Association between exposure to particulate matter and incidence of Parkinson's disease: A nationwide cohort study in Taiwan.

Objective: Emerging evidence suggests that air pollution exposure may increase the risk of Parkinson's disease (PD). We aimed to investigate the association between exposure to fine particulate matter (PM2.5) and the risk of incident PD nationwide. Methods: We utilized data from the Taiwan National Health Insurance Research Database, which was spatiotemporally linked with air quality data from the Taiwan Environmental Protection Administration website. The study population consisted of participants who were followed from the index date (January 1st, 2005) until the occurrence of PD or the end of the study period (December 31st, 2017). Participants who had a prior diagnosis of PD before the index date were excluded. To evaluate the association between exposure to PM2.5 and incident PD, we employed a Cox regression to estimate the hazard ratio with a 95% confidence interval (CI). Results: A total of 454,583 participants were included, with a mean (SD) age of 63.1 (9.9) years and a male proportion of 50%. Over a mean follow-up period of 11.1 (3.6) years, 4% of the participants (n = 18,862) developed PD. We observed a significant positive association between PM2.5 exposure and the risk of PD, with a hazard ratio of 1.22 (95% CI, 1.20-1.23) per interquartile range increase in exposure (10.17 µg/m3) when adjusting for both SO2 and NO2. Conclusion: We provide further evidence of an association between PM2.5 exposure and risk of PD. These findings underscore the urgent need for public health policies aimed at reducing ambient air pollution and its potential impact on PD.

Long-term exposure to particulate matter was associated with increased dementia risk using both traditional approaches and novel machine learning methods.

Air pollution exposure has been linked to various diseases, including dementia. However, a novel method for investigating the associations between air pollution exposure and disease is lacking. The objective of this study was to investigate whether long-term exposure to ambient particulate air pollution increases dementia risk using both the traditional Cox model approach and a novel machine learning (ML) with random forest (RF) method. We used health data from a national population-based cohort in Taiwan from 2000 to 2017. We collected the following ambient air pollution data from the Taiwan Environmental Protection Administration (EPA): fine particulate matter (PM2.5) and gaseous pollutants, including sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), nitrogen oxide (NOx), nitric oxide (NO), and nitrogen dioxide (NO2). Spatiotemporal-estimated air quality data calculated based on a geostatistical approach, namely, the Bayesian maximum entropy method, were collected. Each subject's residential county and township were reviewed monthly and linked to air quality data based on the corresponding township and month of the year for each subject. The Cox model approach and the ML with RF method were used. Increasing the concentration of PM2.5 by one interquartile range (IQR) increased the risk of dementia by approximately 5% (HR = 1.05 with 95% CI = 1.04-1.05). The comparison of the performance of the extended Cox model approach with the RF method showed that the prediction accuracy was approximately 0.7 by the RF method, but the AUC was lower than that of the Cox model approach. This national cohort study over an 18-year period provides supporting evidence that long-term particulate air pollution exposure is associated with increased dementia risk in Taiwan. The ML with RF method appears to be an acceptable approach for exploring associations between air pollutant exposure and disease.

Impacts of hazardous metals and PAHs in fine and coarse particles with long-range transports in Taipei City.

This study assessed the impact on air quality and health risk by long-range transported (LRT) PM2.5-10- and PM2.5-bound metals and PAHs in Taipei City, Taiwan. Several methods with receptor aerosol measurements were used to quantify the effect of LRT. The hybrid single particle lagrangian integrated trajectory model (HYSPLIT) was used in conjunction with the potential source contribution function (PSCF) to distinguish the LRT aerosols. By using a general linear model (GLM) with a marginal mean and positive matrix fraction (PMF), this study also evaluated the annual increased level of LRT (AIRLRT) for each source contribution to the concentration and the resultant health risk of particle-bound metals and polycyclic aromatic hydrocarbons (PAHs). The LRT influenced fine-sized metals and PAHs rather than coarse-sized ones. We found that the level of PM2.5-bound toxic metals (Pb, Cd, and As) and PAHs (Benzo[a]pyrene and dibenzo[a,e]pyrene) could increase by 90% under the influence of LRT in 2014, while an AIRLRT value of 25% for the PM2.5 mass concentration was observed. Overall, the excess cancer risk (ECR) resulting from PM2.5-bound metal and PAH exposures was 6.40 × 10-5 in relation to coal combustions (20.7%), traffic-related emissions (59.7%) and re-suspended aerosols (19.6%). Among these contributors, LRT-related metals and PAHs in PM2.5 accounted for 51% of the total ECR.

