Spatio-Temporal Air Pollutant Characterization for Urban Areas

Urban pollution has now become increasingly recognized as an important determinant of air pollution in developed countries. The effect of urban air pollution in developing countries, on the other hand, has not been adequately addressed in the data Spatio-temporal time series. Thus, this study was intended to characterize the effect of urbanization on air pollution for an urbanized Klang Valley, Malaysia using Spatio-temporal data from 2008 to 2017. The Air Pollution Index (API) data and local pollutant concentration were employed to establish the links between urban air pollution. The analysis will be supported by determining the source of pollutants during the study period using Principal Component Analysis (PCA). The study identified that Carbon monoxide (CO), Nitrogen Dioxide (NO2), and Ozone (O3) are the major air pollution that has contributed to degrading air quality in the Klang Valley due to the vehicles, combustion process, and industries.

Combined pollution of Cd and Zn in soil-rice systems and its indexes

Due to the mining,smelting,sewage irriga-tion,agricultural runoff,and development ofrural enterprises,combined pollution of Cd andZn in soil-rice systems has frequently oc-curred.This problem was studied by using thepot-culture imitative method combined withhemical analysis and mathematical models.

Assessment of water quality suitability for agriculture in a potentially leachate-contaminated region

Dump sites pose a significant threat to groundwater resources due to the possibility of leachate leakage into the aquifer.This study investigated the impact of leachate on groundwater quality in the southwest region of Zanjan City,Iran,where groundwater is utilized for drinking,agricultural,and industrial purposes.We analyzed 18 parameters of dump site leachate,including physicochemical,heavy metals,and bacterial properties,alongside 13 groundwater samples.Sampling was conducted twice,in November 2020 and June 2021,within a five-kilometer radius of the Zanjan dump site.We utilized the Leachate Pollution Index(LPI)to evaluate potential groundwater contamination by leachate leakage from nearby dumpsite.Additionally,due to the predominant agricultural activities in the study area,various indices were employed to assess groundwater quality for agricultural purposes,such as Sodium Adsorption Ratio(SAR),Soluble Sodium Index(SSI),Kelly Ratio(KR),and Permeability Index(PI).Our analysis revealed no observed contamination related to leachate in the study area according to the LPI results.However,with the persistent pollution threat,implementing sanitary measures at the dump site is crucial to prevent potential impacts on groundwater quality.Moreover,the assessment of groundwater quality adequacy for irrigation yielded satisfactory results for SAR,KR,and PI indices.However,during both the dry(November 2020)and wet seasons(June 2021),the SSP index indicated that 80%of the samples were not classified as excellent,suggesting groundwater may not be suitable for agriculture.Overal,our qualitative study highlights the significant impact of the dry season on groundwater quality in the study area,attributed to elevated concentration levels of the investigated parameters within groundwater sources during the dry season.

Mapping Air Quality Using Remote Sensing Technology: A Case Study of Nairobi County

Nairobi County experiences rapid industrialization and urbanization that contributes to the deteriorating state of air quality, posing a potential health risk to its growing population. Currently, in Nairobi County, most air quality monitoring stations use low-cost, inaccurate monitors prone to defects. The study’s objective was to map Nairobi County’s air quality using freely available remotely sensed imagery. The Air Pollution Index (API) formula was used to characterize the air quality from cloud-free Landsat satellite images i.e., Landsat 5 TM, Landsat 7 ETM+, and Landsat 8 OLI from Google Earth Engine. The API values were computed based on vegetation indices namely NDVI, TVI, DVI, and the SWIR1 and NIR bands on the QGIS platform. Qualitative accuracy assessment was done using sample points drawn from residential, industrial, green spaces, and traffic hotspot categories, based on a passive-random sampling technique. In this study, Landsat 5 API imagery for 2010 provided a reliable representation of local conditions but indicated significant pollution in green spaces, with recorded values ranging from -143 to 334. The study found that Landsat 7 API imagery in 2002 showed expected results with the range of values being -55 to 287, while Landsat 8 indicated high pollution levels in Nairobi. The results emphasized the importance of air quality factors in API calibration and the unmatched spatial coverage of satellite observations over ground-based monitoring techniques. The study recommends the recalibration of the API formula for characteristic regions, exploring newer satellite sensors like those onboard Landsat 9 and Sentinel 2, and involving key stakeholders in a discourse to develop a suitable Kenyan air quality index.

