J Environ Sci (China)
March 2025
Airborne microorganisms (AM) have significant environmental and health implications. Extensive studies have been conducted to investigate the factors influencing the composition and diversity of AM. However, the knowledge of AM with anthropogenic activities has not reach a consensus.
View Article and Find Full Text PDFUnderstanding the nitrogen isotopic variations of individual amino acids (AAs) is essential for utilizing the nitrogen isotope values of individual amino acids (δN-AA) as source indicators to identify proteinaceous matter originating from biomass combustion processes. However, the nitrogen isotope effects (ε) associated with the degradation of individual amino acids during combustion processes have not been previously explored. In this study, we measured the nitrogen isotope values of residual free amino acids -following a series of controlled combustion experiments at temperatures of 160-240 °C and durations of 2 min to 8 h, as described in Part 1.
View Article and Find Full Text PDFIn recent years, the atmospheric pollution caused by phthalate esters (PAEs) has been increasing due to the widespread use of PAE-containing materials. Existing research on atmospheric PAEs lacks long-term continuous observation and samples from cities in central China. To investigate the pollution characteristics, sources, and health risks of PAEs in the ambient air of a typical city in central China, daily PM samples were collected in Nanchang from November 2020 to October 2021.
View Article and Find Full Text PDFNonpolar organic compounds (NPOCs) are found in atmospheric aerosols and have significant implications for environmental and human health. Although many studies have quantitatively estimated the sources of NPOCs in different cities, few have evaluated their main influencing factors (e.g.
View Article and Find Full Text PDFNitrate (NO) has become recognized as the most important water-soluble ion in fine particulate (PM), and has been proposed as a driving factor for regional haze formation. However, nitrate formation mechanisms are still poorly understood. In this study, PM samples were collected from September 2017 to August 2018 in Shijiazhuang, a city located on the North China Plain, and NOconcentration, δO-NO and δN-NO values in PM were analyzed.
View Article and Find Full Text PDFAs the dominant mercury species in fish, methylmercury (MeHg) biomagnifies during its trophic transfer through aquatic food webs. MeHg is known to bind to cysteine, forming the complex of MeHg-cysteine. However, relationship between MeHg and cysteine in large-scale food webs has not been explored and contrasted with MeHg biomagnification models.
View Article and Find Full Text PDFSci Total Environ
December 2020
Although fungi are ubiquitous in the atmosphere and have important effect on human health, their spatial variability about diversity and taxonomic composition, remain poorly understood. Considering the differences of environmental conditions, distinct airborne fungal communities were expected in the urban, suburban and forest areas. To test this hypothesis, PM samples were consecutively collected for 14 days across Nanchang, China.
View Article and Find Full Text PDFHaplocladium microphyllum moss samples were collected in Nanchang, China. Free amino acid (FAA) concentrations and N isotope compositions (δN) in the samples were determined and compared with the bulk N concentrations and δN values. The aim was to determine whether δN values in moss (which are very variable) indicate the sources of atmospheric N.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
October 2016
The signatures of natural stable nitrogen isotopic composition (δ(15)N) of individual amino acid (AA) have been confirmed to be a potentially effective tool for elucidating nitrogen cycling and trophic position of various organisms in food webs. In the present study, a two-stage derivatisation approach of esterification followed by acylation was evaluated. The biological samples underwent acid hydrolysis and the released individual AA was derivatived into corresponding N-pivaloyl-isopropyl (NPIP) esters for nitrogen isotopic analysis in gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS).
View Article and Find Full Text PDFThis study analyzed the inorganic sulfur (SSO4) and total sulfur (ST) content as well as the isotopic signatures (delta34SSO4 and 834ST) in leaves of Pinus massoniana lamb. collected from Guizhou and Yunnan areas. The results indicated that the SSO4 and ST content in leaves at Guiyang areas was significantly higher than that at Yunnan areas, and the content of inorganic sulfur in the leaves was found to be directly related to the concentration of ambient sulfur dioxide, but no correlation was seen between the ST content and the ambient sulfur dioxide, showing the SSO4 content in leaves was more reliable to reflect the ambient sulfur input.
View Article and Find Full Text PDFAtmospheric N deposition and N sources in Jiangxi Province were investigated on the basis of the nitrogen concentrations and nitrogen isotope in epilithic mosses which collected from 11 cities of the province during 2009-2010. Mean nitrogen concentrations ranged from 2.46% to 3.
View Article and Find Full Text PDFIn China, coal combustion is the most important source of atmospheric sulfur pollution. Moss sulfur isotopic signatures have been believed to hold source-specific information that can serve as a fingerprint to identify atmospheric sulfur sources. In cities where only local coals were combusted, we observed a good correspondence of average sulfur isotope ratios in urban mosses (Haplocladium microphyllum) to the values of local coals (δ(coals) = 1.
View Article and Find Full Text PDFSulfur source identification previously reported has been based on sulfur isotopic ratios in either rainwater or mosses. The δ(34)S values of rainwater sulfate and the epilithic moss Haplocladium microphyllum in Nanchang region (China) were determined for comparisons and used to delineate atmospheric sulfur sources. At the urban and rural sites, similar mean δ(34)S values were observed between rainwater sulfate (+1.
View Article and Find Full Text PDFNitrogen isotopic composition of new, middle-aged and old camphor leaves in upper and lower canopies has been determined in a living area, near a motorway and near an industrial area (Jiangan Chemical Fertilizer Plant). We found that at sites near roads, more positive δ(15)N values were observed in the camphor leaves, especially in old leaves of upper canopies, and ∆δ(15)N=δ(15)N(upper)-δ(15)N(lower)>0, while those near the industrial area had more negative δ(15)N values and ∆δ(15)N<0. These could be explained by two isotopically different atmospheric N sources: greater uptake from isotopically heavy pools of atmospheric NO(x) by old leaves in upper canopies at sites adjacent to roads, and greater uptake of (15)N-depleted NH(y) in atmospheric deposition by leaves at sites near the industrial area.
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