Assessment of selected metals in the ambient air PM10 in urban sites of Bangkok (Thailand)

Abstract

Estimating the atmospheric concentrations of PM10-bounded selected metals in urban air is crucial for evaluating adverse health impacts. In the current study, a combination of measurements and multivariate statistical tools was used to investigate the influence of anthropogenic activities on variations in the contents of 18 metals (i.e., Al, Sc, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Sb, Ba, La, Ce and Pb) in ambient air. The concentrations of PM10-bounded metals were measured simultaneously at eight air quality observatory sites during a half-year period at heavily trafficked roads and in urban residential zones in Bangkok, Thailand. Although the daily average concentrations of Al, V, Cr, Mn and Fe were almost equivalent to those of other urban cities around the world, the contents of the majority of the selected metals were much lower than the existing ambient air quality guidelines and standard limit values. The sequence of average values of selected metals followed the order of Al > Fe > Zn > Cu > Pb > Mn > Ba > V > Sb > Ni > As > Cr > Cd > Se > Ce > La > Co > Sc. The probability distribution function (PDF) plots showed sharp symmetrical bell-shaped curves in V and Cr, indicating that crustal emissions are the predominant sources of these two elements in PM10. The comparatively low coefficients of divergence (COD) that were found in the majority of samples highlight that site-specific effects are of minor importance. A principal component analysis (PCA) revealed that 37.74, 13.51 and 11.32 % of the total variances represent crustal emissions, vehicular exhausts and the wear and tear of brakes and tires, respectively.

Hazard Quotients, Hazard Indexes, and Cancer Risks of Toxic Metals in PM₁₀ during Firework Displays

“…Although previous studies highlighted Mg as a firework tracer (Kumar et al, 2016;Tsai et al, 2012), the present findings suggest that Mg might not be a good indicator of firework displays. The extremely high Log(EF) values of Se, Sb, and Cd are explained in terms of vehicular emissions, and are in reasonably good accordance with previous studies (Lough et al, 2005;Almeida et al, 2006; Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 20 March 2018 doi:10.20944/preprints201803.0171.v1 Crawford et al, 2007;Pongpiachan and Iijima, 2016). Additionally, the extremely low Log(EF) values observed for Al (i.e., FDP: -0.59; NDP: -0.54) observed here are consistent with earlier studies (Pongpiachan and Iijima, 2016;Wu et al, 1994 Hence, it appears reasonable to assume that the easterly winds were comparatively less influenced by anthropogenic emissions.…”

“…The similar decreasing sequence of selected metals between the two episodes highlights the relatively homogeneous distribution of the 31 target compounds throughout the ambient air of Bangkok during the observation periods. Since previous studies report that vehicle exhaust is the main emission source of air pollutants in Bangkok (Pongpiachan, 2013b;Pongpiachan and Iijima, 2016;Pongpiachan et al, 2013Pongpiachan et al, , 2015a Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 20 March 2018 doi:10.20944/preprints201803.0171.v1…”

“…4, the logarithmic EFs of the 31 selected metals in PM10 detected at both monitoring campaigns from November 2012 to December 2013 followed the sequence: Se>Sb>Cd>Bi>Cu>Sn>Pb>Mo>Zn>As>Tl>Ba>Ni>V>Rb>Ca>Cs>K>Na>Zr>Mn>Li>Be>Sr>Co >Cr>Fe>Y>Sc>Mg>Al. These findings can be categorised into four groups as an arbitrary scale, based on earlier reports (Karageorgis et al, 2009;Pongpiachan and Iijima, 2016). Firstly, Se, Sb, and Cd were excessively enriched (i.e., 3<Log(EF)<4).…”

Characterization of parent and oxygenated-polycyclic aromatic hydrocarbons (PAHs) in Xi’an, China during heating period: An investigation of spatial distribution and transformation

“…When CD jk approaches zero, it determines that sources j and k are similar; while approaches one, it means there are significantly different between the two sources (Pongpiachan and Iijima, 2016;Han et al, 2010a). The CDs between the function zones in this study were summarized in Table S3.…”

“…Wongphatarakul et al (1998) pointed out that CD value of 0.269 reflected the similarity between particles collected in the two cities. Pongpiachan and Iijima (2016) considered that when the CD values were <0.3, they were predominantly affected by comparable sources. The university and urban residential had the minimum CD values for PAHs and OPAHs, which illustrated that the sources contributions were similar to these two areas.…”