Table 2.
Effect of pesticide exposure on five birth outcomes
| Log BW | Low BW | Log gestation | Preterm birth | Birth abnormalities | |
|---|---|---|---|---|---|
| A. Full Estimation Sample (all births excluding 2006) | |||||
| Sum AI | −0.000613 | −4.02e-05 | −0.000522 | 0.00290 | 0.00200 |
| (0.00127) | (0.00157) | (0.000375) | (0.00184) | (0.00155) | |
| Tox Cat 1 & 2 | −0.000466 | 0.000890 | 0.000143 | −0.000491 | −0.00248 |
| (0.00127) | (0.00149) | (0.000383) | (0.00188) | (0.00169) | |
| Tox Cat 3 & 4 | 0.00126 | −0.00319** | −0.000447 | 0.00201 | −9.16e-05 |
| (0.00117) | (0.00115) | (0.000392) | (0.00180) | (0.00159) | |
| Trimester 1 | −0.00144 | −0.000345 | −5.40e-05 | 0.000563 | 7.86e-05 |
| (0.00123) | (0.00121) | (0.000402) | (0.00200) | (0.00136) | |
| Trimester 2 | −0.000485 | 0.000975 | −1.25e-05 | 0.00215 | −0.000157 |
| (0.00118) | (0.00130) | (0.000378) | (0.00163) | (0.00157) | |
| Trimester 3 | 0.00225 | −0.00126 | −0.000123 | −0.00106 | −0.00170 |
| (0.00126) | (0.00152) | (0.000419) | (0.00196) | (0.00155) | |
| N = 692 586 | N = 692 586 | N = 692 586 | N = 692 586 | N = 688 985 | |
| R 2 = 0.06 | R 2 = 0.02 | R 2 = 0.04 | R 2 = 0.03 | R 2 = 0.04 | |
| B. Focal sample (births in regions with births, pesticides in all years) | |||||
| Sum AI | −0.00387* | 0.00213 | −0.00132* | 0.00745*** | 0.00504* |
| (0.00162) | (0.00192) | (0.000558) | (0.00275) | (0.00225) | |
| Tox Cat 1 & 2 | −0.00152 | 0.00224 | −0.000273 | 0.00318 | 0.00128 |
| (0.00169) | (0.00208) | (0.000504) | (0.00264) | (0.00193) | |
| Tox Cat 3 & 4 | −0.000235 | −0.00275 | −0.00135** | 0.00432 | 0.00249 |
| (0.00182) | (0.00182) | (0.000492) | (0.00248) | (0.00236) | |
| Trimester 1 | −0.00362* | 0.00146 | −0.000476 | 0.00276 | 0.00163 |
| (0.00149) | (0.00142) | (0.000548) | (0.00289) | (0.00175) | |
| Trimester 2 | −0.00194 | 0.00363* | −0.000647 | 0.00498* | 0.00247 |
| (0.00132) | (0.00147) | (0.000442) | (0.00221) | (0.00189) | |
| Trimester 3 | 0.000725 | −0.000161 | −0.000401 | 0.000780 | −0.000917 |
| (0.00153) | (0.00176) | (0.000532) | (0.00253) | (0.00204) | |
| N = 137 210 | N = 137 210 | N = 137 210 | N = 137 210 | N = 136 621 | |
| R 2 = 0.06 | R 2 = 0.03 | R 2 = 0.04 | R 2 = 0.03 | R 2 = 0.04 | |
Regression coefficients for three different measures of pesticide exposure in the full estimation sample (A) and the focal sample (B). All exposure variables are coded as binary variables with high exposure (>95% exposure based on all births) and low exposure (all others) groups. Sum AI indicates total kg of pesticide active ingredients applied in the 2.6 km2 region encompassing mothers addresses, “Tox” indicates total kg of active ingredients by toxicity categories based on the EPA signal word, and trimester indicates total kg by trimester. All models include a set of covariates to control for characteristics of the mother and infant as well as regional and temporal dummy variables as described in the text (see Supplementary Table 2 for coefficients). These are omitted from the tables for visual clarity. For all tables, standard errors, clustered at mother’s zipcode, are below the coefficients in parentheses. The statistical significance of two-tailed t-tests is indicated by * p < 0.05, ** p < 0.01, and *** indicates significance with a Bonferroni correction for multiple comparisons. Bold indicates significant coefficients in the expected direction and italics indicates the one significant coefficient with the opposite than expected sign. Values reported in the text are converted to percent or units of change (days, grams) based on rates of outcomes in the sample (Table 1). For example, 9.8% of births are preterm in the focal sample and thus a 0.00745 increase in the probability of preterm birth is equivalent to a 7.6% increase in this sample