Transition of cooking fuels and obesity risk in Chinese adults.

BACKGROUND: Since 1990 s, China has witnessed a widespread transition to clean cooking fuels, presenting an opportunity to investigate whether household fuel transition could mitigate obesity risk and reconcile inconsistencies in the literature regarding the association between cooking fuels and obesity. METHODS: The China Health and Nutrition Survey (CHNS) is a prospective cohort study covering 12 provinces of China (1989-2015). Participants were classified into persistent cleaner fuel users, fuel transitioners, and persistent polluting fuel users according to self-reported primary cooking fuels. Obesity and central obesity were defined as BMI ≥ 28.0 kg/m2 and waist circumference ≥ 90 cm in men and ≥ 85 cm in women according to Chinese criteria. FINDINGS: Among 13,032 participants, 3657 (28.06 %) were persistent cleaner fuel users; 5264 (40.39 %) transitioned from using polluting fuels to cleaner fuels after the baseline survey; and 4111 (31.55 %) were persistent polluting fuel users. During the period of follow-up of 9.0 ± 6.8 years, 1248 (9.58 %) participants were classified into the obesity category, and 4703 (36.09 %) into the central obesity category. Persistent polluting fuel users had a significantly higher risk of developing obesity (hazard ratio [HR]: 1.45, 95 %CI: 1.22-1.72) and central obesity (HR: 1.32, 95 %CI: 1.21-1.44), compared to persistent cleaner fuel users. Persistent polluting fuel use was positively associated with developing obesity in women (HR: 1.64, 95 %CI: 1.30-2.06), but not in men. Subgroup analyses showed higher HR of persistent polluting fuel use among individuals aged 18-44 years (HR: 2.04, 95 %CI: 1.62-2.56). In contrast, the transitioners did not exhibit a significantly different risk of developing obesity (HR: 0.94, 95 %CI: 0.80-1.10) compared to persistent cleaner fuel users, which was consistent across different sex, age and urbanicity. Similar trends were observed for developing central obesity. INTERPRETATION: Persistent polluting fuel use increased obesity risk while the obesity risk of the transition to cleaner fuels was similar to persistent use of cleaner fuels. The finding underscores the significance of advocating for the adoption of cleaner fuels as a strategy to mitigate the disease burden associated with obesity.

Systemic oxidative stress levels during the course of pregnancy: Associations with exposure to air pollutants.

Increased systemic oxidative stress, implicated in adverse pregnancy outcomes for both mothers and fetuses, has been associated with gestational exposure to air pollutants such as polycyclic aromatic hydrocarbons (PAHs), fine particulate matter (PM2.5), and nitrogen dioxide (NO2). However, it is unclear whether exposure to pollutants at levels below the current air quality standards can increase oxidative stress in pregnant women. In a cohort of 305 pregnant persons residing in western New York, we examined the association between exposure to PM2.5, NO2, and PAHs (measured as urinary 1-hydroxypyrene) and urinary biomarkers of oxidative stress (malondialdehyde [MDA] and 8-hydroxy-2'-deoxyguanosine [8-OHdG]) measured in each trimester. After controlling for gestational stage, maternal age, lifestyles, and socioeconomic factors, each interquartile range (IQR) increase in 1-hydroxypyrene concentration (65.8 pg/ml) was associated with a 7.73% (95%CI: 3.18%,12.3%) higher in MDA levels throughout the pregnancy and in the first and second trimester. An IQR increase in PM2.5 concentration (3.20 µg/m3) was associated with increased MDA levels in the first trimester (8.19%, 95%CI: 0.28%,16.1%), but not the 2nd (-7.99%, 95% CI: 13.8%, -2.23%) or 3rd trimester (-2.81%, 95% CI: 10.0%, 4.38%). The average cumulative PM2.5 exposures in the 3-7 days before urine collection were associated with increased 8-OHdG levels during the second trimester, with the largest difference (22.6%; 95% CI: 3.46%, 41.7%) observed in relation to a one IQR increase in PM2.5 concentration in the previous 7 days. In contrast, neither oxidative stress biomarker was associated with NO2 exposure. Observed in pregnant women exposed to low-level air pollution, these findings expanded previously reported associations between systemic oxidative stress and high-level PM2.5 and PAH concentrations. Further, the first and second trimesters may be a susceptible window during pregnancy for oxidative stress responses to air pollution exposure.

Effects of ambient temperature on pediatric incident seizure: A case-crossover analysis using distributed lag non-linear models.

