Association between prenatal exposure to cooking oil fumes and full-term low birth weight is mediated by placental weight

The mediation of the placenta on the association between maternal ambient temperature exposure and birth weight

Studies have indicated that exposure to low and high temperatures during pregnancy negatively affects fetal development. The placenta plays vital functions in fetal development and could also be impacted by suboptimal temperatures. However, whether the placenta mediates the association between suboptimal temperature and birth weight is unknown. Our study aims to evaluate the association between ambient temperature and birth weight as well as the mediation effect of the placenta. A prospective birth cohort study was conducted during 2017-2020 in Guangzhou, China (n = 3349 participants). We defined extreme temperature exposure during the whole pregnancy by using different thresholds, including low temperatures (< 25th, < 15th, < 10th, < 5th percentiles), and high temperatures (> 75th, > 85th, > 90th, > 95th percentiles). Three different approaches (generalized linear model, inverse probability weighting, and doubly robust model) were applied to estimate the effects of low/high temperatures on birth weight and placental indicators, including placental weight, placental volume, and placental-to-birth weight ratio (PFR), respectively. We observed that both low and high ambient temperatures during the whole pregnancy were associated with lower birth weight and negative changes in placental indicators. The estimated lower mean birth weight ranged from -158 g (95 % CI: -192 g, -123 g) to -363 g (95 % CI: -424 g, -301 g) for low temperatures and from -97 g (95 % CI: -135 g, -59 g) to -664 g (95 % CI: -742 g, -585 g) for high temperatures. In mediation analyses, placental weight mediated 28.79 % to 40.47 % and 48.22 % to 54.38 % of the association of low and high temperatures with birth weight, respectively. The findings suggest that placental weight may mediate the association between ambient temperature exposure and birth weight.

Role of ROS-mediated PERK/ATF4 signaling activation in extracorporeal tube formation injury of human umbilical vein endothelial cells induced by cooking oil fume PM2.5 exposure

Cooking oil fume-derived PM2.5 (COF-PM2.5) is a major source of indoor air contamination in China, which has been demonstrated to be a hazard factor of cardiovascular and cerebrovascular diseases. This study aimed to investigate the role of ROS-mediated PERK/ATF4 signaling activation in COF-PM2.5-inhibited extracorporeal tube formation in human umbilical vein endothelial cells (HUVECs). HUVECs were treated with 100 μg/mL COF-PM2.5 at different times, with or without 100 nM PERK activity inhibitor GSK2606414 (GSK) or 200 μM antioxidant N-acetylcysteine (NAC) pretreatment. Our results showed that COF-PM2.5 exposure can inhibit extracorporeal tube formation and down-regulate VEGFR2 expression in HUVECs. Furthermore, our data indicated that COF-PM2.5 exposure can activate the PERK/ATF4 signaling in HUVECs. Mechanistically, pretreatment with GSK interdicted PERK/ATF4 signaling, thereby reversing COF-PM2.5-downregulated VEGFR2 protein expression in HUVECs. Furthermore, NAC reversed VEGFR2 expression downregulated induced by COF-PM2.5 by inhibiting the upregulation of intracellular ROS levels and PERK/ATF4 signaling in HUVECs. As above, COF-PM2.5 exposure could induce ROS release from HUVECs, which in turn activate the endoplasmic reticulum PERK/ATF4 signaling and inhibit tube formation of HUVECs.

The Content and Emission form of Volatile Organic Compounds from Cooking Oils: A Gas Chromatography-Mass Spectrometry (GC-MS) Analysis

Cooking oil fumes are full of dangerous chemicals that are bad for human health. Volatile organic compounds (VOCs) in cooking oil fumes are not only emitted in the form of gas but may also accumulate with other substances in oil fumes and form particulate matter emitted into the atmosphere. Different forms of VOCs can enter different regions of the human body and have varying effects on health. This paper investigated the VOC emission types found in some cooking fumes. The findings demonstrate that organic contaminants from edible oils were released as gas and particle matter, with gas being the predominant component. The fraction of gaseous VOCs steadily declined as oil temperature rose, whereas the proportion of VOCs released as particulate matter gradually rose. It is possible to assume that the increase in oil fume with temperature was caused by the original oil's components volatilizing more frequently under the influence of vapor pressure and that chemical reactions were not the primary cause of oil fume creation.

