A comparative study of noise pollution levels in some selected areas in Ilorin Metropolis, Nigeria

The noise pollution is a major problem for the quality of life in urban areas. This study was conducted to compare the noise pollution levels at busy roads/road junctions, passengers loading parks, commercial, industrial and residential areas in Ilorin metropolis. A total number of 47-locations were selected within the metropolis. Statistical analysis shows significant difference (P < 0.05) in noise pollution levels between industrial areas and low density residential areas, industrial areas and high density areas, industrial areas and passengers loading parks, industrial areas and commercial areas, busy roads/road junctions and low density areas, passengers loading parks and commercial areas and commercial areas and low density areas. There is no significant difference (P > 0.05) in noise pollution levels between industrial areas and busy roads/road junctions, busy roads/road junctions and high density areas, busy roads/road junctions and passengers loading parks, busy roads/road junctions and commercial areas, passengers loading parks and high density areas, passengers loading parks and commercial areas and commercial areas and high density areas. The results show that Industrial areas have the highest noise pollution levels (110.2 dB(A)) followed by busy roads/Road junctions (91.5 dB(A)), Passengers loading parks (87.8 dB(A)) and Commercial areas (84.4 dB(A)). The noise pollution levels in Ilorin metropolis exceeded the recommended level by WHO at 34 of 47 measuring points. It can be concluded that the city is environmentally noise polluted and road traffic and industrial machineries are the major sources of it. Noting the noise emission standards, technical control measures, planning and promoting the citizens awareness about the high noise risk may help to relieve the noise problem in the metropolis.     

The effects of meteorological parameters in ambient noise modelling studies in Delhi

The acoustic environment in urban areas has gained prominence in recent times due to rapid industrial and commercial development in metropolitan cities. Various attempts have been made to predict and model the trends in urban ambient noise levels using different statistical and dynamic models. The present study makes an attempt to examine the role of meteorological parameters affecting the ambient noise levels in Delhi. The results show significant improvement in overall noise scenario of Delhi since the introduction of compressed natural gas vehicles in public transport of Delhi. The noise level is significantly reduced by high vegetation cover as well as by low relative humidity over Delhi. The regression models developed for the present study clearly show the significant contribution of meteorological parameters in governing the ambient noise levels in Delhi.     

Organic matter determination for street dust in Delhi

The organic matter of street dust is considered as one of the causes for high human mortality rate. To understand the association, the street dust samples were collected from four different localities (industrial, residential, residential–commercial, and commercial) situated in the greater Delhi area of India. The loss-on-ignition method was used to determine the organic matter (OM) content in street dust. The OM content, potassium, calcium, sulfate, and nitrate concentrations of street dust in Delhi, India is measured to understand the spatial variation. Correlation analysis, analysis of variance, and factor analysis were performed to define the sources. The dust OM level ranges from 2.63 to 10.22 %. It is found through correlation and factor analysis that OM is primarily contributed from secondary aerosol and vehicular exhaust. The OM levels suggest that the use of a residential–commercial site for commercial purposes is polluting the street dust and creating the environmental and human health problems.     

Monitoring variation in greenhouse gases concentration in Urban Environment of Delhi

Cities across the globe are considered as major anthropogenic sources of greenhouse gases (GHG), yet very few efforts has been made to monitor ambient concentration of GHG in cities, especially in a developing country like India. Here, variations in the ambient concentrations of carbon dioxide (CO₂) and methane (CH₄) in residential, commercial, and industrial areas of Delhi are determined from fortnightly daytime observations from July, 2008 to March, 2009. Results indicate that the average daytime ambient concentration of CO₂ varied from 495 to 554 ppm in authorized residential areas, 503 to 621 ppm in the slums or jhuggies in the unauthorized residential areas, 489 to 582 ppm in commercial areas, and 512 to 568 ppm in industrial areas with an average of 541?±?27 ppm. CH₄ concentration varied from 652 to 5,356 ppbv in authorized residential areas, 500 to15,220 ppbv in the unauthorized residential areas, 921 to 11,000 ppbv in the commercial areas, and 250 to 2,550 ppbv in the industrial areas with an average of 3,226?±?1,090 ppbv. A low mid-afternoon CO₂ concentration was observed at most of the sites, primarily due to strong biospheric photosynthesis coupled with strong vertical mixing.     

