Detecting the Heavy Metal Concentration of PM2.5 in Beijing
Research Background
Clean air is a basic health requirement for every human being. However, air pollution across the globe is
constantly threatening human health.1
On December 18, 2012, Greenpeace and the Public Health Faculty of Peking University jointly issued the
report Dangerous Breathing, PM2.5: Measuring the Human Health and Economic Impacts on China's
Largest Cities, which found that PM2.5 (particles with an aerodynamic diameter less than 2.5μm) pollution
has caused extensive damage to public health. Under existing air quality conditions, the total number of
premature deaths in the four cities of Beijing, Shanghai, Guangzhou and Xi’an in 2012 would be 8,572, and
the economic loss caused by these deaths would reach 6.8 billion RMB.
PM2.5 is prone to absorb hazardous substances, and is a major issue currently endangering Chinese public
health. PM2.5 from different sources has different compositions and various impacts on health. In China, the
concentration monitoring of PM2.5 has just begun, and discussions of PM2.5 sources and how to control it is
also at a primary stage. This research focuses on heavy metal contamination of PM2.5 and the relevant
individual exposure risks.
Toxicology experiments have proven that metal elements are possible components of health hazards in air
particles.2 Compared to PM10, PM2.5 is more capable of carrying heavy metals, and is therefore more
hazardous to human health.3 Based on this observation, we hope more consideration will be given to the
hazardous substance constituents carried by PM2.5 and how it should be dealt with when we talk about PM2.5
control.
From December 3, 2012 to January 18, 2013, Beijing experienced the most severe episode of air pollution
since PM2.5 monitoring data became available. In this period, Greenpeace carried out monitoring of
individual PM2.5 exposure to nine volunteers in the Beijing area using individual samplers (with a duration
of 22 days and 42 samples), and also entrusted the Public Health Faculty of Peking University to monitor
PM2.5 in the air (for 15 days) on the 6th floor platform of their building. A series of detection and analysis
tests were carried out, as well as on the samples from individuals.
Main Conclusions
Analysis of heavy metal concentrations in the air show the concentration of arsenic in PM2.5 is above the
norm. This alarming fact deserves greater attention from the Municipal Government of Beijing and Ministry
of Environmental Protection of the People’s Republic of China.

During the detection period, the average daily concentration median of heavy metal arsenic in
Beijing's PM2.5 was 23.08 Ng /m3. 4 According to Ambient Air Quality Standards issued in February 2012,
the annual mean reference concentration limit value is 6 Ng /m3, meaning the concentration detected during
the course of this research is 3.85 times the limit value. During heavy pollution days, the concentration
median reached 34.68 Ng /m3,5 and the highest average daily concentration during this period reached 70.91
Ng /m3.

During the 15 detection days, there were 12 days in which arsenic concentration rose above the
annual mean reference limit value taken from Ambient Air Quality Standard, four days in which cadmium
concentration rose above the annual limit value, and two days in which lead concentration rose above the
1
limit value.

During the 22 day detection period, the median individual arsenic exposure concentration of the nine
volunteers was 12.13 Ng /m3. During heavy pollution days, the median of individual arsenic exposure
average daily concentration was 24 Ng /m3. On December 19, the arsenic exposure average daily
concentration median for one of the volunteers sat at 58.87 Ng /m3.

Among the 42 person-times detection, the individual arsenic exposure concentration of 29 persontimes is above the annual mean reference limit value.
1 http://apps.who.int/iris/bitstream/10665/69477/3/WHO_SDE_PHE_OEH_06.02_chi.pdf
2 Research Progress on PM2.5 in Environmental Air, Xiao Mei, Guo Lin, and He Zongjian
3 Different Particles Pollution and Their Heavy Metal Distribution Situation in Heating Period, Lin
Zhiqing, Environment and Health Magzine, 2005, 22(1):33-34
4 Arithmetic average value is 23.18 Ng /m3
5 Arithmetic average value is 41.62 Ng /m3

Compared to previous research6 7 8 9, the arsenic concentration of PM2.5 in Beijing is constantly at a
high level. And while the levels of this period are lower than previous, it is still significantly higher than
other international cities.
