Ethylene oxide review: characterization of total exposure via endogenous and exogenous pathways and their implications to risk assessment and risk management

Association Between Ethylene Oxide Exposure and Cognitive Function in US Older Adults: NHANES 2013-2014

Background

Ethylene oxide (EO) is a common organic compound associated with many adverse health outcomes. However, studies exploring the association between EO exposure and cognitive function are limited.

Objective

This study aims to examine this relationship between EO exposure and cognition in older adults.

Methods

This study enrolled 438 older adults from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 cycle. EO exposure was quantified by the measurements of blood hemoglobin adducts of ethylene oxide (HbEO) concentrations. Cognitive function was measured by the Consortium to Establish a Registry for Alzheimer's Disease battery (CREAD), the Animal Fluency test (AFT), and the Digit Symbol Substitution Test (DSST). Linear regression model, generalized additive model, and smooth curve fitting were applied to examine the linear and nonlinear relationship between EO exposure and cognitive function. We used a two-piecewise linear regression model to detect the threshold effect of EO exposure on cognitive function.

Results

Participants with higher HbEO levels had lower AFT and DSST scores than those with lower HbEO levels. After adjusting for all confounding factors, log2-transformed HbEO levels were negatively associated with AFT score. The smooth curve fitting demonstrated the nonlinear relationship between EO exposure and DSST scores. When log-2 transformed HbEO levels >4.34 pmol/g Hb, EO exposure was negatively associated with DSST score.

Conclusions

This study indicated that high levels of HbEO were associated with cognitive decline in US older adults. Future cohort studies are needed to verify our findings.

Synthetic and Natural Antifungal Substances in Cereal Grain Protection: A Review of Bright and Dark Sides

Molds pose a severe challenge to agriculture because they cause very large crop losses. For this reason, synthetic fungicides have been used for a long time. Without adequate protection against pests and various pathogens, crop losses could be as high as 30-40%. However, concerns mainly about the environmental impact of synthetic antifungals and human health risk have prompted a search for natural alternatives. But do natural remedies only have advantages? This article reviews the current state of knowledge on the use of antifungal substances in agriculture to protect seeds against phytopathogens. The advantages and disadvantages of using both synthetic and natural fungicides to protect cereal grains were discussed, indicating specific examples and mechanisms of action. The possibilities of an integrated control approach, combining cultural, biological, and chemical methods are described, constituting a holistic strategy for sustainable mold management in the grain industry.

Associations between Ethylene Oxide Exposure and Liver Function in the US Adult Population

BACKGROUND

Ethylene oxide, a reactive epoxy compound, has been widely used in various industries for many years. However, evidence of the combined toxic effects of ethylene oxide exposure on the liver is still lacking.

METHODS

We analyzed the merged data from the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016. Ultimately, 4141 adults aged 18 and over were selected as the sample. We used linear regression to explore the association between blood ethylene oxide and LFT indicators.

RESULTS

The weighted linear regression model showed that HbEO is positively correlated with ALP (β = 2.61, 95% CI 1.97, 3.24, p < 0.0001), GGT (β = 5.75, 95% CI 4.46, 7/05, p < 0.0001), ALT (β = 0.50, 95% CI 0.09, 0.90, p = 0.0158), and AST (β = 0.71, 95% CI 0.44, 0.98, p < 0.0001) and negatively correlated with TBIL (β = -0.30, 95% CI -0.43, -0.16, p < 0.0001).

CONCLUSIONS

Ethylene oxide exposure is significantly associated with changes in liver function indicators among adults in the United States. Future work should further examine these relationships.

Positive association of ethylene oxide levels with young stroke: a population-based study

Background

Ethylene oxide (EtO), a highly reactive organic compound with extensive industrial applications, poses significant health risks. The association between EtO exposure and stroke was not well established. This study examined the association between EtO exposure and stroke among US adults using data from the 2013-2018 National Health and Nutrition Examination Survey (NHANES).

Methods

We used appropriately weighted multifactorial logistic regression models to analyze the data and validated the findings with smoothed curve fitting. Stratified analysis and interaction assessments were performed to evaluate the robustness of the findings.

Results

The study included 5,071 participants, balanced between men and women, with a stroke prevalence of 4.1%. Higher EtO levels were associated with rising rates of stroke (OR = 1.23, 95% CI: 1.06-1.42). Individuals in the top 25% group displayed a stroke prevalence 1.6 times higher than those in the bottom 25% group (OR = 1.60, 95%CI: 1.03-2.48). Stratified analysis demonstrated a significant positive association between EtO and stroke in individuals under 50 years (OR = 1.94, 95%CI: 1.38-2.72), while no significant association was found in those aged 50 and above (OR = 0.97, 95%CI: 0.83-1.14).

Conclusion

This study identified a significant association between EtO exposure and stroke occurrence in young adults in the United States.

Association between blood ethylene oxide levels and the prevalence of periodontitis: evidence from NHANES 2013-2014

BACKGROUND

The study aimed to establish a link between blood ethylene oxide (EO) levels and periodontitis, given the growing concern about EO's detrimental health effects.

MATERIALS AND METHODS

The study included 1006 adults from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) dataset. We assessed periodontitis prevalence across groups, used weighted binary logistic regression and restricted cubic spline fitting for HbEO-periodontitis association, and employed Receiver Operating Characteristic (ROC) curves for prediction.

