Table 1.
Exposure intervals (μg per m3) | Risk in peak bilirubin levels (mg per dL) | Confidence lower limit (mg per dL) | Confidence upper limit (mg per dL) | P value |
---|---|---|---|---|
(0, 10) | 0.848 | −0.574 | 2.269 | 0.157 |
(10, 35) | 0.076 | 0.027 | 0.125 | 0.003 |
(35,75) | 0.029 | 0.014 | 0.044 | 0.031 |
(75, 200) | 0.009 | 0.002 | 0.016 | 0.008 |
>200 | 0.01 | −0.008 | 0.028 | 0.435 |
For PM2.5 concentrations ∈ [10, 35] μg per m3, a 1.0 μg per m3 increase in PM2.5 concentrations was associated with a 0.076 mg per dL (95% CI: 0.027–0.125) rise in the peak bilirubin level. For a 1.0 μg per m3 increase in PM2.5 concentration, the peak bilirubin level increased by 0.029 mg per dL (95% CI: 0.014–0.044) for PM2.5 concentrations ∈ (35, 75] μg per m3, and by 0.009 mg per dL (95% CI: 0.002–0.016) for PM2.5 concentrations ∈ (75, 200] μg per m3. The relationship between PM2.5 concentrations and the neonatal jaundice risk nearly plateaued at concentrations exceeding 200 μg per m³, such that an additional increase in pollution concentration was not statistically significantly associated with a further increase in bilirubin level