Epidemiological studies on noise and blood pressure in children: Observations and suggestions

Remote work: Aircraft noise implications, prediction, and management in the built environment

The COVID-19 pandemic has greatly changed workplace management. Most workplaces have adopted the work-from-home policy to minimize the risk of community spread. Consequently, housing estates remain largely occupied during office hours. Since some housing estates are situated in the vicinity of an airport, noise pollution resulted from the takeoff and landing of aircraft is now more noticed by residents, causing annoyance. This problem would be most acute for those located directly under the flight path. Before the pandemic, such aircraft operations had lower effect on the residents because most of them were not at home but at workplaces. Evidently, it is timely that more emphasis should now be placed during urban planning to predict and minimize aircraft noise in the built environment. This article first defines the aircraft noise metrics commonly used to assess environmental impact. Preceded by an overview of how aircraft noise affects the built environment, this article reviews how various aircraft noise prediction models have been used in urban planning. Lastly, this article reviews how aircraft noise can be managed for better acoustic comfort of the residents. Anticipating the adoption of hybrid work arrangement moving forward, this article aims to provide urban planning professionals with an avenue to understand how aircraft noise can negatively affect the built environment, which, in turn, justify why prediction and management of aircraft noise should be emphasized from the outset of urban planning.

Human exposure to aerosol from indoor gas stove cooking and the resulting nervous system responses

Our knowledge of the effects of exposure to indoor ultrafine particles (sub-100 nm, #/cm³ ) on human brain activity is very limited. The effects of cooking ultrafine particles (UFP) on healthy adults were assessed using an electroencephalograph (EEGs) for brain response. Peak ultrafine particle concentrations were approximately 3 × 10⁵ particle/cm^3, and the average level was 1.64 × 10⁵ particle/cm³ . The average particle number emission rate (S) and the average number decay rate (a+k) for chicken frying in brain experiments were calculated to be 2.82 × 10¹² (SD = 1.83 × 10¹² , R²  = 0.91, p = 0.0013) particles/min, 0.47 (SD = 0.30, R²  = 0.90, p < 0.0001) min^-1 , respectively. EEGs were recorded before and during cooking (14 min) and 30 min after the cooking sessions. The brain fast-wave band (beta) decreased during exposure, similar to people with neurodegenerative diseases. It subsequently increased to its pre-exposure condition for 70% of the study participants after 30 min. The brain slow-wave band to fast-wave band ratio (theta/beta ratio) increased during and after exposure, similar to observed behavior in early-stage Alzheimer's disease (AD) patients. The brain then tended to return to its normal condition within 30 min following the exposure. This study suggests that chronically exposed people to high concentrations of cooking aerosol might progress toward AD.

The impact on heart rate and blood pressure following exposure to ultrafine particles from cooking using an electric stove

Cooking is a major source of indoor particulate matter (PM), especially ultrafine particles (UFPs). Long-term exposure to fine and ultrafine particles (UFPs) has been associated with adverse human health effects. Toxicological studies have demonstrated that exposure to PM_2.5 (particles with aerodynamic diameter smaller than 2.5 μm) may result in increased blood pressure (BP). Some clinical studies have shown that acute exposure to PM_2.5 causes changes in systolic (SBP) and diastolic blood pressure (DBP), depending on the source of particles. Studies assessing the effect of exposure to cooking PM on BP and heart rate (HR) using electric or gas stoves are not well represented in the literature. The aim of this investigation was to perform controlled studies to quantify the exposure of 50 healthy volunteer participants to fine and ultrafine particles emitted from a low-emissions recipe for frying ground beef on an electric stove. The BP and heart rate (HR) of the volunteers were monitored during exposure and after the exposure (2 h post-exposure). Maximum UFP and PM_2.5 concentrations were 6.5 × 10⁴ particles/cm³ and 0.017 mg/m³, respectively. Exposure to UFPs from frying was associated with statistically significant increases in the SBP. The lack of food and drink during the 2 h post-cooking period was also associated with a statistically significant reduction in SBP. No statistically significant changes in DBP were observed. Physiological factors, including heat stress over the stove, movements and anxiety, could be responsible for an elevation in HR at the early stages of the experiments with a subsequent drop in HR after 90 min post-cooking, when study participants were relaxed in a living room.

Understanding the relationship between air traffic noise exposure and annoyance in populations living near airports in France

Since the 2000s, increased aircraft noise annoyance has been observed in the populations living near airports. The DEBATS-study compared the exposure-response relationship estimated among airports' residents in France with old and new EU standard curves. It also examines whether non-acoustical factors may explain this annoyance. For 1244 adults living near three French airports, information about demographic and socio-economic factors as well as aircraft noise annoyance, situational, personal and attitudinal factors was collected with a face-to-face questionnaire. Outdoor aircraft noise exposure was estimated by linking home address to noise exposure maps. Logistic regression models were used to investigate the association between annoyance and a broad range of other variables in addition to the L_den. Severe noise annoyance was associated not only with increased aircraft noise levels, but also with non-acoustical factors. Annoyance was higher than predicted by the old EU standard curve when estimated with the model including non-acoustical factors in addition to the L_den. It was even higher when only noise exposure was considered. However, annoyance was lower in DEBATS than predicted by the new EU standard curve provided by WHO. The increase of noise annoyance does not seem to be explained by the factors already mentioned in the literature as possible explanations. However, it cannot be ruled out that methodological differences in the HA assessment may be the reason for changes in annoyance over the years. For this reason, we argue for a definition of HA derived substantially as recommended by ICBEN. The findings of the DEBATS study also confirm that taking into account non-acoustical factors such as situational, personal and attitudinal factors would improve annoyance predictions.

