Homemade weaning foods as a source of lead and mercury exposure in Korean infants - A dietary risk assessment study.

Lead (Pb) and mercury (Hg) are neurodevelopmental toxicants that pose risks to cognitive and behavioral health. Given early childhood's vulnerability to these metals, understanding their sources and pathways of exposure during infancy is crucial for public health. During the weaning process, infants may be exposed to metals through the baby food they consume. We aimed to assess metal exposure through homemade weaning foods by analyzing 288 samples consumed by 157 Korean infants aged 6-, 9-, 12-, 15-, and 24-27 months. Pb was detected in 65 % of samples, with levels reaching up to 169 ng/g. Notably, 58 % exceeded the Maximum Level (ML) of 10 ng/g, with a median concentration of 14.7 ng/g fresh weight. Total Hg was found in 88 % of samples, with a median concentration of 4.56 ng/g fresh weight. Estimated median daily intakes of Pb and Hg were 0.29 and 0.09 µg/kg/d, respectively. Considering a benchmark dose for Pb (0.5 µg/kg/d by EFSA), 94 % (the margin of exposure <10) of all age groups was estimated to have a potential health concern associated with homemade baby food consumption. For Hg, only 6 % exceeded a hazard quotients of 1 compared to a provisional tolerable weekly intake for Hg (4 µg/kg/week by WHO). This study marks the first direct assessment of daily Pb and Hg intake through homemade baby food among Korean infants. Our findings underscore the urgent need for heightened awareness regarding metal exposure through homemade baby food.

Ultrasonographic assessment of abnormal fetal growth related to uteroplacental-fetal biometrics and Doppler (U-AID) indices: Protocol for multicenter retrospective cohort study trial.

Fetal growth restriction (FGR) is one of the leading causes of perinatal morbidity and mortality. Many studies have reported an association between FGR and fetal Doppler indices focusing on umbilical artery (UA), middle cerebral artery (MCA), and ductus venosus (DV). The uteroplacental-fetal circulation which affects the fetal growth consists of not only UA, MCA, and DV, but also umbilical vein (UV), placenta and uterus itself. Nevertheless, there is a paucity of large-scale cohort studies that have assessed the association between UV, uterine wall, and placental thickness with perinatal outcomes in FGR, in conjunction with all components of the uteroplacental-fetal circulation. Therefore, this multicenter study will evaluate the association among UV absolute flow, placental thickness, and uterine wall thickness and adverse perinatal outcome in FGR fetuses. This multicenter retrospective cohort study will include singleton pregnant women who undergo at least one routine fetal ultrasound scan during routine antepartum care. Pregnant women with fetuses having structural or chromosomal abnormalities will be excluded. The U-AID indices (UtA, UA, MCA, and UV flow, placental and uterine wall thickness, and estimated fetal body weight) will be measured during each trimester of pregnancy. The study population will be divided into two groups: (1) FGR group (pregnant women with FGR fetuses) and (2) control group (those with normal growth fetus). We will assess the association between U-AID indices and adverse perinatal outcomes in the FGR group and the difference in U-AID indices between the two groups.

Clinical and economic analysis of the 2009 H1N1 influenza pandemic among pregnant Korean women.

BACKGROUND/AIMS: Unlike Western countries, the 2009 pandemic influenza infection among pregnant women was reported as mild in a previous interim study in South Korea. However, several mortalities were reported thereafter, suggesting that nationwide data were lacking. METHODS: This case-control study covers the entire 2009 pandemic inf luenza period, from May 2009 to February 2010. The clinical and economic data of pregnant (case) and age-matched non-pregnant (control) women with influenza A (H1N1) pdm09 virus (H1N1pdm09) infection were retrospectively collected from nine hospitals in South Korea. RESULTS: A total of 130 pregnant women with H1N1pdm09 infection were identified. The mean age of the pregnant women was 31.1 years (range, 19 to 41) and mean gestational age was 18.4 weeks (range, 3 to 40). Both case and control groups were similar in terms of age (p = 0.43) and comorbidities (p = 0.18). The overall rate of complications was comparable between the two groups (p = 0.648). However, mortality was reported only among the cases, so mean economic per capita burden is estimated to be higher for pregnant women compared to the control (4,821,992 Korean won [KRW] vs. 351,233 KRW, p = 0.31). Obstetric complications were observed in 12 cases, including preterm labor (n = 7), low birth-weight (n = 3), miscarriage (n = 1), stillbirth (n = 1), and cleft lip (n = 1). CONCLUSION: Although statistically insignificant, the detrimental impact of influenza A H1N1pdm09 on pregnancy can be serious in some complicated cases in South Korea. Thus, the strong recommendation of influenza vaccination should be maintained for pregnant women as a high priority.

