Comparative study of oxidative stress biomarkers in urine of cooks exposed to three types of cooking-related particles

Diverse Metabolic Effects of Cooking Oil Fume from Four Edible Oils on Human BEAS-2B Cells: Implications for Health Guidelines

The 2021 WHO guidelines stress the importance of measuring ultrafine particles using particle number concentration (PNC) for health assessments. However, commonly used particle metrics such as aerodynamic diameter and number concentrations do not fully capture the diverse chemical makeup of complex particles. To address this issue, our study used high-throughput mass spectrometry to analyze the properties of cooking oil fumes (COFs) in real time and evaluate their impact on BEAS-2B cell metabolism. Results showed insignificant differences in COF number size distributions between soybean oil and olive oil (peak concentrations of 5.20 × 105/cm3), as well as between corn oil and peanut oil (peak concentrations of 4.35 × 105/cm3). Despite the similar major chemical components among the four COFs, variations in metabolic damage were observed, indicating that the relatively small amount of chemical components of COFs can also influence particle behavior within the respiratory system, thereby impacting biological responses. Additionally, interactions between accompanying gaseous COFs and particles may alter their chemical composition through various mechanisms, introducing additional chemicals and modifying existing proportions. Hence, the chemical composition and gaseous components of COFs hold equal importance to the particle number concentration (PNC) when assessing their impact on human health. The absence of these considerations in the current guidelines underscores a research gap. It is imperative to acknowledge that for a more comprehensive approach to safeguarding public health, guidelines must be regularly updated to reflect new scientific findings and robust epidemiological evidence.

Correlation between the non-use of cooking oil fume extractors and bone mineral density in population aged 45 years and older in China: a cross-sectional study

Introduction

The correlation between the non-use of cooking oil fumes (COFs) extractors and bone mineral density (BMD) have not been clarified. Consequently, this study attempted to explore the impact of non-use COFs extractors on BMD in population aged 45 years and older based on a cross-sectional study.

Methods

This study was a cross-sectional study within the framework of an ongoing prospective population-based cohort study in China. The multivariate linear regression models were used to evaluate the correlation between the non-use of fume extractors in family cooking and total lumbar spine (LS), femoral neck (FN), total hip BMD and levels of bone metabolism markers.

Results

A total of 3433 participants were included in the final analyses, of which 2607 (75.93%) participants used fume extractors. The results of models indicated that there were significant correlations of the non-use of fume extractors on total LS BMD (β = -0.024, 95% CI, -0.036, -0.012, p < 0.001), PINP (β = 4.363, 95% CI, 2.371, 6.356, p < 0.001) and ALP (β = 4.555, 95% CI, 2.593, 6.517, p < 0.001) levels.

Conclusions

This study verified that the use of fume extractors is an efficacious measure to prevent LS bone loss. For the sake of public bone health, people should install a fume extractor in the kitchen and use it routinely when cooking.

Formation, migration, derivation, and generation mechanism of polycyclic aromatic hydrocarbons during frying

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and lipophilic, which can be found in frying system. This review summarized the formation, migration and derivation for PAHs, hypothesized the possible mechanism for PAHs generation during frying and presented the research prospects. Some factors like high oil consumption, high temperature, long time and oil rich in unsaturated fatty acids promoted the formation of PAHs and the presence of antioxidants inhibited the PAHs formation. The effect of proteins and carbohydrates in foods on the formation of PAHs is inconclusive. The formed PAHs were migrated into food and air. Moreover, some PAHs transformed into more toxic PAHs-derivatives during frying. The generation of PAHs may be related to low-barrier free radical-mediated reaction and the unsaturated hydrocarbons may be precursors of PAHs during frying. In future, the isotope tracer technology and on-line detection may be applied to discover intermediates and provide clues for studying PAHs generation mechanisms.

Findings of indoor air pollution and childhood obesity in a cross-sectional study of Chinese schoolchildren

BACKGROUND

Air pollution exposures are increasingly suspected to influence the development of childhood adiposity, especially focusing on outdoor exposure, but few studies investigated indoor exposure and childhood obesity.

OBJECTIVES

We aimed to examine the association between exposure to multiple indoor air pollutants and childhood obesity in Chinese schoolchildren.

METHODS

In 2019, we recruited 6499 children aged 6-12 years from five Chinese elementary schools in Guangzhou, China. We measured age-sex-specific body mass index z score (z-BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) on standard procedures. Four different indoor air pollution (IAP) exposures, including cooking oil fumes (COFs), home decoration, secondhand smoke (SHS), and incense burning, were collected by questionnaire and then converted into an IAP exposure index with four categories. Association between indoor air pollutants and childhood overweight/obesity as well as four obese anthropometric indices were assessed by logistic regression models and multivariable linear regression models, respectively.

RESULTS

Children exposed to ≥3 types of indoor air pollutants had higher z-BMI (coefficient [β]:0.142, 95% confidence interval [CI]:0.011-0.274) and higher risk of overweight/obesity (odd ratio [OR]:1.27, 95%CI:1.01-1.60). And a dose-response relationship was discovered between the IAP exposure index and z-BMI as well as overweight/obesity (p_{for trend}<0.05). We also found that exposure to SHS and COFs was positively associated with z-BMI and overweight/obesity (p < 0.05). Moreover, there was a significant interaction between SHS exposure and COFs on the higher risk of overweight/obesity among schoolchildren. Boys appear more susceptible to multiple indoor air pollutants than girls.