Spatial Analysis on Content Distribution of Soil Heavy Metals Copper (Cu) and Cadmium (Cd) in Duanzhou District of Zhaoqing City

This paper used atomic absorption spectrophotometry to determine the content distribution of Cu and Cd in the soil of Duanzhou District,Zhaoqing City.The single factor index method,Nemerow comprehensive index method,pollution load index method,geoaccumulation index method,and potential ecological hazard index method were used to analyze the content and pollution status of Cu and Cd in the soil of Duanzhou District,providing a basis for understanding the pollution status of Cu and Cd in the soil of Zhaoqing City.

Assessment and mapping of environmental quality in agricultural soils of Zhejiang Province, China

Heavy metal concentrations in agricultural soils of Zhejiang Province were monitored to indicate the status of heavy metal contamination and assess environmental quality of agricultural soils. A total of 908 soil samples were collected from 38 counties in Zbejiang Province and eight heavy metal （Cd, Cr, Pb, Hg, Cu, Zn, Ni and As） concentrations had been evaluated in agricultural soil. It was found 775 samples were unpolluted and 133 samples were slightly polluted and more respectively, that is approximately 14.65% agricultural soil samples had the heavy metal concentration above the threshold level in this province by means of Nemerow＇s synthetical pollution index method according to the second grade of Standards for Soil Environmental Quality of China （GB15618- 1995）. Contamination of Cd was the highest, followed by Ni, As and Zn were lower correspondingly. Moreover, Inverse Distance Weighted （IDW） interpolation method was used to make an assessment map of soil environmental quality based on the Nemerow＇s pollution index and the soil environmental quality was categorized into five grades. Moreover, ten indices were calculated as input parameters for principal component analysis （PCA） and the principal components （PCs） were created to compare environmental quality of different soils and regions. The results revealed that environmental quality of tea soils was better than that of paddy soils, vegetable soils and fruit soils. This study indicated that GIS combined with multivariate statistical approaches proved to be effective and powerful tool in the mapping of soil contamination distribution and the assessment of soil environmental quality on provincial scale, which is beneficial to environmental protection and management decision-making by local government.

Study on the Genetic and Physiological Toxicity of Wastewater from a Pharmaceutical Factory Using Root Tip Micronucleus Technology of Vicia faba

ObjectiveThe aim was to assess genetic and physiological toxicity of wastewater from a pharmaceutical factory using root tip micronucleus technology of Vicia faba. MethodThe pollution of wastewater from a pharmaceutical factory was detected by using root tip micronucleus technology of Vicia faba, and the genetic and physiological toxicity of the wastewater to Vicia faba was assessed. ResultNon-processed wastewater had an extremely high level of biological toxicity; the cells were unable to live with the wastewater at a high concentration; the cells were able to grow with the wastewater at a low concentration, though the micronucleus ratio was extremely high. The processed wastewater had no significant impact on cell growth, but the micronucleus ratio was extremely high, showing that the processed water also had a high pollution index. ConclusionThe research could provide scientific references for the national treatment of wastewater from a pharmaceutical factory.

Soil Heavy Metal Pollution Around the Dabaoshan Mine,Guangdong Province,China

Soil contamination in the vicinity of the Dabaoshan Mine, Guangdong Province, China, was studied through determi- nation of total concentrations and chemical speciation of the toxic metals, Cu, Zn, Cd, and Pb, using inductively coupled plasma mass spectrometry. The results showed that over the past decades, the environmental pollution was caused by a combination of Cu, Zn, Cd, and Pb, with tailings and acid mine drainage being the main pollution sources affecting soils. Significantly higher levels （P ≤ 0.05） of Cu, Zn, Cd, and Pb were found in the tailings as compared with paddy, garden, and control soils, with averages of 1486, 2516, 6.42, and 429 mg kg^-1, respectively. These metals were continuously dispersed downstream from the tallings and waste waters, and therefore their concentrations in the paddy soils were as high as 567, 1 140, 2.48, and 191 mg kg^-1, respectively, being significantly higher （P ≤ 0.05） as compared with those in the garden soils. The results of sequential extraction of the above metals from all the soil types showed that the residual fraction was the dominant form. However, the amounts of metals that were bound to Fe-Mn oxides and organic matter were relatively higher than those bound to carbonates or those that existed in exchangeable forms. As metals could be transformed from an inert state to an active state, the potential environmental risk due to these metals would increase with time.

