In utero metal exposures measured in deciduous teeth and birth outcomes in a racially-diverse urban cohort

Abstract

A growing number of studies have examined associations of metal exposures with birth outcomes, however, results from these studies have been inconsistent, and hampered by methodological limitations. We measured direct fetal exposure to three metals (lead, manganese and zinc) during the second and third trimester and examined its association with birth weight and gestational age at delivery. Participants in the Wayne County Health, Environment, Allergy and Asthma Longitudinal Study (WHEALS), a population-based birth cohort established between September 2003 and December 2007, were invited to donate teeth to the study. Lead, manganese and zinc during the second and third trimesters were measured via high-resolution microspatial mapping of dentin growth rings, a validated biomarker for prenatal metal exposure. Gestational age at delivery and infant birth weight were obtained from the delivery medical record. A total of 145 children had tooth metal measurements and birth outcome data. Mean birth weight was 3431±472 g and

Prenatal Metal Mixtures and Birth Weight for Gestational Age in a Predominately Lower-Income Hispanic Pregnancy Cohort in Los Angeles

“…Growing evidence suggests that toxic metal exposures adversely affect fetal growth (Ballester et al 2018;Cabrera-Rodríguez et al 2018;Deyssenroth et al 2018;Hoffman 2000;Jalali and Koski 2018;Khoshhali et al 2020;Kim et al 2017;Kippler et al 2010;Mikelson et al 2019;Milton et al 2017;Nielsen 2012;Pedersen et al 2016;Rabito et al 2014;Ramón et al 2009a;Rodosthenous et al 2017;Sun et al 2018;Thomas et al 2015;Vaktskjold et al 2007;Vejrup et al 2014;Vigeh et al 2018), but the majority of studies have focused on individual metals. Because metals may behave differently in the presence of metal co-exposures owing to synergistic or antagonistic relationships (Claus Henn et al 2014;Davidson et al 2015), studies have begun investigating metal mixture impacts on fetal growth (Cabrera-Rodríguez et al 2018;Cassidy-Bushrow et al 2019;Deyssenroth et al 2018;Govarts et al 2016;Signes-Pastor et al 2019). Using a novel mixture modeling method that can account for possible nonlinear relationships and interactions between mixture components (Bobb et al 2015), we examined the impact of a complex mixture of seven elements on BW for GA.…”

“…Yet, in combination, certain metals may exert toxic effects even at relatively low levels of exposure owing to synergistic effects (Claus Henn et al 2014), whereas other metals may act antagonistically by inhibiting each other's absorption or tissue uptake (Davidson et al 2015). Although several recent studies have begun examining simple mixtures (e.g., three elements) in relation to fetal growth (Cabrera-Rodríguez et al 2018;Cassidy-Bushrow et al 2019;Signes-Pastor et al 2019), few studies have considered complex mixtures (Deyssenroth et al 2018;Govarts et al 2016), which are more representative of human exposures. This has been particularly understudied in minority populations in the United States.…”

Prenatal exposure to metal mixture and sex-specific birth outcomes in the New Hampshire Birth Cohort Study

“…62 A positive association has been found between deciduous tooth Mn and birth weight. 63 However, evidence suggests that Mn follows a U-shaped dose-response curve, and lower and higher maternal urine and blood Mn levels during pregnancy have been related to lower birth weight. 61,64,65 Still, the optimal Mn levels have not been defined.…”

“…66 An inverse association has also been reported between deciduous tooth Pb and newborns’ weight. 63 Potential mechanisms linking prenatal Pb exposure with impaired fetal growth include competition of Pb with calcium for deposition into bone and impact on collagen synthesis, which may be exacerbated at lower levels of essential nutrients such as Mn. 10,66…”

Análise da presença de metais no esmalte em dentes decíduos de crianças residentes em regiões distintas da cidade de Ribeirão Preto - SP: relações neurotóxicas e abertura de dados junto às comunidades escolares

“…O Mn presente na dieta ou na água atravessa a barreira hematoencefálica para se acumular no sistema nervoso central(BJØRKLUND et al, 2017). A exposição excessiva e crônica a este metal produz efeitos tóxicos, particularmente pelo fato dele se acumular no cérebro, principalmente nos gânglios da base(BOUCHARD et al, 2018).No Brasil, estudos já revelaram que a presença de Mn no ar, que causou intoxicação crônica em crianças, diminui de forma significativa o QI e o desempenho neuropsicológico, que foram avaliados por meio de diversos testes de atenção, flexibilidade cognitiva e memória de trabalho verbal e visual(CARVALHO et al, 2014).A exposição fetal ao Mn está, também, diretamente relacionada com maiores escores Z do peso da crianças ao nascer, que indicam grandes diferenças de peso ao nascer e que estão associadas também ao sexo biológico da criança, sendo o sexo masculino mais afetado(CASSIDY-BUSHROW et al, 2019). A exposição de crianças também é mais preocupante pelo fato de terem seus mecanismos homeostáticos subdesenvolvidos, no qual baixas doses podem afetar de forma mais agressiva o sistema nervoso que ainda está em desenvolvimento (ZONI e LUCCHINI, 2013).O esmalte dental é o tecido mais cristalino, denso e duro do corpo, em que sua dureza pode ser até cinco vezes maior que dos ossos.…”