Table 4. Crude and adjusted odds ratios of blood lead levels according to the lead concentration in the lead exposure sources (water, lead or paint).
| Exposure source | n | Crude OR (95% CI) | Adjusteda OR (95% CI) | Adjusted+b OR (95% CI) |
|---|---|---|---|---|
| Kitchen tap waterc (n=306) | ||||
| 1. <0.75 μg/L | 101 | 1.00 (−) | 1.00 (−) | 1.00 (−) |
| 2. 0.75–3.27 μg/L | 105 | 1.37 (0.65–2.91) | 1.55 (0.68–3.57) | 1.24 (0.52–2.93) |
| 3. >3.27 μg/L | 100 | 4.14* (2.07–8.28) | 5.07* (2.37–10.82) | 4.66* (2.12–10.24) |
| Floor dustd (n=305) | ||||
| 1. <0.45 μg/ft2 | 102 | 1.00 (−) | 1.00 (−) | 1.00 (−) |
| 2. 0.45–1.22 μg/ft2 | 103 | 1.36 (0.67–2.74) | 1.10 (0.52–2.35) | 0.95 (0.44–2.09) |
| 3. >1.22 μg/ft2 | 100 | 2.46* (1.26–4.80) | 2.56* (1.26–5.21) | 2.06 (0.97–4.40) |
| Windowsill dust (n=263) | ||||
| 1. <3.54 μg/ft2 | 86 | 1.00 (−) | 1.00 (−) | 1.00 (−) |
| 2. 3.54–14.14 μg/ft2 | 90 | 2.37* (1.10–5.10) | 2.40* (1.04–5.54) | 2.18 (0.90–5.28) |
| 3. >14.14 μg/ft2 | 87 | 2.63* (1.23–5.64) | 3.15* (1.38–7.23) | 3.22* (1.33–7.79) |
| Paint e (n=306) | ||||
| 1. XRF <1 mg/cm2 | 121 | 1.00 (−) | 1.00 (−) | 1.00 (−) |
| 2. XRF ≥1 mg/cm2 or Paint chips <5,000 mg/kg | 143 | 1.11 (0.59–1.92) | 1.06 (0.55–2.04) | 0.92 (0.45–1.86) |
| 3. Paint chips ≥5,000 mg/kg | 42 | 2.61* (1.23–5.57) | 3.30* (1.44–7.56) | 2.28 (0.90–5.76) |
Abbreviations: BLLs, blood lead levels; CI, confidence interval; OR, odds ratios; XRF, X-ray fluorescence analyses.
OR adjusted for age, ethnicity, season, parents' highest education level, daycare used, moderate chronic disease, second-hand smoke exposure, possible parental lead exposure from occupation or hobbies and tap water consumption/bw.
OR adjusted+ for all variables in a(adjusted OR) and for the other lead exposure variables (ie., Tap water, adjusted for floor dust, windowsill dust and paint; Paint, adjusted for tap water, floor dust and windowsill dust; Floor dust and windowsill dust, adjusted for tap water and paint).
Arithmetic mean of the 5 kitchen tap water samples (1 liter after 5 min flushing and 4 consecutive liters after 30-minute stagnation).
Arithmetic mean of 3 floor dust samples.
Highest concentration of lead in paint chip per home. *p<0.05, compared to the first tertile.