Major Traffic Roads Research Articles

Major Traffic Safety Reform and Road Traffic Injuries Among Low-Income New York Residents, 2009-2021.

Objectives. To evaluate the effects of a comprehensive traffic safety policy-New York City's (NYC's) 2014 Vision Zero-on the health of Medicaid enrollees. Methods. We conducted difference-in-differences analyses using individual-level New York Medicaid data to measure traffic injuries and expenditures from 2009 to 2021, comparing NYC to surrounding counties without traffic reforms (n = 65 585 568 person-years). Results. After Vision Zero, injury rates among NYC Medicaid enrollees diverged from those of surrounding counties, with a net impact of 77.5 fewer injuries per 100 000 person-years annually (95% confidence interval = -97.4, -57.6). We observed marked reductions in severe injuries (brain injury, hospitalizations) and savings of $90.8 million in Medicaid expenditures over the first 5 years. Effects were largest among Black residents. Impacts were reversed during the COVID-19 period. Conclusions. Vision Zero resulted in substantial protection for socioeconomically disadvantaged populations known to face heightened risk of injury, but the policy's effectiveness decreased during the pandemic period. Public Health Implications. Many cities have recently launched Vision Zero policies and others plan to do so. This research adds to the evidence on how and in what circumstances comprehensive traffic policies protect public health. (Am J Public Health. 2024;114(6):633-641. https://doi.org/10.2105/AJPH.2024.307617).

Determination of concentration of selected heavy metals in the organs of Guinea pigs reared at the University of Port Harcourt, Rivers State, Nigeria

Vegetation along major traffic roads are predisposed to heavy metals contamination due to wear and tear of vehicular components and emissions from vehicles. The concentration of ten heavy metals (Fe, Mn, Zn, Pb, Cu, Ni, Cr, Co Ag and Cd) in the leaves of four test plants (Panicum maximum Jacq.,Eleusine indica L., Xanthosoma mafafa Schott. and Amaranthus spinosus L.) growing along four busy roads (Aba road, Ikwerre road, East/West road and NTA road) in parts of Obio/Akpor Local Government Area and a control ( in Ozuguru in Ikwerre Ngwo) in Etche Local Government Area, both in Rivers State, Nigeria were investigated in the study area. Along each road, four sampling points were set up at 1 km apart. The test plants were collected randomly and were pooled together to form composite sample. The collected test plants at each sample location were put in different sterile cellophane bags, labelled and served as soilage to the experimental animals. Eighteen guinea pigs were used for this investigation. Three guinea pigs were picked out of the eighteen guinea pigs using randomized block design for a preliminary test. The remaining fifteen guinea pigs were fed with the test plants from the experimental and control sites for six weeks. The concentration of the ten heavy metals were determined using Atomic Absorption Spectrophotometry (ASS). The results revealed that Aba road had the highest mean concentration value of heavy metals in Cu, Zn, Co, Cr and Cd with values (28.75±1.34), (32.46±0.9), (5.14±0.11), (4.79±0.21) and (3.17±0.12) respectively. The highest mean concentration value for Mn and Pb were observed in East/West road with values (7.57±1.48) and (5.39±1.53) respectively, while the highest mean concentration value for Fe was observed in Ikwerre road (192.84±2.64). NTA road had the least values for all heavy metals tested while Ni and Ag were not detected in all livers and kidneys of the experimental animals. The results from this findings show the health implication of roadside grazing of ruminants.

Relationships of Residential Distance to Major Traffic Roads with Dementia Incidence and Brain Structure Measures: Mediation Role of Air Pollution.

