High Traffic Density Areas Research Articles

High levels of tire wear particles in soils along low traffic roads

Traffic pollution has been linked to high levels of metals and organic contaminants in road-side soils, largely due to abrasion of tires, brake pads and the road surface. Although several studies have demonstrated correlations between different pollutants and various traffic variables, they mainly focused on roads with medium to high traffic density (>30,000 vehicles per day). In this study we have focused on investigating tire wear particles and road-related metals (zinc, copper, lead, chromium, nickel, and the metalloid arsenic) in the soils of low traffic roads in rural areas (650–14,250 vehicles per day). Different explanatory factors were investigated, such as traffic density, speed, % heavy vehicles, organic matter content, annual precipitation, soil types and roadside slope profiles. The results show high levels of tire wear particles, from 2000 to 26,400 mg/kg (0.2–2.6 % tire wear in d.w. soil), which is up to five times higher compared to previously reported values in roadside soils of high traffic density areas. A weak but significant correlation was found between tire wear particles, traffic speed and the annual precipitation. No significant relationship was found between tire wear particles metals. The concentrations of metals were comparable to previous studies of high traffic areas of Norway, as well as both urban and rural soils in other countries. For the metals, all factors together explained 45 % of the variation observed, with traffic density (11 %) and organic matter content (10 %) as the most important single variables. The analysis of tire wear particles in soils using Pyrolysis Gas chromatography Mass Spectrometry is challenging, and the results presented demonstrate the need for pretreatment to remove organic matter from the samples before analysis.

An efficient conditional privacy-preserving authentication scheme with scalable revocation for VANETs

In Vehicular Ad Hoc Networks (VANETs), secure information sharing between vehicles is critical for improving traffic efficiency and driving safety. However, existing identity-based communication protocols for VANETs face problems of over-reliance on ideal Tamper-Proof Devices (TPDs) and the efficiency of verifying multiple messages in areas of high traffic density. Besides, many existing authentication schemes suffer from the heavy workload of revoking malicious vehicles when they misbehave. For addressing these problems, we propose an efficient Identity-Based conditional privacy-preserving authentication protocol, which does not rely on the ideal TPD. In our scheme, the System Secret Key (SSK) is not directly preloaded with the TPD, thus avoiding a system crash when a vehicle is corrupted. To revoke malicious vehicles’ identity, we propose an efficient key updating method based on Shamir’s secret sharing algorithm, which improves key-update efficiency from linear to logarithmic in the number of unrevoked vehicles. Moreover, our scheme is based on Elliptic Curves Cryptosystem and avoids bilinear pairing operation while supporting batch verification, enabling faster verification even when the number of signatures is increasing. According to the results of exhaustive comparative analysis, our proposed scheme is secure against key leakage attack and efficient in overhead of computation and communication compared to related schemes.

Road traffic density and recurrent asthma emergency department visits among Medicaid enrollees in New York State 2005–2015

BackgroundEnvironmental exposures such as traffic may contribute to asthma morbidity including recurrent emergency department (ED) visits. However, these associations are often confounded by socioeconomic status and health care access.ObjectiveThis study aims to assess the association between traffic density and recurrence of asthma ED visits in the primarily low income Medicaid population in New York State (NYS) between 2005 and 2015.MethodsThe primary outcome of interest was a recurrent asthma ED visit within 1-year of index visit. Traffic densities (weighted for truck traffic) were spatially linked based on home addresses. Bivariate and multivariate logistic regression analyses were conducted to identify factors predicting recurrent asthma ED visits.ResultsIn a multivariate model, Medicaid recipients living within 300-m of a high traffic density area were at a statistically significant risk of a recurrent asthma ED visit compared to those in a low traffic density area (OR = 1.31; 95% CI:1.24,1.38). Additionally, we evaluated effect measure modification for risk of recurrent asthma visits associated with traffic exposure by socio-demographic factors. The highest risk was found for those exposed to high traffic and being male (OR = 1.87; 95% CI:1.46,2.39), receiving cash assistance (OR = 2.11; 95% CI:1.65,2.72), receiving supplemental security income (OR = 2.21; 95% CI:1.66,2.96) and being in the 18.44 age group (OR = 1.59;95% CI 1.48,1.70) was associated with the highest risk of recurrent asthma ED visit. Black non-Hispanics (OR = 2.35; 95% CI:1.70,3.24), Hispanics (OR = 2.13; 95% CI:1.49,3.04) and those with race listed as “Other” (OR = 1.89 95% CI:1.13,3.16) in high traffic areas had higher risk of recurrent asthma ED visits as compared to White non-Hispanics in low traffic areas.ConclusionWe observed significant persistent disparities in asthma morbidity related to traffic exposure and race/ethnicity in a low-income population. Our findings suggest that even within a primarily low-income study population, socioeconomic differences persist. These differences in susceptibility in the extremely low-income group may not be apparent in health studies that use Medicaid enrollment as a proxy for low SES.