CONCLUSIONS

Indoor air pollution exposures were positively associated with higher obese anthropometric indices and increased odds of overweight/obesity in Chinese schoolchildren. More well-designed cohort studies are needed to verify our results.

Non-carcinogenic and cumulative risk assessment of exposure of kitchen workers in restaurants and local residents in the vicinity of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAH_s) are often formed when organic substances do not burn completely. This study evaluates the non-carcinogenic and cumulative risks associated with PAH_s levels by testing blood and urine samples in kitchen workers and residents near restaurants in Shiraz, Iran. Metabolites of PAH in the urine samples as well as clinical parameters in the blood samples were measured. The non-carcinogenic and cumulative risk assessments from exposure of the study groups to PAH metabolites were also evaluated. The highest average concentrations of PAH metabolites were related to kitchen workers (2126.7 ng/g creatinine (ng/g cr)). The metabolites of 1-Hydroxypyrene (1-OHP) and 9-Phenanthrene (9-OHPhe) had the highest and lowest mean concentrations, respectively. A direct correlation was observed between the levels of PAH metabolites with malondialdehyde (MDA) and total antioxidation capacity (TAC) levels (p < 0.05). Hazard Index (HI_i) was obtained less than one (HI_i < 1), indicating low-risk negative health impacts on the target groups. Nevertheless, conducting more studies to determine the health status of these people is quite evident.

Developing a profile of urinary PAH metabolites among Chinese populations in the 2010s

Polycyclic aromatic hydrocarbons (PAHs) pose significant health risks. However, no nationwide cohort has been established to consistently record biomonitoring data on PAH exposure in the Chinese population. Biomonitoring data from 56 published studies were combined in this study to develop a profile of urinary PAH metabolites among Chinese population in the 2010s. The stacked column charts described the composition profiles of hydroxylated PAHs (OH-PAHs) in general, special, and occupational populations. Hydroxynaphthalene (OH-Nap) and hydroxyfluorene (OH-Flu) accounted for more than half of the urinary OH-PAH in general and special populations. The urine of the occupational populations contained a significant amount of hydroxyphenanthrene (OH-Phe) and 1-hydroxypyrene (1-OHPyr). Furthermore, this study analyzed the distribution profiles of non-occupationally exposed populations, such as spatial distribution, age distribution, and trends over time. The population of the Southern region had higher urinary OH-PAH concentrations than the population of the Northern region. Adults (45-55 years old) had the highest level of internal PAH exposure. Between 2010 and 2018, the overall trend of urinary OH-PAHs in Chinese general populations decreased. The cumulative distribution function (CDF) revealed that 1-OHNap and 1-OHPyr were better at distinguishing internal PAH exposure among different populations. The sum of OH-Flu and OH-Phe in urine can be used to assess the impact of indoor and outdoor environments on human exposure to PAHs. Our findings suggest that more emphasis should be placed on collecting biomonitoring data for adults of all ages (particularly in the Northern region) and vulnerable populations. In conclusion, this study advocates for the establishment of a nationwide cohort study of Chinese populations as soon as possible in the future to evaluate the Chinese population's exposure to environmental contaminants.

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.

Exposure assessment of children living in homes with hookah smoking parents to polycyclic aromatic hydrocarbons: urinary level, exposure predictors, and risk assessment

Children are extremely liable to indoor air pollutants as their physiology and a few metabolic pathways are different from those of adults. The present cross-sectional study aimed to assess exposure of children living with parents who use hookah tobacco smoke to polycyclic aromatic hydrocarbons (PAHs) using a biomonitoring approach. The study was conducted on 25 children (7-13 years of age) exposed to hookah smoke at home and 25 unexposed age-matched children. Urinary levels of five metabolites of PAHs were quantified via headspace gas chromatography-mass spectrometry (GC-MS). Urinary malondialdehyde (MDA) was measured, as well. Information regarding the sociodemographic and lifestyle conditions was collected through interviews using managed questionnaires. The urinary 1-OH-NaP and 9-OH-Phe concentrations were respectively 1.7- and 4.6-folds higher in the case samples compared to the control group (p < 0.05). In addition, urinary MDA levels were 1.4 times higher in the exposed children than in the unexposed group, but the difference was not statistically significant (p > 0.05). Increasing the consumption of grilled and meat food in the diet increased the participants' urinary 2-OH-Flu and 1-OH-Pyr levels, respectively. Moreover, sleeping in the living room instead of the bedroom at night was a significant predictor of high 1-OH-NaP and 2-OH-NaP concentrations in the children's urine. Overall, the findings confirmed that children living in their homes with hookah-smoking parents were significantly exposed to naphthalene and phenanthrene. Hence, implementing protective measures is critical to reduce the exposure of this group of children.

Organic pollutant exposure and health effects of cooking emissions on kitchen staff in food services

This study was conducted to determine the exposure and health risk to cooking fumes of a total of 88 volunteer kitchen staff aged between 18 and 65 years working in five different kitchens in Ankara. Gas- and particle-phase polycyclic aromatic hydrocarbons (PAHs), and volatile organic compound (VOCs) concentrations were evaluated in the indoor air of 5 kitchens. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) levels were analyzed to determine the oxidative damage as a result of the exposure to cooking fumes among the cooks and waiters. Significant positive relationships were found between serum MDA levels of the hot kitchen workers and indoor chrysene (Chr), indeno(1,2,3-c,d)pyrene (Ind), and total VOC levels. Although the carcinogenic risks estimated for the exposed population were between the acceptable/tolerable levels, the hazard quotient (HQ) estimated for the exposure to indoor benzene exceeded the safe level. The results of the study revealed that exposure to organic pollutants in indoor air may be a risk factor for the development of oxidative stress, especially in hot kitchen workers. The importance of efficient ventilation in the kitchen has been pointed out to reduce health risks caused by cooking fumes.