OBJECTIVE: Emerging evidence supports that brain dysfunction may be attributable to environmental factors. This study aims to examine associations of ambient temperature and temperature variability (TV) with seizure incidence in children, which has not been explored. MATERIAL AND METHODS: Data on 2718 outpatient visits due to seizure were collected in Shanghai, China, from 2018 to 2023. Exposure to ambient temperature was estimated at children's residential addresses using spatial-temporal models. A time-stratified case-crossover design with a distributed lag non-linear model (DLNM) was conducted to assess the association between seizure incidence and daily average of ambient temperature over a period of 21 days prior to a case date of disease onset. For a given case date, we selected all dates falling on the same day of the week within the same month as control dates. We calculated a composite index of intra-day and inter-day TV, which was the standard deviation of the daily minimum and maximum temperatures, respectively, over 7 days preceding a case date. We then assessed the association between TV and seizure incidence. Stratified analyses were conducted by age (73.51% < 5 years old and 26.49 % ≥ 5 years old), sex (41.83% female), presence of fever (69.72%), and diagnosis of epilepsy (27.63%). RESULTS: We observed inversed J-shaped temperature-response curves. Lower temperatures had a significant and prolonged effect than higher temperatures. Using 20 °C (with the minimum effect) as the reference, the cumulative odds ratios (ORs) for over 0-21 days preceding the onset at the 5th percentile of the temperature (3 °C) and at the 95th percentile (29 °C) were 3.17 (95% CI: 1.77, 5.68) and 1.54 (95% CI: 0.97, 2.44), respectively. In addition, per 1 °C increases in TV0-7 was associated with OR of 1.08 (95% CI: 1.01, 1.15). Older children and those experiencing seizure with fever exhibited a higher risk of seizure onset at both lower and higher ambient temperatures. CONCLUSION: Both low and high temperatures can contribute to the morbidity related to pediatric seizure. Lower temperatures, however, exerted a longer period of effect prior to seizure onset than higher temperatures. An increased risk for incident seizure was significantly associated with temperature variability during preceding 7 days.

Reduced human fecundity attributable to ambient fine particles in low- and middle-income countries.

BACKGROUND: Exposure to ambient fine particulate matter (PM2.5) has been associated with reduced human fecundity. However, the attributable burden has not been estimated for low- and middle-income countries (LMICs), where the exposure-response function between PM2.5 and the infertility rate has been insufficiently studied. OBJECTIVE: This study examined the associations between long-term exposure to PM2.5 and human fecundity indicators, namely the expected time to pregnancy (TTP) and 12-month infertility rate (IR), and then estimated PM2.5-attributable burden of infertility in LMICs. METHODS: We analyzed 164,593 eligible women from 100 Demographic and Health Surveys conducted in 49 LMICs between 1999 and 2021. We assessed PM2.5 exposures during the 12 months before a pregnancy attempt using the global satellite-derived PM2.5 estimates produced by Atmospheric Composition Analysis Group (ACAG). First, we created a series of pseudo-populations with balanced covariates, given different levels of PM2.5 exposure, using a matching approach based on the generalized propensity score. For each pseudo-population, we used 2-stage generalized Gamma models to derive TTP or IR from the probability distribution of the questionnaire-based duration time for the pregnancy attempt before the interview. Second, we used spline regressions to generate nonlinear PM2.5 exposure-response functions for each of the two fecundity indicators. Finally, we applied the exposure-response functions to estimate number of infertile couples attributable to PM2.5 exposure in 118 LMICs. RESULTS: Based on the Gamma models, each 10 µg/m3 increment in PM2.5 exposure was associated with a TTP increase by 1.7 % (95 % confidence interval [CI]: -2.3 %-6.0 %) and an IR increase by 2.3 % (95 %CI: 0.6 %-3.9 %). The nonlinear exposure-response function suggested a robust effect of an increased IR for high-concentration PM2.5 exposure (>75 µg/m3). Based on the PM2.5-IR function, across the 118 LMICs, the number of infertile couples attributable to PM2.5 exposure exceeding 35 µg/m3 (the first-stage interim target recommended by the World Health Organization global air quality guidelines) was 0.66 million (95 %CI: 0.061-1.43), accounting for 2.25 % (95 %CI: 0.20 %-4.84 %) of all couples affected by infertility. Among the 0.66 million, 66.5 % were within the top 10 % high-exposure infertile couples, mainly from South Asia, East Asia, and West Africa. CONCLUSION: PM2.5 contributes significantly to human infertility in places with high levels of air pollution. PM2.5-pollution control is imperative to protect human fecundity in LMICs.

Arachidonic Acid Metabolites in Self-collected Biospecimens Following Campfire Exposure: Exploring Non-invasive Biomarkers of Wildfire Health Effects.