Sustainable Mobility: A Review of Possible Actions and Policies

In this paper, a review of the main actions and policies that can be implemented to promote sustainable mobility is proposed. The work aims to provide a broad, albeit necessarily not exhaustive, analysis of the main studies and research that from different points of view have focused on sustainable mobility. The structure of the paper enables the reader to easily identify the topics covered and the studies related to them, so as to guide him/her to the related in-depth studies. In the first part of the paper, there is a preliminary analysis of the concept of sustainable mobility, the main transport policies implemented by the European Union and the USA, and the main statistical data useful to analyze the problem. Next, the main policies that can promote sustainable mobility are examined, classifying them into three topics: Environmental, socio-economic, and technological. Many of the policies and actions examined could be classified into more than one of the three categories used; for each of them, there is a description and the main literature work on which the topic can be analyzed in more detail. The paper concludes with a discussion on the results obtained and the prospects for research.

Cyclists' noise exposure in a Brazilian medium-sized city

This study aimed to assess cyclists' exposure to noise in a medium-sized Brazilian city. Mobile sensors were used to conduct noise measurements in streets with and without dedicated cycling infrastructures. The method can be summarized in the following procedures: i) characterization of the study area; ii) data collection and validation; iii) calculation of exposure indicators; and iv) comparison and representation of the results on maps. Two strategies were adopted for the analysis, namely, spatial data aggregation and temporal data aggregation. Thus, measurements were initially organized in 1,200 nodes distributed along the paths. The results indicate that bicycle riders in São Carlos may be exposed, in some routes, to a high proportion of high noise-level segments. In the two routes selected for this study, the cyclist was exposed to noise levels above the adopted threshold (> 75dBA) in 33.2% and 18.9% of the nodes. Also, the possibility of simultaneously working with two related indicators has broadened the classification criteria of the route segments regarding noise exposure.

Assessing personal noise exposure and its relationship with mental health in Beijing based on individuals' space-time behavior

BACKGROUND

Most prior studies adopted a static residence-based approach in the assessment of noise exposure, which may lead to biased exposure estimates and misleading findings in noise-health relationships. Relatively little is known about personal noise exposure based on individuals' space-time behavior and its effect on mental health.

OBJECTIVES

This study aims to analyze and geo-visualize personal exposure to noise in various microenvironments based on individuals' space-time trajectories at a very fine resolution and to further investigate the relationships between mental health and personal noise exposure at both the activity/travel episode level and the entire day level.

METHODS

Individual-level real-time data were collected with portable noise sensors and GPS trackers from a sample of 117 residents aged 18-60 years old from December 2017 to February 2018 in Beijing, China. Descriptive statistics and geo-visualization methods were used to examine how personal noise exposure varied across different activity types, travel modes, and among residents living in the same residential neighborhood on workdays and weekends based on individuals' space-time behaviors. Logistic regression models were applied to examine the relationships between personal noise exposure and self-reported mental health.

RESULTS

We observed substantial differences in personal noise exposure across different activity types. The equivalent sound levels (L_eq, dB(A)) for sleeping were the lowest, while the average L_eq for work-related activities was the highest in indoor environments. The noise exposure levels for activities in outdoor environments were higher than indoor noise levels but differed between workdays and weekends. Variations in noise exposure associated with different travel modes were also evident, with the average L_eq for public transport being much higher than that of other travel modes. A-weighted equivalent sound pressure level measured over 24 h for each individual (L_eq,24h, dB(A)) varied significantly for residents living in the same residential neighborhood, ranging from 36 to 97 dB(A), with the majority of respondents being exposed to noise levels above 55 dB(A) on both workdays and weekends. Regarding the noise-health relationships, the modeling results showed that individual-level objective noise exposure based on space-time behaviors measured over a 24-h period (L_eq,24h) was strongly associated with residents' self-reported mental health. Higher exposure to noise was significantly associated with worse mental health. However, personal noise exposure at the activity/travel episode level (L_eq) was not significantly associated with mental health on weekdays, but this link turned out to be significant in the weekend model.

CONCLUSIONS

There were large variations in personal noise exposure associated with different activity types and travel modes, and the individual-level noise exposure varied significantly across time of day and between residents living in the same residential neighborhood. Variations in personal exposure strongly depend on different space-time behaviors and individual-specific microenvironments experienced in daily life, and they were significantly correlated with mental health.

Green space, air pollution, traffic noise and cardiometabolic health in adolescents: The PIAMA birth cohort

BACKGROUND

Green space has been hypothesized to improve cardiometabolic health of adolescents, whereas air pollution and traffic noise may negatively impact cardiometabolic health.

OBJECTIVES

To examine the associations of green space, air pollution and traffic noise with cardiometabolic health in adolescents aged 12 and 16 years.