Maternal exposure to cooking oil fumes during pregnancy and autistic-like behaviors in Chinese preschoolers

There is growing evidence that cooking oil fumes (COFs) are harmful indoor air pollutants. However, there is a dearth of research investigating whether maternal COFs exposure during pregnancy may affect children's autistic-like behaviors in China. This study aimed to explore this association, and examine the effects of different cooking fuels and ventilation methods used by mothers on the presence of autistic-like behaviors. This study analyzed the survey data of the Longhua Child Cohort Study in 2017 with a total of 62,372 mothers enrolled in this study. A self-administrative questionnaire was used to collect information on socio-demographic characteristics, cooking habits during pregnancy, and autistic-like behaviors (measured using the Autism Behavior Checklist). After adjusting for potential confounders, the results showed that compared with children whose mothers never cooked during pregnancy, children whose mothers cooked sometimes, often, always during pregnancy had the higher risk of autistic-like behaviors. As the amounts of COFs exposed to and the frequency of cooking during pregnancy increased, the risk of a child's autistic-like behaviors also increased. Mothers using natural gas as cooking fuels had a lower risk of their child having autistic-like behaviors, compared with mothers using coal or other cooking fuels. Furthermore, pregnant women using ventilation measures during cooking significantly decreased likelihood of the presence of autistic-like behaviors in their children. These results suggest that maternal exposure to COFs during pregnancy may increase the likelihood of the presence of autistic-like behaviors in offspring. These findings support a recommendation that pregnant women should avoid exposure to COFs and use clean fuels and ventilation equipment in kitchens to reduce the risk of autistic-like behaviors in children.

Household cooking oil type and risk of oral micronucleus frequency in Chinese nonsmokers

Household animal fat has been linked to increased incidence of cancers compared with vegetable fat. However, few epidemiological studies have associated these two cooking oil types with precancerous genotoxic effects, such as occurrence of micronuclei (MN). This study aimed to explore the association between oral MN frequency and household cooking oil type and whether the association can be attributed to polycyclic aromatic hydrocarbons (PAHs). We collected information about individual cooking oil use, measured genotoxic effects by MN tests and urinary PAHs metabolites (OHPAHs) in 245 nonsmokers. The associations between household cooking oil type and MN frequency and OHPAHs were analyzed using generalized linear models (GLMs) and logistic regression models, evaluating odds ratios and coefficient (95% confidence intervals) (ORs, 95% Cls; β, 95% Cls). The odds of animal fat consumers, rather than vegetable fat consumers, was positively associated with higher MN frequency (OR = 1.94, P < 0.05). The associations were discovered in participants only using kitchen ventilation (OR = 2.04, P < 0.05). Animal fat consumers had higher total OHPAHs than vegetable fat consumers (1.58 ± 0.22 mg/mol, Cr vs 1.20 ± 0.12 mg/mol, Cr; P = 0.028). Significant correlations were observed between total OHPAHs quartiles and increased MN frequency (β = 0.38, P-trend = 0.026). After stratifying by household cooking oil type, sensitivity analyses showed that the positive association between total OHPAHs quartiles and increased MN frequency was only observed in animal fat consumers (β = 0.61, P-trend = 0.030). In conclusion, usage of household animal fat was associated with an increased odds of oral MN frequency in Chinese nonsmokers and the odds correlated with increased PAHs exposure. This finding supplemented evidence associating cooking oil type with genotoxic effects and explained its association with PAHs exposure.

