Angel M. Dzhambov

Exploring pathways linking greenspace to health: Theoretical and methodological guidance

Background In a rapidly urbanizing world, many people have little contact with natural environments, which may affect health and well‐being. Existing reviews generally conclude that residential greenspace is beneficial to health. However, the processes generating these benefits and how they can be best promoted remain unclear. Objectives During an Expert Workshop held in September 2016, the evidence linking greenspace and health was reviewed from a transdisciplinary standpoint, with a particular focus on potential underlying biopsychosocial pathways and how these can be explored and organized to support policy‐relevant population health research. Discussions Potential pathways linking greenspace to health are here presented in three domains, which emphasize three general functions of greenspace: reducing harm (e.g. reducing exposure to air pollution, noise and heat), restoring capacities (e.g. attention restoration and physiological stress recovery) and building capacities (e.g. encouraging physical activity and facilitating social cohesion). Interrelations between among the three domains are also noted. Among several recommendations, future studies should: use greenspace and behavioural measures that are relevant to hypothesized pathways; include assessment of presence, access and use of greenspace; use longitudinal, interventional and (quasi)experimental study designs to assess causation; and include low and middle income countries given their absence in the existing literature. Cultural, climatic, geographic and other contextual factors also need further consideration. Conclusions While the existing evidence affirms beneficial impacts of greenspace on health, much remains to be learned about the specific pathways and functional form of such relationships, and how these may vary by context, population groups and health outcomes. This Report provides guidance for further epidemiological research with the goal of creating new evidence upon which to develop policy recommendations. HighlightsAlthough it appears that greenspace benefits health, the pathways are unclear.We have organized pathways into three domains that emphasize greenspace functions.Pathways likely intertwine and vary by context, populations and health outcomes.We identify diverse challenges in measurement and analysis that require attention.Research guided by our discussion will better efforts to enable greenspace‐related health benefits.

Long-term noise exposure and the risk for type 2 diabetes: A meta-analysis: Erratum

Diabetes mellitus is one of the leading causes for disability and mortality in modern societies. Apart from personal factors its incidence might be influenced by environmental risks such as air pollution and noise. This paper reports a systematic review and meta-analysis on the risk for type 2 diabetes due to long-term noise exposure. Electronic searches in MEDLINE, EMBASE and the Internet yielded 9 relevant studies (5 for residential and 4 for occupational exposure). They were checked against a predefined list of safeguards against bias producing individual quality scores, which were then fed to MetaXL to conduct a quality effects meta-analysis. People exposed at their homes to roughly L den > 60 dB had 22% higher risk (95% confidence interval [CI]: 1.09-1.37) for type 2 diabetes in comparison to those exposed to L den < 64 dB; when studies reporting contentious exposure categories were excluded, there was still 19% risk (95% CI: 1.05-1.35) for L den = 60-70 dB versus L den < 60 dB. In occupational environment there was not significant risk (relative risk [RR] = 0.91, 95% CI: 0.78-1.06) for < 85 dB versus >85 dB. There was no heterogeneity in the two groups (I2 = 0.00). The results should be interpreted with caution due to methodological discrepancies across the studies; however, they are indicative of the close links that noise pollution might have not only to cardiovascular diseases but to endocrine dysfunction as well.

Urban green spaces' effectiveness as a psychological buffer for the negative health impact of noise pollution: A systematic review

Noise pollution is one of the four major pollutions in the world. Little evidence exists about the actual preventive benefits of psychological noise attenuation by urban green spaces, especially from the perspective of environmental medicine and, to the best of our knowledge, there is not a systematic analysis on this topic. The aim of this review was to systematically evaluate whether there is conclusive scientific evidence for the effectiveness of urban green spaces as a psychological buffer for the negative impact of noise pollution on human health and to promote an evidence-based approach toward this still growing environmental hazard. MEDLINE and EMBASE databases were searched for experimental and epidemiological studies published before June 04, 2013 in English and Spanish. Data was independently extracted in two step process by the authors. Due to the heterogeneity of the included studies qualitative assessment was performed. We found moderate evidence that the presence of vegetation can generally reduce the negative perception of noise (supported with an electroencephalogram test in one of the experimental studies; consistent with the data from two epidemiological studies; one experiment found no effect and one was inconclusive about the positive effect). This review fills a gap in the literature and could help researchers further clarify the proper implementation of urban green spaces as a psychological buffer in areas with population exposed to chronic noise pollution.