METHODS

Waist circumference, blood pressure, cholesterol and glycated hemoglobin (HbA1c) were measured in subsets of participants of the Dutch PIAMA birth cohort, who participated in medical examinations at ages 12 (n = 1505) and/or 16 years (n = 797). We calculated a combined cardiometabolic risk score for each participant, with a higher score indicating a higher cardiometabolic risk. We estimated exposure to green space (i.e. the average Normalized Difference Vegetation Index (NDVI) and percentages of green space in circular buffers of 300 m and 3000 m), air pollution (by land-use regression models) and traffic noise (using the Standard Model Instrumentation for Noise Assessments (STAMINA) model) at the adolescents' home addresses at the time of the medical examinations. We assessed associations of these exposures with cardiometabolic health outcomes at ages 12 and 16 by multiple linear regression, adjusting for potential confounders.

RESULTS

We did not observe consistent patterns of associations of green space, air pollution and traffic noise with the cardiometabolic risk score, blood pressure, total cholesterol levels, the total/HDL cholesterol ratio and HbA1c. We found inverse associations of air pollution with waist circumference at both age 12 and 16. These associations weakened after adjustment for region, except for particulate matter with a diameter of <2.5 μm (PM_2.5) at age 12. The association of PM_2.5 with waist circumference at age 12 remained after adjustment for green space and road traffic noise (adjusted difference - 1.42 cm [95% CI -2.50, -0.35 cm] per 1.16 μg/m³ increase in PM_2.5).

CONCLUSION

This study does not provide evidence for beneficial effects of green space or adverse effects of air pollution and traffic noise on cardiometabolic health in adolescents.

Traffic noise exposure of high-rise residential buildings in urban area

Noise pollution is a major factor of environmental complaints in many cities, which has significant impacts on human health. As a dominating source of environmental noise, the impact of road traffic noise is increasing. Residents living in high-rise buildings along the main road are severely affected by traffic noise. In order to assess the noise level of urban area along the main road in Guangzhou, three buildings were selected to conduct traffic noise measurements, and the questionnaire about traffic noise impact on human being was completed. Through the questionnaire, around 70% of participants consider the traffic noise has negative effect, and about 60% of participants consider the noise has moderate or much higher impact on physical comfort. Around 65% of participants consider the noise had moderately or much higher impact on their psychological comfort. By analyzing the measured data, all of the measured noise levels in three buildings exceed the recommended limit of 55 dB (A) in the daytime and 45 dB (A) in the night for residence, and the exceeded value can be up to 16 dB (A). By comparing the fitting curve of noise level transfer function on each floor relative to the reference floor, the quadratic polynomial was selected to plot the transfer function rather than cubic polynomial.

Full-time exposure to occupational noise during pregnancy was associated with reduced birth weight in a nationwide cohort study of Swedish women

Noise is a common exposure in the occupational work environment. Earlier studies of occupational noise and pregnancy outcome are few and show mixed results. To investigate if objectively assessed exposure to occupational noise during pregnancy is associated with reduced intrauterine growth and/or preterm birth a nationwide cohort study of 857,010 single births was initiated. Individual information on occupation and risk factors was retrieved from prenatal care interviews at pregnancy week 10. Occupational noise was classified into three exposure categories <75, 75-85, >85 dBA by a job exposure matrix. Odds ratios were adjusted for BMI, smoking, parity, education, physically strenuous work and low job control. Exposure to high (>85 dBA) levels of occupational noise throughout the pregnancy (full time workers) was associated with an increased risk of the child being born small for gestational age, OR 1.44 (95% CI 1.01 to 2.03) compared to noise exposure <75 dBA. A similar increase was seen for low birth weight OR 1.36 (95% CI 1.03 to 1.80) for high levels of noise. No clear association was seen for preterm birth. No consistent effects on birth outcome was observed in women who had worked part-time or were on leave of absence >21 days (median). In summary, full-time exposure to high levels of noise during pregnancy was associated with a slightly reduced fetal growth but not with preterm birth. The effect of intermediate occupational noise exposure (75-85 dBA) showed a small, but statistically increased risk for all studied birth outcomes. The study strengthens the evidence that pregnant women should not be long-term exposed to high levels >85 dBA of occupational noise during pregnancy. Intermediate exposure should be studied further.

The Adverse Effects of Environmental Noise Exposure on Oxidative Stress and Cardiovascular Risk

Epidemiological studies have provided evidence that traffic noise exposure is linked to cardiovascular diseases such as arterial hypertension, myocardial infarction, and stroke. Noise is a nonspecific stressor that activates the autonomous nervous system and endocrine signaling. According to the noise reaction model introduced by Babisch and colleagues, chronic low levels of noise can cause so-called nonauditory effects, such as disturbances of activity, sleep, and communication, which can trigger a number of emotional responses, including annoyance and subsequent stress. Chronic stress in turn is associated with cardiovascular risk factors, comprising increased blood pressure and dyslipidemia, increased blood viscosity and blood glucose, and activation of blood clotting factors, in animal models and humans. Persistent chronic noise exposure increases the risk of cardiometabolic diseases, including arterial hypertension, coronary artery disease, diabetes mellitus type 2, and stroke. Recently, we demonstrated that aircraft noise exposure during nighttime can induce endothelial dysfunction in healthy subjects and is even more pronounced in coronary artery disease patients. Importantly, impaired endothelial function was ameliorated by acute oral treatment with the antioxidant vitamin C, suggesting that excessive production of reactive oxygen species contributes to this phenomenon. More recently, we introduced a novel animal model of aircraft noise exposure characterizing the underlying molecular mechanisms leading to noise-dependent adverse oxidative stress-related effects on the vasculature. With the present review, we want to provide an overview of epidemiological, translational clinical, and preclinical noise research addressing the nonauditory, adverse effects of noise exposure with focus on oxidative stress. Antioxid. Redox Signal. 28, 873-908.