Analysing and mapping spatial and temporal dynamics of urban traffic noise pollution: a case study in Kahramanmaraş, Turkey

This study aimed at quantifying noise pollution from urban traffic in the city of Kahramanmara?, Turkey. A total of 114 measurements for the equivalent noise level (L _Aeq) were made at 38 urban locations classified as “residential areas”, “residential and commercial areas” and “industrial areas” according to the national regulations, during morning, mid-day and evening hours. Our findings tabulated and mapped revealed that mean noise level in “residential and commercial areas” was highest relative to the other land-use types. Minimum and maximum values of noise pollution were recorded during the mid-day and evening hours, regardless of the land-use types. Noise limit values were exceeded at two locations only out of 38 based on the national regulation criteria and at over half of the locations based on the international criteria.     

Evaluation and analysis of noise levels in Ilorin metropolis, Nigeria

Evaluation and analysis of noise pollution levels have been carried out to determine the level of noise and its sources in Ilorin metropolis. Noise measurements have been done in the morning, at noon, in the evening, and at night to determine noise pollution all over the city. The selected areas of study are commercial centers, road junctions/busy roads, passenger loading parks, and high-density and low-density residential areas. The road junctions had the highest noise pollution levels, followed by commercial centers. The results of this study show that the noise levels in Ilorin metropolis exceeded allowed values at 30 of 42 measurements points. There is a significant difference (P?<?0.05) in the noise pollution levels and traffic noise index in all the locations. From the measured noise values, a map of noise pollution was developed for Ilorin. Many solutions proposed for noise abatement in the city are set out.     

Preparation and Validation of Gridded Emission Inventory of Criteria Air Pollutants and Identification of Emission Hotspots for Megacity Delhi

Delhi is one of the many megacities struggling with punishing levels of pollution from industrial, residential, and transportation sources. Over the years, pollution abatement in Delhi has become an important constituent of state policies. In the past one decade a lot of policies and regulations have been implemented which have had a noticeable effect on pollution levels. In this context, air quality models provide a powerful tool to study the impact of development plans on the expected air pollution levels and thus aid the regulating and planning authorities in decision-making process. In air quality modeling, emissions in the modeling domain at regular interval are one of the most important inputs. From the annual emission data of over a decade (1990–2000), emission inventory is prepared for the megacity Delhi. Four criteria pollutants namely, CO, SO₂, PM, and NO _x are considered and a gridded emission inventory over Delhi has been prepared taking into account land use pattern, population density, traffic density, industrial areas, etc. A top down approach is used for this purpose. Emission isopleths are drawn and annual emission patterns are discussed mainly for the years 1990, 1996 and 2000. Primary and secondary areas of emission hotspots are identified and emission variations discussed during the study period. Validation of estimated values is desired from the available data. There is a direct relationship of pollution levels and emission strength in a given area. Hence, an attempt has been made to validate the emission inventory for all criteria pollutants by analyzing emissions in various sampling zones with the ambient pollution levels. For validation purpose, the geographical region encompassing the study area (Delhi) has been divided into seven emission zones as per the air quality monitoring stations using Voronoi polygon concept. Dispersion modeling is also used for continuous elevated sources to have the contributing emissions at the ground level to facilitate validation. A good correlation between emission estimates and concentration has been found. Correlation coefficient of 0.82, 0.77, 0.58 and 0.68 for CO, SO₂, PM and NO _x respectively shows a reasonably satisfactory performance of the present estimates.     

