Academic journal article Environmental Health Perspectives

Adverse Associations of Both Prenatal and Postnatal Exposure to Organophosphorous Pesticides with Infant Neurodevelopment in an Agricultural Area of Jiangsu Province, China

Academic journal article Environmental Health Perspectives

Adverse Associations of Both Prenatal and Postnatal Exposure to Organophosphorous Pesticides with Infant Neurodevelopment in an Agricultural Area of Jiangsu Province, China

Article excerpt

Introduction

Organophosphorous (OP) pesticides--toxicants known to disrupt neurologic development--are extensively used in China and worldwide (Gonzalez-Alzaga et al. 2014). Developmental OP exposure could inhibit DNA synthesis, reduce the numbers of neural cells, and lead to abnormalities of synaptic activity within a critical window of neurodifferentiation (Crumpton et al. 2000; Slotkin and Seidler 2012). Developing fetuses and infants are thought to be highly susceptible to OP exposure, due to the ready maternal-fetal transfer of OP pesticides through the placenta, and the immaturity in neurologic development and metabolic detoxification pathways (Kousba et al. 2007). In daily life, young children may experience long-term, low doses of OP pesticides through historical home use, child care environment, and residues in food (Morgan et al. 2005). Thus, children have the potential risk of adverse neurodevelopmental effects induced by OP exposure, even at doses that do not exceed the degree of cholinesterase inhibition necessary to produce systemic toxicity (Crumpton et al. 2000).

Exposure to OP pesticides has been found to be negatively associated with child growth and neurodevelopment outcomes. Several birth cohort studies were performed to investigate the neurodevelopmental toxicity of prenatal and/or postnatal exposure to OP pesticides among children, which were reviewed by Gonzalez-Alzaga et al. (2014). Prenatal exposure to OP pesticides was associated with decreased fetal growth (Perera et al. 2003), shortened gestation (Eskenazi et al. 2004), poorer neurobehavioral development among infants and toddlers (Engel et al. 2007; Eskenazi et al. 2007; Rauh et al. 2006) and in preschoolers (Bouchard et al. 2011). However, the associations between postnatal exposure to OP pesticides and child neurodevelopment were not definitive. Adverse associations were reported between postnatal OP exposure and behavioral problems, cognitive deficits, longer reaction time, and other neurodevelopmental disorders in children across cross-sectional studies (Bouchard et al. 2010; Rohlman et al. 2005), whereas no associations were found between postnatal OP exposure and children's motor or cognitive function in several studies (Bouchard et al. 2011; Guodong et al. 2012). What was more complex was that the elevated postnatal OP exposure was associated with increases of cognitive scores (Eskenazi et al. 2007). Overall, few studies discussed health effects of both prenatal and postnatal exposure to OP pesticides on child neurodevelopment.

In our previous studies, pregnant women and their infants had shown widespread pyrethroid insecticides exposure in Sheyang County, Jiangsu Province (Qi et al. 2012; Wu et al. 2013). In the present study, 310 2-year-old children of the registered women in the previous study were enrolled to assess the associations of both prenatal and postnatal urinary OP metabolite levels with children's birth outcomes and neurodevelopment at 2 years of age.

Materials and Methods

Study Subjects

A total of 310 mother-infant pairs who lived in Sheyang County were enrolled into the present study. Sheyang County, located north of Jiangsu Province, China, is known as a high-quality cotton and rice production region. Agricultural land area is estimated to be about 129,333 ha, with approximately 2,100 tons of pesticides applied annually to control insect pests and plant diseases (Liu et al. 2013).

During June 2011-January 2012, 405 infants whose mothers were from our previous study (Qi et al. 2012) initially participated in the present investigation and visited Sheyang Maternal and Child Health Care Centre. Subjects who volunteered to participate in the study signed an informed consent form and agreed to donate urine samples. This study was carried out with the permission of the Health Bureau of Sheyang County and the Ethics Committees of Fudan University. We excluded 54 children with missing prenatal urine samples, 33 children without adequate postnatal urine volume of 15 mL, and 8 children who did not complete the questionnaires. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.