Health risk assessment of polycyclic aromatic hydrocarbons in individuals living near restaurants: a cross-sectional study in Shiraz, Iran

Polycyclic aromatic hydrocarbons (PAHs) are persistent toxic substances that have ubiquitous presence in water, air, soil, and sediment environments, posing serious environmental risks. The present study aimed to investigate the concentrations of urinary PAHs and their health effects in individuals living near restaurants via a health risk assessment analysis. This cross-sectional study was performed on 57 people living near restaurants and 30 individuals as the control group. Five urinary metabolites of PAHs were monitored. In order to evaluate the effects of the urinary metabolites of PAHs on Malondialdehyde (MDA) concentration, Total Anti-oxidation Capacity (TAC) in urine samples, and C-Reactive Protein (CRP) in serum samples, regression model was used by considering the effects of the possible confounding factors. Non-carcinogenic health risk was calculated, as well. The median concentration of urinary PAHs was 1196.70 and 627.54 ng/g creatinine in the people living near restaurants and the control group, respectively. Among the metabolites, the lowest and highest mean concentrations were related to 9-OHPhe and 1-OHP, respectively in the two study groups. Moreover, PAHs were significantly associated with MDA level and TAC (p < 0.05). Hazard Quotient (HQ) and Hazard Index (HI) were less than 1. Long-term studies are required to determine the actual health effects by identifying the sources of PAHs emission and to find ways to decrease the production of these compounds.

Urinary Malondialdehyde (MDA) Concentrations in the General Population—A Systematic Literature Review and Meta-Analysis

Oxidative stress has been associated with various inflammation-related human diseases. It is defined as an imbalance between the production and elimination of reactive oxygen species (ROS). ROS can oxidize proteins, lipids, and DNA, and some of these oxidized products are excreted in urine, such as malondialdehyde (MDA), which is considered a biomarker for oxidative damage of lipids. To interpret changes of this biomarker as a measure of oxidative species overproduction in humans, a background range for urinary MDA concentration in the general population is needed. We sought to establish urinary MDA concentration ranges for healthy adult populations based on reported values in the available scientific literature. We conducted a systematic review and meta-analysis using the standardized protocol registered in PROSPERO (CRD42020146623). EMBASE, PubMed, Web of Science, and Cochrane library databases were searched from journal inception up to October 2020. We included 35 studies (divided into 47 subgroups for the quantitative analysis). Only studies that measured creatinine-corrected urinary MDA with high-performance liquid chromatography (HPLC) with mass spectrometry (MS), fluorescence detection, or UV photometry were included. The geometric mean (GM) of urinary MDA concentration was 0.10 mg/g creatinine and 95% percentile confidence interval (CI) 0.07–0.12. Age, geographical location but not sex, and smoking status had a significant effect on urinary MDA concentrations. There was a significant increasing trend of urinary MDA concentrations with age. These urinary MDA values should be considered preliminary, as they are based on mostly moderate to some low-quality evidence studies. Although urinary MDA can reliably reflect excessive oxidative stress in a population, the influence of physiological parameters that affect its meaning needs to be addressed as well as harmonizing the chemical analytical methods.

Health consequences of disinfection against SARS-CoV-2: Exploring oxidative stress damage using a biomonitoring approach

Individuals who get involved in the disinfection of public settings using sodium hypochlorite might suffer adverse health effects. However, scarce information is available on the potential oxidative stress damage caused at low concentrations typically used for disinfection. We aimed to assess whether exposure to sodium hypochlorite during the COVID-19 pandemic causes oxidative stress damage in workers engaged in disinfection tasks. 75 operators engaged in the disinfection of public places were recruited as the case group, and 60 individuals who were not exposed to disinfectant were chosen as the control group. Spot urine samples were collected before (BE) and after exposure (AE) to disinfectants in the case group. Likewise, controls provided two spot urine samples in the same way as the case group. Urinary malondialdehyde (MDA) levels were quantified by forming thiobarbituric acid reactive substances in the urine. In addition, the concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the urine was determined using an ELISA kit. Results showed significant differences in the urinary levels of oxidative stress markers, where median 8-OHdG (AE case: 3.84 ± 2.89 μg/g creatinine vs AE control 2.54 ± 1.21 μg/g creatinine) and MDA (AE case: 169 ± 89 μg/g creatinine vs AE control 121 ± 47 μg/g creatinine) levels in case group AE samples were 1.55 and 1.35-times higher than the control group AE samples (P < 0.05), respectively. Besides, urinary levels of oxidative stress markers in AE samples of the case group were significantly higher than in BE samples (8-OHdG BE 3.40 ± 1.95 μg/g creatinine, MDA BE 136 ± 51.3 μg/g creatinine, P < 0.05). Our results indicated that exposure to even low levels of sodium hypochlorite used in disinfection practices might cause oxidative stress related damage. With this in mind, implementing robust protective measures, such as specific respirators, is crucial to reduce the health burdens of exposure to disinfectants.