RESULTS

In the periodontitis group, HbEO levels were significantly higher (40.57 vs. 28.87 pmol/g Hb, P < 0.001). The highest HbEO quartile showed increased periodontitis risk (OR = 2.88, 95% CI: 1.31, 6.31, P = 0.01). A "J"-shaped nonlinear HbEO-periodontitis relationship existed (NL-P value = 0.0116), with an inflection point at ln-HbEO = 2.96 (EO = 19.30 pmol/g Hb). Beyond this, ln-HbEO correlated with higher periodontitis risk. A predictive model incorporating sex, age, education, poverty income ratio, alcohol consumption, and HbEO had 69.9% sensitivity and 69.2% specificity. The model achieved an area under the ROC curve of 0.761.

CONCLUSIONS

These findings suggest a correlation between HbEO levels and an increased susceptibility to periodontitis.

Positive association between blood ethylene oxide levels and metabolic syndrome: NHANES 2013-2020

Purpose

The exposure of Ethylene oxide (EO) is linked to systemic inflammatory response and various cardiovascular risk factors. Hemoglobin's binding to ethylene oxide (HbEO) was used to measure serum EO level. This research aims to explore the association between metabolic syndrome (MetS) and HbEO, and between HbEO and components of metabolic syndrome.

Method

This research included 1842 participants from 2013 to 2020 in National Health and Nutrition Examination Survey (NHANES) database. Weighted logistic regression models were used to analyze the relationship between HbEO and metabolic syndrome risk, using odds ratio (OR) and 95% confidence interval (CI). The restricted cubic spline plot explores whether there is a dose-response relationship between HbEO and MetS risk. Subgroup analysis was performed to analyze study heterogeneity.

Results

Significant differences were found in gender, educational level, marital status, diabetes status and hypertension among different groups (P < 0.001, P = 0.007, P = 0.003, P < 0.001, P < 0.001, respectively). The serum HbEO level exhibited positive correlation with metabolic syndrome risk in Q2 level (OR=1.64, 1.04~2.48), Q3 level (OR=1.99, 1.29~3.08), and Q4 level (OR=2.89, 1.92~4.34). The dose-response association suggested a possible linear association between serum HbEO and metabolic syndrome risk (P-overall=0.0359, P-non-linear=0.179). L-shaped association was found between HbEO and the risk of MetS in female population, obese population and mid-age and elder population (P-overall<0.001, P-non-linear=0.0024; P-overall=0.0107, P-non-linear=0.0055 P-overall<0.001 P-non-linear=0.0157).

Conclusion

This study indicates a linear correlation between MetS and HbEO, with MetS risk escalating as HbEO levels increase. The prevalence of MetS varies depending on BMI, age and gender, and these factors can also influence MetS prevalence when exposed to EO.

Association between ethylene oxide levels and depressive symptoms: A cross-sectional study based on NHANES 2013-2018 database

BACKGROUND AND AIM

Ethylene oxide (EO) is a commonly used compound with known health risks. However, the specific association between EO exposure and the development of depressive symptoms has not been well established. Therefore, this study aimed to examine the potential association between EO exposure, as indicated by hemoglobin adduct of ethylene oxide (HbEO) levels, and the occurrence of depressive symptoms.

METHODS

We employed logistic regression, restricted cubic spline, and subgroup analysis to investigate the association between EO exposure and the occurrence of depressive symptoms. Additionally, we conducted a mediating effect analysis to explore the potential factors influencing the association between EO exposure and depressive symptoms.

RESULTS

Elevated HbEO levels were associated with the development of depressive symptoms. After adjusting for potential confounders, the highest quartile of HbEO levels showed an odds ratio (OR) of 3.37 [95 % confidence interval (CI): 1.87-6.10, P = 0.002] compared with the lowest quartile. Additionally, a linear association was observed between HbEO levels and the risk of depressive symptoms. We also revealed that the levels of several inflammatory factors and triglycerides mediated the association between EO exposure and the occurrence of depressive symptoms.

CONCLUSIONS

Higher levels of EO exposure were related to an increased risk of developing depressive symptoms. The analysis also suggested that the inflammatory response might play a mediating role in the pathway from EO exposure to depressive symptoms.

Association between blood ethylene oxide levels and periodontitis risk: a population-based study

Background

The etiopathogenesis of periodontitis is closely associated with environmental conditions. However, the relationship between ethylene oxide exposure and periodontitis risk remains unclear.

Methods

We selected qualified participants from National Health and Nutrition Examination Survey (NHANES) 2013-2014. Periodontitis was identified according to the criteria of the Community Periodontal Index (CPI), Centers for Disease Control and Prevention (CDC)/American Academy of Periodontology (AAP) definition. Ethylene oxide exposure was quantified by hemoglobin adducts of ethylene oxide (HbEO) levels. Log2-transformation was used to normalize HbEO levels. We designed three logistic regression models to explore potential relationship between HbEO and periodontitis. Restricted cubic spline (RCS) and subgroup analysis were also conducted with all covariates adjusted. We performed multivariable linear regression to appraise the association between the risk of periodontitis and different indicators of inflammation, including white blood cells, neutrophils, lymphocytes, and monocytes. Mediation analysis was subsequently performed to examine whether ethylene oxide exposure contributed to periodontitis development through systemic body inflammation.