Vitamin D3 protects intrauterine growth restriction induced by cooking oil fume derived fine particulate matters

BACKGROUND

Cooking oil fume (COF) is an important source of indoor air pollution which severely affects human health, and sufficient vitamin D₃ (VitD₃) is necessary for maternal and child health. However, the effects of cooking oil fume-derived PM_2.5 (COF-PM_2.5) on birth outcomes and whether VitD₃ could protect from adverse effects caused by COFs-PM_2.5 are still unclear.

METHODS

Twenty-four pregnant rats were divided into 4 groups and treated with various treatments: normal feeding, COFs-PM_2.5 intratracheal instillation, VitD₃ intragastric administration, and COFs-PM_2.5 and VitD₃ co-treatment, respectively. The fetal rats were obtained in pregnant 21 days and the development of them was recorded. Morphological changes in umbilical cord were measured with HE staining, and the oxidative stress and inflammatory levels were also investigated. Western blotting and RT-PCR was used to detect the expression of angiogenesis related factors.

RESULTS

We successfully established an intrauterine growth restriction model in rats induced by COFs-PM_2.5 where fetus weight significantly decreased after COFs-PM_2.5 exposure. As for the umbilical cord vasculature, the wall thickened and the lumen narrowed down, and the contractility of the umbilical cord vasculature enhanced after COFs-PM_2.5 exposure. COFs-PM_2.5 exposure also increased the oxidative stress and inflammation level and activated the HIF-1α/eNOS/NO and VEGF/VEGFR2/eNOS signaling pathway. Interestingly, VitD₃ intervention significantly increased the fetus weight and attenuated the injury of umbilical cord vascular, and partly or completely reversed the changes in the ROS/eNOS/ET-1 axis caused by COF-PM_2.5.

CONCLUSIONS

The findings of this study suggested that COF-PM_2.5 exposure could contribute to intrauterine growth restriction through disturbing the ROS/eNOS/ET-1 axis, while VitD₃ supplementation could be an effective prophylactic measurement.

Association between prenatal exposure to indoor air pollution and autistic-like behaviors among preschool children

Indoor air pollution is a recognized risk factor for a range of negative health outcomes. This study aimed to investigate the association between maternal prenatal exposure to indoor air pollution and the presence of autistic-like behaviors among preschool children. Data were obtained from the Longhua Child Cohort Study in 2017, in which we enrolled a total of 65 317 preschool children. Associations between maternal exposure to four sources of indoor air pollution (e.g., cooking, environmental tobacco smoke (ETS), mosquito coils, and home decoration) during pregnancy and preschool children's autistic traits were analyzed using multivariate logistic regression. Our results showed that maternal exposure to indoor air pollution from four different sources during pregnancy was associated with the presence of children's autistic-like behaviors. There was dose-response relationship between the accumulative exposure to the four different indoor air pollution sources and the risk of autistic-like behaviors. Furthermore, we found a significant additive interaction between prenatal exposure to both cooking and mosquito coil incense on the risk of autistic-like behaviors. Maternal prenatal exposure to the indoor air pollution from four sources might increase with the risk of autistic-like behaviors being present among preschool children, with an additive interaction effect between some pollution sources.

The mediation effect of placental weight change in the association between prenatal exposure to selenium and birth weight: Evidence from a prospective birth cohort study in China

Supplemental Digital Content is available in the text.

Selenium (Se) is an essential element and also toxic at an excessive level for human body. However, few studies have investigated adverse effects of Se exposure on birth weight and placental weight.