Los Angeles
Birmingham
Greenpeace sampling
Beijing 2012-2013
Literature
Beijing 2007
Beijing 2000
0
10
20
30
40
50
Heavy Metal Concentration Detection Results of PM2.5 from Ambient Air and Individual Inhaling in Beijing
(1) Ambient air
Detection background: During the 15 day testing period from December 3, 2012 to January 18, 2013, there
were four days in which the air quality was excellent, six days which had mild or moderate pollution, and
five days that saw severe pollution. The sampling site was on the 6th floor platform of the Public Health
Faculty of Peking University, which is near the Third Hospital of Peking University.
2
6 The Research on Chemical Elements Contents Variety in PM10 and PM2.5 during the Dust and Sand
Weather in Beijing and Alashan League [J]. Wang Wei, Tao Hui, and Dae-Seon Kim, etc. Environment and
Health Magazine, 2010 (9): 763-766
7 Song Y, Xie S, Zhang Y, et al. Source apportionment of PM2.5 in Beijing using principal component
analysis/absolute principal component scores and UNMIX [J]. Sci Total Environ, 2006, 372 (1): 278-286.
8 Chow JC, Watson JG, Fujita EM, Lu ZQ, Lawson DR, Ashbaugh LL.Temporal and spatial variations of
PM2.5 and PM10 aerosol in the Southern California Air Quality Study. Atmos Environ 1994; 28 (12):
2061–80.
9 Harrison et al. (199)
Heavy
Metal
Detection
results in
this
research
（Ng/m3）
Detection
results during
heavy
pollution
days
（Ng /m3）
Days in
which the
heavy metal
concentration
of PM2.5 was
above the
relevant
reference
annual mean
concentration
limit value in
ambient air
Arsenic
Lead
Cadmium
23.08
244.10
4.20
34.68
312.43
6.68
12/15
2/15
4/15
Ambient Air
Quality
Standard of
China (annual
mean value,
Ng /m3)
European
World Health
Union 11
Organization10
(annual
(annual mean
mean value,
value, Ng /m3)
Ng /m3)
6
500
5
500
6
500
5
(2) Individual inhaling
Previous research into the exposure concentration levels of PM2.5 and the heavy metal exposure
concentration of PM2.5 usually include data from outdoors stationary sites. However, in urban environments
people will spend over 80% of their time indoors. To achieve an authentic level of exposure concentration of
PM2.5 and the heavy metal concentration of PM2.5 by individuals with different behavior patterns, we carried
out testing from December 3, 2012 to January 19, 2013. This was overseen by Greenpeace, with the Public
Health Faculty of Peking University carrying out sampling, detecting and analysis on samples from nine
volunteers living in Beijing and using personal PM2.5 samplers. The results were as follows:
Individual PM2.5 detection in the Beijing area: arsenic content and proportion of days in which arsenic
content was over the national standard
Arithmetic
Occupation of Sampling mean
Median Days in
the volunteers days
value
(Ng/m3) which
(Ng/m3)
arsenic
Proportion
of days in
which
arsenic
PM2.5
arithmetic PM2.5
mean
median
value
3
Singer
Software
engineer
Outdoor
sports
participant
Managers
Office worker
Private
enterprise
owner
Child
Taxi driver
NGO
employee
2
35.95
35.95
content
was
above
the
national
standard
2
content
was above
the
national
standard
(%)
100%
209.61
209.61
5
29.66
22.9
4
80%
81.19
65
5
14.68
14.17
4
80%
116.46
123.76
5
5
14.29
13.95
16.08
12.64
4
4
80%
80%
105.21
112.85
100.87
117.64
5
11.62
4.26
2
40%
132.95
138.65
5
5
9.43
7.98
6.34
7.3
3
3
60%
60%
32.34
105.15
5
6.91
6.01
3
60%
38.23
121.61
55.74
56.52
10 Bai X P, Li H, Fang D, et al. [Application research of data assimilation in air pollution numerical
prediction] [J]. Huan Jing Ke Xue, 2008, 29(2): 283-289.11 PAN Xiaochuan, the Public Health Academy of
Peking University
11 The Method Of Formulating Quality Standard Relating To Several Pollutants In Ambient Air In EC [J]
HU Bi-bin ENVIRONMENTAL SCIENCE AND MANAGEMENT
Hazards to Health due to Heavy Metal in PM2.5
(1)
Intake methods:
PM2.5 can carry many heavy metals.12 Breathing is one of two primary channels for heavy metals to enter the
human body; another is via drinking water and consuming food.