Results

A total of 1,065 participants aged more than 30 were incorporated in this study. We identified that participants with higher HbEO levels showed increased risk of periodontitis after adjusting for all covariates (OR = 1.49, 95% CI: 1.14, 1.95, p = 0.0014). The results of subgroup analysis remained stable. The restricted cubic spline (RCS) curve also revealed a non-linear correlation between log2-transformed HbEO levels with the risk of periodontitis (p for nonlinear < 0.001). Mediation analysis indicated that HbEO level was significantly associated with four inflammatory mediators, with the mediated proportions of 14.44% (p < 0.001) for white blood cell, 9.62% (p < 0.001) for neutrophil, 6.17% (p = 0.006) for lymphocyte, and 6.72% (p < 0.001) for monocyte.

Conclusion

Participants with higher ethylene oxide exposure showed higher risk of periodontitis, which was partially mediated by systemic body inflammation. More well-designed longitudinal studies should be carried out to validate this relationship.

Sex difference in the non-linear relationship between ethylene oxide exposure and depressive symptoms: A cross-sectional study

BACKGROUND

Ethylene oxide (EO) has been recognized as an animal carcinogen and environmental EO exposure was linked to several diseases. However, the association of EO exposure with depression prevalence is still not clear.

METHODS

We included 6016 participants with complete data on HbEO concentrations, depression diagnosis, and necessary covariates using the 2013-2020 National Health and Nutrition Examination Survey. Weighted multivariable logistic model was applied to examine the association of HbEO concentrations with depression risk. Weighted restricted cubic spline model was applied to draw the dose-response curve.

RESULTS

In the total population, individuals in the second, third, and fourth quartile of HbEO respectively had an adjusted OR of 0.99 (95%CI: 0.60, 1.63), 1.13 (95%CI: 0.73, 1.75), and 2.87 (95%CI: 1.86, 4.45) (Ptrend < 0.001) for depression with a significant "J" shaped non-linear dose-response relationship (Pnon-linear < 0.001). Females, drinkers, and smokers were susceptible to the depressive effect of EO. Doubling the HbEO concentrations was respectively associated with a 1.50-fold (95%CI: 1.25, 1.79), 1.29-fold (1.15, 1.44), and 1.17-fold (1.04, 1.33) increased risk of depression for females, drinkers, and smokers.

LIMITATIONS

Cross-sectional study design and self-reported depressive symptoms.

CONCLUSIONS

Environmental EO exposure was associated with increased depression risk, especially among females, drinkers, and smokers. Further prospective studies are required to affirm these findings.

Impact of hemoglobin adducts of ethylene oxide on the prevalence and prognosis of chronic kidney disease in US adults: an analysis from NHANES 2013-2016

Animal experiments have shown that high exposure to ethylene oxide (EO) can cause multiple system damages including the renal system. Recent studies have reported associations between exposure to EO and cancer, dyslipidemia, diabetes, and cardiovascular disease. However, the impact of exposure to EO on the prevalence and prognosis of chronic kidney disease (CKD) in humans is scarcely investigated. The study was designed to investigate the associations between EO exposure and incidence and prognosis of CKD among 2900 US adults. Exposure to EO was measured by detecting the levels of hemoglobin adducts of EO (HbEO). The diagnosis of CKD was made according to an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 and/or a urinary albumin-to-creatinine ratio (UACR) > 30 mg/g. Prognosis of CKD was assessed based on the evaluation system initiated by KDIGO that consists of eGFR and UACR. Survey-weighted generalized linear models and proportional odds models were constructed to assess the associations between HbEO and prevalence and prognosis of CKD, with odds ratios (ORs) and proportional odds ratios (PORs) and their 95% confidence intervals (CIs) reported, respectively. Restricted cubic spline (RCS) function was performed to depict the correlation between HbEO and CKD. The weighted median (interquartile range) of HbEO was 31.3 (23.1-60.3) pmol/g Hb. A total of 491 participants (16.9%) were diagnosed with CKD, and 153 participants (5.31%) were identified to be at high or very high risk. Referred to the first tertile of HbEO, the adjusted ORs (95% CIs) for CKD in the second and third tertile were 1.46 (0.85, 2.50) and 1.69 (1.00, 2.85), and the adjusted PORs (95% CIs) for prognosis of CKD in the second and third tertile were 1.37 (0.94, 1.99) and 1.58 (1.10, 2.26). When HbEO was analyzed as a continuous variable, the adjusted OR (95% CI) for CKD and POR (95% CI for prognosis of CKD were 1.24 (0.97, 1.58) and 1.22 (1.01, 1.47), respectively. RCS analysis revealed a non-linear positive correlation between HbEO and prevalence of CKD (P for nonlinearity < 0.05). Subgroup analysis indicated smoking status had a significant impact on this association, which remained significant among never smokers but lost significance among smokers. Among US adults, increased EO exposure was independently related to increased CKD prevalence and poor CKD outcomes, which was established in never smokers but not among ever smokers.

