Associations between selected perfluoroalkyl acids in serum and hemoglobin in whole blood, a biomarker of anemia: Impact of deteriorating kidney function

Hexafluoropropylene oxide trimer acid, a perfluorooctanoic acid alternative, induces cardiovascular toxicity in zebrafish embryos

As an increasingly used alternative to perfluorooctanoic acid (PFOA), hexafluoropropylene oxide trimer acid (HFPO-TA) has been widely detected in global water environments. However, little is known regarding its toxic effects on cardiovascular development. Here, zebrafish embryos were treated with egg water containing 0, 60, 120, or 240 mg/L HFPO-TA. Results showed that HFPO-TA treatment led to a significant reduction in both larval survival percentage and heart rate. Furthermore, HFPO-TA exposure caused severe pericardial edema and elongation of the sinus venous to bulbus arteriosus distance (SV-BA) in Tg (myl7: GFP) transgenic larvae, disrupting the expression of genes involved in heart development and thus causing abnormal heart looping. Obvious sprouting angiogenesis was observed in the 120 and 240 mg/L exposed Tg (fli: GFP) transgenic larvae. HFPO-TA treatment also impacted the mRNA levels of genes involved in the vascular endothelial growth factor (VEGF) pathway and embryonic vascular development. HFPO-TA exposure significantly decreased erythrocyte number in Tg (gata1: DsRed) transgenic embryos and influenced gene expression associated with the heme metabolism pathway. HFPO-TA also induced oxidative stress and altered the transcriptional levels of genes related to cell cycle and apoptosis, inhibiting cell proliferation while promoting apoptosis. Therefore, HFPO-TA exposure may induce abnormal development of the cardiovascular and hematopoietic systems in zebrafish embryos, suggesting it may not be a suitable or safe alternative for PFOA.

The use of biological fluids in microfluidic paper-based analytical devices (μPADs): Recent advances, challenges and future perspectives

The use of microfluidic paper-based analytical devices (μPADs) for aiding medical diagnosis is a growing trend in the literature mainly due to their low cost, easy use, simple manufacturing, and great potential for application in low-resource settings. Many important biomarkers (proteins, ions, lipids, hormones, DNA, RNA, drugs, whole cells, and more) and biofluids are available for precise detection and diagnosis. We have reviewed the advances μPADs in medical diagnostics have achieved in the last few years, focusing on the most common human biofluids (whole blood/plasma, sweat, urine, tears, and saliva). The challenges of detecting specific biomarkers in each sample are discussed, along with innovative techniques that overcome such limitations. Finally, the difficulties of commercializing μPADs are considered, and future trends are presented, including wearable devices and integrating multiple steps in a single platform.

Association of exposure to per- and polyfluoroalkyl substances with hemoglobin and hematocrit during pregnancy

BACKGROUND

Per- and polyfluoroalkyl substances (PFASs) are common environmental contaminants and are widely detected in humans. Previous studies have linked PFASs exposure to adverse birth outcomes. However, the association between maternal exposure to PFASs and hemoglobin (Hb) and hematocrit (HCT) remains unclear.

OBJECTIVES

We aimed to explore the relationship between PFASs exposure with Hb and HCT during pregnancy.

METHODS

The present birth cohort study included 1044 pregnant women from Wuhan, China. Maternal HCT and Hb were measured in the first, second and third trimesters, and 13 PFASs were detected in the cord sera. Mixed linear models and general linear regression were applied to analyze the association between each single PFASs and Hb and HCT. Weighted quantile sum (WQS) regressions were used to investigate the association between PFASs mixture and Hb and HCT during pregnancy.

RESULTS

In single-PFAS models, 10 PFASs were positively associated with HCT and Hb across pregnancy (a 10-fold increase in PFASs was associated with 1.47-3.54 % change in HCT and 1.46-3.20 % change in Hb (All P-FDR < 0.05). In addition, Hb and HCT were more positively related to PFASs in the second and third trimesters rather than the first trimester. The association between PFASs exposure and maternal HCT and Hb was not significant in the iron supplementation group, whereas significant in the non-iron supplementation group. A significant interaction between iron supplementation and non-iron supplementation was also detected. WQS regressions showed that perfluorononanoic acid (PFNA) and perfluorohexane sulfonate (PFHxS) contributed most to the association between PFASs and HCT and Hb in the second and third trimesters, respectively.

CONCLUSION

Maternal PFASs exposure was positive with serum Hb and HCT. Moreover, maternal iron supplementation may play a modifying effect in influencing the relationship between PFASs and HCT and Hb.

Associations of serum perfluoroalkyl substances with concentrations of blood manganese and selenium

The aim of this study was to estimate the associations of blood manganese and selenium with serum concentrations of selected perfluoroalkyl substances (PFAS). The presence or absence of this association is important because PFAS have documented pro-oxidant properties, whereas manganese and selenium are critical to antioxidant responses. For this purpose, the data from NHANES for US adults aged ≥ 20 years (N = 3982), adolescents aged 12-19 years (N = 1524), and children aged 3-11 years (N = 639) were analyzed. Among adults, concentrations of blood manganese were found to be inversely associated with serum concentrations of perfluorooctanoic acid or PFOA (β =  - 0.04204, p < 0.01), perfluorononanoic acid or PFNA (β =  - 0.02700, p < 0.01), perfluorohexane sulfonate or PFHxS (β =  - 0.04306, p < 0.01), and perfluorooctane sulfonate or PFOS (β =  - 0.04494, p < 0.01). Blood concentrations of selenium were found to be positively associated with PFHxS only among adults (β = 0.000678, p = 0.047) and adolescents (β = 0.01377, p = 0.02). The Mn results but not the less consistent Se associations were robust to adjustments for serum albumin. Possible reasons for the inverse association of PFOA, PFHxS, PFNA, and PFOS with Mn among US adults are discussed. The finding raises concerns about manganese's diminished ability to mount antioxidant responses to PFAS exposure.

