Assessment of microplastic pollution in dry and wet atmospheric fallouts in ho chi minh city, vietnam

VIETNAM NATIONAL UNIVERSITY – HO CHI MINH CITY
UNIVERSITY OF TECHNOLOGY
FACULTY OF ENVIRONMENT AND NATURAL RESOURCES
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
-------------------

TRUONG TRAN NGUYEN SANG
ĐÁNH GIÁ SỰ Ô NHIỄM VI HẠT NHỰA TRONG BỤI KHƠNG KHÍ KHƠ
VÀ ƯỚT Ở THÀNH PHỐ HỒ CHÍ MINH, VIỆT NAM

ASSESSMENT OF MICROPLASTIC POLLUTION
IN DRY AND WET ATMOSPHERIC FALLOUTS
IN HO CHI MINH CITY, VIETNAM

Major: Environmental and Natural Resources Management
Course’s ID: 8850101

MASTER THESIS

Ho Chi Minh City, February, 2020


CƠNG TRÌNH ĐƯỢC HỒN THÀNH TẠI
TRƯỜNG ĐẠI HỌC BÁCH KHOA –ĐHQG –HCM
Cán bộ hướng dẫn khoa học : TS. Kiều Lê Thủy Chung……………………
TS. Emilie Strady……………………………

Cán bộ chấm nhận xét 1 : PGS.TS. Lê Trình
Cán bộ chấm nhận xét 2 : PGS.TS. Đặng Vũ Bích Hạnh.………………….
Luận văn thạc sĩ được bảo vệ tại Trường Đại học Bách Khoa, ĐHQG Tp.
HCM ngày 06 tháng 01 năm 2020.

Thành phần Hội đồng đánh giá luận văn thạc sĩ gồm:
(Ghi rõ họ, tên, học hàm, học vị của Hội đồng chấm bảo vệ luận văn thạc sĩ)
1. PGS.TS. Phùng Chí Sỹ (Chủ tịch Hội đồng)
2. PGS.TS. Lê Trình (Cán bộ phản biện 1)
3. PGS.TS. Đặng Vũ Bích Hạnh (Cán bộ phản biện 2)
4. TS. Trần Bích Châu (Uỷ viên)
5. TS. Lâm Văn Giang (Thư ký hội đồng)
Xác nhận của Chủ tịch Hội đồng đánh giá LV và Trưởng Khoa quản lý
chuyên ngành sau khi luận văn đã được sửa chữa (nếu có).
CHỦ TỊCH HỘI ĐỒNG

TRƯỞNG KHOA
MƠI TRƯỜNG VÀ TÀI NGUN

PGS.TS. PHÙNG CHÍ SỸ


ĐẠI HỌC QUỐC GIA TP.HCM
TRƯỜNG ĐẠI HỌC BÁCH KHOA

CỘNG HÒA XÃ HỘI CHỦ NGHĨA VIỆT NAM
Độc lập - Tự do - Hạnh phúc

NHIỆM VỤ LUẬN VĂN THẠC SĨ
Họ tên học viên: Trương Trần Nguyễn Sang

MSHV: 1870490

Ngày, tháng, năm sinh: 13/02/1995

Nơi sinh: Vĩnh Long

Chuyên ngành: Quản lý Tài nguyên và Môi trường

Mã số : 8850101

I. TÊN ĐỀ TÀI: Đánh giá sự ô nhiễm vi hạt nhựa trong bụi không khí khô và ướt ở Thành
phố Hồ Chí Minh, Việt Nam (Assessment of microplastic pollution in dry and wet
atmospheric fallouts in Ho Chi Minh city,Vietnam).
II. NHIỆM VỤ VÀ NỘI DUNG:
- Nhận diện (i) sự có mặt của vi nhựa (dạng sợi và mảnh) trong bụi khơng khí khơ và ướt ở
TP.HCM và (ii) đặc tính vật lý của vi nhựa: hình dạng, kích thước, màu sắc.
- Khảo sát sự thay đổi của mật độ vi nhựa tích lũy trong khơng khí ở TPHCM theo thời
gian (1 năm khảo sát) và tại các khu vực thu mẫu khác nhau (các yếu tố môi trường xung
quanh).
III. NGÀY GIAO NHIỆM VỤ : 19/08/2019
IV. NGÀY HOÀN THÀNH NHIỆM VỤ: 08/12/2019
V. CÁN BỘ HƯỚNG DẪN (Ghi rõ học hàm, học vị, họ, tên): TS. Kiều Lê Thủy Chung
TS. Emilie Strady