Exposures to road traffic, noise, and air pollution as risk factors for type 2 diabetes: A feasibility study in Bulgaria

Type 2 diabetes mellitus (T2DM) is a growing public health problem in Bulgaria. While individual and lifestyle determinants have been researched; till date there has been no study on environmental risks such as road traffic, noise, and air pollution. As a first step toward designing a large-scale population-based survey, we aimed at exploring the overall associations of prevalent T2DM with exposures to road traffic, noise, and air pollution. A total of 513 residents of Plovdiv city, Bulgaria were recruited. Individual data on self-reported doctor-diagnosed T2DM and confounding factors were linked to objective and self-rated exposure indicators. Logistic and log-link Poisson regressions were conducted. In the fully adjusted logistic models, T2DM was positively associated with exposures to L den 71-80 dB (odds ratio (OR) = 4.49, 95% confidence interval (CI): 1.38, 14.68), fine particulate matter (PM) 2.5 25.0-66.8 μg/m 3 (OR = 1.32, 95% CI: 0.28, 6.24), benzo alpha pyrene 6.0-14.02 ng/m 3 (OR = 1.76, 95% CI: 0.52, 5.98) and high road traffic (OR = 1.40, 95% CI: 0.48, 4.07). L den remained a significant risk factor in the: Poisson regression model. Other covariates with consistently high multivariate effects were age, gender, body mass index, family history of T2DM, subjective sleep disturbance, and especially bedroom location. We concluded that residential noise exposure might be associated with elevated risk of prevalent T2DM. The inferences made by this research and the lessons learned from its limitations could guide the designing of a longitudinal epidemiological survey in Bulgaria.

Urban residential greenspace and mental health in youth: Different approaches to testing multiple pathways yield different conclusions

Background Urban greenspace can benefit mental health through multiple mechanisms. They may work together, but previous studies have treated them as independent. Objectives We aimed to compare single and parallel mediation models, which estimate the independent contributions of different paths, to several models that posit serial mediation components in the pathway from greenspace to mental health. Methods We collected cross‐sectional survey data from 399 participants (15–25 years of age) in the city of Plovdiv, Bulgaria. Objective “exposure” to urban residential greenspace was defined by the Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index, tree cover density within the 500‐m buffer, and Euclidean distance to the nearest urban greenspace. Self‐reported measures of availability, access, quality, and usage of greenspace were also used. Mental health was measured with the General Health Questionnaire. The following potential mediators were considered in single and parallel mediation models: restorative quality of the neighborhood, neighborhood social cohesion, commuting and leisure time physical activity, road traffic noise annoyance, and perceived air pollution. Four models were tested with the following serial mediation components: (1) restorative quality → social cohesion; (2) restorative quality → physical activity; (3) perceived traffic pollution → restorative quality; (4) and noise annoyance → physical activity. Results There was no direct association between objectively‐measured greenspace and mental health. For the 500‐m buffer, the tests of the single mediator models suggested that restorative quality mediated the relationship between NDVI and mental health. Tests of parallel mediation models did not find any significant indirect effects. In line with theory, tests of the serial mediation models showed that higher restorative quality was associated with more physical activity and more social cohesion, and in turn with better mental health. As for self‐reported greenspace measures, single mediation through restorative quality was significant only for time in greenspace, and there was no mediation though restorative quality in the parallel mediation models; however, serial mediation through restorative quality and social cohesion/physical activity was indicated for all self‐reported measures except for greenspace quality. Conclusions Statistical models should adequately address the theoretically indicated interdependencies between mechanisms underlying association between greenspace and mental health. If such causal relationships hold, testing mediators alone or in parallel may lead to incorrect inferences about the relative contribution of specific paths, and thus to inappropriate intervention strategies. HighlightsWe compared single and parallel mediation models to serial mediation models.Single mediation models suggested mediation through neighborhood restorative quality.Parallel mediation models did not find any mediation through restorative quality.There was serial mediation through restorative quality, physical activity and social cohesion.Testing mediators alone or in parallel may lead to incorrect inferences.

Residential road traffic noise and general mental health in youth: The role of noise annoyance, neighborhood restorative quality, physical activity, and social cohesion as potential mediators

