University Students' Self-Rated Health in Relation to Perceived Acoustic Environment during the COVID-19 Home Quarantine.

BACKGROUND: Online education became mandatory for many students during the Coronavirus disease 2019 (COVID-19) pandemic and blurred the distinction between settings where processes of stress and restoration used to take place. The lockdown also likely changed perceptions of the indoor acoustic environment (i.e., soundscape) and raised its importance. In the present study, we seek to understand how indoor soundscape related to university students' self-rated health in Bulgaria around the time that the country was under a state of emergency declaration caused by the COVID-19 pandemic. METHODS: Between 17 May and 10 June 2020, we conducted a cross-sectional online survey among 323 students (median age 21 years; 31% male) from two universities in the city of Plovdiv, Bulgaria. Self-rated health (SRH) was measured with a single-item. Participants were asked how frequently they heard different types of sounds while at home and how pleasant they considered each of those sounds to be. Restorative quality of the home (the "being away" dimension of the Perceived Restorativeness Scale) was measured with a single-item. A priori confounders and effect modifiers included sociodemographics, house-related characteristics, general sensitivity to environmental influences, and mental health. Our analysis strategy involved sequential exploratory factor analysis (EFA), multivariate linear and ordinal regressions, effect modification tests, and structural equation modeling (SEM). RESULTS: EFA supported grouping perceived sounds into three distinct factors-mechanical, human, and nature sounds. Regression analyses revealed that greater exposure to mechanical sounds was consistently associated with worse SRH, whereas no significant associations were found for human and nature sounds. In SEM, exposure to mechanical sounds related to lower restorative quality of the home, and then to poorer SRH, whereas nature sounds correlated with higher restorative quality, and in turn with better SRH. CONCLUSIONS: These findings suggest a role of positive indoor soundscape and restorative quality for promoting self-rated health in times of social distancing.

Does greenery experienced indoors and outdoors provide an escape and support mental health during the COVID-19 quarantine?

BACKGROUND: The COVID-19 pandemic has profoundly changed people's ability to recreate in public green spaces, which is likely to exacerbate the psychological impacts of the pandemic. In the current study, we seek to understand whether greenery can support mental health even with insufficient outdoor exposure in times of physical isolation from the outdoor environment. METHODS: Between 17 May and 10 June, 2020, we conducted an online survey among 323 students (21.99 ± 3.10 years; 31% male) in health-related programs from two universities in the city of Plovdiv, Bulgaria. Severities of depressive and anxiety symptoms over the past two weeks were measured with the Patient Health Questionnaire 9-item and the Generalized Anxiety Disorder 7-item scale. We employed two self-reported measures of greenery experienced indoors (number of houseplants in the home and proportion of exterior greenery visible from inside the home) and two measures of greenery experienced outdoors (presence/absence of a domestic garden and availability of neighborhood greenery). Restorative quality of the home (the "being away" dimension of the Perceived Restorativeness Scale; PRS) and the neighborhood (the "being away" and "fascination" dimensions of the PRS), engagement with outdoor greenery (frequency of different types of interaction) and perceived social support were treated as mediators. Associations between greenery and mental health were tested using generalized linear regression and logistic regression. Structural equation modelling (SEM) techniques were used to test the theoretically-indicated relations among the variables. RESULTS: Clinically-meaningful symptoms of moderate depression and anxiety were reported by approximately 33% and 20% of the students, respectively. The relative abundance of greenery visible from the home or in the neighborhood was associated with reduced depressive/anxiety symptoms and lower depression/anxiety rates. Having more houseplants or a garden was also associated with some of these markers of mental health. As hypothesized, the mental health-supportive effects of indoor greenery were largely explained by increased feelings of being away while at home. Neighborhood greenery contributed to neighborhood restorative quality, which in turn facilitated social support and more frequent engagement with greenery, and that led to better mental health. CONCLUSIONS: Students who spent most of their time at home during the COVID-19 epidemic experienced better mental health when exposed to more greenery. Our findings support the idea that exposure to greenery may be a valuable resource during social isolation in the home. However, causal interpretation of these associations is not straightforward.

