Table 2.

Change in Birth Weight (95% CI) per IQR Increase of PM_10-2.5

Pollutant	N	Exposure Period	Change in Birth Weight (g)a
		Whole Gestation	−6.6 (−7.2, −5.9)
PM10-2.5	8,017,865	1st trimester	−2.0 (−2.6, −1.3)
		2nd trimester	−2.1 (−2.8, −1.4)
		3rd trimester	−2.6 (−3.3, −2.0)
PM10-2.5_alt1b	8,799,256	Whole Gestation	−10.4 (−11.2, −9.6)
PM10-2.5_alt2c	10,597,927	Whole Gestation	−3.4 (−4.1, −2.8)
		Whole Gestation	−5.4 (−6.1, −4.7)
PM10-2.5 (adjusted by PM2.5)	8,017,865	1st trimester	−1.5 (−2.2, −0.8)
		2nd trimester	−1.8 (−2.5, −1.1)
		3rd trimester	−2.1 (−2.8, −1.5)

^aIQRs are 7.8 μg/m³ for PM_10-2.5; for comparison purpose, the same IQR values were applied for PM_10-2.5, PM_{10-2.5_alt1}, and PM_{10-2.5_alt2} estimates. Included adjusted variables were sex of infant, gestational length, maternal age, race, educational attainment, and marital status, birth order, the trimester in which prenatal care began, alcohol and/or tobacco consumption during pregnancy, indicator variable of birth year, season, and state, neighborhood SES (% less than high school education and % of households below poverty line), and apparent temperature for each trimester.

^bPM_{10-2.5_alt1} is estimated by averaging the PM_10-2.5 values estimated only from co-located monitors within a county.

^cPM_{10-2.5_alt2} is based on daily estimates based on using all PM monitors to estimate county levels of PM₁₀ and PM_2.5 separately and then subtracting them.