Ageing at the level of telomeres in association to residential landscape and air pollution at home and work: a review of the current evidence

Lifetime losses due to cardiovascular and respiratory diseases attributable to air pollution in polluted and unpolluted areas

The article assesses differences in lifetime losses caused by premature deaths from cardiopulmonary disease in populations living in areas with different environmental burdens. The results provide different perspectives on data on total years lost and lifetime losses attributable to air pollution. Such lifetime losses in the industrial area related to cardiovascular causes of death are 7.6 or 5.1 years per male or female deceased, representing an average lifetime loss of 0.01907 years (i.e. 7 days) per 1 male or 0.01273 years (i.e. 4.6 days) per 1 female in the entire population. Losses related to cerebrovascular or respiratory causes of death are about 5.4 or 5.9 years per 1 deceased male or 3.9 or 5 years per 1 deceased female, respectively, which represents a loss of 0.00481 (1.8 days), or 0.00148 years (0.5 days) per 1 male or 0.00466 (1.7 days), or 0.00058 years (0.2 days) per 1 female.

Early Environment and Telomeres: a Long-Term Toxic Relationship

PURPOSE OF REVIEW

Telomere length (TL) shortening is a hallmark of biological aging. While studies have extensively focused on the impact of environmental exposures on TL in older populations, consistent evidence indicates that prenatal environmental exposures to air pollutants, polycyclic aromatic hydrocarbons, metals, and endocrine-disrupting chemicals influence TL shortening. Here, we summarize evidence linking prenatal environmental exposures with children's TL and discuss potential long-term effects.

RECENT FINDINGS

Current evidence shows that prenatal environmental exposures alter TL and identify pregnancy as a critical window of susceptibility for telomere damage in children. However, results vary across studies, possibly depending on the source, exposure time window, and stage evaluated. Additional research is needed to investigate whether early TL alterations mediate long-term health effects of offspring. Prenatal environmental exposures induce early childhood changes in TL. Based on known links between TL and biological aging, these alterations may have long-term impact on individuals' health throughout life.

The regulatory feedback of inflammatory signaling and telomere/telomerase complex dysfunction in chronic inflammatory diseases

Inflammation is believed to play a role in the progression of numerous human diseases. Research has shown that inflammation and telomeres are involved in a feedback regulatory loop: inflammation increases the rate of telomere attrition, leading to telomere dysfunction, while telomere components also participate in regulating the inflammatory response. However, the specific mechanism behind this feedback loop between inflammatory signaling and telomere/telomerase complex dysfunction has yet to be fully understood. This review presents the latest findings on this topic, with a particular focus on the detailed regulation and molecular mechanisms involved in the progression of aging, various chronic inflammatory diseases, cancers, and different stressors. Several feedback loops between inflammatory signaling and telomere/telomerase complex dysfunction, including NF-κB-TERT feedback, NF-κB-RAP1 feedback, NF-κB-TERC feedback, STAT3-TERT feedback, and p38 MAPK-shelterin complex-related gene feedback, are summarized. Understanding the latest discoveries of this feedback regulatory loop can help identify novel potential drug targets for the suppression of various inflammation-associated diseases.

Telomere Length: A Cardiovascular Biomarker and a Novel Therapeutic Target

Coronary artery disease (CAD) is a multifactorial disease with a high prevalence, particularly in developing countries. Currently, the investigation of telomeres as a potential tool for the early detection of the atherosclerotic disease seems to be a promising method. Telomeres are repetitive DNA sequences located at the extremities of chromosomes that maintain genetic stability. Telomere length (TL) has been associated with several human disorders and diseases while its attrition rate varies significantly in the population. The rate of TL shortening ranges between 20 and 50 bp and is affected by factors such as the end-replication phenomenon, oxidative stress, and other DNA-damaging agents. In this review, we delve not only into the pathophysiology of TL shortening but also into its association with cardiovascular disease and the progression of atherosclerosis. We also provide current and future treatment options based on TL and telomerase function, trying to highlight the importance of these cutting-edge developments and their clinical relevance.

Neighborhood environment and socioeconomic inequalities in cancer admissions: a prospective study using UK Biobank and linked hospital records

PURPOSE

Neighborhood environments may influence cancer risk. Average population effect estimates might mask differential effects by socioeconomic position. Improving neighborhood environments could inadvertently widen health inequalities if important differences are overlooked.

METHODS

Using linked records of hospital admissions in UK Biobank, we assessed associations between admission with a primary diagnosis of cancer (any/breast/colorectal), and exposure to neighborhood greenspace, physical activity facilities, and takeaway food stores, and whether household income and area deprivation modify these associations. We used adjusted Cox proportional hazards models, and estimated relative excess risks due to interaction (RERI) to assess effect modification.

RESULTS

Associations between neighborhood exposures and cancer-related hospitalizations were weak to null overall, but with some evidence of effect modification. Most notably, more greenspace near home was associated with 16% lower hazard of cancer-related hospital admission in deprived areas (95% CI 2-29%). This was further pronounced for people in low-income households in deprived areas, and for breast cancer.

CONCLUSION

In deprived neighborhoods, increasing the amount of greenspace may help reduce cancer-related hospitalizations. Examining effect modification by multiple socioeconomic indicators can yield greater insight into how social and environmental factors interact to influence cancer incidence. This may help avoid perpetuating cancer inequalities when designing neighborhood environment interventions.

Adverse associations of long-term exposure to ambient ozone with molecular biomarkers of aging alleviated by residential greenness in rural Chinese adults

BACKGROUND

Both ambient ozone exposure and residential greenness are linked to the aging process. However, their interactive effect on molecular biomarkers of aging (telomere length (TL) and mitochondrial DNA copy number (mtDNA-CN)) remains unclear.