Group-based cardiac rehabilitation interventions. A challenge for physical and rehabilitation medicine physicians: a randomized controlled trial.

BACKGROUND: In recent decades, many studies are focused on different training modalities comparison in patients with cardiac diseases. High intensity aerobic interval training (HIAIT) has been considered as an alternative approach to moderate-intensity continuous training (MICT) in rehabilitation of patients with chronic heart failure (CHF). AIM: To highlight the superiority of the modified group-based HIAIT intervention (m-Ullevaal) compared to the moderate-intensity continuous training (MICT), also to encourage physical and rehabilitation medicine (PRM) physicians to apply the m-Ullevaal intervention in routine cardiac rehabilitation (CR) practice. DESIGN: А single-blind, prospective randomized controlled trial. SETTING: Medical Center of Rehabilitation and Sports Medicine, Plovdiv, Bulgaria outpatients were enrolled. POPULATION: One hundred and twenty subjects of both genders, mean age of 63.73±6.68 years, with stable CHF, NYHA classes II to IIIB, were randomly assigned to m-Ullevaal group (N.=60) or to MICT (N.=60) group. Both CR protocols were conducted throughout a 12-week period. METHODS: Functional exercise capacity (FEC), assessed with six-minute walk test, and peak oxygen uptake (VO2peak), left ventricular ejection fraction (LVEF), m-Borg's perceived exertion scale (mBPES), and quality of life (QoL) were outcome measures evaluated. RESULTS: Significant improvement in FEC (P<0.001), LVEF (P<0.001), mBPES and QoL (P<0.001), was observed 12 weeks after both CR interventions (T2). However, the participants performed m-Ullevaal protocol achieved a greater improvement compared to those performed MICT (P<0.001). CONCLUSIONS: The m-Ullevaal protocol seems to be more beneficial and more effective compared to MICT. PRM physicians can efficiently apply the m-Ullevaal protocol in CHF patients rehabilitation. CLINICAL REHABILITATION IMPACT: Group-based HIAIT interventions can be widely applied by PRM physicians in CHF patients rehabilitation.

Residential greenspace is associated with mental health via intertwined capacity-building and capacity-restoring pathways.

BACKGROUND: Experiences afforded by natural settings promote health by helping people to build new adaptive capacities and to restore existing capacities. The aim of this study was to examine relations among restorative experience, mindfulness, rumination and psychological resilience in pathways linking residential greenspace to anxiety and depression symptoms. METHODS: We sampled 529 university students residing in Plovdiv, Bulgaria. Residential greenspace was measured in terms of the Normalized Difference Vegetation Index (NDVI) and tree cover density for different buffer sizes. Symptoms of anxiety and depression were measured with the Generalized Anxiety Disorder scale (7-item) and Patient Health Questionnaire (9-item), respectively. The following mediators were assessed by self-report: perceived greenspace, restorative quality of the neighborhood, dispositional mindfulness, rumination, and psychological resilience. Structural equation modelling techniques were used to test the theoretically-indicated relations among the variables. RESULTS: Across different buffer sizes, higher greenspace was consistently associated with reduced scores on the anxiety and depression scales. This effect was partially mediated via several pathways. Specifically, higher NDVI 500-m was associated with higher perceived greenspace, and in turn, with higher restorative quality, and then with higher mindfulness, lower rumination, and greater resilience to stress, and consequently, with better mental health. CONCLUSIONS: Our findings affirm the potential of greenspace for building psychological resilience and promoting health by offsetting dysfunctional rumination and facilitating mindfulness as components of intertwined capacity-building and capacity-restoring pathways.

Pathways and contingencies linking road traffic noise to annoyance, noise sensitivity, and mental Ill-Health.

