Air pollution-associated blood pressure may be modified by diet among children in Guangzhou, China

Childhood exposure to air pollution, noise, and surrounding greenness and incident hypertension in early adulthood in a US nationwide cohort-the Growing Up Today Study (GUTS)

Exposure to increased air pollution, noise, and reduced surrounding greenness have been suggested as potential environmental risk factors for hypertension in adults, but limited evidence exists regarding early-life exposure, particularly from prospective studies. We investigated independent and joint associations of childhood exposure to these factors with incident hypertension in early adulthood in a US nationwide cohort. Study participants were from the Growing Up Today Study (GUTS) established in 1996 (GUTSI) and 2004 (GUTSII), who were ages 9-14 (GUTSI) or 10-17 (GUTSII) at enrollment. Incident hypertension was identified by self-report on questionnaires from 2010 to 2021. We estimated residential exposures to air pollution (from spatiotemporal models), noise, and surrounding greenness throughout childhood (10-18y). We applied Cox proportional hazards models adjusted for potential confounders to assess hazard ratios (HRs) and 95% confidence intervals (CIs) associated with each interquartile range (IQR) change in exposure. We performed a quantile g-computation to assess the joint association of simultaneous exposure to the mixture. We considered potential effect modification by sex, maternal history of hypertension, overweight/obese status at age 18, urbanicity, and neighborhood socioeconomic status. Among 17,762 participants, 1530 hypertensive cases occurred during an average follow-up of 12.8 years. HRs for all exposures were small with CIs including unity. A joint HR of 1.03 (95% CI: 0.95, 1.11) was associated with a one-quartile increase across simultaneous exposure to the environmental mixture. The joint associations were stronger among non-obese participants or participants living in less advantaged neighborhoods: HRs of 1.07 (95% CI: 0.97, 1.18) and 1.08 (95% CI: 0.98, 1.18), respectively. In conclusion, we did not identify an independent or joint association between childhood exposure to air pollution, noise, and surrounding greenness and early adulthood hypertension. However, a positive joint association was suggested among non-obese participants or those living in less advantaged neighborhoods.

Early-life exposure to ambient air pollution with cardiovascular risk factors in adolescents: Findings from the "Children of 1997" Hong Kong birth cohort

BACKGROUND

Long-term exposure to ambient air pollution is associated with cardiovascular disease (CVD) risk. Little is known about the impact of early-life exposure to air pollutants on CVD risk factors in late adolescence, which may track into adulthood. To clarify, we examined this question in a unique setting with high air pollution and a high level of economic development.

METHODS

This study leveraged the "Children of 1997" Hong Kong birth cohort (N = 8327), including here 3350 participants. We estimated ambient air pollutant exposure including inhalable particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2) and nitrogen monoxide (NO) by growth phase (in utero, infancy, childhood) and overall based on residential address. Generalized linear regression was used to assess the associations of air pollutants exposure by growth phase and sex with CVD risk factors (fasting blood glucose, glycosylated hemoglobin, lipid profile, blood pressure, and body mass index) at 17.6 years. We also assessed whether associations varied by sex.

RESULTS

Early life exposed had little association with glucose metabolism, blood pressure or body mass index, but after considering multiple comparisons early exposure to PM10 was associated with low density lipoprotein (LDL) in boys, with β and 95 % confidence intervals (95 % CI) of 0.184 (0.069 to 0.298) mmol/l, 0.151 (0.056 to 0.248) mmol/l, and 0.157 (0.063 to 0.252) mmol/l by per interquartile range (IQR) increment of PM10 for in utero, infancy, and overall, respectively. No such associations were evident for girls, differences by sex were evident.

CONCLUSIONS

Our study suggested sex-specific associations of early-life PM10 exposure with elevated LDL in adolescence, especially exposure in utero and infancy.

