Project Bibliography

Markel et al., 2015

Markel TA, Proctor C, Ying J, Winchester PD, “Environmental pesticides increase the risk of developing hypertrophic pyloric stenosis,” Journal of Pediatric Surgery, 2015, 50:8, DOI: 10.1016/J.JPEDSURG.2014.12.009.


BACKGROUND: Hypertrophic pyloric stenosis (HPS) is a condition noted within the first several weeks of life that results in hypertrophy of the pyloric muscle between the stomach and duodenum. The etiology has not been elucidated but genetic and environmental influences are suspected. We hypothesized that agricultural pesticides would be associated with an increased incidence of pyloric stenosis.

STUDY DESIGN: Data from infants with HPS were obtained from the Indiana Birth Defects Registry (IBDR) for all counties in Indiana from 2005 to 2009. Data from all live births were obtained from the Indiana State Health Department (ISHD). Maternal demographics and clinical characteristics of infants were abstracted. The US Geological Survey (USGS) provided estimated use of agricultural pesticides (EPEST), and these values were correlated with HPS incidence. Univariate and multivariate logistical regression models were used to assess the association between HPS risk and pesticide use.

RESULTS: A total of 442,329 newborns were studied with 1313 HPS cases recorded. The incidence of HPS was 30/10,000 live births. HPS incidence was correlated with total county pesticide use, as well as subcategories of pesticides (fungicides, fumigants, insecticides, herbicides). Indiana counties were then divided into low, moderate and high pesticide use (mean±standard deviation: 127,722±73,374, 308,401±36,915, and 482,008±97,260pounds of pesticides). Incidence of HPS was 26, 29, and 36 cases per 10,000 in low, moderate and high pesticide-use counties respectively. Subset analysis showed that the positive association between HPS and county pesticide use was more likely for male infants from mothers who were white, aged 20-35 years, had education at high school or lower, and smoked (p<0.05).

CONCLUSION: Pesticide use correlated significantly with incidence of HPS. Positive correlations between HPS risk and pesticide use were found for most risk factors. Further studies will be needed to verify our findings and further delineate the nature of this correlation.

Winchester et al., 2009

Winchester PD, Huskins J, Ying J, “Agrichemicals in surface water and birth defects in the United States,” Acta Paediatrica, 2009, 98:4, DOI: 10.1111/j.1651-2227.2008.01207.


OBJECTIVES: To investigate if live births conceived in months when surface water agrichemicals are highest are at greater risk for birth defects.

METHODS: Monthly concentrations during 1996-2002 of nitrates, atrazine and other pesticides were calculated using United States Geological Survey’s National Water Quality Assessment data. Monthly United States birth defect rates were calculated for live births from 1996 to 2002 using United States Centers for Disease Control and Prevention natality data sets. Birth defect rates by month of last menstrual period (LMP) were then compared to pesticide/nitrate means using logistical regression models.

RESULTS: Mean concentrations of agrichemicals were highest in April-July. Total birth defects, and eleven of 22 birth defect subcategories, were more likely to occur in live births with LMPs between April and July. A significant association was found between the season of elevated agrichemicals and birth defects.

CONCLUSION: Elevated concentrations of agrichemicals in surface water in April-July coincided with higher risk of birth defects in live births with LMPs April-July. While a causal link between agrichemicals and birth defects cannot be proven from this study an association might provide clues to common factors shared by both variables.    FULL TEXT

Winchester et al., 2016

Winchester P, Proctor C, Ying J, “County-level pesticide use and risk of shortened gestation and preterm birth,” Acta Paediatrica, 2016, 105:3, DOI: 10.1111/apa.13288.


AIM: This study assesses the association between pesticide exposure in pregnancy, preterm birth (PTB) and shortened gestation.

METHODS: Pregnancy information was abstracted from the Centers for Disease Control (CDC) Non-Public Use Natality Datasets 1990-2005. Pesticide use in maternal county of residence was calculated using California Pesticide Use Reporting (PUR) data 1990-2005. Counties were ranked by pesticide use, and birth months were sorted by peak (May-June) or nonpeak (other months) pesticide use. Multivariate logistical regression models were used.

RESULTS: Counties with higher pesticide use were associated with higher PTB (low 8.59 ± 0.11%, moderate 9.25 ± 0.07%, high 10.0 ± 0.06%, p’s < 0.001) and shorter gestations (low 39.197 ± 0.014 weeks, moderate 39.126 ± 0.011 weeks, high 39.049 ± 0.011 weeks, p’s < 0.001). Peak pesticide months were associated with higher PTB (10.01 ± 0.05% vs. 9.36 ± 0.05%, p < 0.001) and shorter gestations (39.069 ± 0.007 weeks vs. 39.122 ± 0.007 weeks, p < 0.001). The pesticide effect on shortened gestation and higher PTB was found in all racial groups. Pesticide use was highest for fungicides > insecticides > fumigants > herbicides > others. Each pesticide type was found to be associated with higher PTB and shorter gestation.

CONCLUSION: PTB and shortened gestation were significantly associated with pesticide use in maternal county of residence regardless of race, gestation at birth, and in most risk categories.   FULL TEXT

Winchester et al., 2017

Winchester PD, Parvez S, Proctor C, Ying J, Gerona RR, “Fetal Exposure to Glyphosate,” Pending Presentation, Pediatric Academic Societies, May 6-7, 2017, San Francisco, California.

Winchester Herald Chronicle, 2017

“Tennessee Dept. of Agriculture issues new measures for Dicamba,” July 12, 2017, Winchester Herald Chronicle.


The Tennessee Department of Agriculture responded to increased farmer-to-farmer complaints of damage from dicamba drift by enacting new rules on dicamba use in the state.  The rules include requiring special licensing and record keeping for applicators, banning the use of older formulations for the rest of the season, and limiting the timing that it can be applied, and will be effective through October 1, 2017.  FULL TEXT