PM2.5- and PM10-bound polycyclic aromatic hydrocarbons (PAHs) in the residential area near coal-fired power and steelmaking plants of Taichung City, Taiwan: In vitro-based health risk and source identification.

We investigated spatial and season variations in particle-bound PAH concentrations, identified their potential sources and estimated resultant health risk of activate toxicity pathways in a residential area near coal-fired power and steelmaking plants. Both atmospheric PM2.5 and PM10 samples (n = 94) were simultaneously collected for summer and winter in the Wuqi and Shalu districts of Taichung City, central Taiwan. The principal component analysis (PCA) measure was used to evaluate the sources of particle-bound PAHs. The health risk of PAHs-activated toxicity pathways was estimated through a probabilistic model in cooperation with high-throughput screening (HTS) in vitro assays and measurement data for children and adults. No spatial difference, but significant seasonal variation, in PAH concentrations for PM2.5 (summer = 1.7 ng m-3 and winter = 4.7 ng m-3) and PM10 (summer = 2.1 ng m-3 and winter = 4.8 ng m-3) between two sites was observed, where both sites shared the similar PAH patterns in congener concentrations. PAH contents in the fine mode (PM2.5) of ambient particles are predominant while coarse mode (PM2.5-10) PAHs is negligible. Children with particle-bound PAH exposures have a relatively high health risk of aryl hydrocarbon receptor (AhR)-mediated adverse outcomes than adults, in particular in the winter period, while the activations of Nrf2 and p53 pathways are insignificant. Vehicle emission (67.1%), unburned petroleum (15.0%), steel industry and stationary emission (6.1%), and oil combustion + cooking oil fume (5.6%) associated with PM2.5-bound PAHs were apportioned. The emission from the Taichung coal-fired power plant is rarely attributable to particle-bound PAHs of the study area based on results of spatiotemporal variation of PAHs, wind direction, and source apportionment.

Ambient PM2.5-bound polycyclic aromatic hydrocarbons (PAHs) in Changhua County, central Taiwan: Seasonal variation, source apportionment and cancer risk assessment.

This study investigates PM2.5-bound PAHs for rural sites (Dacheng and Fangyuan) positioned close to heavy air-polluting industries in Changhua County, central Taiwan. A total of 113 PM2.5 samples with 22 PAHs collected from 2014 to 2015 were analyzed, and Positive Matrix Factorization (PMF) and diagnostic ratios of PAHs were applied to quantify potential PAH sources. The influences of local and regional sources were also explored using the conditional probability function (CPF) and potential source contribution function (PSCF) with PMF-modeled results, respectively. Annual mean concentrations of total PAHs were 2.91 ± 1.34 and 3.04 ± 1.40 ng/m3 for Dacheng and Fangyuan, respectively, and their corresponding BaPeq were measured at 0.534 ± 0.255 and 0.563 ± 0.273 ng/m3 in concentration. Seasonal variations with higher PAHs found for the winter than for the spring and summer were observed for both sites. The lifetime excess cancer risk (ECR) from inhalation exposure to PAHs was recorded as 4.7 × 10-5 overall. Potential sources of PM2.5-bound PAHs include unburned petroleum and traffic emissions (42%), steel industry and coal combustion (31%), and petroleum and oil burning (27%), and unburned petroleum and traffic emission could contribute the highest ECR (2.4 × 10-5). The CPF results show that directional apportionment patterns were consistent with the actual locations of local PAH sources. The PSCF results indicate that mainly northeastern regions of China have contributed elevated PM2.5-bound PAHs from long-range transports.