Background: Uncertainty exists regarding the operating pathways between near-roadway exposure and dementia incidence. We intend to examine relationships between proximity to major roadways with dementia incidence and brain MRI structure measures, and potential mediation roles of air and noise pollution. Methods: The cohort study was based on the UK Biobank. Baseline survey was conducted from 2006 to 2010, with linkage to electronic health records conducted for follow-up. Residential distance to major roadways was ascertained residential address postcode. A land use regression model was applied for estimating traffic-related air pollution at residence. Dementia incidence was ascertained using national administrative databases. Brain MRI measures were derived as image-derived phenotypes, including total brain, white matter, gray matter, and peripheral cortical gray matter. Results: We included 460,901 participants [mean (SD) age: 57.1 (8.1) years; men: 45.7%]. Compared with individuals living >1,000 m from major traffic roads, living ≤1,000 m was associated with a 13% to 14% higher dementia risk, accounting for 10% of dementia cases. Observed association between residential distance and dementia was substantially mediated by traffic-related air pollution, mainly nitrogen dioxide (proportion mediated: 63.6%; 95% CI, 27.0 to 89.2%) and PM2.5 (60.9%, 26.8 to 87.0%). The shorter residential distance was associated with smaller volumes of brain structures, which was also mediated by traffic-related air pollutants. No significant mediation role was observed of noise pollution. Conclusions: The shorter residential distance to major roads was associated with elevated dementia incidence and smaller brain structure volumes, which was mainly mediated by traffic-related air pollution.

Phytomonitoring study on intra urban variations of leaves of some evergreen and deciduous trees

This paper explores the hypothesis that the action of stressors changes the state of mineral content at different stages in the leaf development in urban environment, in sites close to the major traffic roads. We evaluate a low-cost method to assess urban habitat quality with relatively easy sampling and no need for complicated and expensive equipment. The method is based on quantifying gravimetric (leaf dry weight – LDW, oganic weight in leaves – LO, ash weight in leaves – LA) and physiological (leaf mineral content – LMC, leaf organic content – LOC, leaf organic content/leaf mineral content ratio – LOC/LMC, leaf mineral deposition in tissues – LTDM) parameters. These parameters are relatively simple, accurate, and inexpensive and can be quickly determined. Kruskal–Wallis tests were used in order to compare LDW, LA, LO, LMC, LOC, LTDM and LOC/LMC among the eight species (Acer platanoides, Acer pseudoplatanus, Tilia platyphyllos, Tilia tomentosa, Aesculus hippocastanum, Aesculus × carnea, Taxus baccata, Picea abies). All these species are considered as valuable forest and decorative ones recommended for planting in the green zones of the towns. These tree species are easily identified, widely distributed, and widely used in bioindication studies. The variable mineral content within leaves can be explained by environmental effects, as well as by the physiological differences between species. Species that exhibit phenotypic plasticity with respect to these parameters (Acer platanoides, Acer pseudoplatanus, Tilia platyphyllos, Tilia tomentosa) reflect changes in the urban environment. With a high mineral content, A. carnea is more suited for the urban environment than A. hippocastanum. Taking into account the existing conditions in Timisoara, we consider evergreen species (T. baccata, P. abies) to be inadequate for cultivation in areas with heavy road traffic because they show stability in leaf mineral content.

Exposure to traffic and mortality risk in the 1991–2011 Canadian Census Health and Environment Cohort (CanCHEC)

There is evidence that local traffic density and living near major roads can adversely affect health outcomes. We aimed to assess the relationship between local road length, proximity to primary highways, and cause-specific mortality in the 1991 Canadian Census Health and Environment Cohort (CanCHEC). In this long-term study of 2.6 million people, based on completion of the long-form census in 1991 and followed until 2011, we used annual residential addresses to determine the total length of local roads within 200 m of postal code representative points and the postal code's distance to primary highways. The association between exposure to traffic and cause-specific non-accidental mortality was estimated using Cox proportional hazards models, adjusting for individual covariates and contextual factors, including census division-level proportion in high school, the percentage of recent immigrants, and neighborhood income. We performed sensitivity analyses, including adjustment for exposure to PM2.5, NO2, or O3, restricting to subjects in core urban areas, and spatial variation by climatic zone. The hazard ratio (HR) for all non-accidental mortality associated with an interquartile increase in length of local roads was 1.05 (95% CI 1.04, 1.05), while for an interquartile range increase in proximity to primary highways, the HR was 1.03 (95% CI 1.02, 1.04). HRs by traffic quartile increased with increasing lengths of local roads, as well as with closer proximity to primary highways, for all mortality causes. The associations were stronger within subjects' resident in urban core areas, attenuated by adjustment for PM2.5, and HRs showed limited spatial variation by climatic zone. In the CanCHEC cohort, exposure to higher road density and proximity to major traffic roads was associated with increased mortality risk from cerebrovascular and cardiovascular disease, ischemic heart disease, COPD, respiratory disease, and lung cancer, with unclear results for diabetes.