(2)
Accumulating health effects:
Heavy metals tend to bio-accumulate in organisms. Once they enter the bodies of animals, it is difficult for
them to be discharged and can lead to disease.
(3)
Health impacts:
Arsenic: The International Agency for Research on Cancer and World Health Organization has declared
arsenic a human carcinogen since 1981. The Agency for Toxic Substances and Disease Registry lists arsenic
as the number one hazardous substance to human health. Intake of arsenic may cause nervous system
damage, cardiovascular disease and urethral carcinoma. Breathing in and touching arsenic may cause both
lung cancer and skin cancer.
4
Lead: Lead is harmful to the nervous system, digestive system, hematopoietic system, urinary system,
cardiovascular system, immune system, and endocrine system. Nor does lead exposure have a safety
threshold (note: even micro-scale ingestion is harmful for health), especially for children.
Cadmium: Cadmium may cause kidney and bone damage. Constant exposure may increase risk of cancer.

Other research shows a correlation between metal components in PM2.5 air pollution and rising blood
pressure of healthy adults in the Beijing area. Results indicate arsenic present leads to a positive correlation
with systolic pressure and diastolic pressure.14 Chronic exposure to arsenic and lead is also related to blood
pressure rising.15

An analysis was conducted of the relation between concentration of metal elements and PEFR (Peak
Expiratory Flow Rate) in school-age children living in Beijing and Alashan League of Inner Mongolia in
China and Seoul, Korea. Testing was conducted during sandstorm season, with researchers Hong Y.C., Pan
Xiaochuan and others finding a statistical correlation between arsenic, lead, cadmium in PM2.5 and the
decline of PEFR.16
(4)
Susceptible population:
According to the research, reactions to harmful factors in environment vary greatly among the population.
While environmental pollutants will generally lead to an increase of physiological load or physiological
changes in the population, there are a few who must also suffer bodily function disorders, poisoning, and
even death. This group has above-average sensitivity and is called the "susceptible population". Compared
to the general population, harmful health effects will appear at much lower exposure levels, or with higher
incidents of illness, or with reactions that are much stronger. Children, the elderly, pregnant women and
patients with severe chronic diseases belong to the susceptible population and often need to pay more
attention to self-protection.
12 http://www.ec.gc.ca/air/default.asp?lang=En&n=BEC329C4-1
13 Public Health Academy of Peking University, PAN Xiaochuan
14 Wu S, Deng F, Huang J, et al. Blood pressure changes and chemical constituents of particulate air
pollution: results from the healthy volunteer natural relocation (HVNR) study [J]. Environ Health Perspect,
2013, 121 (1): 66-72.
15 Mordukhovich I, Wright R O, Hu H, et al. Associations of toenail arsenic, cadmium, mercury,
manganese, and lead with blood pressure in the normative aging study [J]. Environ Health Perspect, 2012,
120 (1): 98-104.
16 Hong Y C, Pan X C, Kim S Y, et al. Asian Dust Storm and pulmonary function of school children in
Seoul [J]. Sci Total Environ, 2010, 408 (4): 754-759.