Optimization strategy of community planning for environmental health and public health in smart city under multi-objectives

As population density increases, environmental hygiene and public health become increasingly severe. As the space where residents stay for the longest time and have the most profound impact on their physical and mental health, the quality of the environment in urban communities largely determines the degree to which residents engage in physical activity, bear the risk of pollution exposure, and obtain healthy food. Therefore, in order to ensure the physical and mental health of residents, this study proposes community planning guided by environmental hygiene and public health, and establishes an environmental health assessment system for this purpose. This system evaluates the community environment from four aspects: land use, service facilities, site convenience, and environmental quality. Established the diversity, density, road network connectivity and facilities accessibility nine criteria, as well as the land function of mix, plot ratio, food environment, network ring α and connected β index, pavement risk level, green configuration and neighborhood material environment disorder degree of 27 indicators of community built environmental evaluation index system. The data is collected through field survey, questionnaire distribution, resident interview and data mapping, and the established evaluation index system is used to evaluate the construction environment of the community. The experimental research data included population data, CAD plan, land use data, street data, POI point data, building data and bus station data, etc. 273 questionnaires were distributed, 264 were recovered, 8 invalid questionnaires were removed, and 256 valid questionnaires were obtained. These experiments confirm that land use, service facilities, site convenience, and environmental quality have a significant impact on the built environment of communities, with impact weights of 0.513, 0.227, 0.135, and 0.125, respectively. The above weights are calculated based on the index judgment matrix and the eigenvectors. The scores of land use, service facilities, site convenience, and environmental quality for the study subjects were 3.44, 1.46, 0.94, and 0.51, respectively, among them, the land use score is less than 3.85, the 1 service facility score is less than 1.71, the site convenience score is less than 1.01, and the environmental quality score is less than 0.94; indicating that the community has serious problems such as single land use types, pollution exposure, and difficulty in obtaining healthy food. Therefore, community planning and transformation based on land use, service facilities, venue convenience, and environmental quality can effectively improve the physical and mental health of residents. In the specific community transformation plan, artificial intelligence and data-driven methods can be used to optimize the land use plan, service facility configuration, site convenience transformation and environmental quality improvement, so as to formulate the optimal community transformation plan and improve the comfort and happiness of community residents. In the future, on the basis of the existing research, the selection of community types will be further enriched and the research cases will be expanded. And through the in-depth practical study of the case, the constructed evaluation index system is optimized and improved to make it more scientific. At the same time, as urban renewal and design have entered the era of stock planning, based on the more perfect evaluation index system, more specific and detailed system discussion of the built communities with public health problems, in order to provide more detailed services for the construction of a better and healthy living environment in the future.

Association of joint exposure to various ambient air pollutants during adolescence with blood pressure in young adulthood

The association of various air pollutants exposure during adolescence with blood pressure (BP) in young adulthood is uncertain. We intended to evaluate the long-term association of individual and joint air pollutants exposure during adolescence with BP in young adulthood. This cross-sectional study of incoming students was conducted in five geographically disperse universities in China during September and October 2018. Mean concentrations of particulate matter with diameters ≤2.5 μm (PM2.5 ), ≤10 μm (PM10 ), nitrogen dioxides (NO2 ), carbon monoxide (CO), sulfur dioxide (SO2 ), and ozone (O3 ) at participants' residential addresses during 2013-2018 were collected from the Chinese Air Quality Reanalysis dataset. Generalized linear mixed models (GLM) and quantile g-computation (QgC) models were utilized to estimate the association between individual and joint air pollutants exposure and systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP). A total of 16,242 participants were included in the analysis. The GLM analyses showed that PM2.5 , PM10 , NO2 , CO, and SO2 were significantly positively associated with SBP and PP, while O3 was positively associated with DBP. The QgC analyses indicated that long-term exposure to a mixture of the six air pollutants had a significant positive joint association with SBP and PP. In conclusion, air pollutant co-exposure during adolescence may influence BP in young adulthood. The findings of this study emphasized the impacts of multiple air pollutants interactions on potential health and the need of minimizing pollution exposures in the environment.

Air Pollution, Built Environment, and Early Cardiovascular Disease

As the world's population becomes increasingly urbanized, there is growing concern about the impact of urban environments on cardiovascular health. Urban residents are exposed to a variety of adverse environmental exposures throughout their lives, including air pollution, built environment, and lack of green space, which may contribute to the development of early cardiovascular disease and related risk factors. While epidemiological studies have examined the role of a few environmental factors with early cardiovascular disease, the relationship with the broader environment remains poorly defined. In this article, we provide a brief overview of studies that have examined the impact of the environment including the built physical environment, discuss current challenges in the field, and suggest potential directions for future research. Additionally, we highlight the clinical implications of these findings and propose multilevel interventions to promote cardiovascular health among children and young adults.