Evaporation rates and pollutants emission from heated cooking oils and influencing factors

The heating of edible oils during cooking activities promotes the emissions of pollutants that have adverse impacts on the health of humans. This study investigated the evaporative emissions of fifteen (15) commonly used cooking oils. Split-plot experimental design under the response surface methodology framework was used to study singular and interaction effects of influencing parameters (temperature, volume of cooking oil and time) on cooking oil evaporation rate and pollutants emissions (i.e. Particulate matter of aerodynamic diameter ≤1 μm (PM_1.0); ≤2.5 μm (PM_2.5); ≤10 μm (PM₁₀); Total Suspended Particulate (TSP); Total Volatile Organic Compounds -TVOCs, and Carbon Monoxide- CO) on a groundnut oil sample that served as a case study. Obtained values of density, viscosity, kinematic viscosity, smoke, flash and fire points were; 873-917 kg/m³; 1.12-9.7 kg/ms; 2.4-3.4 m²/s; 96 -100 °C; 124-179 °C and 142-186 °C, respectively. The role of temperature as the most significant parameter influencing the rate of evaporative emissions was established. Evaporation rate and pollutants emission from unrefined samples were the highest. The restricted maximum likelihood (REML) analysis results suggested a strong relationship between the actual values and the predicted values as R-squared values obtained were greater than 0.8 for all the responses. These results suggest that minimal rates of evaporation and pollutants emission from heating cooking oils can be achieved with a high volume of the cooking oil at moderate temperature levels.

Gestational vitamin D deficiency causes placental insufficiency and fetal intrauterine growth restriction partially through inducing placental inflammation

Several epidemiological studies suggest an association between vitamin D deficiency (VDD) and fetal intrauterine growth restriction (IUGR). Here, we explored the mechanism through which VDD induced fetal IUGR. Pregnant mice were fed with VDD diet to establish VDD model. Cyp27b1^+/- mice were generated to develop a model of active vitamin D3 deficiency. Cyp27b1^+/- mice were injected with either 1α,25(OH)₂D₃ or vehicle once a day throughout pregnancy. As expected, fetal weight and crown-rump length were reduced in VDD diet-fed mice. Correspondingly, fetal weight and crown-rump length were lower in cyp27b1^+/- mice. 1α,25(OH)₂D₃ elevated fetal weight and crown-rump length, and protected cyp27b1^+/- mice from fetal IUGR. Further analysis found that placental proliferation was inhibited and placental weight was decreased in VDD diet-fed mice. Several growth factors and nutrient transfer pumps were downregulated in the placentas of VDD diet-fed mice. Mechanistically, several inflammatory cytokines were upregulated and placental NF-κB was activated not only in VDD diet-fed mice but also in VDD pregnant women. Interestingly, 1α,25(OH)₂D₃ inhibited the downregulated of placental nutrient transfer pumps and the upregulated of placental inflammatory cytokines in Cyp27b1+/- mice. These results provide experimental evidence that gestational VDD causes placental insufficiency and fetal IUGR may be through inducing placental inflammation.

Moderate-temperature catalytic incineration of cooking oil fumes using hydrophobic honeycomb supported Pt/CNT catalyst

Catalytic incineration is one of the cost-effective technologies to deal with odor cooking oil fumes (COFs). Hydrophobic carbon nanotubes (CNT) supported Pt catalysts were prepared by incipient wetness impregnation method. The 2.0 wt.%Pt/CNT catalyst gave the highest activity with the lowest light-off temperature near 200 °C. The catalyst was further coated on the carbonized honeycomb which offered low-pressure drop and high surface area per unit volume. Toward feasibility application, hydrophobic honeycomb supported Pt/CNT catalyst achieved an excellent catalytic performance with the conversion of 88.0-91.3 % in gas hourly space velocity (GHSV) ranging from 5,700 to 17,200 h^-1 at 300 °C. Importantly, the honeycomb supported Pt/CNT catalyst could remove COFs substantially under simulated cooking conditions. Only a slight amount of heptane remained after catalytic incineration. In addition, the honeycomb support used much less Pt/CNT catalyst by maintaining the same performance, compared with powder catalyst. Our research outcome provides an excellent opportunity to apply the honeycomb supported Pt/CNT catalyst for moderate-temperature catalytic incineration of odor exhaust from kitchen hood.