Development of outdoor pollution free zone by fan-assisted devices

Vertical City Air Purification System was designed to reduce the aerosol counts at the playground next to a major traffic road. Columns with air grilles are arranged in circle to create a close loop system. Computational simulation is adopted to study three scenarios. The first simulation covers conventional wind block technology, where strong wind speed is created between columns to stop pollutants from entering the premise. However, it is observed that polluted air can enter the development from the head above. Hence, two other options are created, one with supply air directing to the centre of the development, the other with underfloor air supply. It is studied that at outlet velocity of 6.5 m/s, the underfloor system can contribute to around 40% pollution reduction using MERV13 filter, which is more than 24% better than the baseline. Traditionally, outdoor pollution mitigation deems to be contributing insignificantly. The positive simulation result marks a potential for future outdoor pollution mitigation development.

Traffic Density and Mortality Risk in the 1991 Canadian Census Health and Environment Cohort (CanCHEC)

Background: There is evidence that local traffic density and living near major roads can adversely affect health outcomes. We aimed to assess the relationship between local road length, proximity to primary highways, and cause-specific mortality in the 1991 Canadian Census Health and Environment Cohort (CanCHEC).Methods: In this long-term study of 2.6 million people, based on completion of the long-form Census in 1991 and followed up until 2011, we used annual residential addresses to determine the total length of local roads within 200 m of centroid of postal codes, and the subject’s distance to primary highways. The association between exposure to traffic and cause-specific mortality was estimated using Cox proportional hazards models, adjusting for individual covariates and contextual factors, including census division-level proportion in high school, the percentage of recent immigrants, and neighborhood income. We performed sensitivity analyses, including adjustment for exposure to PM2.5, restricted to subjects in core urban areas, and spatial variation by climatic zone.Results The hazard ratio (HR) for all non-accidental mortality associated with an interquartile increase in length of local roads was 1.05 (95% CI 1.04, 1.05); and for an interquartile range increase in proximity to primary highways, 1.03 (95% CI 1.02, 1.04). However, HRs by traffic quartile increased with increasing lengths of local roads, or closer proximity to primary highways, for all mortality causes. The associations were stronger in subject residing in urban core areas, attenuated by adjustment for PM2.5, and HRs showed limited spatial variation by climatic zone.Conclusion: In the CanCHEC cohort, exposure to greater road density and proximity to major traffic roads were associated with increased mortality risk from cerebrovascular and cardiovascular disease, ischemic heart disease, COPD, respiratory disease, lung cancer, and with unclear results for diabetes.

