PAH levels in parturient and newborns from Aveiro region, Portugal

• Autor(a) principal: Fraga, Marta Pena Gil
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/21960
• topic: Gravidez - Patologias; Recém-nascidos - Patologias; Monitorização biológica; Hidrocarbonetos aromáticos policíclicos

Human exposure to polycyclic aromatic hydrocarbons (PAHs) can arise from forest fires, coal tar combustion, vehicle exhausts and tobacco smoke and can be critical in some residential and working areas. PAHs are considered a group of priority chemicals as they are carcinogenic, mutagenic and teratogenic. Therefore, is crucial to monitor and study human exposure to PAHs, namely during fetal development, which is considered a sensitive window of exposure to contaminants. In this context, the main objectives of this study were: (i) to assess maternal and fetal exposure to PAHs in parturient from the Aveiro region using samples of placenta and blood as biological matrices; (ii) to examine the influence of environmental, sociodemographic, lifestyle and smoking habits that may contribute to PAHs exposure during pregnancy in Aveiro region, Portugal. This study was performed in 49 mother/newborn pairs from Aveiro region. All the matrices sampled (placenta, umbilical cord blood and mothers’ blood) and information gathered was approved by Ethics Committee of Infante D. Pedro Hospital in Centro Hospitalar do Baixo Vouga, Aveiro and all the parturient previously signed an informed consent. A fluorescence spectrophotometer was used to quantify levels of PAHs (naphthalene, phenanthrene, pyrene and benzo[a]pyrene equivalents) in the tissues collected. In general, the studied group presented high levels of PAHs equivalents in the placenta (total homogenate fraction) and low levels in the umbilical cord blood. The low molecular weight PAHs (naphthalene and phenanthrene equivalents) measured in placenta presented higher levels than high molecular weight PAHs (pyrene and benzo[a]pyrene equivalents). Considering the county of residence, the highest PAHs levels in placenta were found in parturient from Aveiro, Ílhavo and Albergaria-a-Velha and the lowest in Águeda. Moreover, increased levels of naphthalene and phenanthrene equivalents were associated with mothers’ exposure to vehicle exhaust, while high levels of benzo[a]pyrene equivalents were associated with their exposure to tobacco smoke at work. The highest levels of naphthalene, phenanthrene and benzo[a]pyrene equivalents were found in homogenized placenta of mothers who smoked in the third trimester of pregnancy. No significant correlations were found between levels of PAHs equivalents present in biological tissues studied and anthropometric data of newborns, but in general, high PAHs levels were found in newborns groups with low weight, head circumference, and length. This work provided an overview of the PAHs levels on pregnant woman from the Aveiro district, identifying the main sources of exposure to PAHs. Furthermore, placenta do accumulate PAHs, but is not a complete barrier for those lipophilic compounds, since they seem to cross cell membranes reaching umbilical cord blood and potentially causing adverse effects in the newborns, such as, low weight, length and head circumference values, despite the lack of statistical significance.