Tp. HCM, ngày
CÁN BỘ HƯỚNG DẪN
(Họ tên và chữ ký)

TS. Kiều Lê Thủy Chung

tháng

năm 2019

CHỦ NHIỆM BỘ MÔN ĐÀO TẠO
(Họ tên và chữ ký)

TS. Emilie Strady

TS. Lâm Văn Giang

TRƯỞNG KHOA MÔI TRƯỜNG VÀ TÀI NGUYÊN
(Họ tên và chữ ký)

PGS.TS. Võ Lê Phú


ACKNOWLEDGEMENT
I would like to express my special appreciation and thanks to my principal
supervisor Dr. KIEU LE THUY CHUNG and co-supervisor Dr. EMILIE STRADY.
I would like to thank them for encouraging my research and for allowing me to grow
as a research scientist. Their advices on both research as well as on my career have
been priceless. Without their supervisions and constant help, this thesis would not
have been possible.
I would also like to thank all academic staffs of the ASIAN CENTER FOR
WATER RESEARCH (CARE) for their valuable advice, comments, suggestions as
well as encouragements during my study. My special thanks to Dr. LE THI MINH
TAM, the CARE laboratory manager, for her useful help and advice for my research.
Thanks to all my colleagues of CARE for their support and encouragement.
Finally, yet importantly, I would like to send my special thanks to my family
and all of my friends. They were always supporting and encouraging me with their
best wishes.

Master Thesis

ABSTRACT

Nowadays, the fate of plastic debris, especially microplastics (MiPs) (particles
smaller than 5 mm) in marine aquatic systems has become a major worldwide
environmental issue due to harmful effects on marine organisms and human health
through seafood or salt ingestion. Last 2 decades, the land-based origin of MiPs and
the role of rivers and estuaries on their emissions to the ocean was considered.
Occurrence of MiPs in urban compartments, consisting of wastewater, surface water
and atmospheric fallout was found in developed countries in recent studies. However,
in low income countries, characterized by high waste mismanagement, relative
studies are still limited. This study firstly addresses a preliminary assessment of
microplastic (MiP) pollution in atmospheric fallout in Ho Chi Minh City. MiP
particles (fibers or fragments) was found in all samples collected from three sampling
sites: S1- urban area (District 10), S2 - sub-urban area (Cu Chi district) and S3 - Phuoc
Hiep landfill. The analysis result showed that average concentrations of microplastics
in the atmospheric fallout during 1 one-year monitoring were 402 ± 209, 142 ± 64,
and 551 ± 139 items.m-2.d-1 from sites S1, S2 and S3, respectively. In terms of size
range and color distribution, over 50 % of found fibers at all sampling sites was under
1,100µm in length, but difference on surface area of fragments was recorded. Items
in blue, made up over 95% of total MiPs was the dominant in comparison with ones
in pink, transparent, violet, white and green.


Master Thesis

TĨM TẮT LUẬN VĂN
Thời gian gần đây, sự tích lũy một khối lượng lớn rác thải nhựa và đặc biệt là
các vi nhựa (MiPs) (nhựa có kích thước nhỏ hơn 5 mm) trong môi trường nước đã trở