WHO Environmental Noise Guidelines for the European Region: A Systematic Review on Environmental Noise and Cardiovascular and Metabolic Effects: A Summary

To update the current state of evidence and assess its quality, we conducted a systematic review on the effects of environmental noise exposure on the cardio-metabolic systems as input for the new WHO environmental noise guidelines for the European Region. We identified 600 references relating to studies on effects of noise from road, rail and air traffic, and wind turbines on the cardio-metabolic system, published between January 2000 and August 2015. Only 61 studies, investigating different end points, included information enabling estimation of exposure response relationships. These studies were used for meta-analyses, and assessments of the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). A majority of the studies concerned traffic noise and hypertension, but most were cross-sectional and suffering from a high risk of bias. The most comprehensive evidence was available for road traffic noise and Ischeamic Heart Diseases (IHD). Combining the results of 7 longitudinal studies revealed a Relative Risk (RR) of 1.08 (95% CI: 1.01-1.15) per 10 dB (LDEN) for the association between road traffic noise and the incidence of IHD. We rated the quality of this evidence as high. Only a few studies reported on the association between transportation noise and stroke, diabetes, and/or obesity. The quality of evidence for these associations was rated from moderate to very low, depending on transportation noise source and outcome. For a comprehensive assessment of the impact of noise exposure on the cardiovascular and metabolic system, we need more and better quality evidence, primarily based on longitudinal studies.

Road traffic noise and children's inattention

BACKGROUND

An increasing number of children are exposed to road traffic noise levels that may lead to adverse effects on health and daily functioning. Childhood is a period of intense growth and brain maturation, and children may therefore be especially vulnerable to road traffic noise. The objective of the present study was to examine whether road traffic noise was associated with reported inattention symptoms in children, and whether this association was mediated by sleep duration.

METHODS

This study was based on the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health. Parental reports of children's inattention at age 8 were linked to modelled levels of residential road traffic noise. We investigated the association between inattention and noise exposure during pregnancy (n = 1934), noise exposure averaged over 5 years (age 3 to 8 years; n = 1384) and noise exposure at age 8 years (n = 1384), using fractional logit response models. The participants were children from Oslo, Norway.

RESULTS

An association with inattention at age 8 years was found for road traffic noise exposure at age 8 years (coef = .0083, CI = [.0012, .0154]; 1.2% point increase in inattention score per 10 dB increase in noise level), road traffic noise exposure average for the last 5 years (coef = .0090, CI = [.0016, .0164]; 1.3% point increase/10 dB), and for pregnancy road traffic noise exposure for boys (coef = .0091, CI = [.0010, .0171]), but not girls (coef = -.0021, CI = [-.0094, .0053]). Criteria for doing mediation analyses were not fulfilled.

CONCLUSION

Results indicate that road traffic noise has a negative impact on children's inattention. We found no mediation by sleep duration.

A preliminary investigation of noise impact within metro stations in the urban city of Guangzhou, China

The noise in the metro station is synthesized from a variety of different noise sources. Excessive noise exposure will bring serious impacts on humans' health. To alleviate the shortage of the urban land, most metro stations are planning to develop convenience stores and shopping malls. In order to evaluate the potential noise impact on humans' comfort in the metro stations, this study selected four representative stations of Guangzhou Metro Line 1 to carry out a preliminary questionnaire survey of 226 respondents for the perception and perform a noise measurement. Additionally, platform screen doors as a potential method for noise mitigation were examined. The results show that the noise caused by trains was dominant in the metro stations; however, the noise impact by public broadcast and passengers cannot be ignored. The noise levels of the transfer stations were obviously greater than the normal stations, especially during the peak hours. In addition, people in the metro stations have potential exposure to noise that the noise levels exceed the criteria limit of China, which would bring discomfort for humans; however, the normal activities of people would not be impacted. The platform screen doors should be further improved or relevant noise mitigation methods should be taken into account to reduce the noise level within the criteria limit.

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.

Suitability of blood-pressure-to-height ratio as the criterion for high blood pressure in children in an environmental study

BACKGROUND

Blood-pressure-to-height ratio is considered a simple, accurate, inexpensive and non-age-dependent index for screening high blood pressure in a clinical setting, but its suitability in epidemiological surveys was not taken into consideration. The aim of this study was to test the suitability of blood-pressure-to-height ratio against blood pressure for age percentiles for the identification of high blood pressure in an environmental study.