Assessment of Indoor and Outdoor PM2.5 in Slums of Mumbai, India

Background/Aim: Mumbai slums, which house more than 50% of the city’s population could be at a higher risk of air pollution due to its proximity to major outdoor air pollution sources, poor ventilation and presence of indoor emission sources. The aim of this study is to measure and model the indoor air pollution exposures of Mumbai slum population vis-a-vis the outdoor levels. Methods: Household questionnaire survey having demographic, indoor source activity, ventilation and respiratory health symptoms was conducted in 500 randomly selected homes of seven slums in Mumbai to identify possible sources and factors affecting indoor air pollutants’ exposures. In two of the slums, inside 10 homes each, 24-hour indoor gravimetric PM2.5 monitoring was also conducted. Results: Significant number of homes are poorly ventilated (~90% homes with no cross ventilation) and experience overcrowding (~30% homes with ≥ 4 person/room). >50% kitchens have no separation from the living rooms. Mean PM2.5 concentrations are 39 ± 17 µg/m3 indoors and 23 ± 4 µg/m3 outdoors. The in/out PM2.5 ratio ranged from 0.9 to 3.7, higher than the values observed in non-slum homes. Frequent brief excursions are observed in indoor PM2.5 and BC, which are 2-3 times higher than the median concentrations, during cooking activities. Multivariate linear regression analysis shows proximity to the major traffic roads and separation of the kitchen from adjacent living rooms as the most dominant determinants of the indoor PM2.5 exposures. Additional indoor PM2.5 monitoring in ~80 homes in these slums is currently underway which will be used for developing models for predicting indoor PM2.5 exposures. Conclusions: Indoor PM2.5 exposures in poorly ventilated homes in slums of Mumbai seem to be driven largely by outdoor road traffic emissions as well as indoor activities such as cooking.

Identification of Major Sources of Atmospheric NH3 in an Urban Environment in Northern China During Wintertime.

To assess the relative contributions of traffic emission and other potential sources to high levels of atmospheric ammonia (NH3) in urban areas in the wintertime, atmospheric NH3 and related pollutants were measured at an urban site, ∼300 m from a major traffic road, in northern China in November and December 2015. Hourly average NH3 varied from 0.3 to 10.8 ppb with an average of 2.4 ppb during the campaign. Contrary to the common perspective in literature, traffic emission was demonstrated to be a negligible contributor to atmospheric NH3. Atmospheric NH3 correlated well with ambient water vapor during many time periods lasting from tens of hours to several days, implying NH3 released from water evaporation is an important source. Emissions from local green space inside the urban areas were identified to significantly contribute to the observed atmospheric NH3 during ∼60% of the sampling times. Evaporation of predeposited NHx through wet precipitation combined with emissions from local green space likely caused the spikes of atmospheric NH3 mostly occurring 1-4 h after morning rush hours or after and during slight shower events. There are still ∼30% of the data samples with appreciable NH3 level for which major contributors are yet to be identified.

Living near major roads and the incidence of dementia, Parkinson's disease, and multiple sclerosis: a population-based cohort study

Emerging evidence suggests that living near major roads might adversely affect cognition. However, little is known about its relationship with the incidence of dementia, Parkinson's disease, and multiple sclerosis. We aimed to investigate the association between residential proximity to major roadways and the incidence of these three neurological diseases in Ontario, Canada. In this population-based cohort study, we assembled two population-based cohorts including all adults aged 20-50 years (about 4·4 million; multiple sclerosis cohort) and all adults aged 55-85 years (about 2·2 million; dementia or Parkinson's disease cohort) who resided in Ontario, Canada on April 1, 2001. Eligible patients were free of these neurological diseases, Ontario residents for 5 years or longer, and Canadian-born. We ascertained the individual's proximity to major roadways based on their residential postal-code address in 1996, 5 years before cohort inception. Incident diagnoses of dementia, Parkinson's disease, and multiple sclerosis were ascertained from provincial health administrative databases with validated algorithms. We assessed the associations between traffic proximity and incident dementia, Parkinson's disease, and multiple sclerosis using Cox proportional hazards models, adjusting for individual and contextual factors such as diabetes, brain injury, and neighbourhood income. We did various sensitivity analyses, such as adjusting for access to neurologists and exposure to selected air pollutants, and restricting to never movers and urban dwellers. Between 2001, and 2012, we identified 243 611 incident cases of dementia, 31 577 cases of Parkinson's disease, and 9247 cases of multiple sclerosis. The adjusted hazard ratio (HR) of incident dementia was 1·07 for people living less than 50 m from a major traffic road (95% CI 1·06-1·08), 1·04 (1·02-1·05) for 50-100 m, 1·02 (1·01-1·03) for 101-200 m, and 1·00 (0·99-1·01) for 201-300 m versus further than 300 m (p for trend=0·0349). The associations were robust to sensitivity analyses and seemed stronger among urban residents, especially those who lived in major cities (HR 1·12, 95% CI 1·10-1·14 for people living <50 m from a major traffic road), and who never moved (1·12, 1·10-1·14 for people living <50 m from a major traffic road). No association was found with Parkinson's disease or multiple sclerosis. In this large population-based cohort, living close to heavy traffic was associated with a higher incidence of dementia, but not with Parkinson's disease or multiple sclerosis. Health Canada (MOA-4500314182).

