Baseline Testing
Because lead builds up over time, the first measurement is the most useful one to have. It is the reference point every later result is compared against.
What a baseline is, and why early matters
A baseline is a measured starting point. For a family, it usually involves two things: a child’s blood lead test and a test of the water the household actually drinks.
Taken early, a baseline helps answer the question, “Is there a problem now?” while there is still time to take action. Testing the household’s water can be one part of that initial assessment, and lead water inspection and testing in Manhattan can help families investigate whether drinking water may be a source of exposure.
Blood tests and water tests answer different questions
A blood lead test measures how much lead is in a child’s blood right now, from all sources combined. The CDC uses a blood lead reference value of 3.5 micrograms per deciliter to identify children with higher levels than most children their age.
New York State requires health care providers to test children for lead at ages one and two, and many families in New Jersey and Connecticut follow a similar schedule through their pediatrician.
A water test measures how much lead comes out of a particular tap under particular conditions. It cannot tell you about a child’s total exposure, but it can tell you whether the water is part of it.
When a water baseline is most useful
Testing is worth considering before or soon after a baby arrives, especially if formula will be prepared with tap water. It is also important when a family moves into a home built before 1986, after plumbing work, a new water heater, or nearby street construction. In older apartments, NYC apartment lead water testing can help families check whether their drinking water may be a source of exposure.
Testing is also a sensible step whenever a child’s blood test shows elevated lead levels, because water is one potential source that can be investigated and addressed directly.
How water is sampled for a baseline
The way water is collected changes the result. A good plan matches the question being asked.
| Sample | How it is collected | What it shows |
|---|---|---|
| First-draw | The first water out of a tap after it has sat unused, usually overnight | The highest exposure someone is likely to get, for example the first glass of the morning |
| Flushed | Collected after the tap has run for a set time | Water from further back in the system, closer to the main |
| Sequential | Several samples in a row from the same tap | Where lead may be coming from: the fixture, the pipes in the walls or the service line |
Using a baseline well
- Keep the report. Note the date, the taps sampled and how each sample was collected.
- Retest after changes. New fixtures, plumbing work or a new water heater can change results.
- Share it with your pediatrician. Especially if a child's blood lead test is above the reference value.
- Use certified filters if needed. Choose a filter certified to reduce lead and replace cartridges on schedule.
Arrange a water baseline
Olympian Water Testing collects first-draw and flushed samples on site, with NELAP accredited laboratory analysis and clear reporting.