Climate change has contributed to increased frequency and intensity of wildfire. Studying its acute effects is limited due to unpredictable nature of wildfire occurrence, which necessitates readily deployable techniques to collect biospecimens. To identify biomarkers of wildfire's acute effects, we conducted this exploratory study in eight healthy campers (four men and four women) who self-collected nasal fluid, urine, saliva, and skin wipes at different time points before, during, and after 4-hour exposure to wood smoke in a camping event. Concentrations of black carbon in the air and polycyclic aromatic hydrocarbons in participants' silicone wristbands were significantly elevated during the exposure session. Among 30 arachidonic acid metabolites measured, lipoxygenase metabolites were more abundant in nasal fluid and saliva, whereas cyclooxygenase and non-enzymatic metabolites were more abundant in urine. We observed drastic increases, at 8 hours following the exposure, in urinary levels of PGE2 (398%) and 15-keto-PGF2α (191%) (FDR<10%), with greater increases in men (FDR < 0.01%) than in women. No significant changes were observed for other metabolites in urine or the other biospecimens. Our results suggest urinary PGE2 and 15-keto-PGF2α as promising biomarkers reflecting pathophysiologic (likely sex-dependent) changes induced by short-term exposure to wildfire.

Neighborhood-level socioeconomic disparities in Radon testing in North Carolina from 2010 to 2020.

Radon is a naturally occurring radioactive gas that poses significant health risks to humans, including increased risk of lung cancer. This study investigates the association of neighborhood-level socioeconomic variables with radon testing and radon exposure levels in North Carolina between 2010 and 2020. Our analysis of the two largest commercial household radon tests reveals that 67% of census tracts had testing rates below 10 tests per 1000 population, indicating low testing prevalence. Low radon levels (<2 pCi/L) were detected in 74.1% of the tracts (n = 1626), while medium levels of 2-4 pCi/L and ≥4 pCi/L were observed in 17.2% (n = 378) and 1.6% (n = 36) of the tracts. A generalized spatial regression model was employed to analyze the association between neighborhood-level socioeconomic variables and radon testing rates (per 1000 households), controlling for median radon testing results. The results show a positive correlation (P-value <0.001) of testing rate with various indicators of neighborhood affluence including education level, income, and occupation. In contrast, neighborhood disadvantage, including poverty, unemployment, and public assistance, was associated with a lower radon-testing rate (P-value <0.001). These findings highlight the need for targeted interventions to address socioeconomic disparities in radon testing and promote awareness and access to testing resources in lower socio-economic neighborhoods. Improving testing rates can effectively address radon-related health risks in North Carolina and across the U.S.

Bi-directional association between outdoor or social activities and cognitive function: do the PM2.5 exposure catalyze the detrimental inactivity-poor cognition cycle?

BACKGROUND: Previous research has shown that lack of leisure activities, either outdoor or social activities, impedes cognitive function. However, the interrelationship between poor cognition and deficient activities is understudied. In addition, whether exposure to air pollution, such as PM2.5, can accelerate the detrimental 'inactivity-poor cognition' cycle, is worthy of investigation. METHODS: We used data from the 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). We assessed the frequency of outdoor or social activities at each wave. The cognitive function was examined using a China-Modified Mini-mental State Examination. We estimated the residential exposure to fine particular matter (PM2.5) via a satellite-based model. We applied cross-lagged panel (CLP) model to examine the bi-directional relationship between outdoor or social activities and cognitive function. We then examined the effect of PM2.5 exposure with sequent cognitive function and activities using generalized estimation equation (GEE) model. FINDINGS: Overall, we observed significant bi-directional associations between outdoor or social activities and cognitive function. Participants with better cognitive function in the last wave were more likely to engage in outdoor or social activities in the following wave (outdoor activities: ß = 0.37, 95% CI [0.27,0.48], P < 0.01; social activities: ß = 0.05, 95% CI [0.02,0.09] P < 0.01). Meanwhile, higher engagement in outdoor or social activities in the last wave was associated with more favorable cognitive function in the following wave (outdoor activities: ß = 0.06, 95% CI [0.03,0.09], P < 0.01; social activities: ß = 0.10, 95% CI [0.03,0.18], P < 0.01). Notably, an increase in PM2.5 exposure during the preceding year was significantly associated with a declining cognitive function (ß = -0.05, 95% CI [-0.08,-0.03], P < 0.01), outdoor activities (ß = -0.02, 95% CI [-0.04, -0.01], P < 0.01) and social activities (ß = -0.02, 95% CI [-0.02, -0.01], P < 0.01) in the current year; the lagged effects of the PM2.5 exposure in the past year of the last wave on activities and cognitive function of the following wave were also observed. INTERPRETATION: Our findings not only indicate the bi-directional links between the frequency of outdoor or social activities and cognitive function, but also report that PM2.5 exposure plays a role in catalyzing the detrimental inactivity-poor cognition cycle. Future research should investigate whether the policy-driven interventions, such as clean air policies, can break the unfavorable activity-cognition cycle, and thereby promoting health from the dual gains in leisure activities and cognition.

Nasal oxidative stress mediating the effects of colder temperature exposure on pediatric asthma symptoms.