METHODS

The sample consisted of 2195 children, aged 3 to 15 years, whose blood pressure was measured as part of an environmental study in Belgrade, Serbia. High blood pressure was estimated using percentiles (gold standard) and blood-pressure-to-height ratios for systolic and diastolic pressures separately (proposed criterion). The optimal cut-offs of the blood-pressure-to-height ratio (BPHR) were selected based on Youden's index (sensitivity + specificity - 1) calculated from the receiver operator characteristic curve analysis.

RESULTS

The proposed criterion identified five times more cases of high blood pressure in the investigated children of all age groups in comparison to the gold standard. The optimal cut-off values were selected based on the sensitivity and specificity values by age groups and gender.

CONCLUSION

Blood-pressure-to-height ratio can be a reliable criterion for the estimation of high blood pressure in epidemiological studies. This is the first study on the applicability of blood-pressure-to-height ratio in Serbian children, but it may not be easily generalized to other populations due to small sample size across the examined age groups and potential diversities in risk factors for high blood pressure. Applied in epidemiological studies, BPHR would help researchers estimate the role of certain environmental factors on blood pressure in children.

Car free cities: Pathway to healthy urban living

BACKGROUND

Many cities across the world are beginning to shift their mobility solution away from the private cars and towards more environmentally friendly and citizen-focused means. Hamburg, Oslo, Helsinki, and Madrid have recently announced their plans to become (partly) private car free cities. Other cities like Paris, Milan, Chengdu, Masdar, Dublin, Brussels, Copenhagen, Bogota, and Hyderabad have measures that aim at reducing motorized traffic including implementing car free days, investing in cycling infrastructure and pedestrianization, restricting parking spaces and considerable increases in public transport provision. Such plans and measures are particularly implemented with the declared aim of reducing greenhouse gas emissions. These reductions are also likely to benefit public health.

AIMS

We aimed to describe the plans for private car free cities and its likely effects on public health.

METHODS

We reviewed the grey and scientific literature on plans for private car free cities, restricted car use, related exposures and health.

RESULTS

An increasing number of cities are planning to become (partly) private car free. They mainly focus on the reduction of private car use in city centers. The likely effects of such policies are significant reductions in traffic-related air pollution, noise, and temperature in city centers. For example, up to a 40% reduction in NO2 levels has been reported on car free days. These reductions are likely to lead to a reduction in premature mortality and morbidity. Furthermore the reduction in the number of cars, and therefore a reduction in the need for parking places and road space, provides opportunities to increase green space and green networks in cities, which in turn can lead to many beneficial health effects. All these measures are likely to lead to higher levels of active mobility and physical activity which may improve public health the most and also provide more opportunities for people to interact with each other in public space. Furthermore, such initiatives, if undertaken at a sufficiently large scale can result in positive distal effects and climate change mitigation through CO2 reductions. The potential negative effects which may arise due to motorized traffic detouring around car free zone into their destinations also need further evaluation and the areas in which car free zones are introduced need to be given sufficient attention so as not to become an additional way to exacerbate socioeconomic divides. The extent and magnitude of all the above effects is still unclear and needs further research, including full chain health impact assessment modeling to quantify the potential health benefits of such schemes, and exposure and epidemiological studies to measure any changes when such interventions take place.

CONCLUSIONS

The introduction of private car free cities is likely to have direct and indirect health benefits, but the exact magnitude and potential conflicting effects are as yet unclear. This paper has overviewed the expected health impacts, which can be useful to underpin policies to reduce car use in cities.

Urban and transport planning, environmental exposures and health-new concepts, methods and tools to improve health in cities

BACKGROUND

The majority of people live in cities and urbanization is continuing worldwide. Cities have long been known to be society's predominant engine of innovation and wealth creation, yet they are also a main source of pollution and disease.

METHODS

We conducted a review around the topic urban and transport planning, environmental exposures and health and describe the findings.

RESULTS

Within cities there is considerable variation in the levels of environmental exposures such as air pollution, noise, temperature and green space. Emerging evidence suggests that urban and transport planning indicators such as road network, distance to major roads, and traffic density, household density, industry and natural and green space explain a large proportion of the variability. Personal behavior including mobility adds further variability to personal exposures, determines variability in green space and UV exposure, and can provide increased levels of physical activity. Air pollution, noise and temperature have been associated with adverse health effects including increased morbidity and premature mortality, UV and green space with both positive and negative health effects and physical activity with many health benefits. In many cities there is still scope for further improvement in environmental quality through targeted policies. Making cities 'green and healthy' goes far beyond simply reducing CO2 emissions. Environmental factors are highly modifiable, and environmental interventions at the community level, such as urban and transport planning, have been shown to be promising and more cost effective than interventions at the individual level. However, the urban environment is a complex interlinked system. Decision-makers need not only better data on the complexity of factors in environmental and developmental processes affecting human health, but also enhanced understanding of the linkages to be able to know at which level to target their actions. New research tools, methods and paradigms such as geographical information systems, smartphones, and other GPS devices, small sensors to measure environmental exposures, remote sensing and the exposome paradigm together with citizens observatories and science and health impact assessment can now provide this information.

