Prenatal exposure to organochlorine pesticides and early childhood communication development in British girls

Abstract

Background: The developing brain is susceptible to exposure to neurodevelopmental toxicants such as pesticides. Aims: We explored associations of prenatal serum concentrations of hexachlorobenzene (HCB), beta-Hexachlorocyclohexane (β-HCH), 2,2-Bis(4-chlorophenyl)-1,1-dichloroethene (p,p’-DDE) and 2,2-Bis(4-chlor-ophenyl-1,1,1-trichloroethane (p,p’-DDT) with maternal-reported measures of verbal and non-verbal communication in young girls. Study design and methods: We studied a sample of 400 singleton girls and their mothers participating in the Avon Longitudinal Study of Parents and Children (ALSPAC) using multivariable linear regression models adjusting for parity, Home Observation Measurement of the Environment (HOME) score, maternal age and education status, and maternal tobacco use during the first trimester of pregnancy. Exposure and outcome measures: Maternal serum samples (collected at median 15 wks. gestation [IQR 10, 28]) were assessed for selected organochlorine pesticide levels. Communication was assessed at 15 and 38 months, using adapted versions of the MacArthur Bates Communicative Development Inventories for Infants and Toddlers (MCDI). Results: At 15 months, girls born to mothers with prenatal concentrations of HCB in the highest tertile had vocabulary comprehension and production scores approximately 16% (p = 0.007) lower than girls born to mothers with concentrations in the lowest tertile. This association varied by maternal parity in that the evidence was stronger for daughters of nulliparous mothers. At 38 months, girls born to mothers with prenatal concentrations of HCB in the highest tertile had mean adjusted intelligibility scores that were 3% (p = 0.03) lower than those born to mothers with concentrations in the lowest tertile; however, results did not vary significantly by parity. Maternal concentrations of β-HCH and p,p’-DDE were not significantly associated with MCDI scores at 15 or 36 months. p,p’-DDT had an inconsistent pattern of association; a significant positive association was observed between p,p’-DDT with verbal comprehension scores at 15 months; however, at 38 months a significant inverse association was observed for p,p’-DDT with communicative scores. This inverse association for p,p’-DDT among older girls tended to be stronger among daughters of mothers who had lower depression scores. Conclusions: Organochlorine pesticide exposure in utero may affect communication development.

Relationship between Autism Spectrum Disorder and Pesticides: A Systematic Review of Human and Preclinical Models

“…Regarding the studies conducted in humans, 17 out of 45 (37.8%) studied OP exposure using urine, blood, and house-dust metabolite measures [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ], with OP being the most studied pesticide in this review. From the remaining articles, 9 out of 45 (20.0%) studied OC exposure by DDT and/or DDE exposure [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ], while Puertas et al [ 72 ] and Boucher et al [ 73 ] used other OC compounds such as Mirex and Chlordecone, respectively. Thus 11 out of 45 (24.4%) of the total studies were related to OC exposure.…”

“…Concerning the quality of the preclinical studies, three out of the 16 were labeled as H (18.8%) [ 30 , 37 , 38 ], 10 as MH (62.5%) [ 31 , 32 , 33 , 34 , 35 , 36 , 40 , 43 , 44 , 45 ], and the remaining three as ML-quality (18.8%) [ 39 , 41 , 42 ]. In a similar vein, 37 out of 45 human studies were classified as VH (82.2%) [ 46 , 48 , 49 , 50 , 51 , 52 , 53 , 56 , 57 , 58 , 59 , 61 , 63 , 64 , 65 , 66 , 67 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 80 , 81 , 82 , 83 , 84 , 85 , 87 , 88 , 89 , 90 , 91 ], 7 as H (15.6%) [ 47 , …”

“…Only 11 out of 45 studies carried out in humans reported an association between OC pesticides and autism. Of these, nine were classified as VH (81.8%, [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]), and Kao et al [ 68 ] and Lyall et al [ 69 ] were classified as H-quality. Prenatal exposure was the most frequently studied exposure for OC, except Kao et al [ 68 ] who studied postnatal exposure, while prenatal and postnatal exposure was reported by Kim et al [ 65 ] and Boucher et al [ 73 ].…”

“…The literature focuses on DDT and one of its principal breakdown products DDE. Authors that studied the effects of this exposure also assessed other metabolites such as hexachlorocyclohexane (HCH) and hexachlorobenzene (HCB) [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ]. Only two studies assessed other OC compounds (Mirex, [ 72 ] and Chlordecone, [ 73 ]).…”

“…All of these use a prenatal exposure protocol, evaluated at early ages (between two and four months of age) [64] and from four to five years of age [66]. In addition, a study using prenatal exposure with a follow-up period between one and five years reported intelligibility, vocabulary comprehension, and production deficits [67], while verbal comprehension, memory, and cognitive problems were observed by Torres-Sánchez et al [71].…”