Associations of ethylene oxide exposure and "Life's Essential 8"

Ethylene oxide (EtO) is a widely used industrial chemical with recognized health risks. While its carcinogenic properties have been extensively studied, emerging evidence suggests potential associations with cardiovascular diseases. Using the recently introduced Life's Essential 8 (LE8) score as a comprehensive cardiovascular health (CVH) measure, this study aimed to elucidate the relationship between EtO exposure and CVH. Data from the National Health and Nutrition Examination Survey (NHANES) encompassing 3748 adults was analyzed. CVH was assessed using the LE8 score, which incorporates diet, physical activity, tobacco/nicotine exposure, sleep duration, BMI, non-HDL cholesterol, blood glucose, and blood pressure. The association between EtO exposure, gauged by Hemoglobin adduct (HbEtO) levels, and CVH was examined using linear regression and Cox regression models. An inverse relationship between EtO exposure and the overall CVH score was identified. Specifically, for every 1-unit increase in ln-transformed HbEtO, a 3.69-point decrease in the total CVH score was observed. An inverted J-shaped association between ln-transformed HbEtO and CVH score emerged, with an inflection point at 3.15 pmol/g Hb. Elevated EtO exposure was not significantly linked to all-cause mortality but was robustly associated with increased cardiovascular mortality. Elevated EtO exposure is negatively associated with CVH, as outlined by the LE8 metrics. Beyond a certain threshold, this association underscores the cardiovascular risks of EtO exposure and highlights the importance of further research to determine underlying mechanisms and recommend preventive strategies.

Accurate selected ion flow tube mass spectrometry quantification of ethylene oxide contamination in the presence of acetaldehyde

In September 2020, traces of ethylene oxide (a toxic substance used as a pesticide in developing countries but banned for use on food items within the European Union) were found in foodstuffs containing ingredients derived from imported sesame seed products. Vast numbers of foodstuffs were recalled across Europe due to this contamination, leading to expensive market losses and extensive trace exposure of ethylene oxide to consumers. Therefore, a rapid analysis method is needed to ensure food safety by high-throughput screening for ethylene oxide contamination. Selected ion flow tube mass spectrometry (SIFT-MS) is a suitable method for rapid quantification of trace amounts of vapours in the headspace of food samples. It turns out, however, that the presence of acetaldehyde complicates SIFT-MS analyses of its isomer ethylene oxide. It was proposed that a combination of the H3O+ and NO+ reagent ions can be used to analyse ethylene oxide in the presence of acetaldehyde. This method is, however, not robust because of the product ion overlaps and potential interferences from other matrix species. Thus, we studied the kinetics of the reactions of the H3O+, NO+, OH- and O-˙ ions with these two compounds and obtained their rate coefficients and product ion branching ratios. Interpretation of these experimental data revealed that the OH- anions are the most suitable SIFT-MS reagents because the product ions of their reactions with acetaldehyde (CH2CHO- at m/z 43) and ethylene oxide (C2H3O2- at m/z 59) do not overlap.

Integrative literature review: Ethylene oxide exposure signs and symptoms

BACKGROUND

Although ethylene oxide (EtO) gas is designated as a human carcinogen, extant literature reports mixed findings on the health effects of exposure. The disparate findings may reflect industry bias as many studies were funded by a large chemical industry lobby.

OBJECTIVE

To conduct an integrative review of studies free from industry bias to facilitate compilation of a comprehensive list of reported signs and symptoms of EtO exposure.

METHODS

We reviewed 1887 papers of which 42 articles met inclusion criteria. The authors conducted this review in accordance with PRISMA guidelines. The presence of bias was assessed using Joanna Briggs Institute checklists.

RESULTS

Non-industry biased literature confirmed serious adverse health effects associated with EtO exposure at the occupational, hospital, and community level. EtO represents a carcinogen, neurotoxin, and respiratory irritant.

CONCLUSION

After removal of industry-biased studies, EtO was unequivocally found to pose a threat to human health. There remains a gap in the number of studies examining community-level exposure, which is essential to understanding the impact of EtO. Given that EtO-emitting facilities are concentrated in diverse and disadvantaged communities, further study of EtO exposure health effects is warranted to inform public policy on toxic air emissions.

Association between hemoglobin adducts of ethylene oxide levels and the risk of short sleep duration in the general population: an analysis based on the National Health and Nutrition Examination Survey

This study aimed to evaluate the association between blood ethylene oxide (HbEtO) levels and short sleep duration (SSD). Data of 3438 participants aged 20 years or older in this study were collected from the National Health and Nutrition Examination Survey (NHANES). The ethylene oxide (EtO) biomarker (HbEtO) was quantified in blood using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. SSD was defined as sleep time equal to or less than 6 h. The analyses utilized weighted logistic regression models and restricted cubic spline. There was a significant non-linear relationship between HbEtO levels and the risk of SSD (P for-nonlinearity = 0.035). After the full adjustment for confounders, compared with the lowest quantile, the odds ratios (ORs) with 95% confidence intervals (CIs) of SSD across the quantiles of ethylene oxide levels were 1.54(1.09-2.18), 1.15(0.87-1.53), and 1.80(1.11-2.92), respectively (P for trend < 0.05). In subgroup analysis, people who were female, who were non-Hispanic Black, who never engaged in physical activity, who consumed alcohol ≤ 14 g/day, who were normal weight or obese had a significantly higher risk of SSD when they had highest quartiles of HbEtO levels than those had lowest (p < 0.05). Our study indicated that HbEtO levels, an indicator for EtO exposure, were associated with SSD in general adult populations.