thành một vấn đề mơi trường lớn trên tồn Thế giới, gây ra nhiều tác động có hại đối
với sinh vật biển và sức khỏe con người thông qua các chuỗi thức ăn và tận dụng độ
mặn của nước biển trong làm muối ăn. Trong 2 thập kỷ qua, nguồn gốc của các MiPs
trong các lục địa và vai trò của các con sông và cửa sông trong việc phát tán chúng
ra các đại dương đã được xem xét và chứng minh trong các nghiên cứu. Sự xuất hiện
của MiPs trong các thành phần đô thị, bao gồm nước thải, nước mặt và bụi khí quyển
đã được tìm thấy ở các nước phát triển trong các nghiên cứu gần đây. Tuy nhiên, ở
các nước kém phát triển, được xem là nguồn phát sinh khối lượng lớn rác thải nhựa
trong môi trường, các nghiên cứu tương tự vẫn còn chưa được tiến hành sâu rộng.
Nghiên cứu này lần đầu tiên tiến hành đánh giá sơ bộ sự ơ nhiễm MiPs trong bụi
khơng khí khơ và ướt tại thành phố Hồ Chí Minh. Trong 72 mẫu được thu thập tại ba
vị trí: S1- khu vực nội thành (quận 10), S2 - khu vực ngoại thành (huyện Củ Chi) và
S3- bãi rác Phước Hiệp trong 1 năm nghiên cứu, các vi nhựa (dạng sợi và mảnh) đều
được tìm thấy. Kết quả phân tích cho thấy mật độ trung bình của vi nhựa có trong bụi
khơng khí lần lượt là 402 ± 209, 142 ± 64 và 551 ± 139 vi nhựa. m-2.ngay-1 tại các vị
trí S1, S2 và S3. Về hình dạng và kích thước của vi nhựa, kết quả nghiên cứu ghi
nhận được hơn 50% các vi nhựa được tìm thấy là dạng sợi và có chiều dài dưới 1.100
µm. Trong khi vi nhựa dạng sợi được tìm thấy trong tất cả 72 mẫu, vi nhựa dạng
mảnh chỉ được tìm thấy trong một số mẫu và có diện tích bề mặt thay đổi khác nhau
từ 10,000 µm2 đến hơn 80,000 µm2. Về mau sắc, các vi nhựa có màu xanh lam chiếm
hơn 95%, các vi nhựa có màu hồng, trong suốt, tím, trắng và xanh lục cũng được tìm
thấy nhưng với phần trăm khơng đáng kể và phân bố khác nhau trong các mẫu quan
sát.


Master Thesis

CERTIFICATE OF ORIGINAL AUTHORSHIP

I, Truong Tran Nguyen Sang, declare that this thesis is submitted in fulfillment

of the requirements for the thesis evaluation, in the Faculty of Environment and
Natural resources at the University of Technology, Vietnam National University Ho
Chi Minh City.
This thesis is wholly my own work unless otherwise references or
acknowledged. In addition, I certify that all information sources and literature used
are indicated in the thesis.
This document has not been submitted for qualifications at any other academic
institution.
This research is supported and funded by Ho Chi Minh City University of
Technology, VNU-HCM, under grant number To-MTTN-2018-11

Signature

Date: February, 10th, 2020


Master Thesis

0

CATEGORY

CATEGORY…………….. ......................................................................................... i
LIST OF FIGURES ................................................................................................... iii
LIST OF TABLES ..................................................................................................... v
LIST OF ACRONYMS ............................................................................................. vi
CHAPTER 1 INTRODUCTION ................................................................................ 1
1.1

Necessity of the research ........................................................................... 1

1.2

Research objective ..................................................................................... 3

1.3

Study area .................................................................................................. 3

1.4

Research content ........................................................................................ 3

1.5

Methodology and research Techniques ..................................................... 3

1.5.1

Methodology .................................................................................... 3

1.5.2

Research Techniques ........................................................................ 4

1.6

Scientific and practical value of the research ............................................ 4

CHAPTER 2 LITERATURE REVIEW ..................................................................... 6

2.1

Situation of plastic pollution in the world and Vietnam ........................... 6

2.2.

Overview on microplastic pollution ........................................................ 10

2.2.1.

Definition and properties of Microplastic ...................................... 10

2.2.2.

Sources of microplastics generation into the environment ............ 11

2.2.3.
MiPs

Formation and factors affecting to the abundance of atmospheric
14

2.2.4.
The harmful effects of MiPs pollution on the environment,
organisms and humans ..................................................................................... 16
2.2.5.
General research situation on Microplastic pollution in the world
and Vietnam...................................................................................................... 19
2.3.

Chapter Summary .................................................................................... 24

CHAPTER 3 MATERIALS AND METHODS ....................................................... 26
3.1.

Study area ................................................................................................ 26

3.2.

Sampling and pre-treatment .................................................................... 27

3.3.

Visual observation and FTIR analysis ..................................................... 30

3.4.