BACKGROUND: Colder temperature exposure is a known trigger for pediatric asthma exacerbation. The induction of oxidative stress is a known pathophysiologic pathway for asthma exacerbation. However, the role of oxidative stress in linking colder temperature exposure and worsened pediatric asthma symptoms is poorly understood. METHODS: In a panel study involving 43 children with asthma, aged 5-13 years old, each child was visited 4 times with a 2-week interval. At each visit, nasal fluid, urine, and saliva samples were obtained and measured for biomarkers of oxidative stress in the nasal cavity (nasal malondialdehyde [MDA]), the circulatory system (urinary MDA), and the oral cavity (salivary MDA). Childhood Asthma-Control Test (CACT) was used to assess asthma symptoms. RESULTS: When ambient daily-average temperature ranged from 7 to 18 °C, a 2 °C decrement in personal temperature exposures were significantly associated with higher nasal MDA and urinary MDA concentrations by 47-77% and 6-14%, respectively. We estimated that, of the decrease in child-reported CACT scores (indicating worsened asthma symptoms and asthma control) associated with colder temperature exposure, 14-57% were mediated by nasal MDA. CONCLUSION: These results suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing nasal oxidative stress. IMPACT: The role of oxidative stress in linking colder temperature exposure and worsened asthma symptoms is still poorly understood. Lower temperature exposure in a colder season was associated with higher nasal and systemic oxidative stress in children with asthma. Nasal MDA, a biomarker of nasal oxidative stress, mediated the associations between colder temperature exposures and pediatric asthma symptoms. The results firstly suggest a plausible pathway that colder temperature exposure worsens pediatric asthma symptoms partly via inducing oxidative stress in the nasal cavity.

A chronic stress-induced microbiome perturbation, highly enriched in Ruminococcaceae_UCG-014, promotes colorectal cancer growth and metastasis.

Purpose: Mounting evidence indicates that psychological stress adversely affects cancer progression including tumor growth and metastasis. The aim of this study was to investigate the role of chronic stress-induced microbiome perturbation in colorectal cancer (CRC) progression. Methods: Chronic restraint stress (CRS) was used to establish the chronic stress mouse model, behavioral tests were used for the CRS model evaluation. Subcutaneous xenograft model and lung metastasis model were established to investigate the growth and metastasis of CRC promoted by CRS exposure. 16S rRNA gene sequencing and liquid chromatograph-mass spectrometer (LC-MS) were applied to observe the effects of CRS exposure on the alteration of the gut microbiome and microbial metabolites. Bioinformatics analysis and correlation analyses were applied to analyse the changes in the frequency of body mass, tumor volume, inflammatory factors, neuroendocrine hormones and metabolites of the gut microbiota. Results: In this study, we identifed that CRS exposure model was appropriately constructed by achieving expected increases in disease activity index and enhanced depressive-like behaviors. CRS exposure can promote growth and metastasis of CRC. Besides, the data indicated that CRS exposure not only increased the neuro- and immune-inflammation, but also weakened the gut mucosal immunological function. The 16s rRNA gene sequencing data showed that CRS exposure increased the abundance of g_Ruminococcaceae_UCG_014. Furthermore, the LC-MS data indicated that with only 2 exceptions of carpaine and DG (15:0/20:4(5Z,8Z,11Z,14Z)/0:0), the majority of these 24 metabolites were less abundant in CRS-exposed mice. Bioinformatics analysis and correlation analyses indicated that only Ruminoscoccaceae-UCG-014 was significantly associated with inflammation (IL-6), neurotransmission (5-HT), and microbial metabolism (PS). Conclusion: CRS exposure altered diversity, composition and metabolites of the gut microbiome, with Ruminococcaceae_UCG-014 perturbation consistently correlated to inflammatory responses, suggesting a particular role of this bacterial genus in CRC growth and metastasis.

Emerging concern on air pollution and health: Trade-off between air pollution exposure and physical activity.

Air pollution is a major contributor to the global disease burden, especially affecting respiratory and cardiovascular health. However, physical activity is associated with improved lung function, a slower decline in lung function, and lower mortality. The public is more likely to be exposed to air pollution during outdoor physical activity. However, studies on how long-term and short-term exposure to air pollution interacts with physical activity yield inconsistent results, and the thresholds for air pollution and physical activity remain unclear. Thus, more studies are needed to provide sufficient evidence to guide the public to safely engage in outdoor physical activity when exposed to air pollution.

Fine particulate matter contributes to COPD-like pathophysiology: experimental evidence from rats exposed to diesel exhaust particles.