Urinary phthalate metabolites over the first 15months of life and risk assessment - CHECK cohort study.

Phthalates are important group of endocrine disruptors. Infants and young children are susceptible to phthalate exposure. However, information on the phthalate exposure during the early stages of life is very limited. This study was conducted to understand the temporal trend of exposure to major phthalates among infants of Korea during the first 15months after birth, and to estimate associated risks. A total of 286 urine samples were collected from 171 children at 3, 9, 12, or 15months of age, with 77 children sampled for two or more times. Four phthalates, i.e., di(2-ethylhexyl) phthalate (DEHP), di-isobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP), and diethyl phthalate (DEP) were chosen, and their major metabolites were analyzed in the urine. The DEHP metabolites were detected in 100% of the urine samples at relatively higher levels compared to those reported in other countries. The levels of mono-ethyl phthalate (MEP) were generally lower. Urinary concentrations of most phthalate metabolites, especially DEHP metabolites, increased as children grew older. Intra-class correlation coefficients (ICCs) calculated for DEHP metabolites over time were high (0.7-0.8), suggesting persistence of consistent exposure sources during this sensitive period of life. Hazard quotient (HQ) and hazard index (HI) were calculated from daily intake estimates divided by recommended toxicity thresholds. Among the study population, 4, 16, and 26% of the children showed HI >1 at 9, 12, and 15months of age, respectively. DEHP exposure explained most of the risk estimates. Considering vulnerability of young children to endocrine disruption, efforts to identify sources of exposure and to develop appropriate mitigation options are warranted.

Occurrence and exposure assessment of polychlorinated biphenyls and organochlorine pesticides from homemade baby food in Korea.

Data on the residue levels of persistent organic pollutants (POPs) in baby food samples are scarce. This is the first study to explore current contamination status and exposure assessment of organochlorines (OCs), including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in baby food from Korea. In this study, the concentrations of OCs were determined in homemade baby food samples (n=100) collected from 6-, 9-, 12- and 15-month-old infant groups. The average concentrations of PCBs, dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordanes (CHLs) in baby food samples were 37.5, 96.6, 26.0, and 13.2 pg/g fresh weight, respectively. The major compounds were CBs 28, 153, 52, and 33 for PCBs and p,p'-DDE, p,p'-DDT and ß-HCH for OCPs. The contribution of DDTs to the total OC concentrations increased from 30% (6-month-old infants) to 67% (15-month-old infants) with increasing infant age, while the concentrations of PCBs, HCHs and CHLs gradually decreased with increasing infant age, suggesting that highest priority for risk reduction of DDTs. The estimated daily intakes (EDIs) of OCs in Korean infants from baby food consumption were lower than the thresholds proposed by the United States Environmental Protection Agency and Health Canada, implying limited potential health risks. However, considering simultaneous exposure from baby food and breast milk consumption, chlordanes and heptachlor epoxide posed potential health risks. Considering the importance of early development and the vulnerability of infants, it is essential to perform systematic monitoring and management programs of OCs in baby food for risk reduction in Korean infants.

Contamination of polychlorinated biphenyls and organochlorine pesticides in breast milk in Korea: time-course variation, influencing factors, and exposure assessment.

Breast milk is a noninvasive specimen to assess maternal and infant exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In this study, 206 breast milk samples were collected from 87 participants during lactation, at <7, 15, 30, or 90 days postpartum in four cities in Korea. The total concentrations of PCBs (ΣPCB) and OCPs (ΣOCP) ranged from