Alleviating air pollutant-associated hypertension by potassium intake in Korean adults: a cross-sectional study from the 2012-2016 Korea National Health and Nutrition Examination Survey

Air pollution may increase the risk of hypertension (HTN) by increasing oxidative stress and inflammation, and reducing sodium excretion. Potassium intake may reduce the risk of HTN through sodium excretion and reduce inflammation and oxidative stress. This study is aimed at investigating the association between air pollutants and HTN and whether these associations differ based on the potassium intake data of Korean adults from the 2012-2016 Korean National Health and Nutrition Examination Survey (KNHANES). This cross-sectional study used data from KNHANES (2012-2016) combined with annual air pollutant data from the Ministry of Environment using administrative units. We included 15,373 adults who responded to the semi-food frequency questionnaire. Associations between ambient PM₁₀, SO₂, NO₂, CO, and O₃ with HTN according to potassium intake were assessed using the survey logistic regression model for complex samples analysis. After adjusting for potential covariates such as, age, sex, education level, smoking status, family income, alcohol consumption, body mass index (BMI), exercise status, and survey year, as the air pollutant score considering the five air pollutants increased (severe air pollution), the prevalence of HTN increased in a dose-dependent manner (p for trend < 0.001). Meanwhile, in the adults with higher potassium intake and who were exposed to lowest levels of air pollutants score (score = 0), the ORs of HTN were significantly lower (OR = 0.56, 95% CI: 0.32-0.97). In conclusion, our study suggests that exposure to air pollutants may increase the prevalence of HTN among Korean adults. However, high potassium intake may help prevent HTN caused by air pollutants.

Pre- and postnatal particulate matter exposure and blood pressure in children and adolescents: A systematic review and meta-analysis

BACKGROUND

Early life is a susceptible period of air pollution-related adverse health effects. Hypertension in children might be life-threatening without prevention or treatment. Nevertheless, the causative association between environmental factors and childhood hypertension was limited. In the light of particulate matter (PM) as an environmental risk factor for cardiovascular diseases, this study investigated the association of pre- and postnatal PM exposure with blood pressure (BP) and hypertension among children and adolescents.

METHOD

Four electronic databases were searched for related epidemiological studies published up to September 13, 2022. Stata 14.0 was applied to examine the heterogeneity among the studies and evaluate the combined effect sizes per 10 μg/m³ increase of PM by selecting the corresponding models. Besides, subgroup analysis, sensitivity analysis, and publication bias test were also conducted.

RESULTS

Prenatal PM_2.5 exposure was correlated with increased diastolic blood pressure (DBP) in offspring [1.14 mmHg (95% CI: 0.12, 2.17)]. For short-term postnatal exposure effects, PM_2.5 (7-day average) was significantly associated with systolic blood pressure (SBP) [0.20 mmHg (95% CI: 0.16, 0.23)] and DBP [0.49 mmHg (95% CI: 0.45, 0.53)]; and also, PM₁₀ (7-day average) was significantly associated with SBP [0.14 mmHg (95% CI: 0.12, 0.16)]. For long-term postnatal exposure effects, positive associations were manifested in SBP with PM_2.5 [β = 0.44, 95% CI: 0.40, 0.48] and PM₁₀ [β = 0.35, 95% CI: 0.19, 0.51]; DBP with PM₁ [β = 0.45, 95% CI: 0.42, 0.49], PM_2.5 [β = 0.31, 95% CI: 0.27, 0.35] and PM₁₀ [β = 0.32, 95% CI: 0.19, 0.45]; and hypertension with PM₁ [OR = 1.43, 95% CI: 1.40, 1.46], PM_2.5 [OR = 1.65, 95% CI: 1.29, 2.11] and PM₁₀ [OR = 1.26, 95% CI: 1.09, 1.45].

CONCLUSION

Both prenatal and postnatal exposure to PM can increase BP, contributing to a higher prevalence of hypertension in children and adolescents.