BACKGROUND: Ambient fine particulate matter (PM2.5) is considered a plausible contributor to the onset of chronic obstructive pulmonary disease (COPD). Mechanistic studies are needed to augment the causality of epidemiologic findings. In this study, we aimed to test the hypothesis that repeated exposure to diesel exhaust particles (DEP), a model PM2.5, causes COPD-like pathophysiologic alterations, consequently leading to the development of specific disease phenotypes. Sprague Dawley rats, representing healthy lungs, were randomly assigned to inhale filtered clean air or DEP at a steady-state concentration of 1.03 mg/m3 (mass concentration), 4 h per day, consecutively for 2, 4, and 8 weeks, respectively. Pulmonary inflammation, morphologies and function were examined. RESULTS: Black carbon (a component of DEP) loading in bronchoalveolar lavage macrophages demonstrated a dose-dependent increase in rats following DEP exposures of different durations, indicating that DEP deposited and accumulated in the peripheral lung. Total wall areas (WAt) of small airways, but not of large airways, were significantly increased following DEP exposures, compared to those following filtered air exposures. Consistently, the expression of α-smooth muscle actin (α-SMA) in peripheral lung was elevated following DEP exposures. Fibrosis areas surrounding the small airways and content of hydroxyproline in lung tissue increased significantly following 4-week and 8-week DEP exposure as compared to the filtered air controls. In addition, goblet cell hyperplasia and mucus hypersecretions were evident in small airways following 4-week and 8-week DEP exposures. Lung resistance and total lung capacity were significantly increased following DEP exposures. Serum levels of two oxidative stress biomarkers (MDA and 8-OHdG) were significantly increased. A dramatical recruitment of eosinophils (14.0-fold increase over the control) and macrophages (3.2-fold increase) to the submucosa area of small airways was observed following DEP exposures. CONCLUSIONS: DEP exposures over the courses of 2 to 8 weeks induced COPD-like pathophysiology in rats, with characteristic small airway remodeling, mucus hypersecretion, and eosinophilic inflammation. The results provide insights on the pathophysiologic mechanisms by which PM2.5 exposures cause COPD especially the eosinophilic phenotype.

Critical windows of greenness exposure during preconception and gestational periods in association with birthweight outcomes.

Few studies have examined the association between greenness exposure and birth outcomes. This study aims to identify critical exposure time windows during preconception and pregnancy for the association between greenness exposure and birth weight. A cohort of 13 890 pregnant women and newborns in Shanghai, China from 2016-2019 were included in the study. We assessed greenness exposure using Normalized Difference Vegetation Index (NDVI) during the preconception and gestational periods, and evaluated the association with term birthweight, birthweight z-score, small-for-gestational age, and large-for-gestational age using linear and logistic regressions adjusting for key maternal and newborn covariates. Ambient temperature, relative humidity, ambient levels of fine particles (PM2.5) and nitrogen dioxide (NO2) assessed during the same period were adjusted for as sensitivity analyses. Furthermore, we explored the potential different effects by urbanicity and park accessibility through stratified analysis. We found that higher greenness exposure at the second trimester of pregnancy and averaged exposure during the entire pregnancy were associated with higher birthweight and birthweight Z-score. Specifically, a 0.1 unit increase in second trimester averaged NDVI value was associated with an increase in birthweight of 10.2 g (95% CI: 1.8-18.5 g) and in birthweight Z-score of 0.024 (0.003-0.045). A 0.1 unit increase in an averaged NDVI during the entire pregnancy was associated with 10.1 g (95% CI: 1.0-19.2 g) increase in birthweight and 0.025 (0.001-0.048) increase in birthweight Z-score. Moreover, the associations were larger in effect size among urban residents than suburban residents and among residents without park accessibility within 500 m compared to those with park accessibility within 500 m. Our findings suggest that increased greenness exposure, particularly during the second trimester, may be beneficial to birth weight in a metropolitan area.

Radon decay product particle radioactivity and oxidative stress biomarkers in patients with COPD.

Radon decay products include α-radiation emitting radionuclides that attach to airborne particles that have potential to promote oxidative tissue damage after inhalation. To assess associations between α-particle radioactivity (α-PR) with urinary biomarkers of oxidative tissue damage, 140 patients with chronic obstructive pulmonary disease (COPD) had up to four 1-week seasonal assessments (N = 413) of indoor (home) and ambient (central site) PM2.5 and black carbon (BC). Following environmental sampling, urine samples were analyzed for total and free malondialdehyde (MDA), biomarkers of lipid oxidation, and 8-hydroxyl-2'-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage. Particle radioactivity was measured as α-activity on PM2.5 filter samples. Linear mixed-effects regression models adjusted for urinary creatinine and other personal characteristics were used to assess associations. Indoor α-PR was associated with an increase in 8-OhdG (8.53%; 95% CI: 3.12, 14.23); total MDA (5.59%; 95% CI: 0.20, 11.71); and free MDA (2.17%; 95% CI: 2.75, 7.35) per interquartile range (IQR) of α-PR [median 1.25 mBq/m3; IQR 0.64], similar adjusting for PM2.5 or BC. The ratio of indoor/ambient α-PR was positively associated with each biomarker and associations with ambient α-PR were positive but weaker than with indoor concentrations. These findings are consistent with a contribution of radon decay products as measured by α-PR to oxidative stress in patients with COPD, with a greater contribution of indoor radon decay products.