Prediction of daily ground-level ozone concentration maxima over New Delhi

The pollution levels in New Delhi from industrial, residential, and transportation sources are continuously growing. As one of the major pollutants, ground-level ozone is responsible for various adverse effects on both humans and foliage. The present study aims to predict daily ground-level ozone concentration maxima over a site situated in New Delhi through neural networks (NN) and multiple-regression (MR) analysis. Although these methodologies are case and site specific, they are being developed and used widely. Therefore, to test these methodologies for New Delhi where no such study is available for ground-level ozone, six models have been developed based on NNs and MR using the same input data set. The changes in the performance capability of the two methods are sensitive to the selection of input parameters. The results are encouraging, and remarkable improvements in the performance of the models have been observed.     

Studies on urban drinking water quality in a tropical zone

Anthropogenic activities associated with industrialization, agriculture and urbanization have led to the deterioration in water quality due to various contaminants. To assess the status of urban drinking water quality, samples were collected from the piped supplies as well as groundwater sources from different localities of residential, commercial and industrial areas of Lucknow City in a tropical zone of India during pre-monsoon for estimation of coliform and faecal coliform bacteria, organochlorine pesticides (OCPs) and heavy metals. Bacterial contamination was found to be more in the samples from commercial areas than residential and industrial areas. OCPs like α,γ-hexachlorocyclohexane and 1,1 p,p-DDE {dichloro-2, 2-bis(p-chlorophenyl) ethene)} were found to be present in most of the samples from study area. The total organochlorine pesticide levels were found to be within the European Union limit (0.5 μg/L) in most of the samples. Most of the heavy metals estimated in the samples were also found to be within the permissible limits as prescribed by World Health Organization for drinking water. Thus, these observations show that contamination of drinking water in urban areas may be mainly due to municipal, industrial and agricultural activities along with improper disposal of solid waste. This is an alarm to safety of public health and aquatic environment in tropics.     

Variability in Voc Concentrations in an Urban Area of Delhi

The variability of pollutants is an important factor in determining human exposure to the chemicals. This study presents the result of investigation of variability of Volatile organic compounds (VOCs) in urban area of Delhi, capital of India. Fifteen locations, in five categories namely residential, commercial, industrial, traffic intersections and petrol pump were monitored for one year every month during peak hours in morning and evening. Measurement focused on target VOCs as defined by USEPA. Variability was divided into measurement, spatial, temporal and temporal–spatial interaction components. Temporal component along with temporal–spatial interaction were found to be the major contributors to the variability of measured VOC concentrations. Need of continuous monitoring to capture short–term peak concentration and averages is evident.     

Heavy metal concentrations in groundwaters and soils of Thane Region of Maharashtra, India

Thane district is one of the most industrialized districts in Maharashtra. The heavy industrialization and the increasing urbanization are responsible for the rapidly increasing stress on the water and soil environment of the area. Therefore, an attempt has been made through comprehensive study on the groundwater contamination and soil contamination due to heavy metals in Thane region of Maharashtra. The area undertaken for the study was Thane and its suburbans Kalwa, Divajunction, Dombivali, Kalyan, and Ulhasnagar. Industrialization and urbanization lead to generation of large volumes of wastewater from domestic, commercial, industrial, and other sources, which discharged in to natural water bodies like river and creek in this region. Groundwater samples and soil samples were collected from residential, commercial, agriculture, and industrial areas. Groundwater samples were analyzed for various water quality parameters. The analytical data shows very high concentration of total dissolved solids, total hardness, total alkalinity, chemical oxygen demand, chloride etc. Groundwater and soil samples were analyzed for ten heavy metals by inductively coupled plasma (ICPE-9000) atomic emission spectroscopy. The analytical data reveal that, very high concentration level of arsenic, cadmium, mercury, and nickel throughout the industrial area. The random dumping of hazardous waste in the industrial area could be the main cause of the groundwater and soil contamination spreading by rainwater and wind. In the residential areas the local dumping is expected to be the main source for heavy metals. A comparison of the results of groundwater with WHO guidelines show that most of the groundwater sampling station are heavily contaminated with organic matter and heavy metals. Groundwater samples are heavily contaminated by arsenic, cadmium, mercury, and nickel. Similarly, the results of heavy metals in soil compared with Swedish soil guideline values for polluted soil show that soil samples collected from residential, commercial and industrial areas are heavily contaminated by arsenic, cadmium, mercury, and nickel.     