Association between long-term air pollution exposure and development of diabetes among community-dwelling adults: Modification of the associations by dietary nutrients

BACKGROUND

Studies on the modifying effects of dietary factors on the association between air pollution and diabetes-related outcomes are limited. We examined whether dietary nutrients could modify the association between long-term air pollution exposure and the development of diabetes.

METHODS

We used data from the Cardiovascular Disease Association Study, which enrolled adults aged 40-69 years in Korea between 2005 and 2011 and followed them up until 2016 (n = 14,667). Annual concentrations of fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂) at each participant's residence(s) were estimated using community multiscale air quality models. Intake of 22 dietary nutrients was assessed using a validated food frequency questionnaire during the baseline survey. We examined the product terms between air pollution levels (continuous) and each dietary nutrient (quartile) using Cox regression models, adjusted for potential confounders.

RESULTS

PM_2.5 [hazard ratio (HR) = 1.49, 95 % confidence interval (CI): 1.11, 2.00] and NO₂ (HR = 1.29, 95 % CI: 1.12, 1.49) concentrations were found to be associated with incident diabetes. NO₂ levels interacted with dietary intake of retinol, vitamin A, and cholesterol (p-values for interaction < 0.05). Stronger associations were observed between NO₂ levels and the occurrence of diabetes among individuals with a lower intake of these nutrients compared to those with a higher intake. No interaction was found between PM_2.5 and the 22 investigated dietary nutrients.

CONCLUSIONS

Adequate intake of dietary nutrients, such as retinol, vitamin A, and cholesterol, from various food items in a balanced diet may prevent the occurrence of diabetes in a setting wherein reduction of air pollution levels cannot be achieved in a short time frame.

Association between long-term exposure to ambient particulate matter and blood pressure, hypertension: an updated systematic review and meta-analysis

Evidence of more recent studies should be updated to evaluate the effect of long-term exposure to particulate matter (PM) on blood pressure and hypertension.        Studies of long-term effects of PM₁, PM_2.5 and PM₁₀ on blood pressure (SBP, DBP, MAP), hypertension were searched in Pubmed, Web of Science and Embase before May, 2021. Meta-analysis of 41 studies showed that exposure to PM₁, PM_2.5 was associated with SBP (1.76 mmHg (95%CI:0.71, 2.80) and 0.63 mmHg (95%CI:0.40, 0.85), per 10 μg/m³ increase in PM), all three air pollutants (PM₁, PM_2.5, PM₁₀) was associated with DBP (1.16 mmHg (95%CI:0.34, 1.99), 0.31 mmHg (95%CI:0.16, 0.47), 1.17 mmHg (95%CI:0.24, 2.09), respectively. As for hypertension, PM₁, PM_2.5 and PM₁₀ were all significantly associated with higher risk of hypertension (OR=1.27 (95%CI:1.06, 1.52), 1.15 (95%CI:1.10, 1.20) and 1.11 (95%CI:1.07, 1.16). In conclusion, our study indicated a positive association between long-term exposure to particulate matter and increased blood pressure, hypertension.

The Association between Air Pollutants Exposure with Pre- and Hypertension by Vitamin C Intakes in Korean Adults: A Cross-Sectional Study from the 2013-2016 Korea National Health and Nutrition Examination

OBJECTIVES

Oxidative stress and systemic inflammation are the main pathways by which air pollutants cause hypertension (HTN). Vitamin C intake may reduce the risk of HTN caused by air pollutants. This study aimed to investigate the association between air pollutants and pre-HTN and HTN in Korean adults and whether these associations were modified by vitamin C intake, using data from the 2013-2016 Korean National Health and Nutrition Examination Survey (KNHANES).

DESIGN

Cross-sectional study.

SETTING

This study used data from the KNHANES VI (2013-2015) and VII (2016) along with the data from the annual air pollution report of the Ministry of Environment.

PARTICIPANTS

We included 11,866 adults who had responded to a semi-food frequency questionnaire.

MEASUREMENTS

We used survey logistic regression models to evaluate the association of ambient PM10, SO2, NO2, CO, and O3 with pre-HTN and HTN according to vitamin C intake.