Data analysis ............................................................................................ 31

3.5.

Chapter summary ..................................................................................... 32

CHAPTER 4 -THE OCCURANCE OF MICROPLASTIC IN DRY AND WET
ATMOSPHERIC FALLOUTS OF HO CHI MINH CITY...................................... 33
4.1.
The occurrence of microplastic in atmospheric fallout of Ho Chi Minh
City…… ............................................................................................................... 33
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Master Thesis

4.1.1.

Number of microplastics found in the sampling sites .................... 33

4.1.2.

Shape of microplastics found at the three sampling sites .............. 34

4.2.

Concentrations of MiPs at the three sampling sites ................................ 38

4.2.1.

Site 1: urban area (District 10) ....................................................... 38

4.2.2.

Site 2: sub-urban area (Cu Chi district) .......................................... 40

4.2.3.

Site 3 – Phuoc Hiep landfill ........................................................... 41

4.3.

Spatial variation of microplastic concentration in atmospheric fallout ... 43

4.4.

Temporal variation of microplastic concentration .................................. 45

4.5.

Chapter summary ..................................................................................... 48

CHAPTER 5 - PHYSICAL CHARACTERISTICS OF MICROPLASTIC IN
ATMOSPHERIC FALLOUTS IN HO CHI MINH CITY ...................................... 50
5.1

Size of fibers and fragments measured at the sampling sites .................. 50

5.1.1.

In District 10 ................................................................................... 50

5.1.2.

In Cu Chi district ............................................................................ 51

5.1.3.

In Phuoc Hiep landfill .................................................................... 52

5.2.

Color distribution of fibers and fragments found at three sampling sites 54

CONCLUSIONS AND RECOMMENDATIONS ................................................... 64
REFERENCES… 67
APPENDIX…….. ................................................................................................... A1

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LIST OF FIGURES
Figure 2.1 The increase of global plastic production, measured in tones per year, from
1950 through to 2015 (Gayer et al., 2017)………………………………………….. 6
Figure 2.2 Estimated historic trends in global plastic disposal method (from 1980 to
2015) (Gayer et al., 2017)…………………………………………………………... 7
Figure 2.3 Route of plastic items enters the world’s oceans (Ritchie and Roser, 2018)
……………………………………………………………………………………….8
Figure 2.4 Global plastic input to the oceans by region, 2015 (Lebreton et al., 2017)
……………………………………………………………………………………….9
Figure 2.5 Size range of plastic debris in comparison with living materials (GESAMP,
2015)………………………………………………………………………………. 11
Figure 2.6 Formation and accumulation of microplastic particles …………………13
Figure 2.7 Potential MiPs sources and pathways (Liu et al., 2019).......................... 14
Figure 2.8 Studies were defined according the number of individuals per groups of
organisms (De et al., 2018)………………………………………………………... 16
Figure 3.1 Sampling sites with geographic distances ………………………………26

Figure 3.2 Sampling device for dry and wet atmospheric fallouts………………… 28
Figure 3.3 Protocol for extraction of MiPs fibers from atmospheric fallout samples
……………………………………………………………………………………...30
Figure 3.4 Stereomicroscopic S6D integrated with a MC170 camera…………….. 30
Figure 4.1 Abundance of micropastic particle found per sample at three sampling
sites (from 15th June, 2018 to 25th May, 2019)……………………………………. 34
Figure 4.2 Percentage of total microplastic fibers and fragments found in all samples
at sampling sites………………………………………………………………….... 37
Figure 4.3. Percentage of total microplastic fibers and fragments found in all samples
of each sampling site………………………………………………………………. 37
Figure 4.4. Concentration of microplastic fibers and fragments found in District 10
40
Figure 4.5 Concentration of microplastic fibers and fragments at Cu Chi district… 41
Figure 4.6. Concentration of microplastic fibers and fragments at Phuoc Hiep landfill
……………………………………………………………………………………...42
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Figure 4.7 Concentration of atmospheric MiPs at each sampling site…………….. 43
Figure 4.8 Concentration of MiPs compared to volume of rain water (ml) at each
sampling site a) site 1, b) site 2 and c) site 3………………………………………. 45
Figure 4.9. Monthly Concentration of microplastic (items m-2 d-1) at the three
sampling sites……………………………………………………………………... 47
Figure 4.10 Concentration of atmospheric microplastics on site S1, S2, S3 in parallel
with daily rainfall (volume of rainwater)………………………………………….. 47
Figure 5.1 Cumulative percentage of a) length of microplastic fibers (m); b) area of