Infrastructural Projects and Territorial Development in Veneto Dolomites: Evaluation of Performances through AHP

The ensemble of European traffic roads is changing in relation to the economic geography that has been developing these recent years and also to the localisation of production centres, logistics and the demand linked to the transportation of goods. The development of communication has been defined through the project of the Trans-European Transport Network (TEN-T). This network has been progressively defined until it has reached the present architecture in which Italy is crossed by four of the nine total corridors that compose the whole network - which means by almost half of the main traffic roads at European level -. Undoubtedly this new geography of European communication offers member States new development opportunities, but it is also true that the distance of the different territories from the major traffic roads can be a disparity factor. In fact, this phenomenon can worsen the marginalisation processes of some European territories, contrary to the objective of the interconnection policy of the EU territories. In front of these possible territorial disparities, the Planning discipline in Italy has not been adequately questioned, aiming instead at the research of the “territorial patching up”, progressively decreasing, rather than at the exploration of new development forms. As a consequence, mobility planning becomes strategic for Italy, especially for its Alpine area. Hence the need to set up valid tools for the environmental evaluation as regards planning and programmes, such as the Strategic Environmental Assessment (SEA), but also projects, as the Environmental Impact Assessment (EIA). The idea to realise an important road infrastructure, which may connect Belluno directly with Austria, is presented in this paper as an emblematic case, in which the application of the Analytic Hierarchy Process (AHP) permits to verify the best performing infrastructure on a territorial scale.

A Beacon Transmission Power Control Algorithm Based on Wireless Channel Load Forecasting in VANETs.

In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing and preventing channel congestion. In this study, the primary factors that influence wireless channel loading are selected to construct the KF-BCLF, which is a channel load forecasting algorithm based on a recursive Kalman filter and employs multiple regression equation. By pre-adjusting the transmission power based on the forecasted channel load, the channel load was kept within a predefined range; therefore, channel congestion was prevented. Based on this method, the CLF-BTPC, which is a transmission power control algorithm, is proposed. To verify KF-BCLF algorithm, a traffic survey method that involved the collection of floating car data along a major traffic road in Changchun City is employed. By comparing this forecast with the measured channel loads, the proposed KF-BCLF algorithm was proven to be effective. In addition, the CLF-BTPC algorithm is verified by simulating a section of eight-lane highway and a signal-controlled urban intersection. The results of the two verification process indicate that this distributed CLF-BTPC algorithm can effectively control channel load, prevent channel congestion, and enhance the stability and robustness of wireless beacon transmission in a vehicular network.