Air quality and respiratory health in Delhi

Delhi is an instructive location for studying the impact of air pollution since it is a rapidly expanding centre of government, trade commerce and industry. We have made an attempt to (1) determine the association between environmental pollution and respiratory morbidity in Delhi for the period 1998–2004, (2) assess the impact on hospital admission of the implementation of recent governmental regulations and (3) calculate the relative risk of hospitalization due to respiratory ailments caused by air pollutants. Seven hospitals from different parts of Delhi were selected. The pollution profiles of these areas were assessed and subsequently Poisson regression model was performed for the patient population. There was a remarkable decrease in monthly average concentration of sulphur dioxide (from 17.9 to 11.1 μg m⁻³) and increase in monthly average concentration of nitrogen dioxide (from 34.2 to 49.1 μg m⁻³) after the newly introduced regulations. Particulates were observed to have marginal fall in their concentration but still remained above the permissible limits. Gaseous pollutants, in spite of being at a level lower than the permissible level, showed more consistent significant association with respiratory admissions. The relative risks of hospitalization due to respiratory diseases were in the range of 1.07–2.82 in residential cum commercial areas. Comparative study of pre and post new stringent governmental regulation showed significant positive association of NO₂ with respiratory disorders in southern (RR: 1.10; CI: 1.09–1.12) and northern regions (RR: 1.33; CI: 1.27–1.39), both mixed use areas. In spite of the improvement in the air quality, the associated health effects were found to be substantial.     

Aircraft-Induced Noise Levels in Some Residential Areas of Delhi

The measurements of aircraft-induced noise levels in some residential areas in the capital city of India were carried out in the month of April and May, 1996. Four areas were chosen which were located underneath the flight path. It has been found that average increase in noise levels over and above the background levels is more than 20 dBA except in case of the most distant site where it is 11 dBA. A good correlation has been found between average peak noise levels (dBA) and the population response in terms of annoyance.     

Atmospheric deposition of heavy metals (Cu, Zn, Cd and Pb) in Varanasi City, India

Rapid growth in urbanization and industrialization in developing countries may significantly contribute in heavy metal contamination of vegetables through atmospheric depositions. In the present study, an assessment was made to investigate the spatial and seasonal variations in deposition rates of heavy metals and its contribution to contamination of palak (Beta vulgaris). Samples of bulk atmospheric deposits and Beta vulgaris for analysis of Cu, Zn, Cd and Pb were collected from different sampling locations differing in traffic density and land use patterns. The results showed that the sampling locations situated in industrial or commercial areas with heavy traffic load showed significantly elevated levels of Cu, Zn and Cd deposition rate as compared to those situated in residential areas with low traffic load. The deposition rates of Cu, Zn and Cd were significantly higher in summer and winter as compared to rainy season, however, Pb deposition rate was significantly higher in rainy and summer seasons as compared to winter season. Atmospheric depositions have significantly elevated the levels of heavy metals in B. vulgaris collected during evening as compared to those collected in morning hours. The study further showed that local population has maximum exposure to Cd contamination through consumption of B. vulgaris. The present study clearly points out the urban and industrial activities of a city have potential to elevate the levels of heavy metals in the atmospheric deposits, which may consequently contaminate the food chain and thus posing health risk to the local population.     