microplastic fragments (m2) in District 10………………………………………. 51
Figure 5.2 Cumulative percentage of a) length of microplastic fibers (m); b) area of
microplastic fragments (m2) in Cu Chi District………………………………….. 51
Figure 5.3 Cumulative percentage of a) length of microplastic fibers (m); b) area of
microplastic fragments (m2) in Phuoc Hiep landfill……………………………… 52
Figure 5.4 Cumulative percentage of a) length of microplastic fibers (m); b) area of
microplastic fragments (m2) in three sampling sites……………………………… 53
Figure 5.5 Total microplastics with colors found in the atmospheric fallout collected
in sampling sites a) S1, b) S2 and c) S3…………………………………………… 54
Figure 5.6 Percentage of fibers in colors found in the atmospheric fallout collected
in sampling sites a) S1, b) S2, c) S3……………………………………………….. 56
Figure 5.7 Percentage of fibers in colors found in the atmospheric fallout collected in
sampling sites a) S1, b) S2, c) S3…………………………………………………. 58
Figure 5.8 The example of microplastics (under stereomicroscope)……………… 63

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0

LIST OF TABLES

Table 2.1 Overview of sources of two types of MiPs (Duis and Coors, 2016)…... 12
Table 4.1. Number of microplastic fibers and fragments found at three sampling
sites………………………………………………………………………………... 33
Table 4.2. Concentration of microplastic fibers and fragments found at three sampling

sites……………………………………………………………………................... 38
Table 4.3 Concentration of microplastics in different areas……………………… 49
Table 5.1 Characteristics of observed microplastics in the similar and different area
studied…………………………………………………………………………….. 61

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1

LIST OF ACRONYMS

Microplastics

MiPs

Microplastic

MiP

Ho Chi Minh City

HCMC

Wastewater treatment plants

WWTPs

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Master Thesis

1. CHAPTER 1 INTRODUCTION
1.1 Necessity of the research
Nowadays, plastic pollution is an emerging concern worldwide. According to
the statistic report, plastic production is continually increasing, with 299 million
metric tons produced in 2013 and estimations of 33 billion tons for 2050 (Rochman
et al., 2014). Number of plastic wastes (consisting of in-use plastics) entering the
oceans was calculated for 2010 at 4 –12 million tons per year (Jamback et al., 2015).
In 2015, there were more than 407 million tons of plastic was produced, followed by
302 million tons of plastic pieces (around three-quarters) were discharged into the
ocean (Gayer et al., 2017). Recently, scientists from Netherland reported that about
1.15 to 2.41 million tones of plastic debris were released into the ocean daily. Besides,
authors firstly pointed out the temporal change of marine plastic emission, with over
74 % of plastic items were distributed into ocean in rainy season (Lebreton et al.,
2017). The presence of plastic wastes caused a dramatic change of the nature of solid
wastes in human society, especially in developing countries where plastic products
are often mismanaged or abandoned in illegal dumping sites (Stanton et al., 2019).
As a result, these plastic particles are scattered throughout the oceans and are found
along the coastal zones, in seabed sediments, beach sands, or floating on water surface
and even in frozen ice in Arctic and Antarctic regions as well as accumulating in
continental aquatic systems, consisting of lakes, canals and rivers. (Barnes et al.,
2009).