Influence of Vehicle Traffic Emissions on Spatial Variation of Ozone and its Precursors in Air of Port Harcourt City, Nigeria

This study aimed at assessing the influence of vehicle traffic on spatial variation of ozone (O3) and its vehicular emission precursors in the air of Port Harcourt city. Sampling was carried out in ten (10) sites, eight (8) located within the high traffic density area (study sites) and two (2) located within the very low traffic density area (reference sites). The precursor pollutants measured were nitrogen dioxide (NO2), carbon monoxide (CO) and volatile organic compounds (VOCSs). Ozone and the precursor pollutants were measured in situ using AeroQUAL 500 series portable ambient air analyzer while traffic flow survey was achieved by direct counting. Measurements were carried out at morning, evening and off-peak traffic periods respectively. The mean concentrations of ozone and the precursor pollutants were significantly higher (p = 0.05) in the study sites than in the reference sites. Mean concentrations were higher at peak traffic periods than at off-peak traffic periods except for ozone that was higher at off-peak than at morning peak. There was significant correlation between traffic density and each of the pollutants including ozone. The spatial variability in concentration of pollutants was influenced by vehicular traffic. VOCs and NO2 levels were higher than the National Ambient Air Quality Standard (NAAQS) limit of 0.05 ppm and 0.04 – 0.06 ppm respectively, O3 concentration was below the standard limit (0.06 ppm) but was at the verge of exceeding. Traffic emission within the city was significant and could be mitigated through regular monitoring and control.

Multi-Criteria Selection of Surface Units for SAR Operations at Sea Supported by AIS Data

The authors discuss currently conducted research aimed at improving the planning and performance of search and rescue (SAR) operations at sea. The focus is on the selection of surface units in areas of high traffic density. A large number of ships in the area of distress can make the process of selection of best suited vessels longer. An analysis of features which may render a vessel unsuitable for the job, depending on the area and type of operation, has been conducted. Criteria of assessment and selection of ships have been described, preceded by an expert analysis. The selection process has been made using Multi-Criteria Decision Analysis (MCDA). The authors propose to apply officially available data from the Automatic Identification System (AIS)—a sensor for the ECDIS and other electronic chart systems—in the analysis of the availability of ships. Algorithms filtering available units have been built and applied in a simulation, using real AIS data, of one of the most common types of SAR operations. The method is proposed as an enhancement of decision support systems in maritime rescue services.

Exploring the Potential Risk of Heavy Metal Pollution of Edible Cultivated Plants in Urban Gardening Contexts Using a Citizen Science Approach in the Project “Heavy Metal City-Zen”

Urban gardening has become increasingly popular, creating green oases in cities; however, many of these activities are undertaken in areas of high traffic density or on ex-brown field sites. As a consequence, there are still some barriers to the adoption of these urban gardening practices for food production. One of the public concerns is the transfer of urban pollutants such as heavy metals into the consumer’s food chain, however, city-wide data is often difficult and expensive to collect. In the citizen science project described herein, we conducted simple citizen-led common collaborative experiments in urban community gardens. These data provided information on the potential risk of heavy metal contaminants and ways in which to mitigate those risks in an urban gardening context. Generally, values were below guideline thresholds, however, at a few garden sites, soil trace metal concentrations (Pb, Cd, Zn) exceeded Austrian recommended limits. Moreover, only at two sites were plant trace metal concentrations shown to be above European food standards limits. Given the citizen’s positive response to the project, we suggest expanding this study to the whole of Vienna, giving newly established gardens a chance to predetermine the risks posed by their local soils.