CONTEXT: Traffic noise may contribute to depression and anxiety through higher noise annoyance (NA). However, little is known about noise sensitivity (NS) and mental health status as contextual factors. OBJECTIVE: We tested three hypotheses: (1) Traffic noise is associated with mental ill-health through higher NA; (2) Mental ill-health and NS moderate the association between traffic noise and NA; and (3) NS moderates the indirect effect of traffic noise on mental ill-health. SUBJECTS AND METHODS: We used a convenience sample of 437 undergraduate students from the Medical University in Plovdiv, Bulgaria (mean age 21 years; 35% male). Residential road traffic noise (LAeq; day equivalent noise level) was calculated using a land use regression model. Depression and anxiety symptoms were measured with the Patient Health Questionnaire 9-item (PHQ-9) and the Generalized Anxiety Disorder 7-item (GAD-7) scale, respectively. NA was measured using a 5-point verbal scale. The Noise Sensitivity Scale Short Form (NSS-SF) was used to measure NS. To investigate how these variables intertwine, we conducted mediation, moderation and moderated mediation analyses. RESULTS: LAeq was indirectly associated with higher PHQ-9/GAD-7 scores through higher NA, but only in the low NS group. The relationship between LAeq and NA was stronger in students reporting depression/anxiety. While high NS was associated with high NA even at low noise levels, LAeq contributed to NA only in students low on NS. CONCLUSIONS: We found complex conditional relationships between traffic noise, annoyance and mental ill-health. Understanding respective vulnerability profiles within the community could aid noise policy and increase efficacy of interventions.

Psychometric Properties and Contribution to Mental Health of the Bulgarian version of the 4-Factor Ruminative Thought Style Questionnaire.

BACKGROUND: The Ruminative Thought Style Questionnaire (RTSQ) is a multifaceted measure of general trait rumination. However, there is no instrument for measuring rumination in Bulgarian, which limits progress in the field. AIM: We aimed to validate the RTSQ in Bulgarian and examine its psychometric properties and contribution to several mental health outcomes. MATERIALS AND METHODS: We sampled 529 undergraduate students (18 ­ 35 years; 33.6% male; 80.9% Bulgarian) from the Medical University in Plovdiv, Bulgaria. They completed a questionnaire asking about rumination (RTSQ), mental health, and sociodemographic information. The RTSQ was first translated to Bulgarian. Its internal consistency was assessed with Cronbach's alpha. Confirmatory factor analysis was performed on the 4-factor RTSQ, and multi-group CFA examined its measurement invariance. Structural equation modelling was used to test the relations between the RTSQ factors, depression, anxiety, and resilience to stress. RESULTS: The RTSQ had acceptable internal consistency (α ≥ 0.8) and its 4-factor model had good fit to the data. In addition, its measurement invariance was supported across languages and cultures of administration. We observed differential associations with depression, anxiety, and resilience, with some of the RTSQ factors emerging as maladaptive (problem-focused thoughts and repetitive thoughts), while others as neutral (anticipatory thoughts) or potentially supportive of resilience (counterfactual thinking). CONCLUSION: The RTSQ was successfully validated in Bulgarian and represents a reliable measure of trait rumination. It could be useful in gaining further insight into strategies adopted by individuals to cope with stressors and could help develop interventions supporting healthy coping styles. These findings should be replicated in other non-clinical/clinical populations.

Lower Noise Annoyance Associated with GIS-Derived Greenspace: Pathways through Perceived Greenspace and Residential Noise.

Growing amounts of evidence support an association between self-reported greenspace near the home and lower noise annoyance; however, objectively defined greenspace has rarely been considered. In the present study, we tested the association between objective measures of greenspace and noise annoyance, with a focus on underpinning pathways through noise level and perceived greenspace. We sampled 720 students aged 18 to 35 years from the city of Plovdiv, Bulgaria. Objective greenspace was defined by several Geographic Information System (GIS)-derived metrics: Normalized Difference Vegetation Index (NDVI), tree cover density, percentage of green space in circular buffers of 100, 300 and 500 m, and the Euclidean distance to the nearest structured green space. Perceived greenspace was defined by the mean of responses to five items asking about its quantity, accessibility, visibility, usage, and quality. We assessed noise annoyance due to transportation and other neighborhood noise sources and daytime noise level (Lday) at the residence. Tests of the parallel mediation models showed that higher NDVI and percentage of green space in all buffers were associated with lower noise annoyance, whereas for higher tree cover this association was observed only in the 100 m buffer zone. In addition, the effects of NDVI and percentage of green space were mediated by higher perceived greenspace and lower Lday. In the case of tree cover, only perceived greenspace was a mediator. Our findings suggest that the potential for greenspace to reduce noise annoyance extends beyond noise abatement. Applying a combination of GIS-derived and perceptual measures should enable researchers to better tap individuals' experience of residential greenspace and noise.