The existence of plastics in the aquatic system poses challenges on the world’s
environment. The 2030 Agenda for Sustainable Development and its Sustainable
Development Goals dedicated several necessary goals that are relevant to this issue
(e.g. SDG 11, SDG 12, SDG 14), especially the Target 14.1 which states: “By 2025,
prevent and significantly reduce marine pollution of all kinds, in particular from landbased activities, including marine debris and nutrient pollution”. Under the impacts
from many factors such as mechanical processes, oxidation, and biodegradation,
microplastics (MiPs), plastic particles that less than 5 mm in size (Arthur, 2009) are
formed and can last thousands of years in the environment due to their chemical
stability and durability. MiPs are considered as a new pollutant that is of great concern
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Master Thesis

by the world due to deleterious effects on the survival and reproduction of aquatic
organisms through ingestion and accumulation (Ma et al., 2019) as well as affect
human health through seafood or salt ingestion and inhalation of airborne MiPs (Prata
et al., 2018).
Recently, global studies have shown the distribution and harmful effects of
MiPs on marine environments such as seas (Zhu et al., 2019; Zhao et al., 2018;
Thompson et al., 2004), freshwater lakes (Rios mendoza & Balcer, 2019; EerkesMedrano et al., 2015), rivers (McCormick et al., 2014; Moore et al. 2008), and
terrestrial environments (Jambeck et al., 2015). In Vietnam, Lahens et al (2018) also
reported that the concentrations of MiPs in the water of HCMC’s canals and Saigon
river varied from 270 to 518×103 fibers/m3 and from 7 to 223 fragments/m3 (Lahens
et al., 2018).
While the presence of plastic debris in the marine environment is widely
documented, their sources, dynamic and fate in rivers and estuaries remain poorly
understood and largely undocumented (Gasperi et al., 2018; Dris et al., 2015b).

Among the sources of MiPs, urban inputs such as wastewater treatment plant
effluents are increasingly studied while the atmospheric compartment is mostly
neglected, though the fact that plastic debris can escape as wind-blown debris was
previously reported, leading to human exposure and the potential for subsequent
health risks (Gasperi et al., 2018).
HCMC is the most dynamic area as a social, cultural and economic center of
Vietnam, where services, exchange of goods and traffic in this area have been
expanded for a long time which drives economic growth, followed by a dramatic
increase of air pollution. In a recent study on the relationship between air pollution
and human health in HCMC, over 90% of children less than 5 years old were infected
by respiratory disease (Ho, 2017). The presence of MiPs in atmospheric fallout have
become an environmental and social challenge due to their ability to spread (i) toxic
additives added during plastics production or (ii) organic and inorganic contaminants
adhering on MiP surface to the aquatic environment. More seriously, these small
particles can accumulate in human’s body during the inhalation, then enter the nose
and mouth and cause lung diseases (Gasperi et al., 2018).
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Therefore, it is urgent to conduct a survey on MiPs contamination in
atmosphere in terms of human health risk. The lack of data on sources and fate of
plastic contamination in rivers and estuaries in developing countries makes HCMC,
the economic capital of Vietnam and one of the most dynamic developing cities from
South East Asia, an adapted pilot study site to study MiPs in the atmospheric fallout.
1.2 Research objective
The objective of the study is to characterize MiPs pollution in the dry and wet

atmospheric fallout in HCMC.
1.3 Study area
Dry and wet atmospheric fallout samples were collected from three following sites:
1) Urban area (on the roof of CARE building, University of Technology, district
10);
2) Suburbs area (house of local people in Cu Chi district);
3) Phuoc Hiep Landfill.
1.4 Research content
To obtain the research objective, a one year monitoring on the occurrence of MiPs in
dry and wet atmospheric fallout was conducted in three different areas of HCMC
(urban zone, countryside, landfill) in order to:
- Determine the presence of MiPs (fragments and fibers) in the dry and wet
atmospheric fallouts in HCMC,
- Characterize (i) their physical characteristics such as type, size, shape and (ii)
chemical composition, and
- Investigate temporal variation of atmospheric MiPs concentration through the
year, respectively related to the surrounding environment.
1.5 Methodology and research Techniques
1.5.1 Methodology
Microplastic pollution has become one of global environmental issues in
recent decades. At present, studies on MiPs mainly based on the investigation of
concentration of these small particles in the environment. In this study, a long-term
monitoring (in 12 months) was conducted at three sampling sites (urban, sub-urban
area and a landfill) for preliminarily assessing the concentration of MiPs in the
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Master Thesis

atmosphere in HCMC. Experiments were set up in 4 main steps: (i) sampling, (ii)
sample treatment, (iii) sample filtration and (iv) visual observation using the
stereoscope. As a results, the presence of MiPs as well as their characteristics (shape,
size, color) in HCMC was illustrated and in comparison with that of different areas
in the world.
1.5.2 Research Techniques
Methods used in implementing the research are as follow:
-

Theory analysis and synthesis: a literature review on definition,
characteristics, sources and impacts of MiPs on the environment, organisms
and human health was necessary for understanding the research field. The
summary on situation of relative studies will clarify the research gaps at the
present, as a result the research objective become more impressive. Besides,
methods for collecting and treating samples used in previous studies can be
applied with adaptation for the current study, allowing more objective
comparisons.

