Identification of origins and influencing factors of environmental odor episodes using trajectory and proximity analyses

The use of gas chromatography combined with chemical and sensory analysis to evaluate nuisance odours in the air and water environment

Varieties of gas chromatography (GC) combined with chemical detection (CD) and sensory analysis at the odour detection port (ODP) for the evaluation of environmental odorants has steadily increased in application and sophistication; this has given rise to a plethora of techniques that cater to specific tasks. With this diversity of approaches in mind, there is a need to assess the critical points at which these approaches differ, as well as likely risks and factors that may affect them. These critical points explained within this review include sample preparation, GC separation techniques (with associated co-elution risks), how the elute is separated between CD and sensory analysis, the type of CD, the type of sensory analysis (with particular attention paid to its factors and guidelines), integrative data techniques, as well as how that data may be used. Additionally, this review provides commentary on the current state of the research space and makes recommendations based on how these analyses should be reported, the standardisation of nomenclature, as well as the impediments to the future goals of this research area. By careful consideration of the critical points of varying analytical processes and how best to communicate these findings, the quality of output within this area will improve. This review provides a benchmark for how GC-CD/sensory analysis should be undertaken and reported.

Spatiotemporal dynamics of near-surface ozone concentration and potential source areas in northern China during 2015-2020

Near-surface ozone (O3) pollution has become one of the main factors hampering urban air quality in northern China. However, on a spatiotemporal scale, dynamic transport paths and potential source areas of O3 in northern China are ambiguous. In addition, we suspect that the contribution of transportation activities to urban O3 concentrations developed in northern China may be underestimated. In this study, the HYSPLIT, PSCF, CWT and GTWR model were used to study the transmission paths, potential source areas and driving factors of urban O3 concentration on a spatiotemporal scale. The average annual concentration of surface O3 (the 90th percentile of MDA8) was 172 ± 29 μg/m3 in northern China from 2015 to 2020. In terms of inter-annual variation, the urban O3 concentration increased from 2015 to 2018, and decreased after 2018. On the spatial scale, the areas with high O3 concentration were mainly clustered in industrial cities (Tangshan, Baoding, Shijiazhuang, Xingtai and Handan). During the study period, the area with high O3 concentration in northern China shifted from northwest to southeast. From 2015 to 2020, the influence of long-distance air mass trajectories from Xinjiang and Siberi on airflow transport in Beijing city dominates (78.60%) The average percentage of short-distance transport trajectories from Shandong Peninsula region is about 21.40%. The core potential source areas of O3 pollution shifted from northwest to southeast, but the contribution to O3 pollution in Beijing gradually weakened during the same period. Temperature and relative humidity were the main meteorological driving factors affecting O3 concentration in the study area, while population density, the proportion of secondary industry in GDP, industrial smoke (dust) emissions, and passenger traffic were the main non-meteorological factors. During the period study, the influence of industrial and traffic emissions had a more significant impact on O3 concentration in northern China, which will require that more attention be paid to emission mitigation in the regional industrial and passenger transportation sector, as well as the joint prevention and control of O3 pollution in northern China in the future.

Temporal and spatial changes of biodiversity in Caverns of Heaven and Places of Blessing, Zhejiang Province, China from 1990 to 2020

Caverns of Heaven and Places of Blessing (CHPB) are the earliest Ecological Reserve in China, but in recent years, due to the accelerated process of urbanization and weak protection, the Chinese traditional ecological reserve represented by CHPB has been damaged to a certain extent. How to accurately measure the dynamic changes of ecological value in existing ecological protection and construct is an initial topic of CHPB protection. To understand the temporal and spatial changes characteristics of biodiversity in CHPB, this paper selects three-time nodes in 1990, 2005, and 2020, and takes CHPB in Zhejiang Province as an example, comprehensive three influencing factors: habitat quality, landscape pattern, and nighttime-light. To provide a relevant theoretical basis for the protection of CHPB, this paper quantitatively analyzes the changes of ecological environment and biodiversity in recent 30 years. The results showed that from 1990 to 2020, the biodiversity of CHPB in Zhejiang Province showed a positive change, the decline in Caverns of Heaven overall area slowed down, and the core area rebounded. The spatial distribution change of biodiversity is highly consistent with the land-use changes. The low value regions of biodiversity are mainly concentrated in the regions with intensive human activities, and the area decreases with the expansion of construction land. The core areas are primary areas with high biodiversity and overlap with nature reserves, natural parks, Scenic and Historic Interest Area, and other protected areas. In a word, CHPB still plays a vital role in ecological and environmental protection. In the future development, we should still pay attention to its biodiversity protection, and give full play to its role in ecological and environmental protection, and realize the contemporary application of CHPB’s traditional ecological knowledge.