METHODS

This study was conducted among 6418 rural Chinese adults. The concentration of ambient ozone was assessed using a random forest model. Residential greenness was represented by the normalized difference vegetation index (NDVI). Molecular biomarkers of aging (relative TL and relative mtDNA-CN) were determined by quantitative real-time polymerase chain reaction. Generalized linear regression models were applied to investigate the independent and combined effects of ambient ozone and residential greenness on relative TL and relative mtDNA-CN.

RESULTS

The estimated percent changes and 95 % confidence intervals (CIs) of relative TL in response to per-unit increase in ambient ozone were -22.43 % (-23.74 %, -21.18 %), -14.19 % (-15.63 %, -12.72 %) and -4.50 % (-6.57 %, -2.27 %) for participants with low (NDVI ≤ 0.53), moderate (0.54-0.55) and high (≥0.56) residential greenness exposure, respectively, while the corresponding figures of relative mtDNA-CN were -12.63 % (-13.84 %, -11.31 %), -9.52 % (-10.60 %, -8.33 %) and 2.12 % (0.20 %, 4.19 %). Furthermore, negative interactive effects between ambient ozone and residential greenness exposure on molecular biomarkers of aging were observed (P_{for interaction} < 0.001 for relative TL, and 0.098 for relative mtDNA-CN).

CONCLUSIONS

Long-term exposure to high concentrations of ambient ozone and low residential greenness was associated with decreased mtDNA-CN and shortened TL. The adverse effect of ambient ozone exposure on molecular biomarkers of aging may be attenuated by increased residential greenness.

A multi-exposure approach to study telomere dynamics in childhood: A role for residential green space and waist circumference

BACKGROUND

Telomeres are vulnerable to various environmental exposures and lifestyle factors, encompassed in the exposome. Recent research shows that telomere length is substantially determined early in life and that exposures in childhood may have important consequences in setting later life telomere length.

OBJECTIVES

We explore in a child population the associations of 17 exposures with telomere length and longitudinal telomere change.

METHODS

Children (2.8-10.3y at baseline, 51.3% boys) were followed-up for five to seven years. Relative telomere length was measured at baseline and follow-up using quantitative real-time PCR. Exposures and lifestyle factors included: body composition (body mass index and waist circumference), dietary habits (sugar- and fat-rich food intake, vegetables and fruit intake), psychosocial stress (events, emotions, behaviour), sleep duration, physical activity, and residential environmental quality (longterm black carbon, particulate matter exposure, and residential green space). Cross-sectional (n=182) and longitudinal (n=150) analyses were assessed using linear regression models, adjusting for age, sex, socioeconomic status and multiple testing.

RESULTS

Our longitudinal analyses showed that higher residential green space at baseline was associated with (β=0.261, p=0.002) lower telomere attrition and that children with a higher waist circumference at baseline showed a higher telomere attrition (β=-0.287, p=0.001). These two predictors were confirmed via LASSO variable selection and correction for multiple testing. In addition, children with more unhealthy exposures at baseline had a significantly higher telomere attrition over the follow-up period compared to children with more healthy exposures (β=-0.200, p=0.017).

DISCUSSION

Waist circumference and residential green space were identified as predictors associated with telomere attrition in childhood. These results further support the advantages of a healthy lifestyle from early age onwards and the importance of a green environment to promote molecular longevity from childhood onwards.

Oxidative stress, aging, antioxidant supplementation and their impact on human health: An overview

Aging is characterized by a progressive loss of tissue and organ function due to genetic and environmental factors, nutrition, and lifestyle. Oxidative stress is one the most important mechanisms of cellular senescence and increased frailty, resulting in several age-linked, noncommunicable diseases. Contributing events include genomic instability, telomere shortening, epigenetic mechanisms, reduced proteome homeostasis, altered stem-cell function, defective intercellular communication, progressive deregulation of nutrient sensing, mitochondrial dysfunction, and metabolic unbalance. These complex events and their interplay can be modulated by dietary habits and the ageing process, acting as potential measures of primary and secondary prevention. Promising nutritional approaches include the Mediterranean diet, the intake of dietary antioxidants, and the restriction of caloric intake. A comprehensive understanding of the ageing processes should promote new biomarkers of risk or diagnosis, but also beneficial treatments oriented to increase lifespan.

A Comprehensive Overview of the Complex Role of Oxidative Stress in Aging, The Contributing Environmental Stressors and Emerging Antioxidant Therapeutic Interventions

Introduction

Aging is a normal, inevitable, irreversible, and progressive process which is driven by internal and external factors. Oxidative stress, that is the imbalance between prooxidant and antioxidant molecules favoring the first, plays a key role in the pathophysiology of aging and comprises one of the molecular mechanisms underlying age-related diseases. However, the oxidative stress theory of aging has not been successfully proven in all animal models studying lifespan, meaning that altering oxidative stress/antioxidant defense systems did not always lead to a prolonged lifespan, as expected. On the other hand, animal models of age-related pathological phenotypes showed a well-correlated relationship with the levels of prooxidant molecules. Therefore, it seems that oxidative stress plays a more complicated role than the one once believed and this role might be affected by the environment of each organism. Environmental factors such as UV radiation, air pollution, and an unbalanced diet, have also been implicated in the pathophysiology of aging and seem to initiate this process more rapidly and even at younger ages.

Aim

The purpose of this review is to elucidate the role of oxidative stress in the physiology of aging and the effect of certain environmental factors in initiating and sustaining this process. Understanding the pathophysiology of aging will contribute to the development of strategies to postpone this phenomenon. In addition, recent studies investigating ways to alter the antioxidant defense mechanisms in order to prevent aging will be presented.

Conclusions

Careful exposure to harmful environmental factors and the use of antioxidant supplements could potentially affect the biological processes driving aging and slow down the development of age-related diseases. Maybe a prolonged lifespan could not be achieved by this strategy alone, but a longer healthspan could also be a favorable target.

