Prenatal exposure to perfluoroalkyl acids and prevalence of infectious diseases up to 4years of age.

Perfluoroalkyl acids (PFAAs) are synthetic chemicals with ability to repel oils and water, and have been widely used in many industrial and household applications such as adhesives and water- and stain-repellent surfaces to nonstick coatings. Animal studies have shown that PFAAs have immunotoxic effects. However, few epidemiological studies have investigated the effects of PFAAs on infectious diseases occurrence. We examined the relationship between prenatal exposure to PFAAs and prevalence of infectious diseases up to 4years of life. A total of 1558 mother-child pairs, who were enrolled in the Hokkaido Study on Environment and Children's Health, were included in this data analysis. Eleven PFAAs were measured in maternal plasma taken at 28-32weeks of gestation using ultra-performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry. Participant characteristics were obtained from medical birth records and self-administered questionnaires during pregnancy and after delivery. Physicians' diagnosis of common infectious diseases including otitis media, pneumonia, respiratory syncytial virus infection, and varicella up to 4years were extracted from the mother-reported questionnaires. The number of children who developed infectious diseases up to 4years of age was as follows: otitis media, 649 (41.4%); pneumonia, 287 (18.4%); respiratory syncytial virus infection, 197 (12.6%); varicella 589 (37.8%). A total of 1046 (67.1%) children had at least one of the diseases defined as total infectious diseases. After adjusting for appropriate confounders, PFOS levels in the highest quartile were associated with increased odds ratios (ORs) of total infectious diseases (Q4 vs. Q1 OR: 1.61; 95% CI: 1.18, 2.21; p for trend=0.008) in all children. In addition, perfluorohexane sulfonate (PFHxS) was associated with a higher risk of total infectious diseases only among girls (Q4 vs. Q1 OR: 1.55, 95% CI: 0.976, 2.45; p for trend=0.045). We found no association between infectious diseases and other examined PFAAs. Our findings suggest that prenatal exposure to PFOS and PFHxS may associated with infectious diseases occurrence in early life. Therefore, prenatal exposure to PFAAs may be immunotoxic for the immune system in offspring.