TABLE 1.
Elevated Blood Lead Levels Among Children During and After the Leaded Gasoline Era: US and Canadian Surveillance Data, 1973–2010
| Elevated Blood Lead Levels | ||||||
| No. | Mean ±SD (Median or 95% CI) | Level I, Range or % | Level II, Range or % | Level III, Range or % | Level IV, Range or % | |
| NHANES II 1976–198065 | ||||||
| Range, μg/dL | 10–19 | 20–29 | 30–39 | ≥ 40 | ||
| White, aged 6 mo–2 y, % | 6186 | 15.0 ±0.56 (14) | 64.1 | 17.3 | 2.2 | 0.2 |
| White, aged 3–5 y, % | 7455 | 14.9 ±0.41 (14) | 13.6 | 15.4 | 1.6 | 0.1 |
| Black, aged 6 mo–2 y, % | 1164 | 20.9 ±0.96 (19) | 50.2 | 34.2 | 13 | 2.3 |
| Black, aged 3–5 y, % | 1421 | 20.8 ±0.55 (20) | 42.5 | 43.3 | 8.3 | 1.9 |
| Canada Health Survey (1978–1979)a70 | ||||||
| Range, μg/dL | <10 | 10–19 | ≥ 20 | Unknownb | ||
| Aged 3 y–adult, % | 21 962 | - | 65.6 | 12.1 | - | 32.5 |
| Boys, aged 3–5 y, % | 521 | - | 40.8 | - | - | 38.4 |
| Girls, aged 3–5 y, % | 474 | - | 70 | 4 | - | 26 |
| Ontario (1984) a32 | ||||||
| Range, μg/dL | 10–19 | 20–25 | > 25 | |||
| Aged 1–6 y, % | 1269 | |||||
| Urban, % | 12.0 ±4.4 | 64 | 3.8 | 1.8 | ||
| Suburban, % | 10.0 ±3.5 | 44.4 | 2.2 | 1.6 | ||
| Rural, % | 8.9 ±3.9 | 33.3 | 2.7 | 0.8 | ||
| Southern and northern Ontario (1984-1987)a31 | ||||||
| Range, μg/dL | 10–19 | 20–25 | > 25 | |||
| Aged 3–6 y, % | 2459 | |||||
| Southern Ontario, % | 10.0 ±4.18 | 64 | 1.1 | 1.8 | ||
| Northern Ontario, % | 7.7 ±2.92 | 44.4 | 2.2 | 1.6 | ||
| NHANES III 1988-1991 Phase 1a73 | ||||||
| Range, μg/dL | ≥ 10 | ≥ 20 | ≥ 25 | |||
| Aged 1–5 y, % | 2234 | 3.5 | 8.6 | |||
| Aged 1–2 y, % | 1309 | 4.1 (3.7, 4.5) | 11.5 | 3.5 | 1.8 | |
| Aged 3–5 y, % | 925 | 3.4 (2.8, 3.5) | 7.3 | 3.1 | 0.4 | |
| Aged 6–11 y, % | 1587 | 2.5 (2.2, 2.7) | 4 | 1.7 | 0.2 | |
| NHANES III 1991–1994 Phase 2a67 | ||||||
| Range, μg/dL | 10–19 | 20–25 | > 25 | |||
| Aged 6 mo–79 y, % | 13642 | 2.3 (2.1, 2.4) | ||||
| Aged 1–2 y, % | 987 | 3.1 (2.8, 3.5) | 5.9 | - | - | |
| Aged 3–5 y, % | 1405 | 2.5 (2.3, 2.7) | 3.5 | - | - | |
| Aged 6–11 y, % | 1345 | 1.9 (1.8, 2.1) | 2.0 | - | - | |
| Quebec City, QC (1991)a75 | ||||||
| Range, μg/dL | ≥ 10 | ≥ 20 | ||||
| Urban, aged 1–6 y, % | 93 | 5.6 (5, 6) | 10.8 | 1 | ||
| Rural, aged 1–6 y, % | 149 | 4 (4.1, 4.8) | 1.3 | |||
| London, ON (1993) a76 | ≥ 10 | |||||
| Range, μg/dL | ||||||
| Aged 0–17 y, % | 164 | 4.7 ±2.00 | 7.3 | |||
| London, ON (1993)77 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 0–8 y, % | 585 | 4 (–) | 17.3 | |||
| St. John, NB (C. Balram and S.C. Giffin, unpublished data, 1993) | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 1–3 y, % | 97 | 4.8 ±3.65 | 11.3 | |||
| Vancouver, BC (1995)a72 | ||||||
| Range, μg/dL | ≥ 10 | ≥ 15 | ||||
| Aged 2–3 y, % | 172 | 6.0 ±2.70 | 8.1 | 0.6 | ||
| Moosonee and Moose Factory, ON (1995)64 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 1–6 y, % | 395 | 3.1 (2.97, 3.23) | 4 | |||
| NHANES 1999-200068 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 1–5 y, % | (1.0, 4.3) | 2.2 | ||||
| NHANES 1999-2004a69 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 1–5 y, % | 2532 | 1.9 (0.8, 2.0) | 1.4 | |||
| Aged 1–2 y, % | 1231 | 2.1 (2.0, 2.2) | 2.4 | |||
| Aged 3–5 y, % | 1301 | 1.7 (1.6, 1.9) | 0.9 | |||
| Quebec survey to establish reference level (2001)a100 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 18-65 y, % | 441 | – | ||||
| 25th–97.5th percentile (μg/dL) | 2.0 | |||||
| Quebec survey to determine presence EBLLs in Quebec adults blood donors (2010)a101 | ||||||
| Range, % | < 3 | > 3 | > 5 | > 10 | ||
| Aged 18–65 y, % | 3490 | 1.9 (0.6, 5.6) | 84 | 15.6 | 4.1 | 0.3 |
| Canada Health Measures Survey (2010)a102 | ||||||
| Range, μg/dL | ≥ 10 | |||||
| Aged 6–79 y, % | 5319 | 1.3 (1.24, 1.44) | < 1 | |||
Note. CI = confidence interval; EBLLs = elevated blood lead levels; NHANES = National Health and Nutrition Examination Survey. Leaded gasoline was banned in Canada and United States circa 1990.
a
Geometric means are reported.
b
The term unknown indicates a laboratory result that was missing or improperly collected.