Multisite greenness exposure and oxidative stress in children. The potential mediating role of physical activity

Residential greenness exposure has been reported to positively impact health mainly by reducing overweight/obesity risk, improving mental health and physical activity. Less is known on biological pathways involved in these health benefits. We aimed to investigate the association between multisite greenness exposure and oxidative stress in children and explore the potential mediating role of physical activity in this association. This cross-sectional study involved 323 healthy subjects (8-11 y) from five schools in Asti (Italy). Children's parents filled a questionnaire providing the residential address, parental education, and physical activity frequency. Oxidative stress was quantified in spot urine by isoprostane (15-F_2t-IsoP) using ELISA technique. Residential and scholastic greenness were defined by the Normalized Difference Vegetation Index (NDVI) in buffers with 100, 250, 300, 500 and 1000 m radii, and vegetated portion was also estimated. Multisite exposures were derived accounting for NDVI around home and school, weighted for time spent in each location. Linear mixed models, age-adjusted, with schools as random intercept, tested the association between 500 m-radius buffer multisite grenness variables and log (15-F_2t-IsoP), reporting decreased oxidative stress per interquartile range (IQR) increase in multisite NDVI (β: 012, 95%CI -0.240 to 0.004) and multisite vegetated portion (β: 0.14, 95%CI -0.270 to -0.006). The mediation analysis did not support the hypothesis that physical activity frequency could mediate these associations. Multisite greenness exposure is associated with decreased oxidative stress in children and our data did not support the mediating role of physical activity.

Telomere Shortening and Its Association with Cell Dysfunction in Lung Diseases

Telomeres are localized at the end of chromosomes to provide genome stability; however, the telomere length tends to be shortened with each cell division inducing a progressive telomere shortening (TS). In addition to age, other factors, such as exposure to pollutants, diet, stress, and disruptions in the shelterin protein complex or genes associated with telomerase induce TS. This phenomenon favors cellular senescence and genotoxic stress, which increases the risk of the development and progression of lung diseases such as idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, SARS-CoV-2 infection, and lung cancer. In an infectious environment, immune cells that exhibit TS are associated with severe lymphopenia and death, whereas in a noninfectious context, naïve T cells that exhibit TS are related to cancer progression and enhanced inflammatory processes. In this review, we discuss how TS modifies the function of the immune system cells, making them inefficient in maintaining homeostasis in the lung. Finally, we discuss the advances in drug and gene therapy for lung diseases where TS could be used as a target for future treatments.

Inorganic elements in occupational settings: A review on the effects on telomere length and biology

The past decades have shown that telomere crisis is highly affected by external factors. Effects of human exposure to xenobiotics on telomere length (TL), particularly in their workplace, have been largely studied. TL has been shown to be an efficient biomarker in occupational risk assessment. This is the first review focusing on studies about the effects on TL from occupational exposures to metals (lead [Pb] and mixtures), and particulate matter (PM) related to inorganic elements. Data from 15 studies were evaluated regarding occupational exposure to metals and PM-associated inorganic elements and impact on TL. Potential complementary analyses and subjects' background (age, length of employment and gender) were also assessed. There was limited information on the correlations between work length and TL dynamics, and that was also true for the correlation between age and TL. Results indicated that TL is affected differently across the types of occupational exposure investigated in this review, and even within the same exposure, a variety of effects can be observed. Fifty-three percent of the studies observed decreased TL in occupational exposure among welding fumes, open-cast coal mine, Pb and PM industries workers. Two studies focused particularly on the levels of metals and association with TL, and both linear and non-linear associations were found. Interestingly, TL modifications were accompanied by increase in DNA damage in 7 out of 8 studies that investigated it, measured either by Cytokinesis-block Micronucleus Assay or Comet assay. Five studies also investigated oxidative stress parameters, and 4 of them found increased levels of oxidative damage along with TL impairment. Oxidative stress is one of the main mechanisms by which telomeres are affected due to their high guanine content. Our review highlights the need of further studies accessing TL in simultaneous occupational exposure to mixtures of xenobiotics.

Rethinking the urban physical environment for century-long lives: from age-friendly to longevity-ready cities

In response to increasing life expectancies and urbanization, initiatives for age-friendly cities seek to facilitate active and healthy aging by strengthening supports and services for older people. While laudable, these efforts typically neglect early-life exposures that influence long-term well-being. With a focus on the urban physical environment, we argue that longevity-ready cities can accomplish more than initiatives focused solely on old age. We review features of cities that cumulatively influence healthy aging and longevity, discuss the need for proactive interventions in a changing climate, and highlight inequities in the ambient physical environment, especially those encountered at early ages, that powerfully contribute to disparities in later life stages. Compared with strategies aimed largely at accommodating older populations, longevity-ready cities would aim to reduce the sources of disadvantages across the life course and simultaneously improve the well-being of older people.

Meta-analyses of maternal exposure to atmospheric particulate matter and risk of congenital anomalies in offspring

Congenital anomalies are the main causes of infant death and disability. Previous studies have suggested that maternal exposure to particulate matter is related to congenital malformation. However, the conclusions of this study remain controversial. Hence, meta-analyses were performed to assess the relationship between maternal exposure to particulate matter and the risk of congenital anomalies. The Medline, Embase, and Web of Science databases were systemically searched from inception until August 2020 to find articles related to birth defects and particulate matter. The pooled risk estimated for the combination of pollution outcomes was calculated for each study by performing fixed effects or random effects models. The existence of heterogeneity and publication bias in relevant studies was also examined. Thirty studies were included in the analysis. A statistically increased summary risk valuation was found. PM₁₀ exposure was associated with an increased risk of congenital heart disease, neural tube defects, and cleft lip with or without cleft palate (OR per 10 μg/m³ = 1.05, 95% CI, 1.03-1.07; OR per 10 μg/m³ = 1.04, 95% CI, 1.01-1.06; OR per 10 μg/m³ = 1.03, 95% CI, 1.01-1.06). Maternal exposure to particulate matter might be associated with an increased risk of congenital anomalies. Our results indicate the dangers of particulate matter exposure on fetal development and the importance of protection against exposure to such particles during pregnancy. The schematic representation of the association between maternal exposure to PM_2.5/PM₁₀ and congenital anomalies in offspring, and geographic distribution of the included reports in the meta-analyses.

