This research article analyzes trends in PM2.5 concentrations across five major Chinese cities from 1999-2008. It finds that PM2.5 levels decreased the most during warmer seasons and were highest in the evening and winter. Even with reductions, PM2.5 concentrations still exceed Chinese standards, especially in northern regions during winter. Stronger policies are needed to reduce energy use and optimize air quality, particularly in northern China in winter.

1. 1.needs to be done in 8 hours.
2.focus on how haze comes.
3.3 pages
4. Title:Research article: Trends of PM2.5 concentrations in
China: A long term approachAuthors:Fontes, Tânia a, b, c, ∗
Li, Peilin a
Barros, Nelson b
Zhao, Pengjun aAffiliation:a Centre for Urban Planning and
Transport Studies, Peking University, Beijing, China
b CIAGEB - Global Change, Energy, Environment and
Bioengineering Center, University Fernando Pessoa, Porto,
Portugal
c INESC TEC – INESC Technology and Science and FEUP-
Faculty of Engineering, University of Porto, Porto,
PortugalSource:In Journal of Environmental Management 1 July
2017 196:719-732Publisher:Elsevier LtdAbstract:The fast
economic growth of China along the last two decades has
created a strong impact on the environment. The occurrence of
heavy haze pollution days is the most visible effect. Although
many researchers have studied such problem, a high number of
spatio-temporal limitations in the recent studies were identified.
From our best knowledge the long trends of PM2.5
concentrations were not fully investigated in China, in
particular the year-to-year trends and the seasonal and daily
cycles. Therefore, in this work the PM2.5 concentrations
collected from automatic monitors from five urban sites located
in megacities with different climatic zones in China were

2. analysed: Beijing (40°N), Chengdu (31°N), Guangzhou (23°N),
Shanghai (31°N) and Shenyang (43°N). For an inter-comparison
a meta-analysis was carried out. An evaluation conducted since
1999 demonstrates that PM2.5 concentrations have been reduced
until 2008, period which match with the occurrence of the
Olympic Games. However, a seasonal analysis highlight that
such decrease occurs mostly during warmer seasons than cold
seasons. During winter PM2.5 concentrations are typically 1.3
to 2.7 higher than in summer. The average daily cycle shows
that the lowest and highest PM2.5 concentrations often occurs
in the afternoon and evening hours respectively. Such daily
variations are mostly driven by the daily variation of the
boundary layer depth and emissions. Although the PM2.5 levels
have showing signs of improvement, even during the warming
season the values are still too high in comparison with the
annual environmental standards of China (35 μg m−3).
Moreover, during cold seasons the north regions have values
twice higher than this limit. Thus, to fulfil these standards the
governmental mitigation measures need to be strongly
reinforced in order to optimize the daily living energy
consumption, primarily in the north regions of China and during
the winter periods. •Long trends of PM2.5 concentrations were
investigated in 5 Chinese megacities.•PM2.5 have decreased
mostly during warmer seasons.•Highest PM2.5 are usually
observed during evening hours and winter seasons.•PM2.5
decreased but values are still too high in comparison with
Chinese standards.•New measures are needed namely during
winter and in the north Chinese regions.Document
Type:ArticleISSN:0301-
4797DOI:10.1016/j.jenvman.2017.03.074Accession
Number:S030147971730289XCopyright:© 2017 Elsevier Ltd.
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3. Cut and Paste:Research article: Trends of PM2.5 concentrations
in China: A long term approach Database:ScienceDirect
Record: 2
Title:The environmental consequences of domestic and foreign
investment: Evidence from ChinaAuthors:Liu, Yiming a, f
Hao, Yu a, b, c, d, e, ⁎, 1
Gao, Yixuan a, gAffiliation:a Center for Energy and
Environmental Policy Research, Beijing Institute of
Technology, Beijing 100081, China
b School of Management and Economics, Beijing Institute of
Technology, Beijing 100081, China
c Sustainable Development Research Institute for Economy and
Society of Beijing, Beijing 100081, China
d Collaborative Innovation Center of Electric Vehicles in
Beijing, Beijing 100081, China
e Beijing Key Lab of Energy Economics and Environmental
Management, Beijing 100081, China
f Department of Building, School of Design and Environment,
National University of Singapore,
4 Architecture Drive, Singapore
S117566, Singapore
g Department of Natural Resources and the Environment,
University of New Hampshire,
56 College Road, Durham, NH 03824, USA
Source:In Energy Policy September 2017 108:271-
280Publisher:Elsevier LtdTopics:ENENAbstract:Fixed asset

4. investment (FAI) and foreign indirect investment (FDI) have
important influences on economic development and
environmental quality. Because environmental performance is
related with economic development, FAI and FDI may affect
environment indirectly through their impacts on economic
growth. In this study, the direct and indirect effects of both FAI
and FDI on China's environmental quality are distinguished and
separately estimated for the first time with a carefully designed
framework of a two-equation model. Because most economic
activities and environmental pollutions occur in the urban areas,
a panel data of 112 Chinese cities for the period 2002–2015 is
utilized. Several spatial factors are also introduced to control
for the potential spatial correlations in economic development
and pollutant emissions. The estimation results indicate that
there exist apparent differences in the environmental effects of
FAI and FDI. The direct effects of FAI on SO2 emissions are
significant positive and dominate the negative indirect effects.
By contrast, the direct, indirect and total effects of FDI on
pollutant emissions are all negative. Therefore, overall
speaking, well designed and targeted policies should be
formulated to reduce the negative environmental impacts of FAI
and to increase the positive influences of FDI on environment.
•Influences of domestic and foreign investment on
environmental quality in China are investigated.•City-level
panel data of fixed asset investment (FAI) and foreign direct
investment (FDI) are used.•Spatial correlations in economic
development and pollutant emissions are controlled for.•The
positive direct effects of FAI on SO2 emissions dominate the
negative indirect effects.•The direct, indirect and total effects
of FDI on both pollutant emissions are all negative.Document
Type:ArticleISSN:0301-
4215DOI:10.1016/j.enpol.2017.05.055Accession
Number:S0301421517303464Copyright:© 2017 Elsevier Ltd.
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live&scope=site
Cut and Paste:The environmental consequences of domestic and
foreign investment: Evidence from China
Database:ScienceDirect