Pathways linking residential noise and air pollution to mental ill-health in young adults.

BACKGROUND: Recent years have seen growing, but still tentative, evidence of the potential associations of environmental noise and air pollution with mental disorders. In the present study, we aimed to examine the associations between residential noise and air pollution exposures and general mental health in young adults with a focus on underlying processes METHODS: We sampled 720 students (18-35 years) from one university in the city of Plovdiv, Bulgaria. Residential noise (LAeq; day equivalent noise level) and air pollution (NO2) were assessed at participant's residential address by land use regression models. General mental health was measured with a short form of the General Health Questionnaire (GHQ). The following putative mediators were considered: annoyance from environmental pollution, sleep disturbance, restorative quality of the neighborhood, neighborhood social cohesion, and commuting/leisure time physical activity. Structural equation modeling was used to analyze the theoretically-indicated interplay between exposures, mediators, and GHQ. RESULTS: We observed an association between higher LAeq and GHQ, in which environmental annoyance and neighborhood restorative quality emerged as key mediators. First, LAeq was associated with higher annoyance, and through it with lower restorative quality, and then in turn with lower physical activity, and thus with higher GHQ. Simultaneously, higher annoyance was associated with higher sleep disturbance, and thereby with higher GHQ. NO2 had no overall association with GHQ, but it was indirectly associated with it through higher annoyance, lower restorative quality, and lower physical activity working in serial. CONCLUSION: We found evidence that increased residential noise was related to mental ill-health through several indirect pathways. Air pollution was associated with mental health only indirectly.

Multiple pathways link urban green- and bluespace to mental health in young adults.

BACKGROUND: A growing body of scientific literature indicates that urban green- and bluespace support mental health; however, little research has attempted to address the complexities in likely interrelations among the pathways through which benefits plausibly are realized. OBJECTIVES: The present study examines how different plausible pathways between green/bluespace and mental health can work together. Both objective and perceived measures of green- and bluespace are used in these models. METHODS: We sampled 720 students from the city of Plovdiv, Bulgaria. Residential greenspace was measured in terms of the Normalized Difference Vegetation Index (NDVI), tree cover density, percentage of green areas, and Euclidean distance to the nearest green space. Bluespace was measured in terms of its presence in the neighborhood and the Euclidean distance to the nearest bluespace. Mental health was measured with the 12-item form of the General Health Questionnaire (GHQ-12). The following mediators were considered: perceived neighborhood green/bluespace, restorative quality of the neighborhood, social cohesion, physical activity, noise and air pollution, and environmental annoyance. Structural equation modelling techniques were used to analyze the data. RESULTS: Higher NDVI within a 300 m buffer around the residence was associated with better mental health through higher perceived greenspace; through higher perceived greenspace, leading to increased restorative quality, and subsequently to increased physical activity (i.e., serial mediation); through lower noise exposure, which in turn was associated with lower annoyance; and through higher perceived greenspace, which was associated with lower annoyance. Presence of bluespace within a 300 m buffer did not have a straightforward association with mental health owing to competitive indirect paths: one supporting mental health through higher perceived bluespace, restorative quality, and physical activity; and another engendering mental ill-health through higher noise exposure and annoyance. CONCLUSIONS: We found evidence that having more greenspace near the residence supported mental health through several indirect pathways with serial components. Conversely, bluespace was not clearly associated with mental health.

Residential road traffic noise as a risk factor for hypertension in adults: Systematic review and meta-analysis of analytic studies published in the period 2011-2017.

