Sample sizes for different classes of pollutants measured in the three NHANES waves assessed
| NHANES wave | Heavy metals (blood) | PFCs (blood) | Pesticides (urine) | Phthalates (urine) | Phenols (urine) | Organophosphate (urine) |
|---|---|---|---|---|---|---|
| 2005–2006 | 4608 | 1513 | 1521 | 1521 | 1521 | NA |
| 2007–2008 | 5172 | 1689 | 1767 | 1767 | 1767 | 1753 |
| 2009–2010 | 5360 | 1726 | 1789 | NA | 1789 | NA |
NA, not applicable; NHANES, National Health and Nutrition Examination Survey.