Housing Environmental Factors Driving Falls Among Middle-Aged and Older Adults: A National Cohort Study.

Background and Objectives: Housing is one of the main places where falls occur; however, few studies have examined housing environmental factors driving fall risk. This study aimed to explore the associations between housing environmental factors and falls in China. Research Design and Methods: The study included data of middle-aged and older adults aged ≥45 years from 4 waves of the China Health and Retirement Longitudinal Study. We assessed 7 housing environmental factors: building materials, toilet types, household tidiness, household cooking fuels, and access to electricity, running water, and bathing facilities. Based on these, we divided housing environments into 3 types: good (0-2 poor factors), moderate (3-5 poor factors), and poor (6-7 poor factors). Falls incidence (yes or no) was self-reported during the survey period. We applied the Cox proportional hazard model to estimate the associations, adjusting for a set of covariates such as sociodemographic characteristics, lifestyles, and disease status. Results: A total of 12,382 participants were analyzed, and the incidence of falls was 31.7%. According to the fully adjusted model, having a squatting toilet (hazard ratio [HR] = 1.14, 95% confidence interval [CI] = 1.03-1.26), household untidiness (HR = 1.09, 95% CI = 1.01-1.18), and solid fuel use for cooking (HR = 1.10, 95% CI = 1.02-1.18) were associated with a higher risk of falls (ps < .05), compared to their counterparts. We found a linear relationship between housing environments and falls (p for trend = .001). Specifically, moderate (HR = 1.16, 95% CI = 1.06-1.27) and poor housing environments (HR = 1.21, 95% CI = 1.08-1.34) were associated with a higher risk of falls compared to a good housing environment. Discussion and Implications: Among middle-aged and older Chinese adults, a better household environment, including sitting toilets, tidy living conditions, and clean fuel use for cooking, may reduce the risk of falls. The evidence from our study suggests the need to implement age-friendly housing environments to prevent falls and disability in an aging society.

Associations between personal apparent temperature exposures and asthma symptoms in children with asthma.

Ambient temperature and relative humidity can affect asthma symptoms. Apparent temperature is a measure of temperature perceived by humans that takes into account the effect of humidity. However, the potential link between personal exposures to apparent temperature and asthma symptoms has not been investigated. We conducted a panel study of 37 asthmatic children, aged 5-11 years, during an early spring season (average daily ambient temperature: 14°C, range: 7-18°C). Asthma symptoms were measured 4 times for each participant with a 2-week interval between consecutive measurements using the Childhood Asthma-Control Test (C-ACT). Average, minimum, and maximum personal apparent temperature exposures, apparent temperature exposure variability (TV), and average ambient temperature were calculated for the 12 hours, 24 hours, week, and 2 weeks prior to each visit. We found that a 10°C lower in 1-week and 2-week average & minimum personal apparent temperature exposures, TV, and average ambient temperature exposures were significantly associated with lower total C-ACT scores by up to 2.2, 1.4, 3.3, and 1.4 points, respectively, indicating worsened asthma symptoms. Our results support that personal apparent temperature exposure is potentially a stronger driver than ambient temperature exposures for the variability in asthma symptom scores. Maintaining a proper personal apparent temperature exposure could be an effective strategy for personalized asthma management.

Identifying critical windows of air pollution exposure during preconception and gestational period on birthweight: a prospective cohort study.

BACKGROUND: Few studies have assessed air pollution exposure association with birthweight during both preconception and gestational periods. METHODS: Leveraging a preconception cohort consisting of 14220 pregnant women and newborn children in Shanghai, China during 2016-2018, we aim to assess associations of NO2 and PM2.5 exposure, derived from high-resolution spatial-temporal models, during preconception and gestational periods with outcomes including term birthweight, birthweight Z-score, small-for-gestational age (SGA) and large-for-gestational age (LGA). Linear and logistic regressions were used to estimate 3-month preconception and trimester-averaged air pollution exposure associations; and distributed lag models (DLM) were used to identify critical exposure windows at the weekly resolution from preconception to delivery. Two-pollutant models and children's sex-specific associations were explored. RESULTS: After controlling for covariates, one standard deviation (SD) (11.5 µg/m3, equivalent to 6.1 ppb) increase in NO2 exposure during the second and the third trimester was associated with 13% (95% confidence interval: 2 - 26%) and 14% (95% CI: 1 - 29%) increase in SGA, respectively; and one SD (9.6 µg/m3) increase in PM2.5 exposure during the third trimester was associated with 15% (95% CI: 1 - 31%) increase in SGA. No association have been found for outcomes of birthweight, birthweight Z-score and LGA. DLM found that gestational weeks 22-32 were a critical window, when NO2 exposure had strongest associations with SGA. The associations of air pollution exposure tended to be stronger in female newborns than in male newborns. However, no significant associations of air pollution exposure during preconception period on birthweight outcomes were found. CONCLUSION: Consistent with previous studies, we found that air pollution exposure during mid-to-late pregnancy was associated with adverse birthweight outcomes.