RESULTS

After adjusting for potential covariates, exposure to ambient PM10, SO2, NO2, and CO was significantly associated with a high prevalence of pre-HTN and HTN, whereas exposure to O3 was significantly associated with a low prevalence of pre-HTN and HTN. In particular, as the air pollutant scores increased (severe air pollution), the prevalence of pre-HTN and HTN increased in a dose-dependent manner (highest score vs. lowest score, OR=1.85, 95% CI=1.39-2.46, p for trend <.0001). However, these associations were found to be pronounced in adults with low vitamin C intake (highest score vs. lowest score, OR=2.30, 95% CI=1.50-3.54, p for trend <.0001), whereas the statistical significance disappeared for adults with high vitamin C intake (highest score vs. lowest score, OR=1.40, 95% CI=0.93-2.12, p for trend=0.007).

CONCLUSION

Exposure to air pollutants such as PM10, SO2, NO2, and CO may increase the prevalence of pre-HTN and HTN among Korean adults. In addition, a high intake of vitamin C may help prevent pre-HTN and HTN caused by air pollutants.

The impact of prolonged exposure to air pollution on the incidence of chronic non-communicable disease based on a cohort in Tianjin

Evidence on the associations of prolonged ambient pollutants exposure with chronic non-communicable diseases among middle-aged and elderly residents is still limited. This prospective cohort study intends to investigate the long-term effects of ambient pollution on hypertension and diabetes incidence among relatively older residents in China. Individual particulate matter exposure levels were estimated by satellite-based model. Individual gaseous pollutants exposure levels were estimated by Inverse Distance Weighted model. A Cox regression model was employed to assess the risks of hypertension and diabetes morbidity linked to air pollutants exposures. The cross-product term of ambient pollutants exposure and covariates was further added into the regression model to test whether covariates would modify these air pollution-morbidity associations. During the period from 2014 to 2018, a total of 97,982 subjects completed follow-up. 12,371 incidents of hypertension and 2034 of diabetes occurred. In the multi-covariates model, the hazard ratios (HR) and 95% confidence interval (CI) were 1.49 (1.45-1.52), 1.28 (1.26-1.30), 1.17 (1.15-1.18), 1.21 (1.17-1.25) and 1.33 (1.31-1.35) for hypertension morbidity per 10 μg/m³ increment in PM₁, PM_2.5, PM₁₀, NO₂ and SO₂, respectively. For diabetes onsets, the HR (95% CI) were 1.17 (1.11-1.23), 1.09 (1.04-1.13), 1.06 (1.02-1.09), 1.02 (0.95-1.10), and 1.24 (1.19-1.29), respectively. In addition, for hypertension analyses, the effect estimates were more pronounced in the participants with age <60 years old, BMI ≥24 kg/m², and frequent alcohol drinking. These findings provided the evidence on elevated risks of morbidity of hypertension and diabetes associated with prolonged ambient pollutants exposure at relatively high levels.

High-normal blood pressure (prehypertension) is associated with PM2.5 exposure in young adults

We aimed to examine PM_2.5 exposure, blood pressure (SBP and DBP) measurement, and hypertension risk factors and to assess the association between PM_2.5 exposure and hypertension among young adults. The mean SBP was 117.78 mmHg, with 11.22% high-normal blood pressure (prehypertension) and 2.51% hypertension (≥ 140 mmHg). DBP was 75.48 mmHg with 26.37% prehypertension and 4.53% hypertension (≥ 90 mmHg). The median PM_2.5 in the past year was 31.79 μg/m³, with highest in winter (49.33 μg/m³), followed by spring (37.34 μg/m³), autumn (29.64 μg/m³), and summer (24.33 μg/m³). Blood pressure was positively correlated with age, height, weight, BMI, daily smoking, alcohol consumption, mental stress, and staying up in the past 1 year, and negatively with season-specific temperature. After adjustment for the covariates, each 10 μg/m³ increase in PM_2.5 was associated with SBP (day 1 = 1.07 mmHg, day 3 = 1.25 mmHg, day 5 = 1.01 mmHg) and DBP (day 1 = 1.06 mmHg, day 3 = 1.28 mmHg, day 5 = 1.29 mmHg, day 15 = 0.87 mmHg, day 30 = 0.56 mmHg). Exposure in winter and the past year was associated with 1.21 mmHg and 0.95 increase mmHg in SBP, respectively. Logistic models showed for every 1 μg/m³ increase of PM_2.5, SBP in day 1 and day 5 was increased by 6% and 4%, and DPB by 3% and 16%, respectively. SBP was increased by 8% in spring and 19% in winter, and DBP was increased by 7% in winter. Our data suggest a certain prevalence of pre- or hypertension among young population, which is associated with short-term fluctuation and season-specific exposure of PM_2.5.