Measurement and modeling of concentrations of ambient air particles, chromium, copper and lead pollutants concentrations, as well as dry deposition in central Taiwan.

The main purpose of this investigation was to monitor ambient air particles and metallic elements (Cr, Cu and Pb) in total suspended particulates (TSP) concentration, dry deposition. Furthermore, the calculated/measured dry deposition flux ratios of ambient air particles and metallic elements (Cr, Cu and Pb) were evaluated using three dry deposition models at five characteristic sampling sites for the 2009-2010. The results show that the average concentrations of metallic elements Cr, Cu and Pb in TSP were highest at Bei-shi (suburban/coastal) and the lowest at Gao-mei (wetland) among the five characteristic sampling sites during the years 2009-2010. This study also shows that the mean rates of dry deposition of metallic elements Cr and Cu were highest at Quan-xing (industrial) and lowest at Bei-shi (suburban/coastal) and Chang-hua (downtown). Finally, the Noll and Fang model was found to yield better predictions of the dry deposition of ambient air particles and metallic elements Cr and Cu than any of the other deposition models.

Atmospheric-particulates-bound mercury Hg(p) study at five characteristic sampling sites in Taiwan.

The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009-2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).

Season variations for metallic elements compositions study in plant Bidens pilosa L. var. radiate Sch. in central Taiwan.

The possibility of using Bidens pilosa L. var. radiate Sch leaves as environmental indicators of metallic element pollution has been investigated. Samples were analyzed with respect to the following pollutants: Zn, Mn, Cu, Ni, Pb, Cd, Cr, Fe, Ca, and Mg by using inductively coupled plasma atomic emission spectrometry. The results obtained on the metallic elements had the following average composition order: Ca > Mg > Fe, Mn > Zn > Cu > Ni > Pb > Cr > Cd for plant B. pilosa L. var. radiate Sch. at HK sampling site. In addition, the metallic elements had the following average composition order: Ca > Mg > Fe > Mn, Zn > Cu > Ni > Pb > Cr > Cd for plant B. pilosa L. var. radiate Sch. at TMP sampling site. Finally, the metallic elements had the following average composition order: Ca > Mg > Fe > Zn > Mn > Cu > Pb > Ni > Cr > Cd for plant B. pilosa L. var. radiate Sch. at LH sampling site. The seasonal average composition for metallic elements Mg, Fe, and Pb were ranked highest at HK sampling site in winter. In addition, seasonal average composition for metallic elements Mn, Zn, and Cd were ranked highest at TMP sampling site in winter. Finally, seasonal average composition for metallic elements Mg, Fe, and Cu were ranked highest at LH sampling site in spring.

Comparison of atmospheric mercury (Hg) among Korea, Japan, China and Taiwan during 2000-2008.

The paper reviewed studies about total gaseous mercury, atmospheric particulate of mercury and average dry deposition fluxes of mercury in Korea, Japan, China and Taiwan. This study compared sample collection and analytical methods for mercury in Asian countries. Analytical results indicated that the primary mercury sources are anthropogenic source (for example coal burning) and high temperature processes. This study also elucidates the sources, analytical tools, and the average concentrations for atmospheric mercury (Hg) for these Asian countries during 2000-2008. This study indicated that the total gaseous mercury concentrations were higher in urban area than that in suburban area in Asian countries (Korea, Japan, China and Taiwan). As for the seasonal variations, in general, the average total gaseous mercury concentrations were higher in winter than that in summer especially in China. In addition, the average total gaseous mercury concentrations were higher in mining areas than that in the rest of the other areas. And the total gaseous mercury concentrations were decreasing as this distance increasing. These phenomena revealed that the total gaseous mercury concentrations are reduced by long-distance transportation especially in the main land of China.

Organic carbon and elemental carbon in Asia: a review from 1996 to 2006.