Physical activity can influence the relationship between ethylene oxide and risk of kidney stones: A cross-sectional study from the NHANES 2013-2016

Ethylene oxide (EO) is known to cause inflammatory damage, and suitable physical activity can reportedly affect the risk of kidney stones. In this study, we aimed to investigate the relationship between EO and kidney stones and whether physical activity can potentially influence the relationship between EO and kidney stones. Overall, 3,336 adult participants were included; of them, 330 (9.9%) had a self-reported history of kidney stones. Data were obtained from the National Health and Nutrition Examination Survey 2013-2016. Physical activity was calculated using metabolic equivalent, weekly frequency, and duration. Logistic regression and restricted cubic spline (RCS) curves were used to explore the association between physical activity, EO, and kidney stones. Dose-response curves from the RCS showed a nonlinear positive association between EO and kidney stones. Multivariate logistic regression analysis revealed an adjusted odds ratio (aOR) of 1.548 (95% confidence interval 1.123-2.135, P = 0.008) for the risk of kidney stones among participants in the highest quartile (Q4) group compared with those in the lowest quartile (Q1) group. Furthermore, compared to the Q1 group, the aOR for risk of kidney stones in the Q4 group was 1.326 in participants without physical activity, a decreased risk (aOR 1.239) in participants with low physical activity, and an increased risk (aOR 1.981) in those with high physical activity. This study suggests that EO is a risk factor for kidney stones and that suitable physical activity may moderate this relationship to some extent; however, excessive physical activity can exacerbate this relationship.

Assessment of Chemical Facility Ethylene Oxide Emissions Using Mobile and Multipoint Monitoring

Ethylene oxide (EtO) is a hazardous air pollutant that can be emitted from a variety of difficult to measure industrial sources, such as fugitive leaks, wastewater handling, and episodic releases. Emerging next generation emission measurement (NGEM) approaches capable of time-resolved, low parts per billion by volume (ppbv) method detection limits (MDLs) can help facilities understand and reduce EtO and other air pollutant emissions from these sources yielding a range of environmental and public health benefits. In October 2021, a first of its kind 4-day observational study was conducted at an EtO chemical facility in the midwestern United States. The study had dual objectives to both improve understanding of EtO emission sources within the facility and advance NGEM methods. Using cavity ring-down spectroscopy (CRDS) instruments, a combination of mobile surveys and stationary multipoint process unit monitoring assessed EtO concentrations in and near facility operations, while testing and comparing measurement methods. The study concluded that four main areas of EtO source emissions existed within the facility, each possessing unique emission characteristics. Episodic EtO emissions from supply railcar switchovers and batch reactor washouts, lasting seconds to minutes in duration, produced EtO concentrations exceeding 500 ppbv inside the process unit in some cases. In one instance, EtO at ~30 ppbv was briefly observed hundreds of meters from the process unit. Lower level but more sustained EtO concentrations were observed near an EtO transfer pump and wastewater tank outfall and drain system. Overall, 4.6% of mobile survey data were above the 1.2 ppbv mobile test MDL while the nine stationary sampling locations ranged from 17.7% to 82.8% of data above the 1.0 ppbv multipoint test MDL. This paper describes the EtO emissions observed in and near the four defined source areas within the facility and provides details of the NGEM method development advances accomplished as part of the study.

Detection of Ethylene with Defined Metal Complexes: Strategies and Recent Advances

Despite its relative simplicity, ethylene is an interesting molecule with wide-ranging impact in modern chemistry and biology. Stemming from ethylene's role as a critical plant hormone, there has been significant effort to develop selective and sensitive molecular sensors for ethylene. Late transition metal complexes have played an important role in detection strategies due to ethylene's lack of structural complexity and limited reactivity. Two main approaches to ethylene detection are identified: (1) coordination-based sensors, wherein ethylene binds reversibly to a metal center, and (2) activity-based sensors, wherein ethylene undergoes a reaction at a metal center, resulting in the formation and destruction of covalent bonds. Herein, we describe the advantages and disadvantages of various approaches, and the challenges remaining for sensor development.

The relationship between ethylene oxide levels in hemoglobin and the prevalence of kidney stones in US adults: an exposure-response analysis from NHANES 2013-2016

Exposure to ethylene oxide may cause a number of diseases. The purpose of this study was to investigate whether there is an association between hemoglobin ethylene oxide (HbEO) and the risk of developing kidney stones in US adults. We analyzed 3348 patients from the National Health and Nutrition Survey (NHANES) 2013-2016 and conducted a cross-sectional study. Dose-response analysis curves of restricted cubic spline function, multiple logistic regression, and subgroup analysis were used to investigate the association between HbEO and the risk of kidney stones. Logistic regression models were used to analyze the correlation between HbEO and kidney stones. Among the 3348 participants, 3016 people self-reported having a kidney stone. After adjusting for age, sex, race, marital status, education level, diabetes, vigorous recreational activity, moderate recreational activity, body mass index, blood urea nitrogen, creatinine, eGFR, and uric acid, we found a positive association between HbEO and the risk of kidney stones. We divided patients into four groups based on quartiles of HbEO levels and performed multifactorial logistic regression after adjusting for confounders, which showed that the incidence of kidney stones increased with increasing HbEO concentrations compared with Q1 (Q2, OR = 0.922, 95% CI, 0. 657-1.295, P = 0.639; Q3, OR = 1.004, 95% CI, 0.713-1.414, P = 0.983; Q4, OR = 1.535, 95% CI, 1.114-2.114, P = 0.009). High levels of HbEO were positively correlated with the risk of kidney stone development and could be used as an indicator of kidney stone prevention.