Different epigenetic signatures of newborn telomere length and telomere attrition rate in early life

Telomere length (TL) and telomere shortening are biological indicators of aging, and epigenetic associates have been found for TL in adults. However, the role of epigenetic signatures in setting newborn TL and early life telomere dynamics is unknown. In the present study, based on 247 participating newborns from the ENVIRONAGE birth cohort, whole-genome DNA methylation, profiled on the Illumina MethylationEPIC BeadChip microarray, and TL were measured in cord blood. In a follow-up visit at a mean age of 4.58 years, leukocyte TL was evaluated. We combined an epigenome-wide association study and a statistical learning method with re-sampling to select CpGs and their two-way interactions to model baseline (cord blood) TL and early-life telomere attrition rate, where distinct epigenetic signatures were identified for the two outcomes. In addition, a stronger epigenetic regulation was suggested in setting newborn TL than that of telomere dynamics in early life: 47 CpGs and 7 between-CpG interactions explained 76% of the variance in baseline TLs, while 72% of the total variance in telomere attrition rate was explained by 31 CpGs and 5 interactions. Functional enrichment analysis based on the selected CpGs in the two models revealed GLUT4 translocation and immune cell signaling pathways, respectively. These CpGs and interactions, as well as the cellular pathways, are potential novel targets of further investigation of telomere biology and aging.

Residing in urban areas with higher green space is associated with lower mortality risk: A census-based cohort study with ten years of follow-up

BACKGROUND

Epidemiological studies suggest that residing close to green space reduce mortality rates. We investigated the relationship between long-term exposure to residential green space and non-accidental and cardio-respiratory mortality.

METHODS

We linked the Belgian 2001 census to population and mortality register follow-up data (2001-2011) among adults aged 30 years and older residing in the five largest urban areas in Belgium (n = 2,185,170 and mean follow-up time 9.4 years). Residential addresses were available at baseline. Exposure to green space was defined as 1) surrounding greenness (2006) [normalized difference vegetation index (NDVI) and modified soil-adjusted vegetation index (MSAVI2)] within buffers of 300 m, 500 m, and 1000 m; 2) surrounding green space (2006) [Urban Atlas (UA) and CORINE Land Cover (CLC)] within buffers of 300 m, 500 m, and 1000 m; and 3) perceived neighborhood green space (2001). Cox proportional hazards models with age as the underlying time scale were used to probe into cause-specific mortality (non-accidental, respiratory, COPD, cardiovascular, ischemic heart disease (IHD), and cerebrovascular). Models were adjusted for several sociodemographic variables (age, sex, marital status, country of birth, education level, employment status, and area mean income). We further adjusted our main models for annual mean (2010) values of ambient air pollution (PM_2.5, PM₁₀, NO₂ and BC, one at a time), and we additionally explored potential mediation with the aforementioned pollutants.

RESULTS

Higher degrees of residential green space were associated with lower rates of non-accidental and respiratory mortality. In fully adjusted models, hazard ratios (HR) per interquartile range (IQR) increase in NDVI 500 m buffer (IQR: 0.24) and UA 500 m buffer (IQR: 0.31) were 0.97 (95%CI 0.96-0.98) and 0.99 (95%CI 0.98-0.99) for non-accidental mortality, and 0.95 (95%CI 0.93-0.98) and 0.97 (95%CI 0.96-0.99) for respiratory mortality. For perceived neighborhood green space, HRs were 0.93 (95%CI 0.92-0.94) and 0.94 (95%CI 0.91-0.98) for non-accidental and respiratory mortality, respectively. The observed lower mortality risks associated with residential exposure to green space were largely independent from exposure to ambient air pollutants.

CONCLUSION

We observed evidence for lower mortality risk in associations with long-term residential exposure to green space in most but not all studied causes of death in a large representative cohort for the five largest urban areas in Belgium. These findings support the importance of the availability of residential green space in urban areas.

Exposure to ambient air pollution in the first 1000 days of life and alterations in the DNA methylome and telomere length in children: A systematic review

BACKGROUND

Exposure to air pollution during the first 1000 days of life (from conception to the 2nd year of life) might be of particular relevance for long-term child health. Changes in molecular markers such as DNA methylation and telomere length could underlie the association between air pollution exposure and pollution-related diseases as well as serve as biomarkers for past exposure. The objective of this systematic review was to assess the association between air pollution exposure during pregnancy and the first two years of life and changes in DNA methylation or telomere length in children.

METHODS

PubMed was searched in October 2020 by using terms relative to ambient air pollution exposure, DNA methylation, telomere length and the population of interest: mother/child dyads and children. Screening and selection of the articles was completed independently by two reviewers. Thirty-two articles matched our criteria. The majority of the articles focused on gestational air pollution exposure and measured DNA methylation/telomere length in newborn cord blood or placental tissue, to study global, candidate-gene or epigenome-wide methylation patterns and/or telomere length. The number of studies in children was limited.

RESULTS

Ambient air pollution exposure during pregnancy was associated with global loss of methylation in newborn cord blood and placenta, indicating the beginning of the pregnancy as a potential period of susceptibility. Candidate gene and epigenome-wide association studies provided evidence that gestational exposure to air pollutants can lead to locus-specific changes in methylation, in newborn cord blood and placenta, particularly in genes involved in cellular responses to oxidative stress, mitochondrial function, inflammation, growth and early life development. Telomere length shortening in newborns and children was seen in relation to gestational pollutant exposure.