Given the ubiquitous nature of both noise pollution and mental disorders, their alleged association has not escaped the spotlight of public health research. The effect of traffic noise on mental health is probably mediated by other factors, which have not been elucidated sufficiently. Herein, we aimed to disentangle the pathways linking road traffic noise to general mental health in Bulgarian youth, with a focus on several candidate mediators - noise annoyance, perceived restorative quality of the living environment, physical activity, and neighborhood social cohesion. A cross-sectional sample was collected in October - December 2016 in the city of Plovdiv, Bulgaria. It consisted of 399 students aged 15-25years, recruited from two high schools and three universities. Road traffic noise exposure (Lden) was derived from the strategic noise map of Plovdiv. Mental health was measured with the 12-item form of the General Health Questionnaire (GHQ-12). Noise annoyance, perceived restorative quality of the living environment, commuting and leisure time physical activity, and neighborhood social cohesion were assessed using validated questionnaires. Analyses were based on linear regression mediation models and a structural equation modeling (SEM) to account for the hypothesized interdependencies between candidate mediators. Results showed that higher noise exposure was associated with worse mental health only indirectly. More specifically, tests of the single and parallel mediation models indicated independent indirect paths through noise annoyance, social cohesion, and physical activity. In addition, the SEM revealed that more noise annoyance was associated with less social cohesion, and in turn with worse mental health; noise annoyance was also associated with lower neighborhood restorative quality, thereby with less social cohesion and physical activity, and in turn with worse mental health. However, causality could not be established. Further research is warranted to expand our still limited understanding of these person-environment interactions.

Neighborhood noise pollution as a determinant of displaced aggression: a pilot study

Noise pollution is still a growing public health problem with a significant impact on psychological health and well-being. The aim of this study was to investigate the impact of noise on displaced aggression (DA) in different subgroups of residents in one of the neighborhoods of Plovdiv city. A cross-sectional semi-structured interview survey was conducted using specially designed data registration forms and 33 close-ended and open-ended questions, divided into two major panels - one original and a modified version of the Displaced Aggression Questionnaire (DAQ). The mean score for DA was 61.12 (±19.97). Hearing noises above the perceived normal threshold, higher noise sensitivity and continuous noises were associated with higher levels of DA. Low frequency and high intensity noises were also associated with higher DA scores. Multiple regression model supported these findings. Contradictory to previous research age was positively correlated with noise sensitivity and aggression. We speculated that this might be due to the relatively lower socio-economic standard and quality of life in Bulgaria. Therefore, social climate might be modifying the way people perceive and react to environmental noise. Finally, the DAQ proved to be a viable measurement tool of these associations and might be further implemented and modified to suit the purposes of psychoacoustic assessment.

NOISE EXPOSURE DURING PREGNANCY, BIRTH OUTCOMES AND FETAL DEVELOPMENT: META-ANALYSES USING QUALITY EFFECTS MODEL

ABSTRACT BACKGROUND: Many women are exposed daily to high levels of occupational and residential noise, so the effect of noise exposure on pregnancy should be considered because noise affects both the fetus and the mother herself. However, there is a controversy in the literature regarding the adverse effects of occupational and residential noise on pregnant women and their fetuses. AIM: The aim of this study was to conduct systematic review of previously analyzed studies, to add additional information omitted in previous reviews and to perform meta-analyses on the effects of noise exposure on pregnancy, birth outcomes and fetal development. MATERIAL AND METHODS: Previous reviews and meta-analyses on the topic were consulted. Additionally, a systematic search in MEDLINE, EMBASE and Internet was carried out. Twenty nine studies were included in the meta-analyses. Quality effects meta-analytical model was applied. RESULTS: Women exposed to high noise levels (in most of the studies ≥ 80 dB) during pregnancy are at a significantly higher risk for having small-for-gestational-age newborn (RR = 1.19, 95% CI: 1.03, 1.38), gestational hypertension (RR = 1.27, 95% CI: 1.03, 1.58) and infant with congenital malformations (RR = 1.47, 95% CI: 1.21, 1.79). The effect was not significant for preeclampsia, perinatal death, spontaneous abortion and preterm birth. CONCLUSION: The results are consistent with previous findings regarding a higher risk for small-for-gestational-age. They also highlight the significance of residential and occupational noise exposure for developing gestational hypertension and especially congenital malformations. РЕЗЮМЕ ВВЕДЕНИЕ: Так как многие женщины живут и работают в условиях шума, то влияние шумовой экспозиции на беременность следует принимать во внимание, так как шум имеет прямые и косвенные эффекты на плод и мать. Несмотря на это в литературе существует противоречивое мнение относительно нежелательных эффектов шума и дома, и на работе на беременных женщин и их плод. ЦЕЛЬ: Работа ставит себе целью провести систематический обзор уже анализированных исследований, добавить дополнительную информацию, невключенную до сих пор в имеющиеся обзоры и сделать мета-анализы эффектов шумовой экспозиции на беременность, исход родов и развитие плода. МАТЕРИАЛ И МЕТОДЫ: Авторы сделали справку со существующими обзорами на эту тему. Кроме того проведен систематический поиск в MEDLINE, EMBASE и Internet. 29 исследований включено в мета-анализы; применена quality effects мета-аналитическая модель. РЕЗУЛЬТАТЫ: Женщины, экспонированные на высокие шумовые уровни (в большинстве исследований ≥ 80 dB), во время беременности подвергнуты значительно более высокому риску родов ребенка небольшой массы тела для гестационного возраста (RR = 1.19, 95% CI: 1.03, 1.38), риску гестационной гипертонии (RR = 1.27, 95% CI: 1.03, 1.58) и риску родов ребенка с врожденными мальформациями (RR = 1.47, 95% CI: 1.21, 1.79). Эффект не оказался значимым для преэклампсии, перинатальной смерти, спонтанного аборта и преждевременных родов. ЗАКЛЮЧЕНИЕ: Результаты подтверждают уже установленный повышенный риск родов маленького для гестационного возраста ребенка; подчеркивают также значимость комунальной и трудовой шумовой экспозиции для развития гестационной гипертонии и особенно для развития врожденных мальформаций.