-

Sampling and laboratory treatment: this technique is important in
experimental researches. Results of these studies were mostly based on the
data from collection and sample analysis at the laboratory. Practical
monitoring data will provide the current sate of the area studied, describe
more realistically environmental conditions affecting to the research subject.
Therefore, discussions and comparisons become more objective and
convincible.

-

Data analysis: results from sampling and laboratory analysis was firstly
showed in raw data and difficult for describing research results. Data analysis
methods, using analytical and statistical tools for arranging, re-formatting,
performing data on tables and charts are necessary to clarify the results and
key findings of the study.

1.6 Scientific and practical value of the research
This study will thus i) be the first one in this scientific topic to be leaded in
Vietnam, ii) will be the first one conducted in a developing country where the waste
and plastic waste management differed strongly from developed country (so far no
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papers dealing in developing country were published, and iii) will bring new
knowledge on the MiPs in the atmospheric environment.
Data on composition, nature, and distribution of MiPs in the atmosphere will
raise awareness of residents on microplastic pollution and be helpful for the
Department of Natural Resources and Environment, as well as the Ministry of Natural
Resources and Environment in making plastic waste management solutions and
propose measures to prevent, control and minimize plastic pollution on rivers and
canals.

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2. CHAPTER 2 LITERATURE REVIEW
2.1

Situation of plastic pollution in the world and Vietnam
In original, plastic was defined as "malleable" or "flexible" material used

widely for manufacturing most of industrial products (Moore, 2008). Due to their
numerous properties such as resistance, lightweight, durability and low cost, plastic
items have been used worldwide in households, schools, hospitals and factories,
leading to the global annual production of plastic polymers has grown tremendously
from 1.7 in 1950 to 350 million tons in 2015 (Gayer et al., 2017) and are forecasted
to double by 2025, and triple by 2050 (Plastic Europe, 2016) (Figure 2.1). Nowadays,
plastic is a common material used in place of glass, metal, wood, leather, fabric, etc.
to produce daily items, such as raincoats, water pipes, household items and industrial
products owing to advantage characteristics as durable, light, cheap, hard to break
and colorful. At present, the most widely used type of plastic are Polyethylene (PE),
Polypropylene (PP), Polystyrene (PS) and Polyethylene terephthalate (PET), more
than 90% of plastic products all over the world are made up these types (Andrady and
Neal, 2009).

Figure 2.1 The increase of global plastic production, measured in tones per year, from
1950 through to 2015 (Gayer et al., 2017)

For decades, the production and consuming of plastic products produce a large
number of plastic wastes, leading to a dramatic nature change of solid wastes in
human society. More seriously, as a results of poor waste management and low

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recycling rate (as can be seen in Figure 2.2, from 1980 to 2015, only 55 percent of
global plastic waste was discarded, the remaining was incinerated and recycled,
accounted for 25% and 20%, respectively) (Geyer et al., 2017; Ritchie & Roser,
2018), significant number of plastic wastes was found on worldwide centennial
environment and finally entered and persisted in marine ecosystems through natural
impacts as river runoff and atmospheric transport, beach littering and human
activities as shipping and fishing. According to data on global estimates from
Jamback et al. (2015) along with plastic waste generation rates, coastal population
sizes and waste management practices by conutry, Ritchie and Roser. (2018)
calculated and described pathway by which plastic enters the world’s oceans, as a
result the amount of plastic in surface waters was estimated ranging from 10,000 to
100,000 tons per year (Figure 2.3).

