer one is rarely a concern. The map tells you the odds; only an inspection tells you your answer.
By the share of a typical county's homes built before 1980, the oldest housing sits in two regions - the industrial Northeast and the rural Plains:
| State | Avg. county % pre-1980 | Avg. % pre-1950 | | --- | --- | --- | | Nebraska | 72% | 37% | | Iowa | 72% | 38% | | Kansas | 71% | 34% | | Rhode Island | 70% | 33% | | New York | 69% | 36% | | Pennsylvania | 66% | 32% | | Massachusetts | 66% | 34% | | Illinois | 65% | 29% |
One honest caveat about this ranking: it averages counties without weighting for how many people live in each. The Plains states rank high partly because they have many small, depopulating rural counties full of old farmhouses. That is real lead-paint risk, but it is spread thin. The risk that touches the most children is in the dense old cities of the Northeast and Rust Belt - which the next section makes clear.
At the other end, the newest housing - and the lowest lead-paint risk - is in the Sun Belt, where most homes went up after 1980: Florida (32% pre-1980), Arizona (33%), and Nevada (38%) have the youngest housing stock in the country.
Zoom into the big old cities and the numbers climb toward totality:
| City / county | % pre-1980 | % pre-1950 | | --- | --- | --- | | St. Louis, MO | 87% | 67% | | Philadelphia, PA | 85% | 51% | | Baltimore, MD | 84% | 54% | | Cleveland (Cuyahoga Co.), OH | 81% | 37% | | Milwaukee, WI | 80% | 38% | | New York (Manhattan) | 79% | 49% | | Providence, RI | 77% | 44% | | Allegheny Co. (Pittsburgh), PA | 78% | 37% |
In St. Louis, two of every three homes were built before 1950 - the leadiest-paint era. These are not coincidentally the same cities that show up in childhood-lead-poisoning data year after year. Old housing plus deferred maintenance plus dense population is the recipe, and it maps almost exactly onto where kids test high for lead.
Lead paint is a hazard you can live with safely and a hazard that can poison a child, and the difference is condition and disturbance, not just age. Intact, well-maintained paint is largely stable. The danger is paint that is chipping, peeling, or on friction surfaces - windows that grind, doors that rub - which grind lead into household dust that small children then breathe and swallow. Renovation is the classic trigger: sanding or scraping old paint without containment can contaminate a whole home in an afternoon.
If your home predates 1980, the practical steps are well established:
And remember the other half of the picture: lead reaches children through water as well as paint. If you are checking your home for lead, check both. See our companion analyses – The State of Lead in US Drinking Water and The State of PFAS in US Drinking Water – read the lead in drinking water pillar, and if you are pregnant or have young kids, our guides on lead and pregnancy and lead in schools. To check what is in your tap specifically, look up your water system.
### How many US homes have lead paint? Lead-based paint was not banned for residential use until 1978, and the EPA considers most homes built before then likely to contain some. In the typical US county, about 53% of homes predate 1980; in the oldest industrial cities it reaches 85% or more. HUD's American Healthy Homes Survey II estimated that about 34.6 million US homes have lead-based paint somewhere in the building.
### Which US cities have the most lead paint risk? The highest risk is in old industrial cities with the oldest housing. St. Louis leads, with 87% of homes built before 1980 and 67% before 1950, followed closely by Philadelphia, Baltimore, Cleveland, Milwaukee, and New York. These are the same cities that consistently report elevated childhood blood lead levels.
### Is a home built before 1980 dangerous? Not necessarily. A pre-1980 home may contain lead paint, but intact, well-maintained paint is largely stable. The hazard comes from paint that is chipping or peeling, from friction surfaces like windows, and from renovation that disturbs old paint. Age tells you the odds; only an inspection tells you your home's actual status.
### Which states have the oldest housing? By the share of a typical county's homes built before 1980, Nebraska, Iowa, Kansas, Rhode Island, New York, Pennsylvania, and Massachusetts have the oldest housing stock. The Sun Belt - Florida, Arizona, and Nevada - has the newest and the lowest lead-paint risk.
### How do I know if my home has lead paint? The only certain way is a lead-paint inspection or risk assessment by a certified professional, or a lab-tested paint sample. Home swab kits give a rough screen. If your home predates 1980 - and especially 1950 - assume lead paint is present, keep it intact, and use EPA RRP-certified contractors for any work that disturbs it.
### Is lead worse in paint or water? Both matter, and they reach children differently. For most exposed US children, deteriorating lead paint and the dust it creates is the larger source, while lead in water is a serious and often overlooked one - especially for formula-fed infants. If you are addressing lead, address both the paint and the tap.
Lead paint is the quiet half of America's lead problem: invisible, legal to live with, and sitting in the majority of homes in the country's oldest cities. You cannot change when your house was built, but you can find out your risk, keep the paint intact, and test the child and the water. Start by looking up your water system and reading how the two halves of lead exposure fit together.
This analysis draws on US Census American Community Survey housing-age data – the share of homes built before the 1978 federal ban on consumer lead paint – as the best available proxy for lead-paint risk at the state and metro level, since no national registry of lead-painted homes exists. Full sources, definitions, and our public corrections log are on our research page. Data as of August 2026.
Cite this analysis (APA):
> Know Your Exposure Research Team. (2026). The State of Lead Paint in US Homes (2026). KnowYourExposure. https://knowyourexposure.com/blog/state-of-lead-paint-in-us-homes-2026
Journalists and researchers are welcome to cite these figures with a link back. For a custom data pull or a quote, contact [email protected].