Combined Pollution and Pollution Index of Heavy Metals in Red Soil

A field experiment was conducted to study the effects of Pb, Cd, Cu, Zn and As coexisting in red soilon growth of rice (Oryza sativa L.), mung bean (Vigna rabiata (Linn.) Wilczek), alfalfa (Medicago sativaL.), slash pine (Pinus elliottii Engelm.) and aspen (Populus L.). Results showed that rice, mung bean andalfalfa were significantly innuenced by combined pollution of the heavy metals. The contents of Pb, cd andAs in rice grains greatly exceeded the National Standards for Food Hygiene of China. Heavy metals at ahigh concentration seriously retarded growth of mung bean and alfalfa, but not so obviously with slash pineand aspen. The composite index is suggested for evaluating the relativity of combined pollution witll heavymetals in soil.

A Comparative Analysis of Environmental Quality Assessment Methods for Heavy Metal-Contaminated Soils

Four assessment methods （two pollution indexes and two fuzzy mathematical models） were employed to investigate the environmental quality of four soils around a ferroalloy plant in Nanjing City. Environmental quality was assessed as class Ⅳ （moderately polluted） for each soil with single-factor index method, and was identified to be classes Ⅳ, Ⅲ （slightly polluted）, Ⅲ, and Ⅲ for soils A, B, C, and D, respectively, with the comprehensive index model. In comparison with the single-factor index method, the comprehensive index model concerned both dominant parameter and average contribution of all factors to the integrated environmental quality. Using the two fuzzy mathematical methods （single-factor deciding and weighted average models）, the environmental risks were determined to be classes Ⅳ, Ⅲ, Ⅱ （clean）, and Ⅱ for soils A, B, C, and D, respectively. However, divergence of the membership degree to each pollution class still occurred between the two methods. In fuzzy mathematical methods, membership functions were used to describe the limits between different pollution degrees, and different weights were allocated for the factors according to pollution contribution. Introduction of membership degree and weight of each factor to fuzzy mathematical models made the methods more reasonable in the field of environmental risk assessment.

Evaluation of ambient air quality in Guangzhou, China

On the basis of the reported air quality index （API） and air pollutant monitoring data provided by the Guangzhou Environment Monitoring Stations over the last twenty-five years, the characteristics of air quality, prominent pollutants, and variation of the average annual concentrations of SOE, NOE, total suspended particulate （TSP）, fine particulates （PM10）, CO and dustfall in Guangzhou City were analyzed. Results showed that TSP was the prominent pollutant in the ambient air environment of Guangzhou City. Of the prominent pollutants, TSP accounted for nearly 62%, SOE 12.3%, and NOx 6.4%, respectively. The average API of Guangzhou over 6 years was higher than that of Beijing, Tianjin, Nanjing, Hangzhou, Suzhou and Shanghai, and lower than that of Shenzhen, Zhuhai and Shantou. Concentrations of air pollutants have shown a downward trend in recent years, but they are generally worse than ambient air quality standards for USA, Hong Kong and EU. SOE and NOx pollution were still serious, impling that waste gas pollution from all kinds of vehicles had become a significant problem for environmental protection in Guangzhou. The possible causes of worsening air quality were also discussed in this paper.