Source Identification and Pollution Factors of Elements in PM2.5 Samples Obtained in Akure, Ondo State, Nigeria

Air quality deterioration is a big concern all over the world. It affects both humans and animals in a variety of ways. Air pollution must be quantified to monitor its negative impacts and stakeholders to proffer mitigation options. On this note, our research team has taken measures in Nigeria to monitor and measure PM2.5, its associated elements, as well as local meteorological parameters during sampling period. In addition, enrichment, contamination index, and principal component analysis of associated elements were studied. For ten months (January–October 2018), PM2.5 samples were collected at three locations in Ondo State, Nigeria with coordinates (the Federal University of Technology, Akure (FUTA)—low-density residential (LDR), Oba Ile (high-density residential (HDR), and Museum (IND, High density traffic and commercial area) (January–October). The Contamination Factor (CF), Enrichment Factor (EF), and Pollution Load Index (PLI), as well as Principal Component Analysis (PCA) of the samples were determined. Average PM2.5 mass concentrations [101 µg/m3 (FUTA); 120 µg/m3 (Oba Ile); and 176 µg/m3 (Museum)] were found to be higher than the WHO (10 µg/m3) and USEPA (15 µg/m3) normal limits. The concentrations of the most prominent elements were in the order; K > Na > Ca > P > Al, while the trace elements displayed Cu > Fe > Zn > Ni > Cr > Mn > Pb. Oba-Ile had the highest metal enrichment in the order: Ti > Mn > Zn > Cu > Ni > Cr. The PCA resolved four factors vis-à-vis vehicular activities, biomass burning, and soil dust as the major PM2.5 emission sources. The findings could be useful in the current drive to develop national air quality guideline for PM2.5.

The Seasonality Impact of the BTEX Pollution on the Atmosphere of Arad City, Romania.

Benzene, toluene, and total BTEX (benzene, toluene, ethylbenzene, and xylene) concentrations registered for one year (2016) have been determined every month for one high-density traffic area. The assessment was performed in Arad City, Romania, to evaluate these pollutants and their influence on the inhabitants’ health. The contaminants were sampled using a static sampling method and analyzed by gas chromatography coupled with mass spectrometry. Benzene was the most dominant among the BTEX compounds—the average concentrations ranged from 18.00 ± 1.32 µg m−3 in December to 2.47 ± 0.74 µg m−3 in August. The average toluene concentration over the year was 4.36 ± 2.42 µg m−3 (with a maximum of 9.60 ± 2.39 µg m−3 in November and a minimum of 1.04 ± 0.29 µg m−3 in May). The toluene/benzene ratio (T/B) was around 0.5, indicating substantial contributions from mobile sources (vehicles). The emission and accumulation of different aromatic compounds (especially benzene) could deteriorate the urban air quality. The lifetime cancer risk (LTCR) for benzene was found to be more than 10−5 in winter, including the inhabitants in the “probable cancer risk” category.

Performance Evaluation of AOMDV on Realistic and Efficient VANet Simulations

The digital transmission amongst vehicles and roadway equipment is necessary for the realization of smart transportation systems. Vehicular ad-hoc network (VANet) is an ascension field of engineering that presents brilliant transport applications, road safety, comfort and luxury to drivers. VANet protocols face many challenges because of the changing nature of vehicular ad-hoc network. VANet routing protocols perform a vital role in terms of the performance efficiency because they decide the mode of sending and receiving packets between mobile vehicular nodes. Finding suitable and efficient routing protocol is very important for the efficient implementation of VANet. The foremost objective of this research is to suggest the relevant and efficient VANet routing protocols in a high traffic density area. This research work presents a practical evaluation of the VANet topology’s features with respect to time for the high traffic situations. This evaluation incorporates the actual creation of roadway layout. An accurate traffic flow is produced by extracting run-time facts and figures from PeMS (Freeway Performance Measurement System) database and assigning this extracted information into a microscopic mobility model. To achieve our goal, we consider three routing protocols i.e., AOMDV, AODV and DSDV. The simulation results prove that the performance of AOMDV is greater in comparison to DSDV and AODV protocols in high traffic density areas. The AOMDV protocol improves overall network performance by achieving maximum throughput and minimum end to end delay.