Exposure to polycyclic aromatic hydrocarbon-induced oxidative stress in individuals living near restaurants: a cross-sectional study in Shiraz, Iran

Polycyclic aromatic hydrocarbons are environmental pollutants caused by the incomplete combustion of organic matter. The aim of this study was to investigate the concentration of urinary PAHs and their health effects in individuals living near restaurants. This cross-sectional study was done on 57 individuals who were living near 36 restaurants, and 30 individuals as the control group. Five urinary metabolites of PAHs (1-OH pyrene, 1-OH naphthalene, 2-OH naphthalene, 2-OH fluorine, and 9-OH phenanthrenen) were monitored. The total anti-oxidation capacity (TAC), malondialdehyde (MDA), C-reactive protein (CRP), and creatinine were also measured. The mean concentration of the sum of urinary PAHs (ΣOH-PAHs) was 1973.7, and 1687.61 ng/g creatinine in people living near restaurants and control group, respectively. Among the metabolites, the highest mean concentration was related to 1-OH Pyrene in the two study groups. In the individuals living near restaurants, the concentration of PAH metabolites was directly related to MDA and TAC (p < 0.05 for both). The present study findings revealed no significant correlation between PAH metabolites and CRP in the two study groups (P > 0.05). People living near restaurants are more exposed to components in cooking fumes, which may adversely affect their health. Further researches are required to elucidate the effect of PAHs exposure on these individuals' health status.

The exposures and health effects of benzene, toluene and naphthalene for Chinese chefs in multiple cooking styles of kitchens

Commercial cooking has higher intensity and more severe instantaneous cooking pollution from volatile organic chemicals compared to home cooking, making health risk assessment of occupational exposure for chefs a priority. In this study, chefs from three cooking styles of kitchens, including steaming, frying, and grilling, were selected to investigate the external and internal exposures, health risks and effects of several typical aromatic hydrocarbons (benzene, toluene and naphthalene). Naphthalene was found to be the most concentrated contaminant in air samples among the different kitchens, while benzene had the lowest concentration. The concentration of toluene in frying kitchens was significantly higher than that in steaming kitchens. Air concentrations of toluene in frying kitchens, as well as benzene concentrations in grilling kitchens exceeded the standard level according to indoor air quality standard (GB/T18883-2002). Regarding the metabolites of pollutants in urine, the content of S-benzylmercapturic acids (S-BMA) for frying chefs was significantly higher than that for other cooking styles of chefs, which was consistent with the relatively higher air concentrations of toluene. There was a good correlation between internal and external exposure of the pollutants. The level of oxidative stress was influenced by 2-hydroxynaphthalene (2-OHN) and S-BMA, indicating the potential health risks of these occupational exposed chefs. This study indicates the need to improve the monitoring of typical aromatic hydrocarbons, as well as to investigate their potential health effects in large-scale groups, and improve the ventilation in kitchens.

Comparative 1H NMR-Based Chemometric Evaluations of the Time-Dependent Generation of Aldehydic Lipid Oxidation Products in Culinary Oils Exposed to Laboratory-Simulated Shallow Frying Episodes: Differential Patterns Observed for Omega-3 Fatty Acid-Containing Soybean Oils

Soybean oil is the second most exported oil from the United States and South America, and is widely marketed as a cooking oil product containing numerous health benefits for human consumers. However, culinary oils with high polyunsaturated fatty acid (PUFA) contents, are known to produce high quantities of lipid oxidation products (LOPs), including toxic aldehydes upon exposure to high-temperature frying episodes. Previous studies have demonstrated causal links between aldehyde ingestion and inhalation with deleterious health perturbations, including mutagenic and carcinogenic effects, along with cardiovascular and teratogenic actions. In this study, aldehydic LOPs were detected and quantified in commercially available samples of soybean, avocado, corn and extra-virgin olive oil products before and after their exposure to laboratory-simulated laboratory frying episodes (LSSFEs) using high-resolution 1H nuclear magnetic resonance (NMR) analysis. Results acquired demonstrated that PUFA-rich soybean and corn oils gave rise to the highest concentrations of oil aldehydes from the thermo-oxidation of unsaturated fatty acids, whereas monounsaturated fatty acid (MUFA)-laden avocado and olive oils were much more resistant to this peroxidation process, as expected. Multivariate chemometrics analyses provided evidence that an orthogonal component pattern of aldehydic LOPs featuring low-molecular-mass n-alkanals such as propanal, and 4-oxo-alkanals, arises from thermo-oxidation of the ω-3 fatty acid (FA) linolenic acid (present in soybean oils at levels of ca. 7% (w/w)), was able to at least partially distinguish this oil from corresponding samples of thermally-stressed corn oil. Despite having a similar total PUFA level, corn oil has only a negligible ω-3 FA content, and therefore generated significantly lower levels of these two aldehyde classes. In view of the adverse health effects associated with dietary LOP ingestion, alternative methodologies for the incorporation of soybean oils within high-temperature frying practices are proposed.

Risk of two common glandular cell-type cancers (breast and colorectal cancers) in Chinese occupational chefs: a nationwide ecological study in Taiwan

OBJECTIVES

Cooking oil fumes (COFs) contain many carcinogens. We investigated the association between COFs and incidence risk of colorectal cancer and female breast in chefs.