CONCLUSION

While in cities there are often silos of urban planning, mobility and transport, parks and green space, environmental department, (public) health department that do not work together well enough, multi-sectorial approaches are needed to tackle the environmental problems. The city of the future needs to be a green city, a social city, an active city, a healthy city.

Health Effects of Noise Exposure in Children

Environmental noise exposure, such as road traffic noise and aircraft noise, is associated with a range of health outcomes in children. Children demonstrate annoyance responses to noise, and noise is also related to lower well-being and stress responses, such as increased levels of adrenaline and noradrenaline. Noise does not cause more serious mental health problems, but there is growing evidence for an association with increased hyperactivity symptoms. Studies also suggest that noise might cause changes in cardiovascular functioning, and there is some limited evidence for an effect on low birth weight. There is robust evidence for an effect of school noise exposure on children's cognitive skills such as reading and memory, as well as on standardised academic test scores. Environmental noise does not usually reach levels that are likely to affect children's hearing; however, increasing use of personal electronic devices may leave some children exposed to harmful levels of noise.

Noise Effects on Health in the Context of Air Pollution Exposure

For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution.

Noise Effects on Health in the Context of Air Pollution Exposure

For public health policy and planning it is important to understand the relative contribution of environmental noise on health compared to other environmental stressors. Air pollution is the primary environmental stressor in relation to cardiovascular morbidity and mortality. This paper reports a narrative review of studies in which the associations of both environmental noise and air pollution with health have been examined. Studies of hypertension, myocardial infarction, stroke, mortality and cognitive outcomes were included. Results suggest independent effects of environmental noise from road traffic, aircraft and, with fewer studies, railway noise on cardiovascular outcomes after adjustment for air pollution. Comparative burden of disease studies demonstrate that air pollution is the primary environmental cause of disability adjusted life years lost (DALYs). Environmental noise is ranked second in terms of DALYs in Europe and the DALYs attributed to noise were more than those attributed to lead, ozone and dioxins. In conclusion, in planning and health impact assessment environmental noise should be considered an independent contributor to health risk which has a separate and substantial role in ill-health separate to that of air pollution.

Blood Pressure and Same-Day Exposure to Air Pollution at School: Associations with Nano-Sized to Coarse PM in Children

BACKGROUND

Ultrafine particles (UFP) may contribute to the cardiovascular effects of particulate air pollution, partly because of their relatively efficient alveolar deposition.

OBJECTIVE

In this study, we assessed associations between blood pressure and short-term exposure to air pollution in a population of schoolchildren.

METHODS

In 130 children (6-12 years of age), blood pressure was determined during two periods (spring and fall 2011). We used mixed models to study the association between blood pressure and ambient concentrations of particulate matter and ultrafine particles measured in the schools' playground.

RESULTS

Independent of sex, age, height, and weight of the child, parental education, neighborhood socioeconomic status, fish consumption, heart rate, school, day of the week, season, wind speed, relative humidity, and temperature on the morning of examination, an interquartile range (860 particles/cm3) increase in nano-sized UFP fraction (20-30 nm) was associated with a 6.35 mmHg (95% CI: 1.56, 11.14; p = 0.01) increase in systolic blood pressure. For the total UFP fraction, systolic blood pressure was 0.79 mmHg (95% CI: 0.07, 1.51; p = 0.03) higher, but no effects on systolic blood pressure were found for the nano-sized fractions with a diameter > 100 nm, nor PM2.5, PMcoarse, and PM10. Diastolic blood pressure was not associated with any of the studied particulate mass fractions.

CONCLUSION

Children attending school on days with higher UFP concentrations (diameter < 100 nm) had higher systolic blood pressure. The association was dependent on UFP size, and there was no association with the PM2.5 mass concentration.

Indoor noise exposure at home: a field study in the family of urban schoolchildren

This article aims at evaluating indoor noise levels at home and investigating the factors that may influence their variability. An 8-day noise measurement campaign was conducted in the homes of 44 schoolchildren attending the public primary schools of Besançon (France). The presence of the inhabitants in the dwelling and the noisy events occurring indoors and outdoors was daily collected using a time-location-activity diary (TLAD); 902 time periods were analyzed. The indoor noise level increased significantly with the outdoor noise level, along with the duration of the presence or level of activity of the inhabitants at home. However, this effect may vary according to the period of day and the day of the week. Moreover, a significant part of the day and evening indoor noise level variability was explained when considering the TLAD variables: 46% and 45% in the bedroom, 54% and 39% in the main room, respectively. Our results highlight the complexity of the indoor environment in the dwellings of children living in an urban area. Combining the inhabitant presence and indoor noise source descriptors with outdoor noise levels and other dwelling or inhabitant characteristics could improve large-scale epidemiological studies. However, additional efforts are still needed, particularly during the night period.

Road traffic noise and hypertension--accounting for the location of rooms

OBJECTIVE

The association between the exposure to road traffic noise and the prevalence of hypertension was assessed accounting for background air pollution and the location of rooms with respect to the road.

METHODS

A cross-sectional study was carried out inviting all subjects aged 35-74 years for participation that lived on 7 major trunk roads in 3-4 storey terraced apartment buildings and in parallel side streets that were completely shielded from noise due to the rows of houses along the major roads. The study was performed on 1770 subjects that did not have a self-reported medical doctor diagnosis of hypertension before they moved into their current residence. Noise levels at the facade of the front and the rear side of the houses were drawn from available noise maps of the area. A large set of covariates were considered to adjust the results for confounding.