Interaction between plant-based dietary pattern and air pollution on cognitive function: a prospective cohort analysis of Chinese older adults

BACKGROUND

Air pollution is a risk factor for poor cognitive function, while a plant-based dietary pattern is associated with better cognitive function. We aimed to explore their interaction with cognitive function among older adults.

METHODS

We used a prospective cohort of old individuals, including 6525 participants of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), aged 65-110 years and with normal cognition at baseline. Air pollution measurement was derived using satellite-derived annual average fine particulate matter (PM2.5) concentrations based on residential locations. Plant-based diet index (PDI) was calculated using survey responses to assess the dietary pattern. Repeated measures of the Mini-Mental State Examination (MMSE) were utilized to assess cognitive function. We applied the Cox proportional hazard regression to explore the associations and further stratified the analysis by PDI.

FINDINGS

During a median of 5·6-year follow-up, 1537 (23·6%) out of 6525 participants with normal cognition at baseline developed poor cognitive function (MMSE <18). Living in areas with the highest quintile of cumulative PM2.5 was associated with a 46% increase in the risk of developing poor cognitive function (hazard ratio (HR): 1·46, 95% confidence interval (CI): 1·20, 1·77), compared to those living in areas with the lowest quintile. We observed a significant interaction between cumulative PM2.5 and PDI (p-interaction: 0·04), with the corresponding associations of cumulative PM2.5 being more pronounced among participants with lower PDI (HR: 1·68, 95% CI: 1·26, 2·24) than those with higher PDI (HR: 1·28, 95% CI: 0·98, 1·68).

INTERPRETATION

Plant-based dietary pattern may attenuate detrimental impacts of PM2.5 on cognitive function among older adults. Adherence to the plant-based dietary pattern could be used to prevent adverse neurological effects caused by air pollution, especially in developing regions.

The impact of PM2.5 on children's blood pressure growth curves: A prospective cohort study

OBJECTIVE

The aim of this study was to explore the association between exposure to particulate matter with an aerodynamic diameter of 2.5 mm or less (PM2.5) and blood pressure (BP) levels in children and adolescents and to illustrate the impact of PM2.5 levels on BP growth curves in a cohort study.

METHODS

A longitudinal study was designed and included 4303 children (7617 BP measurements) living in the selected areas, and evaluations were conducted in 2014-2015 (visit 1) and followed up in 2019 (visit 2). Two-stage stratified cluster sampling was used to include urban-rural areas. A mixed linear regression model and mixed logistic regression model were used to analyze the effect of PM2.5 exposure on BP and the incidence of prehypertension and hypertension in children.

RESULTS

After adjusting for covariates, systolic blood pressure (SBP) (2.21 (95% CIs: 0. 81, 3.62), mmHg), diastolic blood pressure (DBP) (1.92 (95% CIs: 0.74, 3.11), mmHg), mean arterial pressure (MAP) (2.03 (95% CIs: 0.89, 3.17), mmHg) and heart rate (HR) (2.24 (95% CIs: 0.11, 4.37), beats/min) increased significantly in the fourth quartile of PM2.5 exposure levels compared with the first quartile (all P < 0.01). In addition, long-term exposure to PM2.5 was significantly positively correlated with SBP, DBP and MAP, and the effect was more notable in urban areas than that in rural areas. Moreover, the risk of prehypertension and hypertension incidence increased by 1.17 (95% CIs: 1.03, 1.33) fold with a one-quartile increase in PM2.5 exposure. The long-term effects of annual mean PM2.5 exposure on SBP, DBP and MAP were significant from pregnancy to 7, 3 and 4 years of age, respectively.

CONCLUSION

Long-term exposure to PM2.5 was positively associated with growth curves of hemodynamics indexed from pregnancy to childhood and adolescence, and the effect was more significant in urban areas than in rural areas.