METHODS

We identified Chinese food chefs and non-Chinese food chefs from Taiwan's national database of certified chefs in 1984-2007. In total, 379,275 overall and 259,450 females had not been diagnosed as having any cancer before chef certification. We followed these chefs in Taiwan's Cancer Registry Database (1979-2010) and Taiwan's National Death Statistics Database (1985-2011) for newly diagnosed colorectal cancer and female breast cancer.

RESULTS

A total of 4,218,135 and 2,873,515 person-years were included in our analysis of colorectal cancer and female breast cancer incidence, respectively. Compared to non-Chinese food chefs, the Chinese food chefs had an adjusted IRR for colorectal cancer of 1.65 (95% CI  1.17-2.33). The risk of colorectal cancer was even higher among female Chinese food chefs certified for more than 5 years (adjusted incident rate ratio (IRR) = 2.39, 95% CI   1.38-4.12). For female breast cancer, the risk was also significant (adjusted IRR = 1.40, 95% CI 1.10-1.78) and the risks were even higher in female Chinese food chefs certified for more than 5 years (adjusted IRR = 1.74, 95% CI 1.37-2.22).

CONCLUSIONS

This study found that Chinese food chefs had an increased risk of colorectal cancer and female breast cancer, particularly female chefs who had worked for more than 5 years. Future human and animal studies are necessary to re-confirm these findings.

In vivo respiratory toxicology of cooking oil fumes: Evidence, mechanisms and prevention

BACKGROUND

As cooking is an essential part of people's daily life, cooking oil fumes (COF) has been recognized as one of the major indoor air pollutant. Mounting epidemiological evidence has indicated that COF exposure is significantly associated with an increased risk of various health effects including lung cancer, but toxicological studies are very limited.

OBJECTIVES

We conduct a systematic study to provide toxicological evidence of COF exposure on the lungs, to examine the underlying toxicological mechanism, and to suggest intervention measures to mitigate this toxicity.

METHODS

A total 96 female rats were randomly divided into control groups, COF exposure groups (0.2, 2, 20 mg/kg) and vitamin E protection groups, receiving appropriate treatment for 30 days. First we measured airway hyperresponsiveness (AHR) followed by a lung histological analysis to investigate the toxicological effects of COF. We next analyzed the biomarkers of oxidative stress, inflammation, and apoptosis to examine the underlying toxicological mechanism, and finally we investigated the protective effects of vitamin E against the toxicity of COF.

RESULTS

AHR measurement indicated that the airway resistance increased with the COF dose and the lung histological assay showed narrowing of the airway lumen, which provided evidence of the toxicological effects of COF. The biomarkers of oxidative stress (ROS and MDA), pro-inflammation (TNF-α and IL-1β), and apoptosis (NF-κB and Caspase-3) were all significantly increased with COF dose. We observed that above toxicological effects and biomarker levels induced by COF were significantly ameliorated after administration of VE.

CONCLUSION

The toxicity of cooking oil fumes on the lungs is clear from the evidence and mechanism, and can be ameliorated by vitamin E. We suggested that oxidative stress may be primarily responsible for the observed cooking oil fumes-induced toxicity.

Grill Workers Exposure to Polycyclic Aromatic Hydrocarbons: Levels and Excretion Profiles of the Urinary Biomarkers

Grilling activities release large amounts of hazardous pollutants, but information on restaurant grill workers’ exposure to polycyclic aromatic hydrocarbons (PAHs) is almost inexistent. This study assessed the impact of grilling emissions on total workers’ exposure to PAHs by evaluating the concentrations of six urinary biomarkers of exposure (OHPAHs): naphthalene, acenaphthene, fluorene, phenanthrene, pyrene, and benzo(a)pyrene. Individual levels and excretion profiles of urinary OHPAHs were determined during working and nonworking periods. Urinary OHPAHs were quantified by high-performance liquid-chromatography with fluorescence detection. Levels of total OHPAHs (∑OHPAHs) were significantly increased (about nine times; p ≤ 0.001) during working comparatively with nonworking days. Urinary 1-hydroxynaphthalene + 1-hydroxyacenapthene and 2-hydroxyfluorene presented the highest increments (ca. 23- and 6-fold increase, respectively), followed by 1-hydroxyphenanthrene (ca. 2.3 times) and 1-hydroxypyrene (ca. 1.8 times). Additionally, 1-hydroxypyrene levels were higher than the benchmark, 0.5 µmol/mol creatinine, in 5% of exposed workers. Moreover, 3-hydroxybenzo(a)pyrene, biomarker of exposure to carcinogenic PAHs, was detected in 13% of exposed workers. Individual excretion profiles showed a cumulative increase in ∑OHPAHs during consecutive working days. A principal component analysis model partially discriminated workers’ exposure during working and nonworking periods showing the impact of grilling activities. Urinary OHPAHs were increased in grill workers during working days.