CONCLUSIONS

Ambient air pollution during pregnancy is associated with changes in both global and locus-specific DNA methylation and with telomere length shortening. Future studies need to test the robustness of the association across different populations, to explore potential windows of vulnerability and assess the role of the methylation and telomere length as mediators in the association between early exposure to ambient air pollutants and specific childhood health outcomes.

Cardiovascular effects of air pollution: current evidence from animal and human studies

Air pollution is a global health concern. Particulate matter (PM)_2.5, a component of ambient air pollution, has been identified by the World Health Organization as one of the pollutants that poses the greatest threat to public health. Cardiovascular health effects have been extensively documented, and these effects are still being researched to provide an overview of recent literature regarding air pollution-associated cardiovascular morbidity and mortality in humans. Additionally, potential mechanisms through which air pollutants affect the cardiovascular system are discussed based on human and additional animal studies. We used the strategy of a narrative review to summarize the scientific literature of studies that were published in the past 7 yr. Searches were carried out on PubMed and Web of Science using predefined search queries. We obtained an initial set of 800 publications that were filtered to 78 publications that were relevant to include in this review. Analysis of the literature showed significant associations between air pollution, especially PM_2.5, and the risk of elevated blood pressure (BP), acute coronary syndrome, myocardial infarction (MI), cardiac arrhythmia, and heart failure (HF). Prominent mechanisms that underlie the adverse effects of air pollution include oxidative stress, systemic inflammation, endothelial dysfunction, autonomic imbalance, and thrombogenicity. The current review underscores the relevance of air pollution as a global health concern that affects cardiovascular health. More rigorous standards are needed to reduce the cardiovascular disease burden imposed by air pollution. Continued research on the health impact of air pollution is needed to provide further insight.

Long-term exposure to particulate matter and roadway proximity with age at natural menopause in the Nurses' Health Study II Cohort

Evidence has shown associations between air pollution and traffic-related exposure with accelerated aging, but no study to date has linked the exposure with age at natural menopause, an important indicator of reproductive aging. In this study, we sought to examine the associations of residential exposure to ambient particulate matter (PM) and distance to major roadways with age at natural menopause in the Nurses' Health Study II (NHS II), a large, prospective female cohort in US. A total of 105,996 premenopausal participants in NHS II were included at age 40 and followed through 2015. Time-varying residential exposures to PM10, PM2.5-10, and PM2.5 and distance to roads was estimated. We calculated hazard ratios (HR) and 95% confidence intervals (CIs) for natural menopause using Cox proportional hazard models adjusting for potential confounders and predictors of age at menopause. We also examined effect modification by region, smoking, body mass, physical activity, menstrual cycle length, and population density. There were 64,340 reports of natural menopause throughout 1,059,229 person-years of follow-up. In fully adjusted models, a 10 μg/m3 increase in the cumulative average exposure to PM10 (HR: 1.02, 95% CI: 1.00, 1.04), PM2.5-10 (HR: 1.03, 95% CI: 1.00, 1.05), and PM2.5 (HR: 1.03, 95% CI: 1.00, 1.06) and living within 50 m to a major road at age 40 (HR: 1.03, 95%CI: 1.00, 1.06) were associated with slightly earlier menopause. No statistically significant effect modification was found, although the associations of PM were slightly stronger for women who lived in the West and for never smokers. To conclude, we found exposure to ambient PM and traffic in midlife was associated with slightly earlier onset of natural menopause. Our results support previous evidence that exposure to air pollution and traffic may accelerate reproductive aging.

The Chemical Exposome of Human Aging

Aging is an inevitable biological phenomenon displayed by single cells and organs to entire organismal systems. Aging as a biological process is characterized as a progressive decline in intrinsic biological function. Understanding the causative mechanisms of aging has always captured the imagination of researchers since time immemorial. Although both biological and chronological aging are well defined and studied in terms of genetic, epigenetic, and lifestyle predispositions, the hallmarks of aging in terms of small molecules (i.e., endogenous metabolites to chemical exposures) are limited to obscure. On top of the endogenous metabolites leading to the onset and progression of healthy aging, human beings are constantly exposed to a natural and anthropogenic "chemical" environment round the clock, from conception till death, affecting one's physiology, health and well-being, and disease predisposition. The research community has started gaining sizeable insights into deciphering the aging factors such as immunosenescence, nutrition, frailty, inflamm-aging, and diseases till date, without much input from their interaction with exogenous chemical exposures. The "exposome" around us, mostly, accelerates the process of aging by affecting the internal biological pathways and signaling mechanisms that result in the deterioration of human health. However, the entirety of exposome on human aging is far from established. This review intends to catalog the known and established associations of the exposome from past studies focusing on aging in humans and other model organisms. Further discussed are the current technologies and informatics tools that enable the study of aging exposotypes, and thus, provide a window of opportunities and challenges to study the "aging exposome" in granular details.

Association of greenspace exposure with telomere length in preschool children

Exposure to greenspace has been associated with a wide range of health benefits; however, the available evidence on the association of this exposure with telomere length (TL), an early marker of ageing, is still scarce. We investigated the association of greenspace exposure with TL in a sample of 200 preschool children (aged 5-7 years) residing in Sabzevar, Iran (2017). We comprehensively characterized different aspects of greenspace exposure encompassing residential, kindergarten, and total (including both residential and kindergarten) surrounding greenspace (using satellite-derived Normalized Difference Vegetation Index), residential and kindergarten distance to green spaces, time spent in private gardens and public green spaces, and the number of plant pots at home. Relative leukocyte TL (LTL) in blood samples of the study participants was measured using quantitative polymerase chain reaction (qPCR). We applied mixed effects linear regression models with kindergarten and qPCR plate as random effects, to estimate the association of indicators of greenspace exposure (one at a time) with LTL, controlled for relevant covariates. We observed an inverse association between distance from home and kindergarten to green spaces larger than 5000 m² and LTL. Moreover, higher total surrounding greenspace at 300m and 500m buffers and higher surrounding greenspace at 300m buffer around kindergarten and home were associated with longer LTL. Furthermore, longer time spent (h/week) in the public green spaces was associated with longer LTL. Our findings for residential and kindergarten distance to any green space (regardless of the size), residential surrounding greenspace at 100m and 500m buffers, kindergarten surrounding greenspace at 100m buffer, time spent in private gardens (h/week) and the number of plant pots at home were not conclusive. Our findings were generally suggestive for a positive association between greenspace exposure and LTL in preschool children. More studies are needed to confirm these findings in other settings with different climates and populations.