An Efficient and Provably Secure ECC-Based Conditional Privacy-Preserving Authentication for Vehicle-to-Vehicle Communication in VANETs

In vehicular ad-hoc networks (VANETs), safety messages are exchanged among vehicles and between vehicles and infrastructure to ensure passengers’ safety and efficiency in traffic. The source authentication as well as integrity checking of these messages are very necessary for a receiver. Based on certificateless cryptography (CLC), some state-of-the-art signature schemes have been proposed to address these. Although they fulfill the requirements of authentication and privacy, they are not efficient with respect to performance. Bilinear pairings and map-to-point hash functions are used in these schemes. These require a huge amount of time to process. The computational power and storing capacity of an on-board unit (OBU) in each vehicle are limited. Therefore, computational overhead is induced on vehicles that need to authenticate messages in areas of high traffic density. In this paper, a provably secure and efficient certificateless short signature-based conditional privacy-preserving authentication (CLSS-CPPA) scheme for V2V communication is designed. This scheme does not use bilinear parings and is based on the elliptic curve cryptosystem (ECC). In addition, instead of map-to-point hash functions, general hash functions are used. Furthermore, the CLSS-CPPA scheme supports the batch signature verification method which allows multiple signatures to be verified simultaneously and efficiently. The CLSS-CPPA scheme ensures security against type-I and type-II attackers with respect to existential unforgeability against adaptively chosen message attacks (EUF-CMA) under a hardness assumption of the elliptic curve discrete logarithm problem (ECDLP) in the random oracle model (ROM). The proposed scheme significantly improves performance in terms of computational and communication costs in comparison with state-of-the-art schemes.

An Efficient Identity-Based Conditional Privacy-Preserving Authentication Scheme for Secure Communication in a Vehicular Ad Hoc Network

The security and privacy issues in vehicular ad hoc networks (VANETs) are often addressed with schemes based on either public key infrastructure, group signature, or identity. However, none of these schemes appropriately address the efficient verification of multiple VANET messages in high-density traffic areas. Attackers could obtain sensitive information kept in a tamper-proof device (TPD) by using a side-channel attack. In this paper, we propose an identity-based conditional privacy-preserving authentication scheme that supports a batch verification process for the simultaneous verification of multiple messages by each node. Furthermore, to thwart side-channel attacks, vehicle information in the TPD is periodically and frequently updated. Finally, since the proposed scheme does not utilize the bilinear pairing operation or the Map-To-Point hash function, its performance outperforms other schemes, making it viable for large-scale VANETs deployment.

Search for effective eluent for Pd separation on ion-exchange sorbent before voltammetric determination

Determination of Pd traces in environmental samples is still a challenging analytical task. The aim of this study was to propose an efficient system (i.e. ion-exchange resin and eluent) for Pd elution from SPE column after the analyte preconcentration. Moreover, the search was focused on solvents that would not interfere voltammetric determination of Pd, as well as ICP-MS analysis. Five ion-exchange sorbents were compared in terms of effective Pd separation from matrix components when using different eluents. The highest recovery (up to 91%) of palladium was obtained for Dowex 1 and ammonium buffer as the eluent. This solution not only provides relatively high palladium elution efficiency but also allows both voltammetric and ICP-MS determinations, without any additional sample preparation. It was proven that the proposed procedure including SPE separation and determination with AdSV and/or ICP-MS could be used for quantitative Pd measurement in environmental samples, such as quartz sand used for the monitoring of Pd emission in the areas of high traffic density.

Smart Street Lighting System with Adafruit Cloud

Street Lights consume a lot of power overnight, even though they do not appear to. This paper describes a way to reduce that power consumption while also storing the data in the cloud. In a fast trending world, storing data on the cloud is good for better maintenance and monitoring. This paper also gives a method to control the lights remotely, if required. The lights will be ON in the evening from dusk, and will remain ON in high density traffic areas, till late night. Then, the time when traffic reduces, lights will start working autonomously. This traffic intensity and timings will vary from place to place. These street lights communicate via the fields in the cloud, and will ON the lights before the vehicle even reaches the next area, for a safe margin and to prevent accidents. The main aim of this proposal is to not only reduce power consumption of unused street lights at night, but to also implement it with the help of a cloud to get data for future implementations, which will help make a better cloud-based system in the future.