The impact of particulate matter 2.5 on the risk of hepatocellular carcinoma: a meta-analysis

OBJECTIVE

The convoluted element of PM2.5 may cause various biological reactions. Nowadays, few studies have indicated the long-term health effects of PM2.5 on HCC. Therefore, this meta-analysis first aims to obtain more precise estimates of the effects of PM2.5 exposure on HCC to assess the strength of the evidence.

METHODS

A combination of computer and manual retrieval was used to search in Medline through PubMed, EMBASE and Web of Science. Review Manager 5.3 software was used to examine the heterogeneity among the studies.

RESULTS

Finally, 8 qualified articles meet the inclusion criteria. The results were I² = 0%, P > 0.1 indicating that there was no heterogeneity. The results showed that the concentration of PM2.5 increased by 10 μg/m³ was significantly correlated with liver cancer, and HR was 1.22 (95% CI 1.14-1.30, P < 0.05), indicating that maternal exposure to PM2.5 was positively correlated with liver cancer.

CONCLUSIONS

Our meta-analysis showed that the patients with HCC significance related to PM2.5 exposure. However, more studies investigating the combined effects of different air pollutants on HCC incidence are warranted to provide more comprehensive evidence for assessing the different levels impacts of PM2.5 exposure on HCC incidence.

Associations between ambient air pollutants and blood pressure among children and adolescents: A systemic review and meta-analysis

OBJECTIVE

Numerous epidemiological studies have investigated the effects of short-term and long-term exposure to ambient air pollution on hypertension and blood pressure among children and adolescents. However, the results were controversial. To provide researchers reliable evidence, this meta-analysis was performed.

METHODS

We searched all published studies in four databases examining the effects of particulate matter (PM₁₀, PM_2.5 and PM_1.0), nitrogen oxide (NO₂), sulfur dioxide (SO₂), ozone (O₃) and carbon monoxide (CO) on hypertension and blood pressure in children and adolescents. Overall risk estimates associated with per 10 μg/m³ increase of air pollution were analyzed by a random-effect model for articles with significant heterogeneity, otherwise, a fixed-effect model was applied. Subgroup analysis was conducted for studies with significant heterogeneity.

RESULTS

Of 3918 identified literatures, 154 were evaluated in-depth with 15 satisfying inclusion criteria. Increased risk of hypertension was associated with long-term PM₁₀ exposure (OR = 1.17, 95% confidence interval [CI]:1.13, 1.21). For systolic blood pressure (SBP), significant results were found for short-term PM₁₀ (β = 0.26, 95% CI: -0.00, 0.53) exposure, long-term PM_2.5 (β = 1.80, 95% CI: 0.94, 2.65) and PM₁₀ (β = 0.50, 95% CI: 0.19, 0.81) exposure. The corresponding estimates of diastolic blood pressure (DBP) were 0.32 mmHg (95% CI: 0.19, 0.45) for short-term PM₁₀ exposure, 1.06 mmHg (95% CI: 0.32, 1.80), 0.34 mmHg (95% CI: 0.11, 0.57) and 0.44 mmHg (95% CI: 0.25, 0.63) for long-term PM_2.5, PM₁₀ and NO₂ exposure, respectively. Stratified analyses showed stronger effects of PM₁₀ on blood pressure among studies with ≥50% boys' percentage (0.57 mmHg [95% CI: 0.44, 0.70] for SBP, 0.44 mmHg, [95% CI: 0.34, 0.54] for DBP, respectively) and articles using models to estimate exposure (0.90 mmHg [95% CI: 0.20 1.59] for SBP).

CONCLUSION

Ambient air pollution was associated with higher hypertension prevalence and elevated blood pressure in children and adolescents.