The association between ethylene oxide exposure and asthma risk: a population-based study

Ethylene oxide (EO) is a reactive epoxide. However, the association between EO exposure and the risk of developing asthma in humans is unknown. The aim of this study was to investigate the relationship between EO exposure and the risk of developing asthma in the general US population. In this cross-sectional study, data of 2542 patients from the National Health and Nutrition Examination Survey (NHANES) between 2013 and 2016 were obtained and analyzed. Hemoglobin adducts of EO (HbEO) level be used as the main factor for predicting EO exposure. The association between the level of EO exposure and the risk of developing asthma was evaluated with logistic regression models and dose-response analysis curves of restricted cubic spline function. Mediation analysis and linear regression analysis were utilized to evaluate the association between EO exposure and inflammation indicators. According to the quartiles of HbEO level, the patients were divided into four groups. The results indicated that an increased HbEO level was associated with a higher risk of asthma onset. Compared with the lowest quartile, the odds ratio (OR) with the 95% confidence interval (CI) for the highest quartile was 1.960 (95% CI: 1.348-2.849, P = 0.003). After being adjusted for numerous potential confounders, the OR of quartile 4 relative to quartile 1 was 1.991 (95% CI: 1.359-2.916, P = 0.001). Consistent results were also obtained in most subgroup analyses and dose-response analysis curves. In addition, EO levels were positively correlated with the inflammatory indicators (P = 0.006 for WBC, P = 0.015 for lymphocyte, and P = 0.015 for neutrophil). This study revealed a positive correlation between the level of EO exposure and the risk of asthma in a representative US population. In addition, inflammatory response may prove to be a potential biological mechanism underlying EO-induced asthma.

Current trends in read-across applications for chemical risk assessments and chemical registrations in the Republic of Korea

Read-across, an alternative approach for hazard assessment, has been widely adopted when in vivo data are unavailable for chemicals of interest. Read-across is enabled via in silico tools such as quantitative structure activity relationship (QSAR) modeling. In this study, the current status of structure activity relationship (SAR)-based read-across applications in the Republic of Korea (ROK) was examined considering both chemical risk assessments and chemical registrations from different sectors, including regulatory agencies, industry, and academia. From the regulatory perspective, the Ministry of Environment (MOE) established the Act on Registration and Evaluation of Chemicals (AREC) in 2019 to enable registrants to submit alternative data such as information from read-across instead of in vivo data to support hazard assessment and determine chemical-specific risks. Further, the Ministry of Food and Drug Safety (MFDS) began to consider read-across approaches for establishing acceptable intake (AI) limits of impurities occurring during pharmaceutical manufacturing processes under the ICH M7 guideline. Although read-across has its advantages, this approach also has limitations including (1) lack of standardized criteria for regulatory acceptance, (2) inconsistencies in the robustness of scientific evidence, and (3) deficiencies in the objective reliability of read-across data. The application and acceptance rate of read-across may vary among regulatory agencies. Therefore, sufficient data need to be prepared to verify the hypothesis that structural similarities might lead to similarities in properties of substances (between source and target chemicals) prior to adopting a read-across approach. In some cases, additional tests may be required during the registration process to clarify long-term effects on human health or the environment for certain substances that are data deficient. To improve the quality of read-across data for regulatory acceptance, cooperative efforts from regulatory agencies, academia, and industry are needed to minimize limitations of read-across applications.

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens.

Systematic review of the scientific evidence on ethylene oxide as a human carcinogen

Ethylene oxide is a highly reactive chemical primarily used as an intermediate in chemical production and as a sterilant of medical equipment and food products; it also is produced endogenously as a result of physiological processes. We conducted a systematic review of the potential carcinogenicity of inhaled ethylene oxide in humans using methods that adhere to PRIMSA guidelines and that incorporate aspects from the Institute of Medicine (IOM) (now the National Academy of Medicine) as well as several US Environmental Protection Agency (EPA) frameworks for systematic reviews. After a comprehensive literature search and selection process, study quality was evaluated following a method adapted from the EPA Toxic Substances Control Act (TSCA) framework. The literature screening and selection process identified 24 primary studies in animals or humans and more than 50 mechanistic studies. Integrating epidemiological, animal, and mechanistic literature on ethylene oxide and cancer according to the IOM framework yielded classifications of suggestive evidence of no association between ethylene oxide and stomach cancer, breast cancer and lymphohematopoietic malignancies at human relevant exposures. However, we acknowledge that there is additional uncertainty in the classification for lymphohematopoietic malignancies owing to a paucity of evidence for specific types of these tumors, each of which is a distinct disease entity of possibly unique etiology.

Recent Advances in Ethylene Gas Detection

The real-time detecting and monitoring of ethylene gas molecules could benefit the agricultural, horticultural and healthcare industries. In this regard, we comprehensively review the current state-of-the-art ethylene gas sensors and detecting technologies, covering from preconcentrator-equipped gas chromatographic systems, Fourier transform infrared technology, photonic crystal fiber-enhanced Raman spectroscopy, surface acoustic wave and photoacoustic sensors, printable optically colorimetric sensor arrays to a wide range of nanostructured chemiresistive gas sensors (including the potentiometric and amperometric-type FET-, CNT- and metal oxide-based sensors). The nanofabrication approaches, working conditions and sensing performance of these sensors/technologies are carefully discussed, and a possible roadmap for the development of ethylene detection in the near future is proposed.

