Land

Lead concentrates in the top 2 inches

Lead is the most common concern around older homes, and it got there 2 ways: decades of leaded paint flaking off exterior walls, and leaded gasoline settling out of the air before the phaseout finished. Both left a residue that doesn't break down.

It concentrates in the top 2 inches of soil, which is where children play and where gardens root. The age of a neighborhood is a better guide to soil lead than the appearance of any particular yard, because a tidy lawn over contaminated ground looks identical to a tidy lawn over clean ground.

Paint is the heavier source close to a house, and gasoline the wider one near old roads. Both settle into the same few inches, and a test reports the total rather than the origin.

Paint is the heavier source close to a house, and gasoline the wider one near old roads. Both land in the same few inches, and a test reports the total rather than the origin.

Every lot had a use before your house

Gas stations, dry cleaners, orchards, small industrial operations and farm fields all leave residues that outlast the buildings that created them. The house is newer than the ground it stands on, and the ground is what keeps the record.

Old pesticides show this. Compounds that would degrade outdoors under sunlight and weather can persist for years in soil and settle into indoor dust, protected from the very conditions that would otherwise break them apart.

Knowing a property's history is the fastest route to knowing what is worth testing for, and it costs an afternoon in the county records rather than a laboratory fee.

An orchard points at arsenic and lead from old sprays. A filling station points at solvents and fuel. A former dry cleaner points somewhere else again, which is why the history has to come before the test order.

Radon is the second leading cause of lung cancer

Radon is a radioactive gas that seeps up from the natural breakdown of uranium in soil and rock. The EPA links it to around 21,000 lung cancer deaths a year, which places it behind smoking and ahead of everything else.

It has no color, no smell and no taste. Two houses on the same street can carry very different levels depending on the geology underneath them, so a neighbor's result is not your result.

A test kit from a hardware store costs about $20. That is the cheapest definitive answer in environmental health, and a high reading is a fixable problem rather than a permanent condition.

Winter readings run higher than summer ones, because a sealed house keeps what seeps in. Test in the season you live in, and retest after any work that changes how the house breathes.

A $20 test and an afternoon of records covers most of it

Test for radon first. Place the kit in the lowest lived-in room, mail it to the lab, and go from there. If levels come back high, a venting system brings them down.

Then look into the history of the lot through local planning records or a property search. Older homes reward 3 cheap habits: keep bare soil covered with grass or mulch, take shoes off at the door, and test the soil before planting anything you intend to eat.

A state certified lab runs a basic soil panel for a modest fee. Order it once you know what the lot used to be, because the history tells the lab what to look for.