RESULTS

Significant increases between road traffic noise and hypertension were found with respect to the 24h A-weighted average noise indicator L(DEN). The adjusted odds ratio (OR) per noise level increment of 10 dB(A) was 1.11 (95% confidence interval (CI): 1.00-1.23). Stronger significant estimates of the noise effect were found in subjects with long residence time (OR=1.20, CI=1.05-1.37), and with respect to the exposure of the living room during daytime (OR=1.24, CI=1.08-1.41) compared with the exposure of the bedroom during night-time (OR=0.91, CI=0.78-1.06).

CONCLUSION

Chronic exposure to road traffic noise is associated with an increased risk of high blood pressure. Daytime noise exposure of the living room had a stronger impact on the association than night-time exposure of the bedroom.

Associations between traffic noise, particulate air pollution, hypertension, and isolated systolic hypertension in adults: the KORA study

BACKGROUND

Studies on the association between traffic noise and cardiovascular diseases have rarely considered air pollution as a covariate in the analyses. Isolated systolic hypertension has not yet been in the focus of epidemiological noise research.

METHODS

The association between traffic noise (road and rail) and the prevalence of hypertension was assessed in two study populations with a total of 4,166 participants 25-74 years of age. Traffic noise (weighted day-night average noise level; LDN) at the facade of the dwellings was derived from noise maps. Annual average PM2.5 mass concentrations at residential addresses were estimated by land-use regression. Hypertension was assessed by blood pressure readings, self-reported doctor-diagnosed hypertension, and antihypertensive drug intake.

RESULTS

In the Greater Augsburg, Germany, study population, traffic noise and air pollution were not associated with hypertension. In the City of Augsburg population (n = 1,893), where the exposure assessment was more detailed, the adjusted odds ratio (OR) for a 10-dB(A) increase in noise was 1.16 (95% CI: 1.00, 1.35), and 1.11 (95% CI: 0.94, 1.30) after additional adjustment for PM2.5. The adjusted OR for a 1-μg/m3 increase in PM2.5 was 1.15 (95% CI: 1.02, 1.30), and 1.11 (95% CI: 0.98, 1.27) after additional adjustment for noise. For isolated systolic hypertension, the fully adjusted OR for noise was 1.43 (95% CI: 1.10, 1.86) and for PM2.5 was 1.08 (95% CI: 0.87, 1.34).

CONCLUSIONS

Traffic noise and PM2.5 were both associated with a higher prevalence of hypertension. Mutually adjusted associations with hypertension were positive but no longer statistically significant.

Assessment of Noise Exposure to Children: Considerations for the National Children's Study

Evidence has been accruing to indicate that young children are vulnerable to noise in their physical environment. A literature review identified that, in addition to hearing loss, noise exposure is associated with negative birth outcomes, reduced cognitive function, inability to concentrate, increased psychosocial activation, nervousness, feeling of helplessness, and increased blood pressure in children. While increasing attention has been given to the health effects of noise in children, research about noise exposure is sparse and often the measure of exposure is simply proximity to a noise source. The U.S. National Children's Study (NCS) provides a unique opportunity to investigate noise exposures to pregnant women and children using a number of assessment modalities at different life stages. Measurement of noise levels in homes and other environments, personal dosimetry measurements made over a period of days, and questionnaires addressing sources of noise in the environment, annoyance to noise, perceived noise level, use of head phones and ear buds, noisy activity exposures, and occupational exposures, are planned for evaluation within the NCS Vanguard pilot study. We describe the NCS planned approach to addressing noise exposure assessment in study visits over a child's lifetime.

The associations between traffic-related air pollution and noise with blood pressure in children: results from the GINIplus and LISAplus studies

Although traffic emits both air pollution and noise, studies jointly examining the effects of both of these exposures on blood pressure (BP) in children are scarce. We investigated associations between land-use regression modeled long-term traffic-related air pollution and BP in 2368 children aged 10 years from Germany (1454 from Munich and 914 from Wesel). We also studied this association with adjustment of long-term noise exposure (defined as day-evening-night noise indicator "Lden" and night noise indicator "Lnight") in a subgroup of 605 children from Munich inner city. In the overall analysis including 2368 children, NO2, PM2.5 mass (particles with aerodynamic diameters below 2.5μm), PM10 mass (particles with aerodynamic diameters below 10μm) and PM2.5 absorbance were not associated with BP. When restricting the analysis to the subgroup of children with noise information (N=605), a significant association between NO2 and diastolic BP was observed (-0.88 (95% confidence interval: -1.67, -0.08)). However, upon adjusting the models for noise exposure, only noise remained independently and significantly positively associated with diastolic BP. Diastolic BP increased by 0.50 (-0.03, 1.02), 0.59 (0.05, 1.13), 0.55 (0.03, 1.07), and 0.58 (0.05, 1.11)mmHg for every five decibel increase in Lden and by 0.59 (-0.05, 1.22), 0.69 (0.04, 1.33), 0.64 (0.02, 1.27), and 0.68 (0.05, 1.32)mmHg for every five decibel increase in Lnight, in different models of NO2, PM2.5 mass, PM10 mass and PM2.5 absorbance as the main exposure, respectively. In conclusion, air pollution was not consistently associated with BP with adjustment for noise, noise was independently and positively associated with BP in children.