Blood ethylene oxide, systemic inflammation, and serum lipid profiles: Results from NHANES 2013-2016

BACKGROUND

Using data from the National Health and Nutrition Examination Survey (NHANES), this study aimed to explore the relationship between ethylene oxide (EO) exposure and serum lipid profiles as well as the mediation effect of systemic inflammation among the general adult population.

METHODS

This cross-sectional study analyzed NHANES data from 2013 to 2016, examining a total of 2721 participants. The EO biomarker (hemoglobin adduct of EO [HbEO]) was quantified in blood using a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method. The association among HbEO levels, inflammatory biomarkers, and four serum lipids was evaluated using a multivariable linear regression model. Mediating analysis was performed to examine the effect of inflammatory biomarkers on the relationship between HbEO levels and serum lipid profiles.

RESULTS

As the quartiles of HbEO increased, high-density lipoprotein cholesterol (HDL-C) monotonically decreased (p for trend <0.001). Using the lowest quartile of HbEO as a reference, the percent change for HDL-C was 6.30% (95% CI: 3.89%, 8.71%) in the highest quartile of HbEO. HbEO levels were dose-dependently associated with triglycerides (TG) (p for trend = 0.001). The percent change in TG in the fourth quartile of HbEO was 17.24% (95% CI: 2.01%, 32.48%) compared to the first quartile. Overall, inflammatory biomarkers (hs-CRP, alkaline phosphatase, white blood cell count, neutrophil count, and lymphocyte count) increased monotonically in correlation with increasing HbEO levels (all p for trend <0.01); were positively correlated with total cholesterol (TC), TG, and low-density lipoprotein cholesterol (LDL-C); and were negatively associated with HDL-C. Additionally, inflammatory biomarkers strongly mediated the relationships between HbEO and HDL-C and TG with maximum mediated proportions of 21.40% and 33.40%, respectively.

CONCLUSIONS

These findings suggest that HbEO is closely linked to serum lipid profiles and that systemic inflammation may be a key mediator of this association.

The role of endogenous versus exogenous sources in the exposome of putative genotoxins and consequences for risk assessment

The "totality" of the human exposure is conceived to encompass life-associated endogenous and exogenous aggregate exposures. Process-related contaminants (PRCs) are not only formed in foods by heat processing, but also occur endogenously in the organism as physiological components of energy metabolism, potentially also generated by the human microbiome. To arrive at a comprehensive risk assessment, it is necessary to understand the contribution of in vivo background occurrence as compared to the ingestion from exogenous sources. Hence, this review provides an overview of the knowledge on the contribution of endogenous exposure to the overall exposure to putative genotoxic food contaminants, namely ethanol, acetaldehyde, formaldehyde, acrylamide, acrolein, α,β-unsaturated alkenals, glycation compounds, N-nitroso compounds, ethylene oxide, furans, 2- and 3-MCPD, and glycidyl esters. The evidence discussed herein allows to conclude that endogenous formation of some contaminants appears to contribute substantially to the exposome. This is of critical importance for risk assessment in the cases where endogenous exposure is suspected to outweigh the exogenous one (e.g. formaldehyde and acrolein).

Monitored and Modeled Ambient Air Concentrations of Ethylene Oxide: Contextualizing Health Risk for Potentially Exposed Populations in Georgia

Recent studies have monitored and modeled long-term ambient air concentrations of ethylene oxide (EO) around emitting facilities in Georgia with the intent of informing risk management of potentially exposed nearby residential populations. Providing health context for these data is challenging because the U.S. Environmental Protection Agency’s risk-specific concentrations lack practical utility in distinguishing a health significant increase in exposure. This study analyzes EO data for eight emitting facilities, using a previously published alternative exposure metric, the total equivalent concentration, which is based on U.S. Centers for Disease Control biomarker data for the non-smoking U.S. population. Mean concentrations for monitoring sites were compared to mean background concentrations to assess whether emissions contribute significantly to environmental concentrations. To assess the health significance of potential exposure at nearby residential locations, the 50th percentile concentration was added to the 50th percentile endogenous equivalent concentration and compared to the total equivalent concentration distribution for the non-smoking U.S. population. The findings demonstrate that impacts from nearby emission sources are small compared to mean background concentrations at nearby locations, and the total equivalent concentrations for exposed populations are generally indistinguishable from that of the 50th percentile for the non-smoking U.S. population.

Inverse association between blood ethylene oxide levels and obesity in the general population: NHANES 2013-2016

BACKGROUND

Ethylene oxide (EO) has been shown to associate with increased cardiovascular risk. This study aimed to explore the relationship and its meditating factors between EO exposure and the major cardiovascular risk factor of obesity among the general adult population.

METHODS

Cross-sectional data of 3,220 participants from National Health and Nutritional Examination Survey (NHANES) 2013-2016 were enrolled. Obesity was defined as body mass index (BMI) ≥30 kg/m², and abdominal obesity was defined as waist circumference (WC) ≥102 cm in men and ≥88 cm in women. The association among hemoglobin adduct of EO (HbEO), inflammatory biomarkers, and obesity was evaluated using restricted cubic splines and the multivariable linear regression model. Mediation analysis was used to further assess their association.