Associations of single and multiple perfluoroalkyl substances exposure with folate among adolescents in NHANES 2007-2010

BACKGROUND

The accumulation of perfluoroalkyl substances (PFAS) in human body has raised concerns about the potential health impacts on children and adolescents. However, no study has evaluated the associations of PFAS exposure with folate concentrations among adolescents.

METHODS

In the present study, we mainly used three statistical approaches, namely multiple linear regression, Bayesian Kernel Machine Regression (BKMR), and quantile-based g-computation (Q-gcomp) models, to evaluate associations of individual PFAS and their mixtures with serum and red blood cell (RBC) folate concentrations in a sample of 721 adolescents from the NHANES 2007-2010.

RESULTS

In multiple linear regression models, for per unit increase in ln-transformed perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) concentrations, RBC folate concentrations decreased by 72.4 (95% confidence interval (CI): -112.7, -32.2), 58.3 (95% CI: -115.0, -1.6), 60.7 (95% CI: -107.5, -13.8), and 76.5 (95% CI: -119.0, -33.9) nmol/L, respectively. A similar significant inverse association was also observed between ln-transformed PFDA and serum folate. BKMR models further confirmed inverse associations of serum PFOS and PFDA with RBC folate, and serum PFDA with serum folate. However, the inverse associations of PFOA and PFNA with RBC folate shown in multiple linear regression model were not observed or less evident in BKMR analyses. We observed interactions of PFOA with PFOS, PFNA, and PFDA on RBC folate in BKMR models, with the negative slopes for PFOS, PFNA, and PFDA increased when PFOA concentration increased from the 10th percentile to the 90th percentile. Both BKMR and Q-gcomp models suggested that the mixtures of five PFAS showed inverse overall associations with RBC folate concentration.

CONCLUSIONS

The present study revealed that adolescent exposure to PFAS might affect serum and RBC folate concentrations.

Association between the total plasma isomers of per- and polyfluoroalkyl substances and erythrograms in young and middle-aged Taiwanese populations

PURPOSE

Per- and polyfluoroalkyl substances (PFAS) are human-made chemicals used in daily use products. Recent studies have shown that different perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS) isomers may have different biological effects. In vitro studies have also reported that PFAS exposure can alter the structure of hemoglobin (Hb). In epidemiology, however, few studies have investigated the relationship between PFAS exposure and erythrocytes. Additionally, the correlation between PFOA/PFOS isomers and full erythrograms has never been explored.

APPROACH AND RESULTS

In cohorts comprising young and middle-aged Taiwanese populations, we enrolled 1483 participants (aged between 12 and 63 years) to analyze the correlations between the plasma levels of PFOA/PFOS isomers and whole-blood erythrograms. The study comprised 868 men and 615 women with a mean age of 31.2 years. When all PFOA/PFOS isomers were entered into the multiple linear regression model, the linear PFOA (L-PFOA) levels were positively correlated with the Hb, hematocrit (HCT), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) levels while the branched PFOS (B-PFOS) levels were positively associated with the Hb, HCT, and mean corpuscular hemoglobin concentration (MCHC). The mean value of Hb was the highest (14.66 mg/dL (95% CI =14.52-14.80); P for trend <0.001) when both the L-PFOA and B-PFOS levels were above the 50th percentile.

CONCLUSIONS

The results imply that PFOA/PFOS isomers may increase the weight and volume of Hb/RBC and that L-PFOA/B-PFOS may have an additive effect on the Hb levels. However, it is also possible PFAS detected at a higher concentration may due to its binding to higher levels of Hb. Further studies are needed to investigate the effects of PFOA/PFOS isomers on RBCs in humans.

Impact of the co-occurrence of obesity with diabetes, anemia, hypertension, and albuminuria on concentrations of selected perfluoroalkyl acids

Data (N = 10644) for US adults aged ≥20 years for 2003-2016 from National Health and Nutrition Examination Survey were analyzed to evaluate the impact of co-occurrence of obesity with diabetes, anemia, albuminuria, and hypertension on concentrations of five perfluoroalkyl acids (PFAA), namely, perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorodecanoic acid (PFDA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). For the total population, males, and females, co-occurrence of obesity with hypertension, albuminuria, anemia, and diabetes was found to be associated with lower adjusted geometric means (AGM) than nonobese for every PFAA. For example for females, for PFOS, AGMs for obese with no diseases, hypertension, albuminuria, anemia, and diabetes were 8.2, 10.8, 5.8, 4.6, and 7.7 ng/mL respectively. In comparison, for PFOS, for nonobese females, AGMs for those with no diseases, hypertension, albuminuria, anemia, and diabetes were found to be 8.9, 13.4, 7.7, 6.0, and 10.2 ng/mL respectively. This implies obesity is associated with higher excretion rates. Females, in general, had lower AGMs than males for both obese and nonobese for every PFAA for every disease group. For example, percent ratios of obese females to males AGMs for PFOA were 66.7%, 87.1%, 88.2%, 70.6%, and 90% for those with no diseases, hypertension, albuminuria, anemia, and diabetes respectively. The ratios of obese to nonobese AGMs for females were lower than males for every PFAA for those with no diseases and hypertension only. For example, for PFOA for those with no diseases, obese to nonobese AGM ratios were 87% for females and 100% for males. Thus, additional excretion of certain PFAAs due to obesity is higher in females than males for those with no diseases and hypertension only.