Citrus peel extract protects against diesel exhaust particle-induced chronic obstructive pulmonary disease-like lung lesions and oxidative stress.

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and characterized by emphysema, small airway remodeling and mucus hypersecretion. Citrus peels have been widely used as food spices and in traditional Chinese medicine for chronic lung disease. Given that citrus peels are known for containing antioxidants and anti-inflammatory compounds, we hypothesize that citrus peel intake can suppress oxidative stress and inflammatory response to air pollution exposure, thereby alleviating COPD-like pathologies. This study aimed to investigate the efficacy of citrus peel extract, namely Guang Chenpi (GC), in preventing the development of COPD induced by diesel exhaust particles (DEPs) and its potential mechanism. DEP-induced COPD-like lung pathologies, inflammatory responses and oxidative stress with or without GC treatment were examined in vivo and in vitro. Our in vivo study showed that GC was effective in decreasing inflammatory cell counts and inflammatory mediator (IL-17A and TNF-α) concentrations in bronchoalveolar lavage fluid (BALF). Pretreatment with GC extract also significantly decreased oxidative stress in the serum and lung tissue of DEP-induced COPD rats. Furthermore, GC pretreatment effectively reduced goblet cell hyperplasia (PAS positive cells) and fibrosis of the small airways, decreased macrophage infiltration as well as carbon loading in the peripheral lungs, and facilitated the resolution of emphysema and small airway remodeling in DEP-induced COPD rats. An in vitro free radical scavenging assay revealed robust antioxidant potential of GC in scavenging DPPH free radicals. Moreover, GC demonstrated potent capacities in reducing ROS production and enhancing SOD activity in BEAS-2B cells stimulated by DEPs. GC treatment significantly attenuated the increased level of IL-8 and MUC5AC from DEP-treated BEAS-2B cells. Mechanistically, GC treatment upregulated the protein level of Nrf-2 and could function via MAPK/NF-κB signaling pathways by suppressing the phosphorylation of p38, JNK and p65. Citrus peel extract is effective in decreasing oxidative stress and inflammatory responses of the peripheral lungs to DEP exposure. These protective effects further contributed to the resolution of COPD-like pathologies.

Gestational age modifies the association between exposure to fine particles and fetal death: findings from a nationwide epidemiological study in the contiguous United States.

BACKGROUNDS: The vulnerability of fetuses differs at different developmental stages, in response to environmental stressors such as fine particulate matter (PM2.5), a ubiquitous air pollutant. Whether gestational age (GA) modifies the association between prenatal fine particulate matter (PM2.5) exposure and fetal death remains unclear. METHODS: We selected approximately 47.8 million eligible United States (US) livebirth and fetal death (defined as a termination at a GA of 20-43 weeks) records from 1989 to 2004. For each record, we took the level of prenatal exposure to PM2.5 as the average concentration in the mother's residential county during the entire gestational period, or a specific trimester (i.e., GA-specific exposure), according to well-established estimates of monthly levels across the contiguous US. First, we evaluated the associations between PM2.5 exposure and fetal death at a specific GA (i.e., GA-specific outcome) using five different logit models (unadjusted, covariate-adjusted, propensity-score, double robust, and diagnostic-score models). Double robust model was selected as the main model due to its advantages in causal inference. Then, we conducted meta-analyses to pool the estimated GA-specific associations, and explored how the pooled estimates varied with GA. RESULTS: According to the meta-analysis, all models suggested gestational PM2.5 exposure was associated with fetal death. However, there was slight heterogeneity in the estimated effects, as different models revealed a range of 3.6-10.7% increase in the odds of fetal death per 5-µg/m3 increment of PM2.5. Each 5-µg/m3 increase in PM2.5 exposure during the entire gestation period significantly increased the odds of fetal death, by 8.1% (95% confidence interval [CI]: 5.1-11.2%). In terms of GA-specific outcomes, the odds of fetal death at a GA of 20-27, 28-36, or ≥ 37 weeks increased by 11.0% (5.9-16.4%), 5.2% (0.4-10.1%), and 8.3% (2.5-14.5%), respectively. In terms of GA-specific exposure, the odds of fetal death increased by 6.0% (3.9-8.2%), 4.1% (3.9-8.2%), and 4.3% (0.5-8.2%) with 5-µg/m3 increases in PM2.5 exposure during the first, second, and third trimester, respectively. The association had the largest effect size (odds ratio = 1.098, 95% CI: 1.061-1.137) between PM2.5 exposure during early gestation (i.e., first trimester) and early fetal death (i.e., 20-27 weeks). CONCLUSIONS: Prenatal exposure to PM2.5 was significantly associated with an increased risk of fetal death. The association was varied by gestational-age-specific exposures or outcomes, suggesting gestation age as a potential modifier on the effect of PM2.5. The fetus was most vulnerable during the early stage of development to death associated with PM2.5 exposure.