Land fragmentation and variation of ecosystem services in the context of rapid urbanization: the case of Taizhou city, China

This study analyzes land use dynamics, land fragmentation, variation of ecosystem service value (ESV), and the underlying driving forces in the context of rapid urbanization in Taizhou city, China. An integrated approach utilizing geographic information system and remote sensing was used to analyze land use/land cover change, spatiotemporal patterns of land fragmentation and variation of ESV over the period of 1995–2010. The results show that the areal extent of built-up land increased by 3.72 times, whereas loss of the cropland, forest, and fallow land accounted for 18.52, 34.80, and 28.94 % of the new built-up land, respectively. As observed, in-filling of the major traffic road networks and axis-based expansion of built-up land occurred. Outward expansion of the built-up land, in particular, indicated that human encroachment into surrounding natural and semi-natural ecosystems leading to decreased total ecosystem service functions of the study area. As a whole, significant change in key landscape, especially a net decrease in forest, and remarkable socioeconomic development should be responsible for an overall decline in 36.29 % of total ESV during the recently rapid urbanization process. Therefore, sustainable development policies should address the decline of ESV.

Seasonal differences of the atmospheric particle size distribution in a metropolitan area in Japan

We compared the effect of ambient temperature observed in two different seasons on the size distribution and particle number concentration (PNC) as a function of distance (up to ~250m) from a major traffic road (25% of the vehicles are heavy-duty diesel vehicles). The modal particle diameter was found between 10 and 30nm at the roadside in the winter. However, there was no peak for this size range in the summer, even at the roadside. Ambient temperature affects both the atmospheric dilution ratio (DR) and the evaporation rate of particles, thus it affects the decay rate of PNC. We corrected the DR effect in order to focus on the effect of particle evaporation on PNC decay. The decay rate of PNC with DR was found to depend on the season and particle diameter. During the winter, the decay rate for smaller particles (<30nm) was much higher (i.e., the concentration decreased significantly against DR), whereas it was low during the summer. In contrast, for particles >30nm in diameter, the decay rate was nearly the same during both seasons. This distinction between particles less than or greater than 30nm in diameter reflects differences in particle volatility properties. Mass-transfer theory was used to estimate evaporation rates of C20–C36 n-alkane particles, which are the major n-alkanes in diesel exhaust particles. The C20–C28 n-alkanes of 30-nm particles completely evaporate at 31.2°C (summer), and their lifetime is shorter than the transport time of air masses in our region of interest. Absence of the peak at 10–30nm and the low decay rate of PNC <30nm in diameter in the summer were likely due to the evaporation of compounds of similar volatilities comparable to the C20–C36 n-alkanes from particles near the exhaust pipes of vehicles, and complete evaporation of semivolatile materials before they reached the roadside. These results suggest that the lifetime of particles <30nm in diameter depends on the ambient temperature, which differs between seasons. This leads us to conclude that these particles show distinctly different spatial distributions depending on the season.

No exercise-induced increase in serum BDNF after cycling near a major traffic road

Commuting by bike has a clear health enhancing effect. Moreover, regular exercise is known to improve brain plasticity, which results in enhanced cognition and memory performance. Animal research has clearly shown that exercise upregulates brain-derived neurotrophic factor (BDNF – a neurotrophine) enhancing brain plasticity. Studies in humans found an increase in serum BDNF concentration in response to an acute exercise bout. Recently, more evidence is emerging suggesting that exposure to air pollution (such as particulate matter (PM)) is higher in commuter cyclists compared to car drivers. Furthermore, exposure to PM is linked to negative neurological effects, such as neuroinflammation and cognitive decline. We carried-out a cross-over experiment to examine the acute effect of exercise on serum BDNF, and the potential effect-modification by exposure to traffic-related air pollution. Thirty eight physically fit, non-asthmatic volunteers (mean age: 43, 26% women) performed two cycling trials, one near a major traffic road (Antwerp Ring, R1, up to 260,000 vehicles per day) and one in an air-filtered room. The air-filtered room was created by reducing fine particles as well as ultrafine particles (UFP). PM10, PM2.5 and UFP were measured. The duration (∼20 min) and intensity of cycling were kept the same for each volunteer for both cycling trials. Serum BDNF concentrations were measured before and 30 min after each cycling trial. Average concentrations of PM10 and PM2.5 were 64.9 μg/m 3 and 24.6 μg/m 3 in cycling near a major ring way, in contrast to 7.7 μg/m 3 and 2.0 μg/m 3 in the air-filtered room. Average concentrations of UFP were 28,180 particles/cm 3 along the road in contrast to 496 particles/cm 3 in the air-filtered room. As expected, exercise significantly increased serum BDNF concentration after cycling in the air-filtered room (+14.4%; p = 0.02). In contrast, serum BDNF concentrations did not increase after cycling near the major traffic route (+0.5%; p = 0.42). Although active commuting is considered to be beneficial for health, this health enhancing effect could be negatively influenced by exercising in an environment with high concentrations of PM. Whether this effect is also present with chronic exercise and chronic exposure must be further elucidated.