Environmental exposures and health behavior in association with mental health: a study design

BACKGROUND

Air pollution, green space and smoking are known to affect human health. However, less is known about their underlying biological mechanisms. One of these mechanisms could be biological aging. In this study, we explore the mediation of biomarkers of exposure and biological aging to explain the associations between environmental exposures, health behavior and mental health.

METHODS

The study population of this cross-sectional study (n = 1168) is a subsample of the Belgian 2018 Health Interview Survey (BHIS). Mental health indicators including psychological and severe psychological distress, life satisfaction, vitality, eating disorders, suicidal ideation, subjective health and depressive and anxiety disorders, demographics and health behavior such as smoking are derived from the BHIS. Urine and blood samples are collected to measure respectively the biomarkers of exposure (urinary black carbon (BC) and (hydroxy)cotinine) and the biomarkers of biological aging (mitochondrial DNA content (mtDNAc) and telomere length (TL)). Recent and chronic exposure (μg/m3) to nitrogen dioxide (NO2), particulate matter ≤2.5 μm (PM2.5) and ≤ 10 μm (PM10) and BC at the participants' residence are modelled using a high resolution spatial temporal interpolation model. Residential green space is defined in buffers of different size (50 m - 5000 m) using land cover data in ArcGIS 10 software. For the statistical analysis multivariate linear and logistic regressions as well as mediation analyses are used taking into account a priori selected covariates and confounders.

RESULTS

As this study combined data of BHIS and laboratory analyses, not all data is available for all participants. Therefore, data analyses will be conducted on different subsets. Data on air pollution and green space exposure is available for all BHIS participants. Questions on smoking and mental health were answered by respectively 7829 and 7213 BHIS participants. For biomarker assessment, (hydroxy) cotinine, urinary BC and the biomarkers of biological aging are measured for respectively 1130, 1120 and 985 participants.

CONCLUSION

By use of personal markers of air pollution and smoking, as well as biological aging, we will gain knowledge about the association between environmental exposures, health behavior, and the mental health status. The results of the study can provide insights on the health of the Belgian population, making it a nationwide interesting study.

Air Pollution, Stress, and Allostatic Load: Linking Systemic and Central Nervous System Impacts

 Air pollution is a risk factor for cardiovascular and respiratory morbidity and mortality. A growing literature also links exposure to diverse air pollutants (e.g., nanoparticles, particulate matter, ozone, traffic-related air pollution) with brain health, including increased incidence of neurological and psychiatric disorders such as cognitive decline, dementia (including Alzheimer’s disease), anxiety, depression, and suicide. A critical gap in our understanding of adverse impacts of pollutants on the central nervous system (CNS) is the early initiating events triggered by pollutant inhalation that contribute to disease progression. Recent experimental evidence has shown that particulate matter and ozone, two common pollutants with differing characteristics and reactivity, can activate the hypothalamic-pituitary-adrenal (HPA) axis and release glucocorticoid stress hormones (cortisol in humans, corticosterone in rodents) as part of a neuroendocrine stress response. The brain is highly sensitive to stress: stress hormones affect cognition and mental health, and chronic stress can produce profound biochemical and structural changes in the brain. Chronic activation and/or dysfunction of the HPA axis also increases the burden on physiological stress response systems, conceptualized as allostatic load, and is a common pathway implicated in many diseases. The present paper provides an overview of how systemic stress-dependent biological responses common to particulate matter and ozone may provide insight into early CNS effects of pollutants, including links with oxidative, inflammatory, and metabolic processes. Evidence of pollutant effect modification by non-chemical stressors (e.g., socioeconomic position, psychosocial, noise), age (prenatal to elderly), and sex will also be reviewed in the context of susceptibility across the lifespan.

Increased telomere length and mtDNA copy number induced by multi-walled carbon nanotube exposure in the workplace

Carbon nanotubes (CNTs) except MWCNT-7 have been classified as Group 3 ["Not classifiable as to its carcinogenicity to humans"] by the IARC. Despite considerable mechanistic evidence in vitro/in vivo, the classification highlights a general lack of data, especially among humans. In our previous study, we reported epigenetic changes in the MWCNT exposed workers. Here, we evaluated whether MWCNT can also cause alterations in aging related features including relative telomere length (TL) and/or mitochondrial copy number (mtDNAcn). Relative TL and mtDNAcn were measured on extracted DNA from peripheral blood from MWCNT exposed workers (N = 24) and non-exposed controls (N = 43) using a qPCR method. A higher mtDNAcn and longer TL were observed in MWCNT exposed workers when compared to controls. Independent of age, sex, smoking behavior, alcohol consumption and BMI, MWCNT-exposure was associated with an 18.30 % increase in blood TL (95 % CI: 7.15-30.62 %; p = 0.001) and 35.21 % increase in mtDNAcn (95 % CI: 19.12-53.46 %). Our results suggest that exposure to MWCNT can induce an increase in the mtDNAcn and TL; however, the mechanistic basis or consequence of such change requires further experimental studies.