The principal sources of organic carbon (OC) and elemental carbon (EC) are anthropogenic or biogenic, whereas secondary sources are atmospheric oxidation processes of specific precursor gases. These compounds are considered atmospheric contaminants and adversely affect human health. Numerous studies have monitored atmospheric particulates and gaseous phases of OC and EC in Asia over the last decade. This work compares and analyzes different sample collection, pretreatment and analytical approaches. The principal carbonaceous sources are traffic exhaust and industrial emissions. The OC and EC concentrations are highest in high traffic areas, followed by urban sites, and lowest in suburban sites. Many characteristics of these sites, such a dense population, are important to research. The major OC to EC ratios in Asia cities were 1.0-3.0. This work elucidates the characteristics, sources, distributions, and characteristics of atmospheric carbonaceous species in Asia.

Influence of meteorological parameters on particulates and atmospheric pollutants at Taichung harbor sampling site.

Atmospheric aerosol particles and metallic concentrations, ionic species were monitored at the Experimental harbor of Taichung sampling site in this study. This work attempted to characterize metallic elements and ionic species associated with meteorological conditions variation on atmospheric particulate matter in TSP, PM2.5, PM2.5-10. The concentration distribution trend between TSP, PM2.5, PM2.5-10 particle concentration at the TH (Taichung harbor) sampling site were also displayed in this study. Besides, the meteorological conditions variation of metallic elements (Fe, Mg, Cr, Cu, Zn, Mn and Pb) and ions species (Cl(-), NO3 (-), SO4 (2-), NH4+, Mg2+, Ca2+ and Na+) concentrations attached with those particulate were also analyzed in this study. On non-parametric (Spearman) correlation analysis, the results indicated that the meteorological conditions have high correlation at largest particulate concentrations for TSP at TH sampling site in this study. In addition, the temperature and relative humidity of meteorological conditions that played a key role to affect particulate matter (PM) and have higher correlations then other meteorological conditions such as wind speed and atmospheric pressure. The parameter temperature and relative humidity also have high correlations with atmospheric pollutants compared with those of the other meteorological variables (wind speed, atmospheric pressure and prevalent wind direction). In addition, relative statistical equations between pollutants and meteorological variables were also characterized in this study.

Atmosphic pollutants study of particles ionic species during high wind speed (>7 m s(-1)) near Taiwan strait in central Taiwan from 2004 to 2005.

This study monitored atmospheric pollutants during high wind speed (> 7 m s(-1)) at two sampling sites: Taichung Harbor (TH) and Wuci traffic (WT) during March 2004 to January 2005 in central Taiwan. The correlation coefficient (R (2)) between TSP, PM(2.5), PM(2.5-10) particle concentration vs. wind speed at the TH and WT sampling site during high wind speed (< 7 m s(-1)) were also displayed in this study. In addition, the correlation coefficients between TSP, PM(2.5) and PM(2.5-10) of ionic species vs. high wind speed were also observed. The results indicated that the correlation coefficient order was TSP > PM(2.5-10) > PM(2.5) for particle at both sampling sites near Taiwan strait. In addition, the concentration of Cl(-), NO(3) (-), SO(4) (2-), NH(4) (+), Mg(2+), Ca(2+) and Na(+) were also analyzed in this study.

A review of atmospheric fine particulate matter and its associated trace metal pollutants in Asian countries during the period 1995-2005.

Many studies have monitored atmospheric particulates and gaseous phases of PM(2.5) in Asia over the past 10 years. This work also compared and discussed different sample collection, pretreatment and analytical methods in Asia countries in past decade. The results indicated that the main PM(2.5) sources are traffic exhausts. PM(2.5) concentrations are also ranked highest in the areas of traffic, followed by the urban sites, and lowest in rural sites in Asian countries. This work elucidates the sources, analytical tools, and the average concentrations for PM(2.5) and related metallic elements during 1995-2005. The results indicated that the average highest concentrations order of metallic elements for PM(2.5) were Fe>Mg>Zn, and the average concentrations of lowest metallic elements was Pb>Cu>Mn>Cr>Cd. The results also indicated that the concentration of metallic element Cu increased as the averaged concentrations of metallic element Zn and Mn increased during the past 10 years in Asian countries.