The ecological context of soundscapes for children's blood pressure

Although the majority of studies on community noise levels and children's physiological stress responses are positive, effect sizes vary considerably, and some studies do not confirm these effects. Employing a contextual perspective congruent with soundscapes, a carefully constructed sample of children (N = 115, M = 10.1 yr) living in households in relatively high (>60 dBA) or low (<50 dBA) noise areas created by proximity to major traffic arterials in Austria was reanalyzed. Several personal and environmental factors known to affect resting cardiovascular parameters measured under well-controlled, clinical conditions were incorporated into the analyses. Children with premature births and elevated chronic stress (i.e., overnight cortisol) were more susceptible to adverse blood pressure responses to road traffic noise. Residence in a multi-dwelling unit as well as standardized assessments of perceived quietness of the area did not modify the traffic noise impacts but each had its own, independent effect on resting blood pressure. A primary air pollutant associated with traffic volume (NO2) had no influence on any of these results. The scope of environmental noise assessment and management would benefit from incorporation of a more contextualized approach as suggested by the soundscape perspective.

The physical environment and child development: an international review

A growing body of research in the United States and Western Europe documents significant effects of the physical environment (toxins, pollutants, noise, crowding, chaos, and housing, school and neighborhood quality) on children and adolescents' cognitive and socioemotional development. Much less is known about these relations in other contexts, particularly the global South. We thus briefly review the evidence for relations between child development and the physical environment in Western contexts, and discuss some of the known mechanisms behind these relations. We then provide a more extensive review of the research to date outside of Western contexts, with a specific emphasis on research in the global South. Where the research is limited, we highlight relevant data documenting the physical environment conditions experienced by children, and make recommendations for future work. In these recommendations, we highlight the limitations of employing research methodologies developed in Western contexts (Ferguson & Lee, 2013). Finally, we propose a holistic, multidisciplinary, and multilevel approach based on Bronfenbrenner's (1979) bioecological model to better understand and reduce the aversive effects of multiple environmental risk factors on the cognitive and socioemotional development of children across the globe.

Traffic noise and blood pressure in low-socioeconomic status, African-American urban schoolchildren

The primary aim of this field study was to investigate the relationships among residential noise exposure at home and at school and blood pressure in low-socioeconomic status African-American children. Children were recruited from Boys and Girls Clubs in a mid-sized, Northeastern city. The sample consisted of 250 schoolchildren (128 boys and 122 girls) aged 6-14 years. Each child was interviewed prior to anthropometric and blood pressure measurement. An oscillometric monitor was used for measurement of resting blood pressure. Correlation analysis in the overall sample showed no significant relationship between noise exposure and children's blood pressure. No interactions were found between noise at home and at schools as well as orientation of bedroom and/or living room and noise at home with blood pressure. A sub-sample of children was also examined by adding the orientation of bedroom and living room as inclusion criteria (n = 128), and there was an interaction between noise exposure and age on systolic blood pressure. In younger children aged 6-10 years, a significant positive relation was found between noise levels at homes and systolic blood pressure, controlling for body mass index (B = 0.48, 95% C.I. = 0.07 -0.88, p = 0.02).

Proximity of public elementary schools to major roads in Canadian urban areas

BACKGROUND

Epidemiologic studies have linked exposure to traffic-generated air and noise pollution with a wide range of adverse health effects in children. Children spend a large portion of time at school, and both air pollution and noise are elevated in close proximity to roads, so school location may be an important determinant of exposure. No studies have yet examined the proximity of schools to major roads in Canadian cities.

METHODS

Data on public elementary schools in Canada's 10 most populous cities were obtained from online databases. School addresses were geocoded and proximity to the nearest major road, defined using a standardized national road classification scheme, was calculated for each school. Based on measurements of nitrogen oxide concentrations, ultrafine particle counts, and noise levels in three Canadian cities we conservatively defined distances < 75 m from major roads as the zone of primary interest. Census data at the city and neighborhood levels were used to evaluate relationships between school proximity to major roads, urban density, and indicators of socioeconomic status.

RESULTS

Addresses were obtained for 1,556 public elementary schools, 95% of which were successfully geocoded. Across all 10 cities, 16.3% of schools were located within 75 m of a major road, with wide variability between cities. Schools in neighborhoods with higher median income were less likely to be near major roads (OR per $20,000 increase: 0.81; 95% CI: 0.65, 1.00), while schools in densely populated neighborhoods were more frequently close to major roads (OR per 1,000 dwellings/km²: 1.07; 95% CI: 1.00, 1.16). Over 22% of schools in the lowest neighborhood income quintile were close to major roads, compared to 13% of schools in the highest income quintile.

CONCLUSIONS

A substantial fraction of students at public elementary schools in Canada, particularly students attending schools in low income neighborhoods, may be exposed to elevated levels of air pollution and noise while at school. As a result, the locations of schools may negatively impact the healthy development and academic performance of a large number of Canadian children.