Arsenic Pollution Source Analysis of PM2.5 and Policy Suggestions
(1)
Arsenic source analysis of PM2.5
Emission of coal combustion is a major source of arsenic found in the air. According to research, around one
third of arsenic in coal volatilizes directly into the air. 84.6% of total arsenic in coal at high concentrations of
PM2.5 enter the atmosphere and can travel long distances, causing widespread pollution during the process
of coal combustion.17 Many other studies have shown that smelting furnace18, fly ash19 and coal soot20 from
coal combustion emission also increase arsenic concentrations of the air. Furthermore, some studies indicate
that arsenic content is more than 1000mg/g of PM2.5 in emissions from coal-fired power plants, causing
great harm to people’s health.21 With these test results in mind, Beijing Municipal Government and Ministry
5
of Environmental Protection must pay greater attention to arsenic in PM2.5.
Figure 2-3 Diagram of the environmental migration of air pollution, caused by coal combustion and leading
to human exposure.
The words in the figure from left to right, from above to below then from left to right again are: spread to the
air, particulate matters, heavy metal, settle, soil, water, food, through alimentary canal, through respiratory
tract, fat-soluble substances through the skin mucus, and human body.
Coal consumption of Beijing-Tianjin-Hebei region reached 384.2 million tons in 2011, with coal
consumption in Hebei province alone more than 300 million tons. This accounts for 80% of the coal
consumption in this region22 and even exceeds levels from Germany, the biggest economy in Europe.
According to the China Environmental Statistical Yearbook (2012), three major pollutant emissions
from Hebei province accounted for 77-90% of the total emissions in the Beijing-Tianjin-Hebei region.
Due to the huge scale of energy consumption in Hebei province, the Beijing-Tianjin-Hebei region must
control coal consumption and solve the problem of air pollution at a regional level.
17 Characterization of Arsenic Emissions from a Coal-Fired Power Plant, Guo Xin, Zheng Chuguang and
Chen Dan
18 Pollution Characteristics and Research of PM2.5 in Beijing, Yang Fumo, Tsinghua University
19 The True Cost of Coal - the Coal Dust Storms along with Wind Hitting, Zhuang Guoshun, Fudan
University
20 Determination and Distributed Characteristics Research on Metal Elements in PM2.5s, Peng Xilong, He
Zongjian and the others
21 Distribution and Enrichment of Heavy Metal Elements in Inhalable Particalate (PM10) Caused by Coal
Combustion, Lu Jing, Sun Junmin, State Key Laboratory of Coal Resources and Safe Mining, China Mining
University
22 China Energy Statistical Yearbook (2012)
Air pollution problems in Beijing are a regional and cross-border problem. According to a study published in
Atmospheric Chemistry and Physics Magazine, 39% of ingredients in PM2.5 in Beijing come, on average,
from non-local emissions. The same study also found if wind blows continuously from the south into
Beijing, non-locally produced air pollutants will account for 50-70% of PM2.5 in Beijing.23
6
To control air pollution, the Beijing Municipal Government has proposed to cut down coal consumption to
15 million tons in 2015.24 But coal consumption in Hebei province, near Beijing, continues to be in rapid
expansion. In view of this present situation, we put forward the following four policy suggestions:
Coal Consumption Statistics of BeijingTianjin-Hebei Region
Ten thousand tonst
40000
30000
Hebei
20000
10000
Tianjin
Beijing
0
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
(2)




Policy suggestions
According to the 12th Five-Year Plan of Atmospheric Pollution Prevention in Key Region approved by
State Council in October 2012, the Ministry of Environmental Protection should publish a priority list
for national toxic air pollutant control. They should also improve the relevant emission standards and
technical control specifications for toxic air pollutants.
Carry out toxic air pollutant monitoring in key areas and strengthen research into harmful material
composition and sources of PM2.5 in various districts. Also, reduce the concentration level of PM2.5,
along with bolstering harmful substance prevention and control in PM2.5, such as heavy metals.
Strengthen research into the effect of arsenic on public health in relation to PM2.5. China's energy
structure heavily relies on coal and the three areas of Beijing-Tianjin-Hebei, Yangtze River Delta and
Pearl River Delta consume 40% of the country's coal consumption and yet occupy just 6.3% of the area.