Mediation of the association between polycyclic aromatic hydrocarbons exposure and telomere attrition by oxidative stress: A prospective cohort study

Previous studies have reported associations between polycyclic aromatic hydrocarbons (PAHs) exposure and telomere attrition, but the underlying mechanisms remain to be elucidated. This study aimed to explore the mediation role of oxidative stress on the effects of PAHs exposure on telomere attrition in a cohort study of 1180 coke-oven workers. We determined baseline urinary concentrations of ten urinary PAH metabolites, two oxidative stress biomarkers [8-hydroxydeoxyguanosine (8-OHdG) and 8-iso-prostaglandin-F2α (8-isoPGF2α)] and peripheral leukocytes telomere length (TL) in both baseline and follow-up visits. Mediation analysis was applied to assess effects of oxidative stress biomarkers on the PAHs-TL attrition associations. The baseline 8-OHdG had a significant dose-response relationship with TL decline [β(95 %CI) = 0.07(0.03-0.12), P = 0.001] and TL ratio [β(95 %CI)]=0.07 (0.02-0.12), P = 0.003]. Mediation analyses indicated that 8-OHdG mediated a separate 39.1 %, 47.0 %, 43.3 %, and 58.0 % of the associations between 1-hydroxynaphthalene (1-OHNa), 2-OHNa, ΣOHNa, 1-hydroxypyrene (1-OHP) and TL decline (P = 0.016, 0.008, 0.012, and 0.014, respectively). Additionally, 8-OHdG mediated a separate 44.8 %, 49.4 %, 49.2 %, and 35.5 % of the associations between 1-OHNa, 2-OHNa, ΣOHNa, 1-OHP and TL ratio (P = 0.012, 0.008, 0.012, and 0.046, respectively). Our study proposed the positive association of 8-OHdG with TL attrition and revealed the mediation roles of 8-OHdG in PAHs-TL attrition associations.

Biomarkers and indoor air quality: A translational research review

Introduction:

Air pollution is linked to mortality and morbidity. Since humans spend nearly all their time indoors, improving indoor air quality (IAQ) is a compelling approach to mitigate air pollutant exposure. To assess interventions, relying on clinical outcomes may require prolonged follow-up, which hinders feasibility. Thus, identifying biomarkers that respond to changes in IAQ may be useful to assess the effectiveness of interventions.

Methods:

We conducted a narrative review by searching several databases to identify studies published over the last decade that measured the response of blood, urine, and/or salivary biomarkers to variations (natural and intervention-induced) of changes in indoor air pollutant exposure.

Results:

Numerous studies reported on associations between IAQ exposures and biomarkers with heterogeneity across study designs and methods. This review summarizes the responses of 113 biomarkers described in 30 articles. The biomarkers which most frequently responded to variations in indoor air pollutant exposures were high sensitivity C-reactive protein (hsCRP), von Willebrand Factor (vWF), 8-hydroxy-2′-deoxyguanosine (8-OHdG), and 1-hydroxypyrene (1-OHP).

Conclusions:

This review will guide the selection of biomarkers for translational studies evaluating the impact of indoor air pollutants on human health.

Effects of chef operation on oil fume particle collection of household range hood

Kitchen range hood is used to remove cooking oil fume in most of family. The oil fume collection efficiency of range hood is demand to be improved for reaching healthy indoor air quality in residential kitchen. The effects of chef disturbance intensity on the fume particle collection of range hood are quantified by computational fluid dynamics (CFD) model. The chef operation is considered by introducing a moving momentum source where the collection efficiency of fume particle is defined by the particle residence time. The collection efficiency of fume particle is proposed to be classified as the primary collection efficiency and the secondary collection efficiency of fume particle. The results indicate that the primary collection efficiency of fume particle is decreased by 26.4% in vertical disturbance (VD) mode of chef stirring with the rotation velocity from 0 to 1.5 rps. Meanwhile, the primary collection efficiency is decreased by 8.5% in horizontal disturbance (HD) mode for the same range of the rotation velocity of chef stirring. It is further found that the secondary collection efficiency of fume particle can be used as an indicator of the fume particle concentration of kitchen.

Non-linear relationships between seasonal exposure to polycyclic aromatic hydrocarbons and urinary 8-hydroxy-2'-deoxyguanosine levels among Chinese young students

Limited data are available on seasonal associations of polycyclic aromatic hydrocarbons (PAHs) exposure with oxidative DNA damage. We conducted a pilot study with 20 postgraduates, and measured urinary levels of mono-hydroxyl PAHs (OH-PAHs) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) for 7 consecutive days in the four seasons. We assessed the relationships of urinary OH-PAHs with urinary 8-OHdG in the whole year as well as cold- and warm-seasons. Summed OH-PAHs (∑OH-PAHs) were higher in cold season than in warm season. Each ln-unit (ln-transformed unit) increase in ∑OH-PAHs in the whole year corresponded to a 34%, 16% or 23% increase in urinary 8-OHdG levels at lag0, lag1 or lag2 day as well as a 26% increase in urinary 8-OHdG levels at lag0-2 days (cumulative effects). Each ln-unit increase in ∑OH-PAHs corresponded to a 36%, 26% or 46% increase in urinary 8-OHdG levels in cold season at lag0 day, lag1 day or lag2 day as well as a 36% increase in urinary 8-OHdG in warm season at lag0 day. Distributed non-linear cumulative lag models (DLNMs) indicated that each ln-unit increase in ∑OH-PAHs within the range of 5.7-8.1 nmol/mmol Cr had a stronger effect (coefficient β: 1.11-2.97 nmol/mmol Cr) on urinary 8-OHdG rather than non-cumulative DLNMs (coefficient β: 1.08-1.43 nmol/mmol Cr) as well as the non-linear dose-response relationships of ∑OH-PAHs with urinary 8-OHdG. PAHs exposure exhibited the lagged and cumulative effects on urinary 8-OHdG levels.