Multiple cross-sectional studies indicated an association between hypertension and road traffic noise and they were recently synthetized in a WHO systematic evidence review. However, recent years have seen a growing body of high-quality, large-scale research, which is missing from the WHO review. Therefore, we aimed to close that gap by conducting an updated systematic review and meta-analysis on the exposure-response relationship between residential road traffic noise and the risk of hypertension in adults. Studies were identified by searching MEDLINE, EMBASE, the Internet, conference proceedings, reference lists, and expert archives in English, Russian, and Spanish through August 5, 2017. The risk of bias for each extracted estimate and the overall quality of evidence were evaluated using a list of predefined safeguards against bias related to different study characteristics and the Grading of Recommendations Assessment, Development and Evaluation system, respectively. The inverse variance heterogeneity (IVhet) model was used for meta-analysis. The possibility of publication bias was evaluated by funnel and Doi plots, and asymmetry in these was tested with Egger's test and the Luis Furuya-Kanamori index, respectively. Sensitivity analyses included leave-one-out meta-analysis, subgroup meta-analysis with meta-regressions, and non-linear exposure-response meta-analysis. Based on seven cohort and two case-control studies (n = 5 514 555; 14 estimates; Lden range ≈ 25-90 dB(A)), we found "low" evidence of RR per 10 dB(A) = 1.018 (95% CI: 0.984, 1.053), moderate heterogeneity (I2 = 46%), and no publication bias. In the subgroup of cohort studies, we found "moderate" evidence of RR per 10 dB(A) = 1.018 (95% CI: 0.987, 1.049), I2 = 31%, and no publication bias. In conclusion, residential road traffic noise was associated with higher risk of hypertension in adults, but the risk was lower than previously reported in the systematic review literature.

Implementation of Instrument Based on Eight Health Related Quality of Life Domains for Measuring of Willingness to Pay for Psoriasis Treatment.

BACKGROUND: Psoriasis vulgaris (PsV) is a chronic skin condition that has a major impact on health-related quality of life (HRQOL). AIM: To determine the individual burden of PsV on HRQOL using willingness to pay (WTP) instrument. MATERIALS AND METHODS: Fifty-one consecutive PsV patients were asked to evaluate their overall health and psoriasis affected health by visual analogue scale (VAS), and interviewed on 8 domains (physical, emotional, sleep, work, social, self-care, intimacy, and concentration) of HRQOL and WTP for a hypothetical cure in each domain. Two additional questions proposing 6 alternatives for therapy were also asked. The analysis is performed with descriptive and frequency statistics, Mann-Whitney and Kruskal-Wallis tests. RESULTS: The domains ranked highly were: physical comfort (90%), social comfort (77%), emotional health (75%) and work (53%). The following tendencies concerning WTP for top four impacted domains were found: the median WTP were the highest in the top impacted domains; the younger patients were willing to pay more than the older ones; the highest median WTP amounts appear in the lowest income group; the highest median WTP is associated with smaller psoriasis affected health VAS scores. The largest proportion and number of patients (37.3%, n=19) stated preferences for the systemic therapy. The second preferred choice was the thalassotherapy (29.4%, n=15). CONCLUSIONS: The utility and reliability of the instrument based on the assessment of WTP stated preferences for 8 domains of HRQOL for evaluation the individual burden of psoriasis were strongly supported.

Self-reported occupational noise may be associated with prevalent chronic obstructive pulmonary disease in the us general population.

INTRODUCTION: Occupational noise exposure and chronic obstructive pulmonary disease (COPD) are common in the United States, but so far their association has not been explored. Given the neuroimmunological effects of noise, such an association seems plausible. Thus, the present study aimed to explore the association of occupational noise exposure with prevalent COPD in the US general population. MATERIALS AND METHODS: We used data from the population-based National Health Interview Survey (NHIS) 2014. The cross-sectional association of self-reported duration of exposure to very loud noise during participants' occupational lifetime with self-reported COPD and emphysema was explored using weighted logistic regression. RESULTS AND DISCUSSION: The fully adjusted model yielded odds ratio (OR)≥15 years = 1.68 [95% confidence interval (CI): 1.28, 2.21] for COPD and OR≥15 years = 1.61 (95% CI: 1.13, 2.30) for emphysema. Race/ethnicity was a significant effect modifier. In sensitivity analysis with cumulative noise exposure based on a job exposure matrix, we found no effect. CONCLUSION: In conclusion, we found a relationship between self-reported occupational noise exposure and the risk of prevalent COPD in the US general population, but none with objective noise levels. Being the first study on the subject matter, and given the design limitations, these findings are tentative and should be treated with caution.