Telomere erosion as a placental clock: From placental pathologies to adverse pregnancy outcomes

The placenta provides nutritional and gas exchange between fetus and mother. Early in pregnancy, placental trophoblasts proliferate rapidly and invade aggressively. As pregnancy progresses, placental cells begin to age. Indeed, pregnancy itself has a tightly regulated duration, determined in large part by placental lifespan. Late in pregnancy, placental cells reach a senescent apoptotic state, activated by a number of intrinsic and extrinsic factors, including oxidative stress (OS), and DNA damage. Pregnancy complications, stillbirths and neonatal deaths have been related to OS and abnormal placental aging. Telomeres, the protective nucleoprotein structures at the ends of linear chromosomes, shorten both from cell replication and from exposure to OS. When telomeres become critically short they trigger cell cycle arrest and eventually cell death. Telomere attrition thus provide an intrinsic mechanism to explain tissue senescence and aging. Mounting evidence suggests that senescence of placental and fetal membrane cells results from telomere attrition. We review the studies that have addressed the role of telomere length (TL) in placentas from normal and complicated pregnancies, including pre-eclampsia, intrauterine growth restriction, gestational diabetes, and stillbirth. To date studies have uncovered associations between TL and a number of obstetrical complications. Future research is needed to determine whether these associations are causative, i.e. whether these clinical conditions result from telomere dysfunction, and whether particular features of telomeres, e.g. mean or shortest length, etc. could serve as clinically useful biomarkers of placental health.

The environment as a determinant of successful aging or frailty

The number of elderly persons is rising rapidly, and healthspan is a key factor in determining the well-being of individuals and the sustainability of national health systems. Environmental health is crucial for a "successful aging". Complex relationships between environmental factors and non-communicable diseases play a major role, causing or accelerating disabilities. Besides genetic factors, aging results from the concurrence of several environmental factors starting from early (i.e. in utero) life, able to increase susceptibility to diseases in adulthood, and to promote frailty in the elderly. In aged people, an unhealthy environment contributes to a fast and early decline and increases vulnerability. Exposure to pollutants facilitates the onset and progression of cardiovascular, respiratory, metabolic and neurologic diseases through direct effects and epigenetic mechanisms negatively affecting biological age. Healthy diet, healthy environment and constant physical activity could counteract, at least in part, the negative effects of environmental stressors. Almost all environmental factors generating detrimental effects on aging are modifiable, with relevant implications in terms of primary prevention measures potentially leading to decreased frailty, to an increase in the number of years lived without diseases or disability, and to a significant reduction in health expenditure.

Personal exposure to NO2 and benzene in the Cape Town region of South Africa is associated with shorter leukocyte telomere length in women

Air pollution exposure is a major global health concern and has been associated with molecular aging. Unfortunately, the situation has not received much attention in the African region. The aim of this study was to investigate whether current personal ambient NO₂ and benzene, toluene, ethyl-benzene and xylenes (ortho (o)-, meta (m)- and para (p)-xylene (BTEX) exposure is associated with leukocyte telomere length (LTL), a marker of molecular ageing, in apparently healthy women (mean ± SD age: 42.5 ± 13.4 years) residing in the Cape Town region of South Africa. The repeated measures study collected data from 61 women. Seven-day median (interquartile range (IQR)) personal NO₂ and BTEX exposure levels were determined via compact passive diffusion samplers carried on the person prior to baseline (NO₂: 14.2 (9.4-17.2) μg/m³; Benzene: 3.1 (2.1-5.3) μg/m³) and 6-month follow-up (NO₂: 10.6 (6.6-13.6) μg/m³; Benzene: 2.2 (1.3-4.9) μg/m³) visits. LTL was measured at baseline and follow-up using a real-time PCR method. Multiple linear mixed model analyses (adjusting for age, body mass index, smoking, employment status, level of education and assessment visit) showed that each IQR increment increase in NO₂ (7.0 μg/m³) and benzene (3.3 μg/m³) was associated with -7.30% (95% CI: -10.98 to -3.46%; p < 0.001) and -6.78% (95% CI: -11.88 to -1.39%; p = 0.015) difference in LTL, respectively. The magnitude of these effects of NO₂ and benzene corresponds to the effect of an increase of 10.3- and 6.0-year in chronological age on LTL. Our study shows that personal exposures to NO₂ and benzene are associated with molecular ageing as indicated by LTL in healthy women residing in the Cape Town region.

Shorter Leukocyte Telomere Lengths in Healthy Relatives of Patients with Coronary Heart Disease

Telomere length (TL), sirtuin (SIRT) 1, growth differentiation factor (GDF) 11, as well as inflammaging have been related to age-related diseases. In healthy subjects, we aimed to investigate whether leukocyte TL (LTL) associated with family history of coronary heart disease (CHD), age, sex, and lifestyle, and further potential covariations between LTL, GDF11, SIRT1 and selected proinflammatory markers. In 118 healthy subjects (18-81 years, 58% females), whole blood was collected for DNA and RNA isolation and polymerase chain reaction relative quantification of LTLs and gene-expression of SIRT1, GDF11, interleukin (IL)-18, and interferon (IFN)ƴ, respectively, and serum SIRT1 and IL-18 analyses. Shorter LTLs were associated with a seven-fold higher frequency of hereditary CHD in subjects with LTLs in quartile (Q)1 compared with Q2-4 (odds ratio = 7.5, 95% confidence interval: 2.5-21.6, p < 0.001, adjusted). We also observed that LTLs in Q4 compared with Q1-3 associated with higher leukocyte expression of SIRT1 and GDF11 (p = 0.052 and p = 0.058), lower IFNƴ expression (p = 0.009), and lower circulating IL-18 levels (p = 0.027). SIRT1 and GDF11 expression were strongly intercorrelated (Spearman's rho = 0.85, p < 0.001). Overall, smoking, snus, and alcohol consumption were not associated with LTLs. The observed shorter LTLs in association with elevated expression of SIRT1 and GDF11 and dampened inflammation in hereditary CHD subjects, suggest impending risk of disease. More research are warranted to shed light on early lifestyle interventions targeting these mechanisms, to promote healthier aging in individuals with hereditary burden. Graphical Abstract [Figure: see text].