These three urban centers are the most densely populated areas in China. Prevention and control of
relative atmospheric pollution sources in these areas has become urgent.
Considering the regional dispersion of air pollution, conditions in the Beijing area can only be improved
with regional cooperation in the Beijing-Tianjin-Hebei area. A coal consumption cap in this region must
be set up as soon as possible. If coal consumption of the Beijing-Tianjin-Hebei region cannot be
controlled effectively, the air quality of the whole region will not see any obvious improvement.
23 Air quality during the 2008 Beijing Olympic Games, David G. et al, Atmospheric Environment
24 Work Plan for Speeding up Cutting down Coal Combustion and Promoting Air Quality Improvement,
Beijing Municipal Government
Appendices
(Appendix 1) Experiment Method in the Concentration Detection of Individual Exposure to PM2.5
The concentration sampling of individual exposure to PM2.5 was made according to regulations set in GB
3095-2012 Ambient Air Quality Standard and HJ618-2011 Weight Determination of PM10 and PM2.5 in
7
Ambient Air. It used a sampler that was capable of extracting rational volume air at a constant speed,
trapping PM2.5 in the air to the filter membrane, and then using analytical balances to weigh the difference
between the filter membrane before and after sampling. We were then able to calculate the average
concentration of PM2.5 during the testing time.
In this experiment, individual sampler components included a sampling head (PMI) and sampling pump
(PCXR8 type, SKC of USA), which are connected by a hose. The sampling pump extracts air, with a flow
rate of 3L/minute. Volunteers take the sampler with them, and it records sampling time automatically. The
sampling head is fixed to the volunteer's shirt collar with a clamp (this area is close to the nose and mouth,
that is, the "breathing zone"). The sampler filters out particles whose aerodynamic diameter are greater than
2.5 micron, and absorbing particulate matters whose aerodynamic diameter is less than or equal to 2.5
micron (PM2.5) on quartz filter membrane (SKC of USA).
Individual sampler of PM2.5
After sampling, the filter membranes before and after sampling are tested in a box with standardized
temperature and humidity in order to prevent these factors from affecting the weight. A balance called
XS105 (Mettler-Toledo Company, Switzerland), which has 0.00001 accuracy is then used to weigh the
samples. The concentration of PM2.5 during sampling is the net weight divided by the volume in standard
temperature and pressure (using the sampling volume to convert).
In addition, portions of the metal compositions of PM2.5 were also analyzed. Fine particle samples of this
study were analyzed using an Ultra WAVE type microwave digestion instrument (Milestone Company of
Italy) of Central Laboratory of Medical Science Department of Peking University. The concentration of Cr,
Mn, As, Se, Ni, Cu, Zn, Cd, Hg and Pb of PM2.5 included in this study were determined by a DRC - II type
inductively coupled plasma mass spectrometer (ICP-MS) of PE Company of USA.
Parameters of the DRC - II type inductively coupled plasma mass spectrometer include: atomizing gas flow
rate: 0.96 L/min; assisting gas flow rate: 1.80 L/min; plasma gas flow rate: 15.0 L/min; duration: 100 ms;
quantity of sample improvement: 1 ml/min; scanning mode: single point jump peak; resolution: 0.7-0.9 aum.
(Appendix 2) Experiment Method in the Metal Concentration Detection of PM2.5 in the Environment
The stationary sampling site of PM2.5 was on a platform of the 6th floor of the teaching building of the
Public Health Faculty of Peking University. The monitoring method of PM2.5 in the air and metal
component detection method were the same as that used for monitoring individual exposure to PM2.5.
8
(Appendix 3) Limitations of the Experiment
1. According to Ambient Air Quality Standard, the ambient monitoring objects of arsenic are arsenic in
the air, but this experiment is detecting the concentrations of arsenic in PM2.5.
2. We have only used average annual value standards for some of the metals in ambient air, not average
daily concentration standards at present in China. This study assumed the average daily value to be
comparable with the average annual value standard, which will have some limitations in terms of
interpretation of results.
9