Urinary Amino-PAHs in relation to diesel engine emissions and urinary mutagenicity.

Diesel exhaust has long been of health concern due to established toxicity including carcinogenicity in humans. However, the precise components of diesel engine emissions that drive carcinogenesis are still unclear. Limited work has suggested that nitrated polycyclic aromatic hydrocarbons (NPAHs) such as 1-nitropyrene and 2-nitrofluorene may be more abundant in diesel exhaust. The present study aimed to examine whether urinary amino metabolites of these NPAHs were associated with high levels of diesel engine emissions and urinary mutagenicity in a group of highly exposed workers including both smokers and nonsmokers. Spot urine samples were collected immediately following a standard work shift from each of the 54 diesel engine testers and 55 non-tester controls for the analysis of five amino metabolites of NPAHs, and cotinine (a biomarker of tobacco smoke exposure) using liquid chromatography-mass spectrometry. An overnight urine sample was collected in a subgroup of non-smoking participants for mutagenicity analysis using strain YG1041 in the Salmonella (Ames) mutagenicity assay. Personal exposure to fine particles (PM2.5) and more-diesel-specific constituents (elemental carbon and soot) was assessed for the engine testers by measuring breathing-zone concentrations repeatedly over several full work shifts. Results showed that it was 12.8 times more likely to detect 1-aminopyrene and 2.9 times more likely to detect 2-aminofluorene in the engine testers than in unexposed controls. Urinary concentrations of 1-aminopyrene were significantly higher in engine testers (p < 0.001), and strongly correlated with soot and elemental carbon exposure as well as mutagenicity tested in strain YG1041 with metabolic activation (p < 0.001). Smoking did not affect 1-aminopyrene concentrations and 1-aminopyrene relationships with diesel exposure. In contrast, both engine emissions and smoking affected 2-aminofluorene concentrations. The results confirm that urinary 1-aminopyrene may serve as an exposure biomarker for diesel engine emissions and associated mutagenicity.

Urinary 1-hydroxypyrene in pregnant women in a Northeastern U.S. city: socioeconomic disparity and contributions from air pollution sources.

BACKGROUND: Maternal exposure to polycyclic aromatic hydrocarbons (PAHs), ubiquitous constituents of air pollution, has been associated with adverse birth outcomes. Yet it remains unclear whether and how socioeconomic status (SES) affects gestational PAH exposure. OBJECTIVE: To examine whether there are socioeconomic disparities in PAHs exposure among pregnant women from Rochester, NY, and if so, to what extent disproportionate proximity to air pollution sources, measured by residential distance to transportation-related sources, contributed to the exposure disparity. METHODS: We measured 1-hydroxypyrene concentrations in 726 urine samples collected from 305 pregnant women up to three samples throughout pregnancy. Residential distances to transportation-related sources were calculated based on participants' home addresses. We used linear mixed-effects models with random intercepts of participants to examine associations between 1-hydroxypyrene, SES indicators, and distance to transportation-related sources. We used structural equation modelling to assess to what extent distance to transportation-related sources contributes to the socioeconomic disparity in 1-hydroxypyrene concentrations. RESULTS: Reduced household income and maternal education level were both significant SES predictors of 1-hydroxypyrene concentrations, after the adjustment for other maternal demographic characteristics. Each interquartile range (IQR) increases in residential proximity to the airport (from 14.3 to 6.0 km), the railroad yard (from 22.3 to 6.0 km), and annual average daily traffic within 300 m (from 3796 to 99,933 vehicles/year) were associated with 15.0% (95%CI: 7.0-22.2%), 15.4% (95%CI: 6.5-23.5%), and 13.6% (95%CI: 4.7-23.3%) increases in 1-hydroxypyrene concentrations, respectively. Proximity to these sources jointly explained 10% (95%CI: 1.6-18.4%) of the 1-hydroxypyrene concentration change associated with decreases in SES as a latent variable defined by both household income and education level. IMPACT STATEMENT: Our findings suggest that efforts to address disproportionate residential proximity to transportation-related sources may reduce the socioeconomic disparity in PAH exposure.