Load of Heavy Metals in the Airborne Dust Particulates of an Urban City of Central India

The geographical and temporal distribution patterns of airborne dust particulates have been studied in different representative areas of Raipur City. Dust fall samples from different sites were collected and some selected toxic metals namely Cr, Mn, Fe, Ni, Cu, Zn, Sb and Pb in them were determined by AAS. Total annual flux of 11.7, 541.4, 2751.0, 14.2, 9.8, 90.9, 17.6, and 17.7 kg km(-2) y(-1) were measured for Cr, Mn, Fe, Ni, Cu, Zn, Sb, and Pb respectively. The occurrence of metal concentration were generally in the order industrial > heavy traffic > commercial > residential area in Raipur city. The results of analysis show the existence of toxic metal concentration in the order Fe > Mn > Zn > Pb approximately Sb > Ni > Cr > Cu in Raipur city. These large levels of metal pollutants have also been correlated with some meteorological parameters like temperature, relative humidity and wind velocity, and strong positive correlations have been observed.     

常州市秋季大气PM2.5中多环芳烃污染水平及来源

为了研究常州市秋季大气PM2.5中多环芳烃的污染水平及其来源,在常州市布设了6个采样点,分别代表交通干道区、商业混合区、居民文教区、远郊区、工业区和对照点,于2013年10月进行大气PM2.5的采样,采用微波萃取-高效液相色谱法测定其中16种USEPA优控多环芳烃的浓度值,并分别通过比值法和因子分析法判断其主要来源。结果表明,常州市秋季大气PM2.5中多环芳烃的主要来源为煤燃烧和机动车排放。     

郑州市大气环境中半挥发性有机污染物分布规律研究

在郑州市交通密集区、工业区、居民文化区等不同功能区设置监测点位,分春、夏、秋、冬4季对大气环境中半挥发性有机污染物的污染状况进行初步研究。结果表明:不同季节半挥发性有机物检出数量的变化趋势为:冬季秋季春季夏季;不同功能区SVOC检出数量变化趋势为:交通密集区工业区混合区文化区对照区。     

Noise disturbance caused by outdoor activities�� a simulated-environment study for Ali Sami Yen Stadium, ?stanbul

Negative effects of noise on individuals, the inevitable result of urbanization, have become a significant urban problem in our day. Introduction of an approach to the noise problem on an urban-planning scale lightens the burden of measures required to be taken against noise at the stages of regional and developmental planning. Stadiums, which should be also evaluated from the point of noise problem when planning decisions are made on the urban planning scale, may cause very serious problems differing depending on the region they are located in. In this article, various dimensions of the noise problem caused by stadiums have been exemplified by making an assessment on Ali Sami Yen football stadium located in Mecidiyeköy district which is among important residential and commercial centres of ?stanbul or Turkey. When the simulation results obtained for ordinary days and match days are evaluated, it has been found out that the people living in the area are exposed to noise levels substantially exceeding the acceptable values. Results of the survey conducted in the area have clearly revealed the existence of noise problem, too.     

A preliminary investigation of BDE-209, OCPs, and PAHs in urban road dust from Yangtze River Delta, China

Urban road dust samples were collected from different land use areas in Suzhou, Wuxi, and Nantong, Yangtze River Delta, China. The dust samples were analyzed for the levels and compositional profiles of deca-polybrominated diphenyl ethers (Deca-BDE), 22 organochlorine pesticides (OCPs), and 16 polycyclic aromatic hydrocarbons (PAHs). The levels of BDE-209, ∑OCPs, and ∑PAHs in samples ranged from 4.01–1,439 μg/kg, 3.15–615 μg/kg, and 2.24–58.2 mg/kg, respectively. PAHs were the predominant target compounds in road dust samples, comprising on average 97.7 % of total compounds. The spatial gradient of the pollutants (commercial/residential area> industrial area > urban park concentrations) was observed in the present study. The results indicated that the levels of BDE-209, OCPs, and PAHs observed in road dust were usually linked to anthropogenic activities in the urban environment. In addition, there might be a reflection of current usage or emissions of OCPs in urban environment.