Traffic exposure and incident venous thromboembolism in the Atherosclerosis Risk in Communities (ARIC) Study

Two recent case-control studies in Italy reported that long-term exposure to particulate air pollution or living near major traffic roads was associated with an increased risk of deep vein thrombosis (DVT). No prospective evidence exists on the possible association between long-term traffic-related air pollution and incident venous thromboembolism (VTE). To examine the association between long-term traffic exposure and incident VTE in a population-based prospective cohort study. We studied 13,143 middle-aged men and women in the Atherosclerosis Risk in Communities Study without a history of DVT or pulmonary embolism at baseline examination (1987-1989). The Geographical Information System-mapped traffic density and distance to major roads in the four study communities served as measures of traffic exposure. We examined the association between traffic exposure and incident VTE with proportional hazards regression models. A total of 405 subjects developed VTE in 2005. Traffic density was not significantly associated with VTE. Relative to those in the lowest quartile of traffic density, the adjusted hazard ratios across increasing quartiles were 1.18 (95% confidence interval [CI] 0.88-1.57), 0.99 (95% CI 0.74-1.34) and 1.14 (95% CI 0.86-1.51) (P-value for trend across quartiles = 0.64). For residents living within 150 m of major roads, as compared with subjects living further away, the adjusted hazard ratio was 1.16 (95% CI 0.95-1.42, P = 0.14). This first prospective study in the general population does not support an association between air pollution exposure or traffic proximity and risk of DVT. More data may be needed to clarify whether traffic or air pollution influences the risk of VTE.

Current Traffic Noise Exposure Assessment and Noise Effect of Distraction in Class Among Children in Xiʼan City

ISEE-0169 Background and Objective: The purpose of this study was to investigate the current traffic noise level in Xi'an city and to examine exposure-effect relationships between traffic noise exposure and children's distraction in class. Methods: The overall current noise levels were monitored, especially noise from traffic. We set up 126 monitoring sites in the whole city, and collected data for three months. We compared the noise level in different life zones to try to find out which was the highest. We also conducted a study assessing 1890 pupils, aged 8–10, from 42 schools near major traffic roads and not, from all eight urban areas in Xi'an. Children were selected on the basis of exposure to external road traffic noise exposure. A well-administered questionnaire concerning distraction in class and demographic information was distributed to these pupils and their teachers. Results: The noise from major roads was above 20% of the overall noise in Xi'an city, and reached an average level of 62 dB, exceeding the concern level for causing public health problems. Among all the life zones, the ones near the major traffic roads had the highest noise levels. Traffic noise exposure was significantly associated with an increased score on distracted behavior among children after full adjustment. Conclusion: The assessment of noise level in Xi'an city suggested that noise level in urban areas of Xi'an has reached an alarming level. Meanwhile, a population survey in children revealed that living near a road with heavy traffic volume is one of the risk factors for distraction in class among pupils–this is an important problem impacting on behaviour at school and effective learning among children.