Air pollution-induced placental alterations: an interplay of oxidative stress, epigenetics, and the aging phenotype?

According to the "Developmental Origins of Health and Disease" (DOHaD) concept, the early-life environment is a critical period for fetal programming. Given the epidemiological evidence that air pollution exposure during pregnancy adversely affects newborn outcomes such as birth weight and preterm birth, there is a need to pay attention to underlying modes of action to better understand not only these air pollution-induced early health effects but also its later-life consequences. In this review, we give an overview of air pollution-induced placental molecular alterations observed in the ENVIRONAGE birth cohort and evaluate the existing evidence. In general, we showed that prenatal exposure to air pollution is associated with nitrosative stress and epigenetic alterations in the placenta. Adversely affected CpG targets were involved in cellular processes including DNA repair, circadian rhythm, and energy metabolism. For miRNA expression, specific air pollution exposure windows were associated with altered miR-20a, miR-21, miR-146a, and miR-222 expression. Early-life aging markers including telomere length and mitochondrial DNA content are associated with air pollution exposure during pregnancy. Previously, we proposed the air pollution-induced telomere-mitochondrial aging hypothesis with a direct link between telomeres and mitochondria. Here, we extend this view with a potential co-interaction of different biological mechanisms on the level of placental oxidative stress, epigenetics, aging, and energy metabolism. Investigating the placenta is an opportunity for future research as it may help to understand the fundamental biology underpinning the DOHaD concept through the interactions between the underlying modes of action, prenatal environment, and disease risk in later life. To prevent lasting consequences from early-life exposures of air pollution, policy makers should get a basic understanding of biomolecular consequences and transgenerational risks.

Skin inflammation induced by ambient particulate matter in China

Most published studies on particulate matter (PM) concerning PM_2.5 and PM₁₀ have focused on PM-induced effects on the respiratory system (particularly lung) and cardiovascular system effects. However, epidemiological and mechanistic studies suggest that PM_2.5 and PM₁₀ also affects the skin, which is a key health issue. In this study, we first reviewed the current status of PM_2.5 and PM₁₀ in China, including relevant regulations, concentration levels, chemical components, and emission sources. Next, we summarized the association between PM_2.5 and PM₁₀ or its representative components, in relation to skin inflammation as well as inflammatory skin diseases, such as atopic dermatitis, acne, eczema, and skin aging. Finally, we determined the mechanism of oxidative stress or programmed cell death induced through PM, which can provide useful information for future research on PM-induced skin inflammation.

Prenatal polycyclic aromatic hydrocarbons metabolites, cord blood telomere length, and neonatal neurobehavioral development

BACKGROUND

Prenatal exposure to polycyclic aromatic hydrocarbon (PAH) is a potential risk factor for child neurobehavioral development. Telomere length (TL) has important implications for health over the life course.

OBJECTIVE

In this study, we aimed to investigate whether prenatal urinary PAH metabolites were associated with adverse neonatal neurobehavioral development and altered cord blood TL and to explore whether the change of TL was a predictor of neonatal neurobehavioral development.

METHOD

We enrolled 283 nonsmoking pregnant women in Taiyuan city. Eleven PAH metabolites were measured in maternal urine samples. TL in cord blood was measured by real time quantitative polymerase chain reaction. Neonatal behavioral neurological assessment (NBNA) tests were conducted when the infants were three days old. Multiple linear regression models were used to analyze the associations of maternal urinary PAH metabolites with NBNA scores and cord blood TL, and restricted cubic spline models were further used to examine the shapes of dose-response relationships. A mediation analysis was also conducted.

RESULT

We observed dose-response associations of maternal urinary 2-hydroxyfluorene (2-OHFlu) and 2-hydroxyphenanthrene (2-OH Phe) with decreased active tone scores, sum of NBNA scores, and cord blood TL (P for trend<0.05). Each 1 unit increase in urinary levels of Ln (2-OH Flu) or Ln (2-OH Phe) was associated with a 0.092 or 0.135 decrease in the active tone scores and a 0.174 or 0.199 decrease in the sum of NBNA scores. Mediation analysis showed TL could explained 21.74% of the effect of sum of NBNA scores change related to prenatal exposure to 2-OH Phe (P for mediator = 0.047).

CONCLUSION

Our data indicates maternal urinary specific PAH metabolites are inversely associated with neonatal neurobehavioral development and cord blood TL. TL mediates the associations of 2-OH Phe with neonatal neurobehavioral development and partly explains the effect of 2-OH Phe on neonatal neurobehavioral development.

Research challenges for cultural ecosystem services and public health in (peri-)urban environments

Urbanization is a global trend, and consequently the quality of urban environments is increasingly important for human health and wellbeing. Urban life-style is typically associated with low physical activity and sometimes with high mental stress, both contributing to an increasing burden of diseases. Nature-based solutions that make effective use of ecosystem services, particularly of cultural ecosystem services (CES), can provide vital building blocks to address these challenges. This paper argues that, the salutogenic, i.e. health-promoting effects of CES have so far not been adequately recognised and deserve more explicit attention in order to enhance decision making around health and wellbeing in urban areas. However, a number of research challenges will need to be addressed to reveal the mechanisms, which underpin delivery of urban CES. These include: causal chains of supply and demand, equity, and equality of public health benefits promoted. Methodological challenges in quantifying these are discussed. The paper is highly relevant for policy makers within and beyond Europe, and also serves as a review for current researchers and as a roadmap to future short- and long-term research opportunities.