Children's blood pressure and its association with road traffic noise exposure – A systematic review with meta-analysis

Background Primary and synthetic research on road traffic noise (RTN) and blood pressure (BP) is more common for adults than it is for children and adolescents. Given the conflicting evidence from primary studies, this study aimed to conduct an up‐to‐date systematic review with meta‐analysis of the association between RTN and childrens BP, by using advanced statistical techniques, to take into account the heterogeneity in primary studies. Methods MEDLINE (PubMed), EMBASE (ScienceDirect with filters), and the Internet (Google) were searched (last update: July 21, 2016) in English, Spanish, and Russian. Thirteen articles (total n=8 770) were included in the systematic review and 37 effect size estimates were pooled in different meta‐analyses under the quality effects model. Results Results showed 0.48 mmHg (95% CI: −0.87, 1.83) increase in systolic blood pressure (SBP) and 0.22 mmHg (95% CI: −0.64, 1.07) in diastolic blood pressure (DBP) per 5 dB increase in RTN at school/kindergarten; and 0.20 mmHg (95% CI: −0.30, 0.71) increase in SBP and 0.03 mmHg (95% CI: −0.18, 0.25) in DBP per 5 dB increase in RTN at home. There was high heterogeneity in the first three models and evidence of publication bias in the first. The following categorical and linear factors were significant effect modifiers in different exposure – outcome scenarios: country where the study was conducted, the mode of noise assessment, the mode of BP measurement, the type of reported effect size estimate, the overall quality score of the estimate, the minimum number of BP readings, and childrens mean age. Conclusions All evidence considered, the observed association between RTN and BP is weak and further flattened by methodological issues of primary studies, but its long‐term consequences should not be ignored. HighlightsConflicting association road traffic noise – childrens blood pressure so far.A quality effects meta‐analysis was conducted.Non‐significant increase in systolic and diastolic blood pressure per 5 dB found.Significant effect found only in some subgroups of studies.Overall weak association and low quality of the evidence

Occupational noise and ischemic heart disease: A systematic review.

Noise exposure might be a risk factor for ischemic heart disease (IHD). Unlike residential exposure, however, evidence for occupational noise is limited. Given that high-quality quantitative synthesis of existing data is highly warranted for occupational safety and policy, we aimed at conducting a systematic review and meta-analysis of the risks of IHD morbidity and mortality because of occupational noise exposure. We carried out a systematic search in MEDLINE, EMBASE, and on the Internet since April 2, 2015, in English, Spanish, Russian, and Bulgarian. A quality-scoring checklist was developed a priori to assess different sources of methodological bias. A qualitative data synthesis was performed. Conservative assumptions were applied when appropriate. A meta-analysis was not feasible because of unresolvable methodological discrepancies between the studies. On the basis of five studies, there was some evidence to suggest higher risk of IHD among workers exposed to objectively assessed noise >75–80 dB for <20 years (supported by one high, one moderate, and one low quality study, opposed by one high and one moderate quality study). Three moderate and two low quality studies out of six found self-rated exposure to be associated with higher risk of IHD, and only one moderate quality study found no effect. Out of four studies, a higher mortality risk was suggested by one moderate quality study relying on self-rated exposure and one of high-quality study using objective exposure. Sensitivity analyses showed that at higher exposures and in some vulnerable subgroups, such as women, the adverse effects were considerably stronger. Despite methodological discrepancies and limitations of the included studies, occupational noise appeared to be a risk factor for IHD morbidity. Results suggested higher risk for IHD mortality only among vulnerable subgroups. Workers exposed to high occupational noise should be considered at higher overall risk of IHD.