Exposure
to fine particulate-bound toxic metals in ambient air
poses adverse effects to human. This study aims to determine the spatial
variability in heavy metals in PM2.5 samples, for identifying
their potential sources and to perform health risk modelling. PM2.5 samples were collected using a high-volume sampler on a
24 h basis from three sites in Johor areas in Malaysia from January
to March 2019. Metals were initially extracted using microwave-assisted
digestion and the metal concentrations were analyzed using inductively
coupled plasma mass spectroscopy. Overall, the abundant metals in
PM2.5 among the metals analyzed were Zn with mean 29.92
ng/m3 and Se with mean 27.02 ng/m3. The sources
of PM-bound metals were identified using absolute principal component
score with multiple linear regression. The major contribution was
noted from vehicle emission (41%). Other potential sources for the
metals in PM2.5 were from coal-fired power plants (34%)
and oil refineries and industrial emission (4%), leaving 22% of metals
undefined. From the health risk analysis, the hazard quotient (HQ)
and excess lifetime cancer risk (ELCR) values of the metals were within
the tolerance level. The trend for HQ values was Co < Zn < Pb
< Cu < Ni < As for adolescents and Co < Zn < Cu <
Pb < Ni < As for adult age, whereas for ELCR values, the trends
were the same for both adolescent and adult age groups as Pb <
Ni < As. Few of the toxic metals showed comparatively high HQ values
that might be a risk in long-term exposure. Considering the highest
noted contribution from vehicular emissions, it is advised to raise
public awareness to practice carpooling and use public transportation
to reduce emissions from vehicular sources.
Your article is protected by copyright and all rights are held exclusively by Shiraz University. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Carbonaceous
aerosols play a key role in climate modification and
exert a deleterious effect on human health. Thus, this study aimed
to determine the thermally derived carbonaceous fraction in particulate
matter (PM)2.5 from the Southern Malay Peninsula, a tropical
area in Malaysia, during January 2019 to March 2019. PM2.5 was captured on quartz filters using a high-volume sampler on a
24 h basis. Eight of the carbon fractions were measured using the
thermal optical reflectance method. Carbonaceous aerosol was thoroughly
characterized by estimating elemental carbon (EC), organic carbon
(OC), total carbon, secondary OC, soot-EC, and char-EC to determine
the mechanism of emission from fossil fuel combustion, biomass, and
secondary origins. The effect of local meteorological factors and
air mass transport on the change in the light-absorbing aerosol fraction
was also examined. Secondary organic sources and primary sources emitted
46 and 54% of OC, respectively. The estimated char-EC in this study
was 10-fold higher than soot-EC, indicating that biomass burning and
coal combustion were the predominant routes of EC emission, whereas
petrol or diesel engines were the less predominant generators of soot-EC.
Trajectory modeling showed that biomass fires in the Indochina region
were the potential origin of carbonaceous aerosols transported from
the northeasterly direction.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.