Lifetime exposure to self-reported occupational noise and prevalent rheumatoid arthritis in the National Health and Nutrition Examination Survey (2011-2012).

Multiple risk factors for rheumatoid arthritis (RA) have been studied, but there is a dearth of research on occupational noise, which is highly prevalent in the United States (U.S.). This study aimed to determine whether occupational noise exposure was associated with an elevated risk of prevalent RA in the U.S. general population. Data from the 2011 to 2012 cross-sectional, population-based National Health and Nutrition Examination Survey were used for secondary analysis. Self-reported lifetime exposure to very loud noise was linked to self-reported doctor-diagnosed RA in a sample of 4192 participants. Weighted logistic regression was used to obtain nationally representative prevalence odds ratios (OR). The main and fully adjusted models yielded OR = 3.98 (95% CI: 1.74, 9.11) and OR = 2.84 (95% CI: 1.23, 6.57) for participants exposed for ≥ 15 years compared to never exposed participants. Excluding those diagnosed with RA more than five years before the interview, the effect dropped to OR = 3.67 (95% CI: 1.06, 12.75) in the main model, and was no longer significant in the fully adjusted model (OR = 2.68, 95% CI: 0.80, 8.96). The only significant effect modifier was race/ethnicity, with higher risk in Non-Hispanic whites. To conclude, long-term occupational noise exposure might be a modifiable risk factor for RA, but currently, the evidence base is very thin and tenuous.

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 children's 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 0.48mmHg (95% CI: -0.87, 1.83) increase in systolic blood pressure (SBP) and 0.22mmHg (95% CI: -0.64, 1.07) in diastolic blood pressure (DBP) per 5dB increase in RTN at school/kindergarten; and 0.20mmHg (95% CI: -0.30, 0.71) increase in SBP and 0.03mmHg (95% CI: -0.18, 0.25) in DBP per 5dB 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 children's 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.

Heart disease attributed to occupational noise, vibration and other co-exposure: Self-reported population-based survey among Bulgarian workers.

BACKGROUND: Cardiovascular disease (CVD) is the main mortality cause worldwide. Noise and vibration are considered to be occupational risk factors, but little is known about their cardiovascular effects in Bulgaria in terms of gender and various professional groups. The aim of this study has been to investigate the risk of prevalent CVD, associated with occupational noise and vibration exposure. MATERIAL AND METHODS: We conducted a secondary analysis of the data from 3 waves of the European Working Conditions Survey (EWCS) 2001-2010 - a nationally-representative cross-sectional questionnaire survey covering 3149 workers aged ≥ 15 years in Bulgaria. Data on self-reported heart disease were linked to self-reported occupational noise and vibration, adjusting for other factors. Results from the 3 waves were pooled together using the inverse variance heterogeneity (IVhet) meta-analysis. RESULTS: For noise, the risk was elevated among women (relative risk (RR) = 1.26, 95% confidence interval (CI): 0.53-3.01), but not men (RR = 0.49, 95% CI: 0.14-1.65). Long-term workers had RR = 1.01, 95% CI: 0.60-1.69. For vibration, the risk was increased in all participants. It was higher among men (RR = 2.56, 95% CI: 1.60-4.09) than it was among women (RR = 1.32, 95% CI: 0.77-2.27). Among long-term, industrial, and service workers it was RR = 1.56, 95% CI: 1.02-2.40; RR = 1.10, 95% CI: 0.61-1.98, and RR = 1.18, 95% CI: 0.57-2.46, respectively. CONCLUSIONS: Occupational vibration was a risk factor for prevalent heart disease in Bulgaria. Noise was an alleged risk factor only among long-term workers and women. Med Pr 2016;67(4):435-445.

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.

Exposure-response relationship between traffic noise and the risk of stroke: a systematic review with meta-analysis.