Genotoxic Effects of Exposure to Urban Traffic Related Air Pollutants on Children in Klang Valley, Malaysia

Traffic-related air pollutants (TRAPs) are currently increasing due to the increment of vehicle numbers in Malaysia. The emission of pollutants from these vehicles have genotoxic properties that can potentially induce genetic damage in human. In this study, micronuclei assay is used to determine the potential genotoxic exposure by assessing the presence of micronuclei frequency (MN) in buccal cells. The specific objective of this study is to determine the association between TRAPs and frequency of MN among school children in Klang Valley. A comparative cross-sectional study was conducted among primary school children (9�11 years old) in high-density traffic area (n = 94, Kuala Lumpur) and low-density traffic area (n = 94, Hulu Langat). A questionnaire was distributed to the parents to obtain respiratory symptoms information. Buccal cells were analyzed to determine the frequency of micronuclei. Air quality assessment was carried out in a total of 6 schools (consisted of exposed and comparative groups) by using TSI DustTrak DRX Aerosol Monitor 8534 for measurement of PM2.5 and PM10, LaMotte�s Model BD Air Sampling Pump for measurement of Nitrogen dioxide (NO2) and Sulphur dioxide (SO2), ppbRAE 3000 for total Volatile Organic Compound (TVOC) and TSI Q-TRAK 7565 for measurement of Carbon dioxide (CO2) and Carbon monoxide (CO). The concentrations of PM10, PM2.5, NO2, SO2, TVOC and CO at exposed schools were significantly higher (p < 0.005). compared to those in comparative schools. All pollutants were significantly associated (p < 0.001) with respiratory symptom phlegm and MN frequency. Additionally, the MN frequency in the exposed group was significantly higher (p < 0.001) than in the comparative group. All in all, this study demonstrated that air pollutants, especially NO2 and CO, have significantly influenced the MN frequency among children in primary schools. This study suggested that exposure to TRAPs among Malaysian school children has increased the risk for respiratory complications with the formation of MN. © The Author(s).

LSWBVM: A Lightweight Security Without Using Batch Verification Method Scheme for a Vehicle Ad Hoc Network

Recently, Vehicle Ad Hoc Networks (VANETs) have been increasingly developed in Intelligent Transportation Systems (ITSs). However, VANETs are vulnerable to security issues because of the open-medium nature of Vehicle-To-Vehicle (V2V) and Vehicle-To-Infrastructure (V2I) communication. Recently, many studies have proposed security schemes to address these issues. However, many of these schemes have massive computational overheads, especially in the process of batch verification method, which verifies multiple messages simultaneously. In this article, a Lightweight Security Without Using Batch Verification Method (LSWBVM) scheme is proposed based on Elliptic Curve Cryptography (ECC). The proposed LSWBVM scheme uses the XOR operation and general hash function during mutual authentication. Meanwhile, to verify a large number of messages, the proposed scheme uses an efficient single verification instead of batch verification in a high traffic density-area. BAN logic proves that the LSWBVM achieves the security goals to mutually authenticate between the nodes. The security analysis indicates that the LSWBVM satisfies the security requirements, such as: identity privacy preserving, tractability and revocability; and secure non-forgery under the random oracle model in an adaptively chosen message attack. The preference evaluation shows that the single verification of proposed LSWBVM is more efficient when compared with batch verification of the related works.

An efficient identity-based signature scheme without bilinear pairing for vehicle-to-vehicle communication in VANETs

Vehicles exchange traffic-related messages with neighboring vehicles to aid passengers and provide efficient traffic management. This is done via wireless communication channels in Vehicular Ad Hoc Networks (VANETs). Security and privacy issues are a major concern in VANETs. A typical attack consists of a malicious third party modifying and retransmitting intercepted messages. Current state of the art solutions enable a verifier to authenticate the source of received messages as well as to check their integrity before accepting them. However, these solutions do not adequately address the efficiency with which multiple messages are verified in VANETs deployed in high traffic density areas. Due to this, the computational load on a verifier is increased. In this paper, an efficient Identity-Based Signature with Conditional Privacy-Preserving Authentication (IBS-CPPA) scheme based on the Elliptic Curve Cryptography (ECC) and general one-way hash functions for V2V communication is proposed. This scheme supports the batch signature verification method, which enables each vehicle to authenticate a large number of messages at the same time. We provide a security proof of the proposed IBS-CPPA scheme in the random oracle model. The performance evaluation indicates that our scheme is more efficient in terms of computational cost with respect to similar schemes.

SMART STREET SYSTEM WITH IOT BASED STREET LIGHT OPERATION AND PARKING APPLICATION

A smart street lighting and parking monitoring system that works in alignment with smart city application. The system provides high energy efficiency and data security. It can help in reducing the existing concern of finding parking space in high traffic density areas and also in managing parking violations. It improves the productivity and reduces the rate of violation. Along with these features, the smart street lamp also monitors the temperature, humidity and air pollution. The street lamps and traffic signals are interlinked with the traffic monitoring system in the control room with the help of Internet of Things (IoT).