Urinary 8-OHdG as a Biomarker for Oxidative Stress: A Systematic Literature Review and Meta-Analysis

Oxidative stress reflects a disturbance in the balance between the production and accumulation of reactive oxygen species (ROS). ROS are scavenged by the antioxidant system, but when in excess concentration, they can oxidize proteins, lipids, and DNA. DNA damage is usually repaired, and the oxidized products are excreted in urine. 8-hydroxy-2-deoxyguanosine is considered a biomarker for oxidative damage of DNA. It is needed to define background ranges for 8-OHdG, to use it as a measure of oxidative stress overproduction. We established a standardized protocol for a systematic review and meta-analysis to assess background ranges for urinary 8-OHdG concentrations in healthy populations. We computed geometric mean (GM) and geometric standard deviations (GSD) as the basis for the meta-analysis. We retrieved an initial 1246 articles, included 84 articles, and identified 128 study subgroups. We stratified the subgroups by body mass index, gender, and smoking status reported. The pooled GM value for urinary 8-OHdG concentrations in healthy adults with a mean body mass index (BMI) ≤ 25 measured using chemical methods was 3.9 ng/mg creatinine (interquartile range (IQR): 3 to 5.5 ng/mg creatinine). A significant positive association was observed between smoking and urinary 8-OHdG concentrations when measured by chemical analysis. No gender effect was observed.

Impact of Grilling Meat or Fish at Home on Peak Expiratory Flow Rate in Adults With Asthma

Grilling, a common cooking method worldwide, can produce more toxic gases than other cooking methods. However, the impact of frequently grilling meat or fish at home on airflow limitation in adult asthma has not been well elucidated. We performed a prospective cohort study of 91 adult patients with asthma enrolled from 2 university hospitals. Of the patients, 39 (42.9%) grilled meat or fish at least once a week and 52 (57.1%) less than once a week. Patients who grilled at least once a week tended to have lower peak expiratory flow rate (PEFR) than those who grilled less than once a week (median, 345.5 L/min; 95% confidence interval [CI], 291.8–423.2 L/min vs. median, 375.1 L/min; 95% CI, 319.7–485.7 L/min; P = 0.059). Among patients with severe asthma who received step 4-5 treatment, PEFR was significantly lower in patients who grilled at least once a week compared with those who grilled less than once a week (median, 297.8 L/min; 95% CI, 211.3–357.7 L/min vs. median, 396.1 L/min; 95% CI, 355.0–489.6 L/min; P < 0.001). Our results suggest that the frequency of grilling meat or fish at home may affect PEFR in asthmatic patients, especially those with severe asthma who needed a high level of asthma treatment.

Maternal cooking during pregnancy may increase hyperactive behaviors among children aged at around 3 years old

Cooking is one of the main sources of indoor air pollution in China. Given emerging evidence of a link between air pollutants and neurodevelopmental delays, we examined whether maternal experiences with cooking during gestation might increase their child's hyperactivity at 3 years of age. The participants involved 45 518 mothers of children who were newly enrolled at kindergarten in the Longhua District of Shenzhen from 2015 to 2017. The results show that maternal exposure to cooking fumes during pregnancy was related to an increased risk of their offspring having hyperactivity behaviors at the age of 3 years. Compared with pregnant mothers who never cooked, pregnant mothers who cooked sometimes, often, or always had children who showed a significantly higher hyperactivity risk. Households using cooking fuels such as coal, gas during the mothers' pregnancy, exhibited more hyperactivity behaviors in the young child when compared to those using electricity for cooking. In addition, poor ventilation during cooking, while mothers were pregnant, was found to be a significant risk factor for clinical levels of the offspring's hyperactive behaviors. Furthermore, the positive association with maternal cooking during pregnancy and their offsprings' hyperactivity was relatively consistent across strata defined by social class, education, and other covariates.

Protective effect of exogenous 8-oxo-2'-deoxyguanosine on Drosophila melanogaster larval stages under heat shock

The influence of exogenous 8-oxo-2'-deoxyguanosine on the development of Drosophila melanogaster under normal conditions, and under the influence of short-term heat shock was studied. It was shown that 8-oxo-2'-deoxyguanosine was not toxic at concentrations of up to 1 μM. A tendency to accelerate larval development and fly emergence was observed under the influence of this compound in our experiments. Short-term heat shock causes a 50-80% decrease in the number of larvae that complete development. The addition of exogenous 8-oxo-2'-deoxyguanosine to the food before thermal influence negates this effect and brings the levels of the imago emergence indicators back to the basal level. The obtained results are further evidence of the possible bioregulatory and adaptogen functions of 8-oxo-2'-deoxyguanosine.

Interventions targeted at oxidatively generated modifications of nucleic acids focused on urine and plasma markers

Oxidative stress is associated with the development and progression of numerous diseases. However, targeting oxidative stress has not been established in the clinical management of any disease. Several methods and markers are available to measure oxidative stress, including direct measurement of free radicals, antioxidants, redox balance, and oxidative modifications of cellular macromolecules. Oxidatively generated nucleic acid modifications have attracted much interest due to the pre-mutagenic oxidative modification of DNA into 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), associated with cancer development. During the last decade, the perception of RNA has changed from that of a 'silent messenger' to an 'active contributor', and, parallelly oxidatively generated RNA modifications measured as 8-oxo-7,8-dihydro-guanosine (8-oxoGuo), has been demonstrated as a prognostic factor for all-caused and cardiovascular related mortality in patients with type 2 diabetes. Several attempts have been made to modify the amount of oxidative nucleic acid modifications. Thus, this review aims to introduce researchers to the measurement of oxidatively generated nucleic acid modifications as well as critically review previous attempts and provide future directions for targeting oxidatively generated nucleic acid modifications.