Atmospheric Deposition-Carried Pb, Zn, and Cd from a Zinc Smelter and Their Effect on Soil Microorganisms

Dust emissions from smelters, as a major contributor to heavy metal contamination in soils, could severely influence soil quality. Downwind surface soils within 1.5 km of a zinc smelter, which was active for 10 years but ceased in 2000, in Magu Town, Cuizhou Province, China were selected to examine Pb, Zn, and Cd concentrations and their fractionation along a distance gradient from a zinc smelter, and to study the possible effects of Pb, Zn, and Cd accumulation on soil microorganisms by comparing with a reference soil located at a downwind distance of 10 km from the zinc smelter. Soils within 1.5 km of the zinc smelter accumulated high levels of heavy metals Zn （508 mg kg^-1）, Pb （95.6 mg kg^-1）, and Cd （5.98 mg kg^-1） with low ratios of Zn/Cd （59.1-115） and Pb/Cd （12.4-23.4）. Composite pollution indices （CPIs） of surface soils （2.52-15.2） were 3 to 13 times higher than the reference soils. In metal accumulated soils, exchangeable plus carbonate-bound fractions accounted for more than 10% of the total Zn, Pb, and Cd. The saturation degree of metals （SDM） in soils within 1.5 km of the smelter （averaging 1.25） was six times higher than that of the reference soils （0.209）. A smaller soil microbial biomass was found more frequently in metal accumulated soils （85.1-438 μg C g^-1） than in reference soils （497 μg C g^-1）, and a negative correlation （P 〈 0.01） of soil microbial biomass carbon to organic carbon ratio （Cmic/Corg） with SDM was observed. Microbial consumption of carbon sources was more rapid in contaminated soils than in reference soils, and a shift in the substrate utilization pattern was apparent and was negatively correlated with SDM （R = -0.773, P 〈 0.01）. Consequently, dust deposited Pb, Zn, and Cd in soils from zinc smelting were readily mobilized, and were detrimental to soil quality mainly in respect of microbial biomass .

Heavy Metal Pollution in Soils on Railroad Side of Zhengzhou-Putian Section of Longxi-Haizhou Railroad, China

The pollution status and horizontal distribution of heavy metals (Ni, Pb, Cr, Zn, Cu, and Cd) in the soil on railroad side along the Zhengzhou-Putian section of Longxi-Haizhou Railroad were studied by collecting soil samples along a sampling section perpendicular to the railroad at the distances of 0, 10, 20, 30, 50, 100, 200, 300, and 500 m from the railroad edge. The concentrations of heavy metals in the sampling soils were higher than those of the control site. The concentrations of Pb, Zn, and Cd were found to be the highest in the soils at the railroad edge, and then decreased with increasing distance from the railroad. The highest concentrations of Ni, Cr, and Cu in soils were located at about 10-30 m from the railroad. Compared with the single factor pollution index (SFPI) of heavy metals calculated for the control site, the average SFPI from the sampling sites decreased in the order of Cr > Cd > Pb > Zn > Ni > Cu. There were notable negative correlations between the integral pollution index (IPI) of soil heavy metals at all sampling sites and the distances from the railroad. According to three IPIs calculated from the background values of heavy metals in och-aquic Cambisols, the heavy metal concentrations in the control soil, and the 2nd levels for soil heavy metals in GB15618-1995, the study area could be divided, based on the distances from the railroad, into four pollution zones: heavy pollution zone (0-10 m), medium pollution zone (10-50 m), slight pollution zone (50-100 m), and warning zone (100-500 m), respectively.

Characterization of Air Pollution in Urban Areas of Yangtze River Delta,China

The hallmark of development in the Yangtze River Delta(YRD) of East China has been sprawling urbanization. However, air pollution is a significant problem in these urban areas. In this paper, we investigated and analyzed the air pollution index(API) in four cities(Shanghai, Nanjing, Hangzhou and Ningbo) in the YRD from 2001 to 2012. We attempted to empirically examine the relationship between meteorological factors and air quality in the urban areas of the YRD. According to the monitoring data, the API in Shanghai, Nanjing, Hangzhou slightly declined and that in Ningbo increased over the study period. We analyzed the inter-annual, seasonal, and monthly variations of API, from which we found that the air quality had different temporal changes in the four cities. It was indicated that air quality was poor in winter and spring and best in summer. Furthermore, different weather conditions affected air quality level. The wind direction was considered as an important and influential factor to air pollution, which has an impact on the accumulating or cleaning processes of pollutants. The air quality was influenced by the different wind directions that varied with seasons and cities.