Traffic noise is an established risk factor for some cardiovascular diseases such as hypertension and ischaemic heart disease, but the evidence regarding stroke is still limited. In this study we aimed to systematically review the related epidemiological data and make a meta-analysis of the risk of stroke morbidity associated with road and air traffic noise exposure. We searched articles in English, Spanish, and Russian indexed in MEDLINE, EMBASE, and Google Scholar on 24 November 2015. Qualitative synthesis was made for 13 studies, and 11 studies were included in quality effects meta-analyses. Overall, they were of high quality. Based on six studies (n≈8,790,671 participants) for road traffic noise, we found a pooled relative risk (RR) of stroke per 10 dB to be 1.01 (95 % CI: 0.96, 1.06). In the 70-75 dB noise range (versus <55 dB) RR increased to 1.29 (95 % CI: 0.74, 2.24). For air traffic noise we pooled five studies (n≈16,132,075 participants) and the RR per 10 dB was 1.01 (95 % CI: 1.00, 1.02). Road traffic group showed high heterogeneity whereas the air traffic group had none. Both groups showed evidence of publication bias. In conclusion, we have established a small but elevated risk of stroke to be associated with both road and air traffic noise exposure, but the association was statistically significant only with the latter. The effect of road traffic noise followed a non-linear trend.

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.

Association between Noise Pollution and Prevalent Ischemic Heart Disease.

BACKGROUND: Noise pollution is considered a risk factor for ischemic heart disease (IHD). Both are highly prevalent in Bulgaria, but their association has not been studied sufficiently. AIM: The aim of the present study was to examine the risk of IHD associated with road traffic (Lden) and lifetime occupational noise exposure (LONE) in a Bulgarian sample. MATERIALS AND METHODS: A cross-sectional survey was carried out among 513 residents of Plovdiv, Bulgaria. A questionnaire asked about doctor-diagnosed IHD, LONE and confounding factors. Lden was derived from official noise map after geocoding participants' addresses. In log-link Poisson regressions we investigated the relative risks of prevalent IHD. Sensitivity analyses examined subgroup differences. RESULTS: Lden ≥ 65 dB was associated with higher risk (RR=1.84, 95% CI: 0.61, 5.57) of IHD in long-term residents (≥ 20 years). LONE was associated with RR=1.76 (0.82, 3.78) for ever-exposed; and RR=2.35 (1.00, 5.52) for 15 - 47 years exposure. CONCLUSIONS: Exposure to Lden≥65 dB was associated with non-significantly higher risk of IHD. Longer LONE was consistently associated with higher risk. In some subgroups the effect of noise was more pronounced.

Evaluation of the social and economic burden of road traffic noise-attributed myocardial infarction in Bulgarian urban population.

Road traffic noise is a widely studied environmental risk factor for ischaemic heart disease and myocardial infarction in particular. Given that myocardial infarction is a leading disability and mortality cause in Bulgaria and that a significant proportion of the urban population is exposed to high noise levels, quantification of the burden of disease attributable to traffic noise is essential for environmental health policy making and noise control engineering. This study aimed at estimating the burden of the myocardial infarction cases attributable to road traffic noise in the Bulgarian urban population. We used the methodology for estimating the burden of disease attributable to environmental noise outlined by the World Health Organization. Risk data were extracted from a recently published meta-analysis providing updated exposure-response relationship between traffic noise and the risk for myocardial infarction. Based on these data we calculated the fraction of myocardial infarction cases attributable to traffic noise, loss of quality-adjusted life-years (QALYs), and the economic burden, assuming € 12,000 per QALY. About 2.9 % or 101 of all myocardial infarction cases could be attributed to road traffic noise. Fifty-five of these were fatal. Nine hundred and sixty-eight QALYs were lost to these cases. The monetary value of these QALYs was about € 11.6 million. Although the measures used in this study are crude and give only an approximation of the real burden of disease from road traffic noise, they are indicative of the important social and economic aspect of noise pollution in Bulgaria. Hopefully, these results will direct the attention of epidemiologists, environmental hygienists, and health economists to this pivotal environmental issue.