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

OBJECTIVE

Evidence regarding the association between prenatal exposure to cooking oil fumes (COF) and full-term low birth weight (FTLBW) is still controversial, and the mechanism remains unclear. This study thus aims to explore the association of prenatal COF exposure with off-spring FT-LBW as well as the mediating role of placenta in their association.

METHODS

A case-control study enrolling 266 pregnant women delivering FTLBW newborns (cases) and 1420 delivering normal birth weight (NBW) newborns (controls) was conducted. Information on prenatal COF exposure, socio-demographics, and obstetric conditions were collected at the Women's and Children's Hospitals of Shenzhen and Foshan in Guangdong, China. Linear and hierarchical logistic regression models were undertaken to explore the associations among COF exposure, placenta and birth weight, as well as the mediation effect of placental weight.

RESULTS

After controlling for potential confounders, prenatal COF exposure was significantly associated with the higher risk of FT-LBW (OR = 1.31, 95% CI= 1.06-1.63) and the lower placental weight (ß = -0.12, 95% CI= -0.23 ~ -0.005). Compared with mothers who never cooked, those cooking sometimes (OR= 2.99, 95% CI= 1.48-6.04) or often (OR= 3.41, 95% CI= 1.40-8.34) showed a higher risk of FT-LBW, and likewise, those cooking for less than half an hour (OR= 2.08, 95% CI= 1.14-3.79) or cooking between half to an hour (OR= 2.48, 95% CI= 1.44-4.29) were also more likely to exhibit FT-LBW. Different cooking methods including pan-frying (OR= 2.24, 95% CI= 1.30-3.85) or deep-frying (OR= 1.78, 95% CI= 1.12-2.85) during pregnancy were associated with increased FT-LBW risks as well. The further mediation analysis illustrated that placental weight mediated 15.96% (95% CI: 12.81~28.80%) and 15.90% (95% CI= 14.62%~16.66%) of the associations of cooking during pregnancy and frequency of prenatal COF exposure, respectively, with FT-LBW.

Cooking behaviors are related to household particulate matter exposure in children with asthma in the urban East Bay Area of Northern California

BACKGROUND

Asthma is a common childhood disease that leads to many missed days of school and parents' work. There are multiple environmental contributors to asthma symptoms and understanding the potential factors inside children's homes is crucial.

METHODS

This is a dual cohort study measuring household particulate matter (PM2.5), behaviors, and factors that influence air quality and asthma symptoms in the urban homes of children (ages 6-10) with asthma; one cohort had cigarette smoke exposure in the home (n = 13) and the other did not (n = 22). Exposure data included measurements every 5 minutes for a month.

RESULTS

In the entire study population, a large contributor to elevations in indoor PM2.5 above 35 μg/m3 was not using the stove hood when cooking (8.5% higher, CI 3.1-13.9%, p<0.005). Median PM values during cooking times were 0.88 μg/m3 higher than those during non-cooking times (95% CI 0.33-1.42). Mean monthly household PM2.5 level was significantly related to the presence of a cigarette smoker in the home (10.1 μg/m3 higher, 95% CI 5.2-15.1, p<0.001) when controlling for use of the stove hood and proximity to major roadway. There was a trend toward increased odds of persistent asthma with increases in average monthly PM2.5 (OR 1.1, 95% CI 0.97-1.3, p = 0.16).

CONCLUSIONS

Consideration of only outdoor PM2.5 may obscure potentially modifiable risks for asthma symptoms. Specifically, this preliminary study suggests that cooking behaviors may contribute to the burden of PM2.5 in the homes of children with asthma and thus to asthma symptoms.

An improved method for determining dermal exposure to polycyclic aromatic hydrocarbons

Many workers are occupationally exposed to polycyclic aromatic hydrocarbons (PAHs), which may cause various health problems, and some PAHs are known or suspected carcinogens. PAH exposure is primarily monitored by air sampling, but contamination may also occur through dermal exposure. PAHs adsorbed to the skin can be sampled by tape-stripping, but subsequent extraction of sampling tapes in organic solvent also releases diverse co-eluting substances that are difficult to remove before analysis of the PAHs by gas chromatography/mass spectrometry (GC/MS). The objective of this study was to optimise a procedure for analytical clean-up after extraction of 32 PAHs from tape-strips, by dialysis in organic solvent using semipermeable membranes. With triplicate subsamples, the developed method yields acceptable precision and repeatability for both the 32 PAHs, across the concentration range 10-160 ng per sample, and for a certified reference material (urban dust). The optimized clean-up procedure and GC/MS methodology was used to assess PAHs on skin from the lower part of the ventral side of the wrist and just below the collar bone of three firefighters and seven controls (office workers). Several gaseous and particle-bound PAHs were detected in all samples, including controls. Thus, the optimized procedure using semipermeable membranes for clean-up of tape-strip extracts can be used to assess the dermal exposure of both occupational and general populations to multiple PAHs. The results also show that both gaseous and particle-bound PAHs, including alkylated species, may be present on skin.