Prenatal exposure to the herbicide 2,4-D is associated with deficits in auditory processing during infancy

Details

• Alternative Title:
  Environ Res
• Personal Author:
  Silver, Monica K. ; Shao, Jie ; Li, Mingyan ; Ji, Chai ; Chen, Minjian ; Xia, Yankai ; Lozoff, Betsy ; Meeker, John D.
• Description:
  Introduction
  
  Despite widespread use, many herbicides and fungicides are not well studied for neurological effects. Fetal and infant brains are rapidly developing, yet the effects of early-life exposure to these classes of pesticides on visual and auditory function are unknown. Here we examined the effects of prenatal herbicide and fungicide exposure on infant grating visual acuity (VA) and auditory brainstem response (ABR).
  
  Methods
  
  9 herbicides and 13 fungicides were measured in umbilical cord blood plasma from a cohort of infants in Fuyang County, China (n=232). Grating VA and ABR latencies for waves I, III, V were measured at 3 time points: 6 weeks, 9 months, and 18 months. Outcomes included VA score, ABR wave V latency and ABR central conduction time (CCT [wave V- wave I]). Pesticides were analyzed as 3- level ordinal (non-detect [ND]/medium/high), or dichotomous (ND/detect), depending on detection rates. Linear mixed models were used to evaluate relations between pesticides and VA and ABR outcomes.
  
  Results
  
  2,4-dichloroacetic acid (2,4-D), prometryn, simazine, and tetrahydrophthalamide (THPI, a metabolite of captan) were detected in 27, 81, 17, and 16% of samples, respectively. Infants prenatally exposed to 2,4-D had slower auditory response times at 6 weeks. Infants with cord levels of 2,4-D >1.17 ng/mL had wave V latencies that were 0.12 (95% CI: 0.03, 0.22) ms slower (p=0.01) and overall CCTs that were 0.15 (95% CI: 0.05, 0.25) ms slower (p=0.003) than infants with non-detectable 2,4-D in their cord blood. No other statistically significant findings were observed for the other herbicides and fungicides or for the grating VA outcome.
  
  Conclusions
  
  Prenatal exposure to the herbicide 2,4-D was associated with slower auditory signal transmission in early infancy. ABR latencies reflect auditory pathway maturation and longer latencies may indicate delayed auditory development.
  
  
• Subjects:
  2,4-Dichlorophenoxyacetic Acid Auditory Perceptual Disorders China Evoked Potentials, Auditory, Brain Stem Female Herbicides Humans Infant Male Pregnancy Prenatal Exposure Delayed Effects

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• Keywords:
  Auditory Processing Fungicides Herbicides Neonates Visual Acuity
• Source:
  Environ Res. 172:486-494
• Pubmed ID:
  30851698
• Pubmed Central ID:
  PMC6511332
• Document Type:
  Journal Article
• Funding:
  P01 HD039386/HD/NICHD NIH HHSUnited States/ ; P30 ES017885/ES/NIEHS NIH HHSUnited States/ ; R01 ES021465/ES/NIEHS NIH HHSUnited States/ ; T42 OH008455/OH/NIOSH CDC HHSUnited States/
• Volume:
  172
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha-512:792179bb69f70c82af713018cdbca158678e4cd2f0ac389d31c8e15e9c035e81c49ad3871a3899b62e87e180c33c85049f966f1267e94524704c6f4018fabec5
• Download URL:
  https://stacks.cdc.gov/view/cdc/78409/cdc_78409_DS1.pdf
• File Type:
  [PDF - 551.20 KB ]