Impact of COVID-19 lockdown on ambient levels and sources of volatile organic compounds (VOCs) in Nanjing, China

Wang, Ming; Lü, Sihua; Shao, Min; Zeng, Limin; Zheng, Jun; Xie, Fusheng; Lin, Haotian; Hu, Kun; Lu, Xingdong

doi:10.1016/j.scitotenv.2020.143823

Cited by 36 publications

(24 citation statements)

References 32 publications

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“…During the lockdown period, students did not get permission to go outside the campus. Most of the people, except for those involved in epidemic prevention and control, the police, and few workers of necessary industries, were required to stay at home (51,52). Under the government policies on COVID-19, universities of China, especially in the Wuhan region, issued strict rules for local and international students to prevent the transmission of the virus in the university community.…”

Section: Discussionmentioning

confidence: 99%

Psychological Outcomes and Associated Factors Among the International Students Living in China During the COVID-19 Pandemic

Alam

et al. 2021

Front. Psychiatry

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Background: The emergence of coronavirus disease 2019 (COVID-19) has created a severe mental health problem for international students living in China. Despite the little information on the psychological impact on international students, we aimed to assess the psychological outcomes and associated factors among international students currently living in China during the COVID-19 pandemic.Methods: An online cross-sectional survey was conducted from May 28, 2020 to June 12, 2020 on 402 full-time international students across 26 provinces in China. The frequency of symptoms of depression, anxiety, stress, insomnia, psychological distress, loneliness, and fear was assessed with the English versions of the Depression Anxiety Stress Scale (DASS-21), Insomnia Severity Index (ISI), Kessler Psychological Distress Scale (K6), University of California, Los Angeles, Loneliness Scale (UCLA-LS), and Fear of COVID-19 scale (FCV-19S) scales, respectively.Results: The prevalence of symptoms of depression (73.4%), anxiety (76.6%), stress (58.5%), insomnia (77.6%), psychological distress (71.4%), loneliness (62.4%), and fear (73.1%) among international students during the COVID-19 pandemic was shown. The prevalence of moderate to extremely severe symptoms of all psychological outcomes was significantly associated with 26–30-year-old students, students who lived with roommates, and students who stayed in China shorter than 2 years. Participants in the central region reported significantly moderate to extremely severe symptom levels of all the psychological outcomes except fear symptoms. Univariate analysis indicated that a significant association of all psychological outcomes was found among 26–30-year-old students and students who stayed in China shorter than 2 years. Multivariate analysis showed that Engineering, Business, Social Sciences and Law, and Language students were significantly associated with the symptoms of depression, anxiety, insomnia, and fear. Participants staying in China for shorter than 2 years were associated with a higher risk of all psychological outcomes except psychological distress and loneliness symptoms.Conclusions: We found a higher prevalence of psychological outcomes and risk factors among international students during the COVID-19 pandemic. We immediately appealed to university authorities, mental health professionals, and government officials to provide mental health interventions and strategies for their international students, particularly young, central region students, living with roommates, different study backgrounds, and short time staying during the pandemic.

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Section: Discussionmentioning

confidence: 99%

Psychological Outcomes and Associated Factors Among the International Students Living in China During the COVID-19 Pandemic

Alam

et al. 2021

Front. Psychiatry

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“…The inter-annual variation of VOCs gradually reduced as follows: 45.0±25.2 ppbv (in 2018), 36.7±22.0 ppbv (in 2019), and 30.5±15.4 ppbv (in 2020). The decrease trend of VOCs could be attributed to the increasingly stringent policies for emission reduction and the influence of COVID-19 lockdown on air quality in 2020 (Wang et al, 2021a).…”

Section: Inter-annual Variation Of Vocsmentioning

confidence: 99%

Measurement report: Intra-, inter-annual variability and source apportionment of VOCs during 2018–2020 in Zhengzhou, Central China

Shang

Wang

et al. 2022

Preprint

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Abstract. Ambient volatile organic compounds (VOCs) were measured continuously to investigate their characteristics, sources, atmospheric oxidation capacity (AOC) and chemical reactivity from January 2018 to December 2020 at an urban site in Zhengzhou, China. In this study, the total concentration of observed VOCs was 38.2 ± 15.6 ppbv during the sampling period, with the characteristics that alkanes were the major VOC species, accounting for 60 % of total VOCs. During the sampling period, the inter-annual variation of VOCs gradually reduced from 45.0 ± 25.2 ppbv in 2018 to 36.7 ± 22.0 ppbv in 2019, and to 30.5 ± 15.4 ppbv in 2020. Ethane, ethene, and propane were the top three abundant species during the three-year observation period. The results showed that total AOC, dominated by OH radical reactions, was 7.4 × 107 molecules cm−3 s−1. The total OH reactivity was 45.3 s−1, and mainly contributed by NOx. The AOC and •OH reactivity exhibited well-defined seasonal and inter-annual patterns. Therefore, the control strategy should focus on key species among inter-annual and seasonal variations. Meanwhile, diagnostic ratios of VOC species indicated VOCs in Zhengzhou were greatly affected by vehicle emissions and liquefied petroleum gas/natural gas (LPG/NG). Positive matrix factorization analysis showed six sources were identified, consisting of industrial sources, solvent use, vehicle exhaust, LPG/NG, coal+biomass burning and biogenic sources. Vehicle emissions, solvent use and LPG/NG made the largest contributions to VOC emission in all three years. The proportion of the contribution of vehicle emissions and LPG/NG has increased with each passing year. However, the proportion of industrial and solvent sources presented a decreasing trend, which is speculated that the policy control effect is remarkable. The effect of VOCs on ozone formation suggests that vehicle emission and solvent utilization were still key sources. Therefore, it is necessary to formulate effective strategies for reducing ground-level O3, and those sources mentioned above should be strictly controlled by the regulatory authorities.

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“…For gaseous pollutants, most of the results from these studies are consistent; that is, nitric oxide (NO), NO 2 , carbon monoxide (CO) and sulfur dioxide (SO 2 ) decreased, while O 3 increased. For PM 2.5 , although its concentration decreased in some cities, such as Hangzhou ( Liu et al, 2021 ), Nanjing ( Wang et al, 2021b ) and Wuhan ( Zheng et al, 2020 ), serious pollution episodes still occurred in some cities or regions, such as Shanghai ( Chang et al, 2020 ) and the Beijing–Tianjin–Hebei region ( Zhao et al, 2020 ), and unfavorable meteorological conditions, local emission sources, regional transmission and the formation of secondary pollutants were important causes of these episodes.…”

Section: Introductionmentioning

confidence: 99%

Particle composition, sources and evolution during the COVID-19 lockdown period in Chengdu, southwest China: Insights from single particle aerosol mass spectrometer data

Zhang

Chen

et al. 2022

Atmospheric Environment

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Impact of COVID-19 lockdown on ambient levels and sources of volatile organic compounds (VOCs) in Nanjing, China

Cited by 36 publications

References 32 publications

Psychological Outcomes and Associated Factors Among the International Students Living in China During the COVID-19 Pandemic

Psychological Outcomes and Associated Factors Among the International Students Living in China During the COVID-19 Pandemic

Measurement report: Intra-, inter-annual variability and source apportionment of VOCs during 2018–2020 in Zhengzhou, Central China

Particle composition, sources and evolution during the COVID-19 lockdown period in Chengdu, southwest China: Insights from single particle aerosol mass spectrometer data

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