Air Quality and Cardiovascular Health

Ambient particulate matter has been associated consistently with an increased risk for mortality largely due to cardiovascular diseases.1 Although the relative risk estimates from epidemiological studies are small, they apply to almost the entire population of the United States. Consequently, exposure to ambient particles produces considerable burden of disease, and its mitigation offers the benefit of improving life expectancy.2 Articles see pp 941 and 949 Over the past decade, research has substantiated the understanding of the pathophysiological mechanisms linking ambient particles to the cardiovascular system3,4 once it was noted that ambient air pollution elicits systemic inflammatory responses in the general population.5 An update of the American Heart Association statement on air pollution and cardiovascular disease3 is under way. Mechanisms considered for active and secondhand smoke as well as ambient air pollution are strikingly similar.4,6,7 They include progression of atherosclerotic plaques to vulnerable forms, prothrombotic states, endothelial dysfunction, and altered autonomic nervous system control (Figure). Increased systemic oxidative stress is considered the key mechanism responsible for most of these pathophysiological changes. Increased risks for cardiovascular disease in general and coronary artery disease in particular have been documented for active and secondhand smoke as well as ambient particulate matter. Deep venous thrombosis has been added to this list recently.8 Figure. Overview on pathomechanism linking ambient air pollution,4 secondhand smoke,7 and active smoking to acute coronary syndromes. Nevertheless, the public health relevance of particulate matter in the light of the smoking literature remains hotly debated. Smokers are exposed to considerably higher cumulative doses of particulate matter than the general nonsmoking population. Mortality due to low doses of ambient particles may be considered counterintuitive compared with doses of particles tolerated by smoking individuals. A systematic assessment of the exposure-response function ranging from low doses of inhaled particles …

Living Near Major Traffic Roads and Risk of Deep Vein Thrombosis

Particulate air pollution has been consistently linked to increased risk of arterial cardiovascular disease. Few data on air pollution exposure and risk of venous thrombosis are available. We investigated whether living near major traffic roads increases the risk of deep vein thrombosis (DVT), using distance from roads as a proxy for traffic exposure. From 1995 through 2005, we examined 663 patients with DVT of the lower limbs and 859 age-matched controls from cities with population >15 000 inhabitants in Lombardia Region, Italy. We assessed distance from residential addresses to the nearest major traffic road using geographic information system methodology. The risk of DVT was estimated from logistic regression models adjusting for multiple clinical and environmental covariates. The risk of DVT was increased (odds ratio=1.33; 95% confidence interval, 1.03 to 1.71; P=0.03 in age-adjusted models; odds ratio=1.47; 95% confidence interval, 1.10 to 1.96; P=0.008 in models adjusted for multiple covariates) for subjects living near a major traffic road (index distance of 3 meters, 10th centile of the distance distribution) compared with those living farther away (reference distance of 245 meters, 90th centile). The increase in DVT risk was approximately linear over the observed distance range (from 718 to 0 meters) and was not modified after adjusting for =0.008 for 10th versus 90th distance centile in models adjusting for area levels of particulate matter <10 mum in aerodynamic diameter in the year before diagnosis). Living near major traffic roads is associated with increased risk of DVT.

Open‐air theatre in the centre of the city: Acoustic design and noise environment control

The municipal open‐air Garden Theatre of Thessaloniki has for decades been located in the biggest urban park of the city next to a busy crossroads, where five major traffic roads meet. The intensification of traffic noise over the years led to the degradation of its use. In 1997, the organisation of the Cultural Capital of Europe served as a springboard for a study conducted by the author on redesigning the theatre. The design comprised a variety of arrangements, such as the rotation of the auditorium according to the results of the noise environment study, the choice of a closed plan in the type of the Greek‐Roman Odeion, the sinking of the theatre space and the construction of barriers and shades. Various problems (such as archaeological findings, existence of big trees inside the auditorium, high level of underground water) and budget cuts during the design and construction, led to restricted execution of the planned architectural interventions. This paper deals with the design parameters that optimise acoustic function and maximise sound protection in an urban, open‐air theatre and includes an analysis of the theatre's initial state, acoustic proposals and an assessment of the final applications.