Study of ambient air particulates pollutants near Taichung airport sampling site in central Taiwan.

This study monitored the atmospheric pollutants at Taichung airport (TA) sampling site during September to December of 2005 near Taiwan Strait in central Taiwan. The distributions of the particle concentrations between the TSP, coarse and fine were also displayed at TA sampling site. Analysis the average percentage of various kinds of metallic elements, the data obtained here indicated that the average percentage concentrations of metallic elements Fe and Mg were higher in fine particulate than that of the coarse particulate at Taichung airport sampling site. These foundry factories were by the TA sampling site was the possible reason responsible for this result. In addition, by a non-parametric (Spearman) correlation analysis, the results indicated that Fe, Mn and Pb have high correlation coefficients of metallic elements in different particle size. The results indicate that the airport pollutants might come from similar pollutant sources at this airport sampling site. In addition, high correlation coefficients of non-airport pollutants were observed on the ionic species of SO(4)(2-), NH(4)(+) and K(+). The r(sp) correlate values between closed to r(sp)=0.7 and 0.9 at different particles size mode. Besides, the ionic Ca(2+) has high negative values (r(sp)=-0.66, -0.66 and 0.61) with the increasing of the temperature, relative humidity and wind speed, respectively at fine particle size.

Overall dry deposition velocities of trace elements measured at harbor and traffic site in central Taiwan.

For reasonable and convenient assessments of the characteristics of the dry deposition velocities between Taichung harbor site and Wuchi town site in central Taiwan, the overall dry deposition velocities of several metallic elements were calculated as the particulate diameter (D(p)) distributions of large particles (D(p) > 10 microm), coarse particles (10 microm < D(p) < 2.5 microm), and fine particles (D(p) < 2.5 microm) based on the ambient measurements during March-December of 2004. In this work, the dry deposition fluxes showed the higher correlation with coarse particle concentrations than large particle concentrations; however, the least well correlation was observed between the dry deposition fluxes and the fine particle concentrations. The calculated best-fit overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 0.2 cm s(-1) for Cr to 1.5 cm s(-1) for Pb and 0.2 cm s(-1) for Fe to 2.6 cm s(-1) for Pb at Taichung harbor and Wuchi town site, respectively. In general, the crustal elements had higher deposition velocities than anthropogenic elements. In addition, overall dry deposition velocities for crustal elements were higher in Wuchi town site than in Taichung harbor site. The results identified the dry deposition flux was mainly contributed from large and coarse particles due to their high deposition velocities. The results also indicated that the best approach to estimate overall dry deposition was by depending on the characteristics of particles with diameters larger than 2.5 microm.

Photoirradiation of polycyclic aromatic hydrocarbons with UVA light - a pathway leading to the generation of reactive oxygen species, lipid peroxidation, and dna damage.

Polycyclic aromatic hydrocarbons (PAHs) are a class of genotoxic environmental contaminants. We have long been interested in determining the mechanisms by which PAHs induce genotoxicity. Although the metabolic activation of PAHs leading to biological activities has been well studied, the photo-induced activation pathway has seldom reported. In this paper, we review the study of photoirradiation of PAHs with UVA irradiation results in (i) cytotoxicity and DNA damage (ii) DNA single strand cleavage; (iii) formation of 8-hydroxy-2'-deoxyguanosine adduct (8-OHdG), and (iv) formation of lipid peroxidation. Evidence has been shown that these photobiological activities are mediated by reactive oxygen species (ROS).

Seasonal variation in concentration and metallic constituents of atmospheric particulates near the western coast of central Taiwan.