RESULTS

The increased quartiles of HbEO were inversely associated with BMI and WC [Q1 vs. Q4, BMI: β = -2.98 (-3.74, -2.22), WC: β = -6.50 (-8.60, -4.39); all p for trend < 0.05], and were inversely associated with obesity after full adjustment [obesity: OR = 0.43 (0.31, 0.58), abdominal obesity: OR = 0.42 (0.27, 0.65); all p for trend < 0.05]. The levels of alkaline phosphatase, white blood cells, lymphocytes, and neutrophils were also positively associated with BMI and WC (all p < 0.05). Mediation analysis showed that exposure of EO not only had a negative direct effect on BMI and WC, but also generated an inverse indirect effect.

CONCLUSIONS

Current findings showed an inverse association between HbEO and obesity, and suggested that systemic inflammation may not be their only mediator. Additional research is required to explore the underlying link of EO and system metabolism.

Association of exposure to ethylene oxide with risk of diabetes mellitus: results from NHANES 2013-2016

Animal studies suggested that exposure to ethylene oxide (EO) might induce hepatic lipid peroxidation and inflammatory lesions in various organs. However, the association between EO exposure and diabetes risk in humans is unknown. This study aimed to examine the association of EO exposure with the prevalence of diabetes mellitus in a general population of US adults. This study consisted of 3448 participants aged 20 years and older from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 cycle and 2015-2016 cycle. Circulating levels of EO biomarker (hemoglobin adducts of EO (HbEO)) was measured by using high-performance liquid chromatography coupled with tandem mass spectrometry. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate logistic regression. The weighted median level of HbEO was 29.9 (95% CI: 21.8, 56.0) pmol/g Hb. Elevated levels of HbEO were associated with higher HbA1c and lower high-density lipoprotein cholesterol (both P_trend <0.01). After multivariate adjustment including demographics, lifestyle factors, and body mass index (BMI), higher HbEO levels were significantly associated with an increased prevalence of diabetes mellitus. The OR (95% CI) of diabetes across increasing quartiles of HbEO was 1.00 (reference), 1.45 (1.08, 1.96), 1.76 (1.31, 2.36), and 1.77 (1.22, 2.57), respectively (P_trend <0.001). Similar results were observed when analyses were stratified by smoking status, age, sex, race/ethnicity, and BMI. In a nationally representative sample of US adults, higher levels of HbEO were significantly associated with an increased prevalence of diabetes mellitus. Further prospective studies are needed to confirm these findings.

Characterization of the association between cigarette smoking intensity and urinary concentrations of 2-hydroxyethyl mercapturic acid among exclusive cigarette smokers in the National Health and Nutrition Examination Survey (NHANES) 2011-2016

BACKGROUND

2-Hydroxyethyl mercapturic acid (2HEMA, N-acetyl-S-(2-hydroxyethyl)-L-cysteine) is a urinary metabolite of several volatile organic compounds including acrylonitrile and ethylene oxide, which are found in cigarette smoke.

METHODS

We measured 2HEMA concentrations in urine specimens collected during the National Health and Nutrition Examination Survey (2011-2016) from eligible participants aged >12 years (N = 7,416). We developed two multiple linear regression models to characterize the association between cigarette smoking and 2HEMA concentrations wherein the dependent variable was 2HEMA concentrations among participants who exclusively smoked cigarettes at the time of specimen collection and the independent variables included sex, age, race/ethnicity, creatinine, diet, and either cigarettes smoked per day (CPD) or serum cotinine.

RESULTS

We detected 2HEMA in 85% of samples tested among exclusive cigarette smokers, and only 40% of specimens from non-smokers. When compared to exclusive cigarette smokers who smoked 1-9 CPD, smoking 10-19 CPD was associated with 36% higher 2HEMA (p < 0.0001) and smoking >19 CPD was associated with 61% higher 2HEMA (p < 0.0001). Additionally, 2HEMA was positively associated with serum cotinine.

CONCLUSIONS

This study demonstrates that cigarette smoking intensity is associated with higher urinary 2HEMA concentrations and is likely a major source of acrylonitrile and/or ethylene oxide exposure.

Ethylene Oxide Exposure in U.S. Populations Residing Near Sterilization and Other Industrial Facilities: Context Based on Endogenous and Total Equivalent Concentration Exposures

Given ubiquitous human exposure to ethylene oxide (EO), regardless of occupation or geography, the current risk-specific concentrations (RSCs: 0.0001-0.01 ppb) from the U.S. Environmental Protection Agency (EPA) cancer risk assessment for EO are not useful metrics for managing EO exposures to the general U.S. population. The magnitude of the RSCs for EO are so low, relative to typical endogenous equivalent metabolic concentrations (1.1-5.5 ppb) that contribute ~93% of total exposure, that the RSCs provide little utility in identifying excess environmental exposures that might increase cancer risk. EO monitoring data collected in the vicinity of eight EO-emitting facilities and corresponding background locations were used to characterize potential excess exogenous concentrations. Both 50th and 90th percentile exogenous exposure concentrations were combined with the 50th percentile endogenous exposure concentration for the nonsmoking population, and then compared to percentiles of total equivalent concentration for this population. No potential total exposure concentration for these local populations exceeded the normal total equivalent concentration 95th percentile, indicating that excess facility-related exposures are unlikely to require additional management to protect public health.