Sulfur isotope analysis for representative regional background atmospheric aerosols collected at Mt. Lulin, Taiwan

Abstract

Air pollution resulted from fossil fuel burning has been an environmental issue in developing countries in Asia. Sulfur-bearing compounds, in particular, are species that are regulated and monitored routinely. To assess how the species affect at local and global scales, regional background level has to be defined. Here, we report analysis of sulfur isotopes in atmospheric sulfate, the oxidation end product of sulfur species, in particulate phase collected at the Lulin observatory located at 2862 m above mean sea level in 2010. The averaged sulfate concentration for 44 selected samples is 2.7 ± 2.3 (1-σ standard deviation) μg m−3, and the averaged δ34S is 2.2 ± 1.6‰, with respect to the international standard Vienna Canyon Diablo Troilite. Regardless of the origins of air masses, no noticeable difference between the low-altitude Pacific and high-altitude free troposphere sulfate aerosols is observed. Also, no identifiable seasonal cycle in seen. Correlation analysis with respect to coal burning tracers such as lead and oil industry tracers such as vanadium shows sulfate concentration is in better correlation with vanadium (R2 = 0.86, p-value < 0.001) than with lead (R2 = 0.45, p-value < 0.001) but no statistically significant correlation is found in δ34S with any of physical quantities measured. We suggest the sulfate collected at Lulin can best represent the regional background level in the Western Pacific, a quantity that is needed in order to quantitatively assess the budget of sulfur in local to country scales.

On the seasonality of long-range transport of acidic pollutants in East Asia

“…The sulfur and nitrogen isotope analysis also supported the seasonal patterns and the contribution of LRT on winter deposition of nss-SO 2− 4 and NO − 3 at the Mt. Lulin site [47,48]. A recent estimation suggested that the domestic fractions of SO 2 and NO x reduced by 55% and 15% in Taiwan between 1994 and 2010, however the local emission control was nullified by LRT from China [10].…”

Determining the Authenticity of Spirulina Dietary Supplements Based on Stable Isotope and Elemental Composition

“…Therefore, higher δ 34 S values in rainwater and plants and algae are expected in regions closer to the sea [75]. In addition, Taiwan is a volcanic island, and therefore higher δ 34 S values can be also expected [46,76]. Higher δ 34 S values in Chinese samples, on the other hand, could be attributed, as mentioned previously, to high pollution levels in the area [70][71][72].…”

Iron (Fe) speciation in size-fractionated aerosol particles in the Pacific Ocean: The role of organic complexation of Fe with humic-like substances in controlling Fe solubility

“…S3a and b). The sources of nss-SO 2− 4 in East Asia and its outflow were mainly derived from anthropogenic emissions owing to the lower S isotope ratio (about few ‰, Inomata et al, 2016;Chung et al, 2019) than that of biogenic S (18 ‰-20 ‰, Amrani et al, 2013). Previous studies have reported that the good relationship between Fe sol % and nss-SO 2− 4 is attributed to the solubilization of Fe by coal-derived SO 2 (Fang et al, 2015;Wong et al, 2020), and a good correlation between Fe sol % and nss-SO 2− 4 was found in this study (Fig.…”