Association of personal fine particulate matter and its respiratory tract depositions with blood pressure in children: From two panel studies

Evidence is limited regarding the acute effects of personal fine particulate matter (PM_2.5) exposure and its respiratory tract depositions on the alteration of children's blood pressure (BP). We conducted 2 longitudinal panel studies in 2 cities to evaluate the relations of 72-h real-time personal PM_2.5 exposure and its depositions in 3 respiratory tract regions over different lag times with BP and the risk of prehypertension and hypertension among 286 children aged 4-12 years. We found the strongest effects of PM_2.5 exposure on increased BP and risk of prehypertension and hypertension at lag 2 day, in dose-response manner, even when PM_2.5 below Chinese Ambient Air Quality Standard (CAAQS) Grade II. Moreover, compared to PM_2.5, tracheobronchial and alveolar depositions displayed more evident effects on BP outcomes. Interestingly, all above relationships were stronger among children in Guangzhou with lower PM_2.5 and its deposited doses than those in Weinan. Additionally, boys and those with daily extra-school activity ≥ 1 h were more susceptible to PM_2.5-induced BP effects with significant interactions. Our results highlighted that short-term PM_2.5 exposure and its respiratory tract depositions were dose-responsive related to higher BP, prevalence of prehypertension and hypertension among children, even when PM_2.5 below CAAQS II.

Ambient Particulate Matter Induces Vascular Smooth Muscle Cell Phenotypic Changes via NOX1/ROS/NF-κB Dependent and Independent Pathways: Protective Effects of Polyphenols

Epidemiological studies have demonstrated an association between ambient particulate matter (PM) exposure and vascular diseases. Here, we observed that treatment with ambient PM increased cell migration ability in vascular smooth muscle cells (VSMCs) and pulmonary arterial SMCs (PASMCs). These results suggest that VSMCs and PASMCs transitioned from a differentiated to a synthetic phenotype after PM exposure. Furthermore, treatment with PM increased intracellular reactive oxygen species (ROS), activated the NF-κB signaling pathway, and increased the expression of proinflammatory cytokines in VSMCs. Using specific inhibitors, we demonstrated that PM increased the migration ability of VSMCs via the nicotinamide–adenine dinucleotide phosphate (NADPH) oxidase 1 (NOX1)/ROS-dependent NF-κB signaling pathway, which also partially involved in the induction of proinflammatory cytokines. Finally, we investigated whether nature polyphenolic compounds prevent PM-induced migration and proinflammatory cytokines secretion in VSMCs. Curcumin, resveratrol, and gallic acid prevented PM_2.5-induced migration via the ROS-dependent NF-κB signaling pathway. However, honokiol did not prevent PM_2.5-induced migration or activation of the ROS-dependent NF-κB signaling pathway. On the other hand, all polyphenols prevented PM_2.5-induced cytokines secretion. These data indicated that polyphenols prevented PM-induced migration and cytokine secretion via blocking the ROS-dependent NF-κB signaling pathway in VSMCs. However, other mechanisms may also contribute to PM-induced cytokine secretion.

Effects of Ambient Air Pollution on Blood Pressure Among Children and Adolescents: A Systematic Review and Meta-Analysis

Background

Previous studies have investigated the association of ambient air pollution with blood pressure (BP) in children and adolescents, however, the results are not consistent. We conducted a systematic review and meta‐analysis to assess the relationship between short‐term and long‐term ambient air pollutant exposure with BP values among children and adolescents.

Methods and Results

We searched PubMed, Web of Science, and Embase before September 6, 2020. Two reviewers independently searched and selected studies, extracted data, and assessed study quality. The studies were divided into groups by composition of air pollutants (NO₂, particulate matter (PM) with diameter ≤10 μm or ≤2.5 μm) and length of exposure. The beta regression coefficients (β) and their 95% CIs were calculated to evaluate the strength of the effect with each 10 μg/m³ increase in air pollutants. Out of 36 650 articles, 14 articles were included in this meta‐analysis. The meta‐analysis showed short‐term exposure to PM with diameter ≤10 μm (β=0.267; 95% CI, 0.033‒0.501) was significantly associated with elevated systolic BP values. In addition, long‐term exposure to PM with diameter ≤2.5 μm (β=1.809; 95% CI, 0.962‒2.655), PM with diameter ≤10 μm (β=0.526; 95% CI, 0.095‒0.958), and NO₂ (β=0.754; 95% CI, 0.541‒0.968) were associated with systolic BP values and long‐term exposure to PM with diameter ≤2.5 μm (β=0.931; 95% CI, 0.157‒1.705), and PM with diameter ≤10 μm (β=0.378; 95% CI, 0.022‒0.735) was associated with diastolic BP.

Conclusions

Our study indicates that both short‐term and long‐term exposure to some ambient air pollutants may increase BP values among children and adolescents.