In addition to determining the concentration and metallic constituents of particulate matter at Taichung Harbor in central Taiwan, this study attempts to characterize the mass, metallic elements, composition and concentrations of total suspended particulates (TSP), fine particles and coarse particles. Statistical approaches, such as the Spearman tests, were also adopted to determine the seasonal variations of concentrations of these pollutants. Experimental results indicate that the mean TSP, fine particulate and coarse particulate concentrations in spring and winter are higher than in summer and autumn on the western coast of central Taiwan. Spearman statistical analysis of metallic elements Mn and Pb showed high concentration coefficients for fine and coarse particulates on the western coast of central Taiwan. The order of mean metallic concentrations in TSP, coarse particulates and fine particles was Fe > Zn > Mg > Cu> Cr > Mn > Pb in TSP, Fe > Cu > Zn > Mg > Mn > Pb > Cr in coarse particulates and Fe > Cu > Mg > Pb > Zn > Mn > Cr in fine particulates.

Estimating the frequency distributions of particulate matter and their metal elements in a temple.

Air quality inside Asian temples is typically poor because of the burning of incense. This study measured and analyzed concentrations of fine (PM2.5) and coarse (PM2.5-10) particulate matter and their metal elements inside a temple in central Taiwan. Experimental results showed that the concentrations of metals Cd, Ni, Pb, and Cr inside the temple were higher than those at rural, suburban, urban, and industrial areas in other studies. Three theoretical parent distributions (lognormal, Weibull, and gamma) were used to fit the measured data. The lognormal distribution was the most appropriate distribution for representing frequency distributions of PM10, PM2.5, and their metal elements. Furthermore, the central limit theorem, H-statistic-based scheme, and parametric and nonparametric bootstrap methods were used to estimate confidence intervals for mean pollutant concentrations. The estimated upper confidence limits (UCLs) of means between different methods were very consistent, because the sample coefficient of variation (CV) was < 1. When the sample CV was > 1, the UCL based on H-statistical method tended to overestimate the UCLs when compared with other methods. Confidence intervals for pollutant concentrations at different percentiles were evaluated using parametric and nonparametric bootstrap methods. The probabilities of pollutants exceeding a critical concentration were also calculated.

Characteristic study of dry deposition, concentration, compositions for particulates mass and ionic species during summer and autumn season at a traffic sampling site.

Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl(-), NO(3)(-), SO(4)(2-), Na(+), NH(4)(+), K(+), Mg(2+) and Ca(2+)). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 microg m(-3)) were higher than the nighttime period (averaged 542.1 microg m(-3)). And the daytime dry deposition fluxes (averaged 58.12 microg m(-2) sec(-1)) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 microg m(-2) sec(-1)) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 microg m(-2) sec(-1)) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 microg m(-2) sec(-1)). Moreover, the results also indicate that SO(4) (2-) and Ca(2+) have higher average composition for total suspended particulates in the daytime period while Ca(2+), SO(4) (2-), and Na(+) have the higher average composition for total suspends particulates in the nighttime period.

Ambient air particulate concentrations and metallic elements principal component analysis at Taichung Harbor (TH) and WuChi Traffic (WT) near Taiwan Strait during 2004-2005.

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter of total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter <2.5 microm, PM(2.5)), coarse particle (particle matter with aerodynamical diameter 2.5-10 microm, PM (2.5-10)) at the Taichung Harbor (TH) and WuChi Traffic (WT) sampling site of central Taiwan during March 2004 to February 2005. The result indicated the average total suspended particulate concentration in 1 year was 157.31 and 112.58 microg m(-3) at TH and WT sampling site, respectively. Fine particle (PM(2.5)) size was the dominant species at TH and WT sampling site. In TH sampling site, higher correlation coefficient was observed on total suspended particulates of metallic elements Fe and Zn. And in WT sampling site, higher correlation coefficients displayed on total suspended particulates of metallic elements Fe and Zn, Fe and Mn. Ambient airborne particle principal component analysis of metallic metals was used to identify the possible pollutant sources in this study. At the TH sampling site, 50.81% of the total variance of the data was observed in factor 1. Higher loading of Fe (0.86), Zn (0.79), Pb (0.76), and Mn (0.68) were contributed by traffic emission and the soil source. At the WT sampling site, factor 1 explained 53.74% of the total variance of the data and had high loading for Zn (0.86) and Cu (0.85), which were identified as industrial/traffic emission sources.