Identification of potential indoor air pollutants in schools

Abstract Indoor air quality in school buildings plays an important role in students' wellbeing and performance. The presence and evolution of different compounds are directly affected by indoor activities, classroom materials and equipment, along with outside conditions derived from location and surrounding activities. Despite high CO2 concentration levels in classrooms being regulated in some regions, there is a wide range of pollutant substances that should be considered. This paper analyses a wide spectrum of air pollutants in school buildings to identify their relative impact and relevance. Measured values are compared to the recommended indoor air guideline values (IAGVs) reported in different national regulations and health organisations. This characterisation helps to evaluate the impact of potential indoor and outdoor air pollutant sources in schools; to define appropriate criteria to analyse the exposure to a wide range of air pollutants; and to develop appropriate strategies in order to reduce the exposure to air pollutants and minimise adverse health effects. A set of high priority pollutants, such as CO2, PM2.5, PM10, TVOC and a set of specific aldehydes and volatile organic compounds, were monitored through active and passive measurement in 18 classrooms of 9 Mediterranean schools. These schools were selected according to their construction period, design typology, and students’ ages. The measurements taken during teaching hours show mean CO2 concentration values of 1530 ppm, oscillating in a range from −24% to +31%. The analysis highlights that along with occupancy, the main indoor air pollutant sources in schools are related to settled dust that produces suspension particles during classroom activity, affecting the relative differences in the mean PM concentration value from +36% to +193%. Moreover, aldehydes show high concentration values in infant classrooms, showing relative differences in the mean value from +163% to +313%. Additionally, the study demonstrates that outdoor air pollutant sources in school surroundings, such as high-density traffic areas or industrial activities, play an important role in final indoor air quality performance, affecting PM10, PM2.5, TVOC, benzene and toluene levels. The measurements show good indoor air quality values, below the recommended indoor air quality guidelines, but they also highlight the monitoring interest of some specific compounds for future regulations, such as PM2.5, PM10, TVOC, benzene, toluene or formaldehyde.

Enhancing Cooperative Driving in IEEE 802.11 Vehicular Networks Through Full-Duplex Radios

On the path to zero fatalities on the roadways, all vehicles have to periodically broadcast cooperative awareness messages (CAMs) in a timely and reliable manner, even in areas of high traffic density. The carrier senses multiple access with collision avoidance (CSMA/CA) scheme of IEEE 802.11, the de-facto standard for vehicular communications, is known to offer no reliability to broadcast packets that cannot be acknowledged, and to poorly perform at high network load due to collisions and interference. In this paper, an enhanced CSMA/CA protocol is analyzed for vehicular networks, which improves the CAM timeliness and reliability by leveraging full-duplex (FD) transceivers on board. FD devices can listen to the channel while transmitting, thus making collision detection viable. A FD vehicle can detect a CAM collision while sending, promptly abort the packet and retransmit it later. Results achieved through an analytical model under mathematically tractable assumptions, and through extensive system-level simulations in a complex urban environment, show the effectiveness of the protocol to cope with direct collisions , especially in high traffic areas, paving the way towards the realization of cooperative automated driving.

SEASONAL ASSESSMENT OF HEAVY METAL POLLUTION IN STREET DUST OF NICOSIA CITY IN NORTH CYPRUS

Heavy metals concentration is increasingly becoming health concern in the world, particularly on street dust of urban cities with high density traffic. Road dust samples were analyzed for determination of concentrations of the environmentally sensitive elements As, Co, Cr, Cu, Ni, Pb, and Zn in fraction of dust smaller than 100 μm. The dust particles were collected during winter and summer seasons from highways, residential and industrial areas representing different activities across the Nicosia city. The dust samples were measured for their contamination levels and particles size distribution. The assessment of pollution was based on single pollution indices, integrated pollution indices and Pearson moment correlation in order to determine their possible source, spatial distribution and seasonal variations. Single Indices include Contamination Factor (Cf), Index of Geo-accumulation (Igeo) and the integrated indices include degree of contamination (Dc) and Pollution Load Index (PLI). The general pattern of occurrence of heavy metals follows the order of Cr>Zn>Cu>Ni>Pb>Co>As. The highest levels of Cr, Zn and Cu were found in the high traffic density area, and strong positive correlations were found between these metals, implying that automobile exhausts are the dominant source of these metals. Keywords: Heavy metals, pollution indices, particles size distribution, seasonal variation.