Heavy metal contamination of urban topsoil in a petrochemical industrial city in Xinjiang, China

Heavy metal pollution is a widespread phenomenon in many countries of the world. In this study, we conducted a field investigation to assess the status of heavy metal pollution in urban soils of Dushanzi, a district of Karamay city in Xinjiang, China. A total of 56 soil samples in the topsoil layer of 0-15 cm were collected within the urban area and seven elements （Cu, Zn, Cd, Pb, Cr, As and Ni） were analyzed. The mean concentrations of these metals were all higher than their corresponding background values of soils in Xinjiang. We used the pollution index and ecological risk index to assess the degree of heavy metal pollution and the potential ecological risk of urban soils. The pollution index values of Cu, Zn, Cd, Pb, Cr, As and Ni were 1.81, 1.35, 4.64, 1.27, 1.80, 1.39 and 1.22, respectively; and the potential ecological risk index values for them were 12.03, 1.79, 185.05, 8.39, 4.78, 18.44 and 1.79, respectively. These results indicated that urban soils in Dushanzi were polluted by heavy metals to some extent and demonstrated a high ecological risk, as influenced by industrial activities. Cd was the key element for the metal pollution of urban soils in the study area. Correlation analyses, principal component analysis coupled with the spatial distribution maps of element concentrations further soils can be mainly attributed to petrochemical commercial activities. revealed that heavy metal pollution of urban ndustry, coal chemical industry, traffic and

TYPICAL WEATHER CHARACTERISTICS ASSOCIATED WITH AIR POLLUTION IN HONG KONG AREA

With the hourly data of Air Pollution Index （AP1） by Hong Kong Environmental Protection Department （HKEPD） during the 6 years of 2000 - 2005 and NCEP / NCAR reanalysis data of 2.5°× 2.5° wind and pressure fields, the characteristics of API in Hong Kong area and the impacts of typical weather characteristics on the air pollution in Hong Kong have been studied. The results are shown as follows. （1） The API exhibits obvious seasonal variability as the number of air pollution days increases by the year. For most of the local monitoring stations, it is the most from January to March, a little less from July to September and the least from April to June. （2） There are four typical types of weather situations that are responsible for the air pollution in Hong Kong： tropical cyclones, continental cold highs, transformed highs that have moved out to sea and low pressure troughs.

Content and Ecological Risk Assessment of Heavy Metals in Surface Sediment in Weishan Lake

[Objective] The aim was to analyze the content of heavy metals in surface sediment in Weishan Lake and further assess its ecological risk.[Method] Heavy metal pollution in surface sediment in Weishan Lake was studied,and the pollution indices and potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were calculated to assess the potential ecological risk of heavy metal pollution.[Result] In surface sediment in Weishan Lake,the average contents of Cu,Zn,Pb,Cd,Cr and Ni were 64.78,185.05,78.76,0.17,37.76 and 46.84mg/kg respectively.Cr and Cd weren’t beyond standards in all stations,while Cu and Pb exceeded standards in all stations,with average super-standard multiple of 0.85 and 0.31,respectively,and Zn content wasn’t beyond standard in S2 station,with average super-standard multiple of 0.24.The average pollution indices of Cu,Zn,Pb,Cd and Cr were 1.85,1.23,1.31,0.34 and 0.47 respectively,with average comprehensive pollution index of 5.21,which showed that heavy metal pollution was light.In addition,heavy metal pollution in entryway portion and sea-route portion were more serious than that of breeding portion.Potential ecological risk assessment showed that the average potential ecological risk indices of Cu,Zn,Pb,Cd and Cr were 9.25,1.23,6.56,10.34 and 0.94 respectively,with average comprehensive potential ecological risk index of 28.33,and it revealed that potential ecological risk of heavy metals was slight.Besides,the potential ecological risk order of heavy metal pollution was sea-route portion>entryway portion>breeding portion.[Conclusion] The study could provide references for the regulation and improvement of ecological environment in Weishan Lake in the east route of south-to-north water transfer project.

Physico-chemical characteristics and heavy metal concentrations of copper mine wastes in Zambia:implications for pollution risk and restoration

Soil characterization is a vital activity to develop appropriate and effective restoration protocols for mine wastelands while insights into the total content of heavy metals in the soil is an important step in estimating the hazards that the metals may pose to the vital roles of soil in the ecosystem.This study addressed the following research questions:(1)To what extent do the physico-chemical characteristics vary between mine waste sediments and the nearby forest soil?(2)Are the concentrations of heavy metals high enough to be considered as toxic?and(3)Are heavy metals present in mine waste sediments potential sources of pollution?We hypothesized that the physicochemical characteristics of mine waste sediments are less favorably for plant establishment and growth while the concentrations of heavy metals are very high,thus restricting the success of revegetation of mine waste lands.Mine waste sediments were sampled following a diagonal transect across tailings dams,overburden dump sites and the local forest soil from the top layer(0-20 cm)using a closed auger.Samples were analyzed for arsenic,barium,lead,cadmium,cobalt,copper,chromium,nickel,vanadium,and zinc as well as for soil physico-chemical properties.The mine waste sediments were dominated by silt whilst the forest soil by sand particles,with significantly high bulk density in the former.Both the forest soil and overburden sediments were acidic than the alkaline tailings dam sediment.Total organic carbon and nitrogen contents were significantly low in mine wasteland substrates but the concentration of Ca and Mg were significantly higher in tailings dam substrate than the forest soil.The concentrations of available P,K and Na were similar across sites.The mean concentrations of heavy metals were significantly(p<0.01)higher in mine waste sediments than the forest soil;except for cadmium(p=0.213).The order of contamination by heavy metals on the tailings was Cu>Co>Ba>Ni>As>Zn>Pb>Cr>V>Cd,and that on the overburdens was Cu>Co>Ba>Ni>Zn>Cr>Pb>V>As>Cd.The pollution load index(PLI)was nearly twice higher for the tailings dam(8.97)than the overburden(5.84).The findings show that the copper mine wastes(the tailings dams and overburden waste rock sites)are highly contaminated by heavy metals;which,in turn,might pose serious hazards to human health and agricultural productivity.In addition,poor macro-nutrient availability,substrate compaction and soil acidity(particularly on overburden sites)coupled with toxic level of heavy metals would be the main challenges for successful phytostabilization of copper mine wastelands.

Evaluation of groundwater quality using pollution index of groundwater(PIG) and non-carcinogenic health risk assessment in part of the Gangetic Basin

The aim of this study was to evaluate groundwater fitness for domestic and irrigational use in Unnao district of Uttar Pradesh,India.For this study,block wise(n=16)groundwater samples were collected,and measured parameters were analyzed using the pollution index of groundwater(PIG),various irrigational indices,and graphical techniques.The results of this study suggested that most of the parameters were within the prescribed limits of WHO and BIS,excluding F-(0.4 to 2.6 mg L^(-1))and Fe^(2+)(0.1 to 1.7 mg L^(-1)).Concentrations of total dissolved solids(TDS)were exceeded the desirable limit(>500 mg L^(-1))in 43.75%of samples at some sites.The Gibbs plot revealed that groundwater chemistry was governed by rock-water interaction in the region,especially silicate weathering.The Piper plot suggested that Ca^(2+)-HCO3-is dominant hydrochemical facies in the area followed by mixed Ca^(2+)-Na^(+)-HCO_(3)^(-)type,Na^(+)-Cl^(-)type,and Na^(+)-HCO_(3)^(-)type.PIG evaluation revealed that the contribution of F-and Fe2+in groundwater degradation is high in comparison to other elements in the region,about 18.75%samples showed low pollution,while about 6.25%samples shows moderate pollution,and 6.25%samples reflected high pollution.The human health risk(HHR)assessment finding suggested that children(mean:1.36)are more vulnerable than adults(mean:1.01).Sodium absorption ration(SAR),Residual sodium carbonate(RSC),and Permeability index(PI)indicated that most of the groundwater was suitable for irrigation,whereas,Magnesium hazard ration(MHR)and Potential salinity(PS)indices suggested that only 37.5%and 56.25%of the samples were suitable for irrigational use,respectively.This regional study would help in decision making for stakeholders and relevant authorities in the execution of groundwater management and remediation plans in the area.

Association between medical resources and the proportion of oldest-old in the Chinese population

The potential association between medical resources and the proportion of oldest-old(90 years of age and above)in the Chinese population was examined,and we found that the higher proportion of oldest-old was associated with the higher number of beds in hospitals and health centers.