Figure 2.2 Estimated historic trends in global plastic disposal method (from 1980 to 2015)
(Gayer et al., 2017)

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Figure 2.3 Route of plastic items enters the world’s oceans (Ritchie and Roser, 2018)

The fate of plastic debris in marine aquatic systems has become a major
worldwide environmental concern in term of adverse consequences to marine life and
potentially human health.
The 2030 Agenda for Sustainable Development and its Sustainable
Development Goals dedicated several goals that are relevant to this issue (e.g. SDG
11, SDG 12, SDG 14), especially the Target 14.1 which states: “By 2025, prevent
and significantly reduce marine pollution of all kinds, in particular from land-based
activities, including marine debris and nutrient pollution”. In 2015, the United Nation
Environmental Assembly (UNEA), adopted the Resolution 1/6 on ‘Marine plastic
debris and microplastics’ which stated to focus on the “identification of the key
sources of marine plastic debris and microplastics” and on taking into account the
“specification of areas especially in need of more research, including key impacts on
the environment and on human health” (UNEP, 2016). The UNEP (United Nation for
Environmental Protection) report on ‘global lessons and research to inspire action
and guide policy change’ (UNEP, 2016) emphasized as key messages that “The
‘leakage’ of plastics into the ocean can occur at all stages of the production-usedisposal cycle, especially due to inadequate wastewater and solid waste collection
and management, but the amount of marine plastic is so far poorly quantified”.
Being considered as the dominant input of plastic debris to oceans, role of
centennial rivers and estuaries on their emissions to the ocean is now recognized.
Lebreton et al. (2017) reported that there are 1.15 to 2.41 million tones of plastic enter
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the oceans from global rivers system annually, most of them mostly located in Asia

(accounted for 86%), Africa, South and central America and Europe (as showed in
figure 2.4). However, these estimations are mainly based on solid waste data and
hydrological information of rivers. More insitu plastic assessment need to be
conducted in rivers for better understanding, and the effects of factors such as
population density, levels of urbanization and industrialization by region, rainfall
rates and the presence of weirs and dams also play a significant role in littering river
plastic into the ocean and need to be widely considered (Lebreton et al., 2017).

Figure 2.4 Global plastic input to the oceans by region, 2015 (Lebreton et al., 2017)

In Vietnam, plastic industry is a global sector that has grown rapidly in the
recent years with an annual growth rate of 16 - 18%. More than 80% of this
production, which mostly are consumer products and packaging, is localized in the
South of Vietnam, near Ho Chi Minh City – the economic capital of the country.
Unfortunately, the almost absence of treatment of domestic (i.e. 10%) and industrial
wastewaters and the weaknesses of solid waste management have pushed Vietnam to
be among the main contributors of plastic waste to rivers and oceans (Jambeck et al,
2015; Lahens et al., 2018). According to statistic data from Bliss Saigon (2016), in
Ho Chi Minh City, there are 250,000 tones of plastic wastes were generated each
year, but only 19.2 % of them was transferred to landfills, the rest are either recycled
or released directly into the environment, leading to soil and water pollution. On the

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other side, the informal waste recycling, leading to an increase in air and water

pollution is also an important sector in Vietnam.
2.2. Overview on microplastic pollution
2.2.1. Definition and properties of Microplastic
In 1972, the world first recognized small pieces of plastic in water
environments when a large number of small plastic particles (plasticles) were found
floating on the surface of the Sargassco Sea (Carpenter and Smith, 1972). At that
time, these small pieces of plastic were simply called "plastic particles". Until a
publication in 2004, the new "MiPs" term was introduced by Thompson (2004). For
distinguishing small plastic samples (about 50 μm in size) collected from beaches and
sediments in Plymouth, UK from larger plastic debris such as fishing nets, plastic
bottles, plastic bags, etc, scientists used the term "MiPs". In 2009, Arthur suggested
that MiPs also include pieces less than 5 mm, which are lightweight, resistant, durable
and easy to ubiquitous in the aquatic environment, such as ocean, river, estuary, lake,
and even rainwater (Arthur, 2009). Nowadays, the term of “MiPs”, plastic particles
of less than 5 mm in size was commonly used in all current studies. In 2015,
GESAMP proposed provided a more scientifically rigorous definition of microplastic
pieces base on comparing the size corellation between microplastic particles and
other organisms (GESAMP, 2015).

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Figure 2.5 Size range of plastic debris in comparison with living materials (GESAMP,
2015)

2.2.2. Sources of microplastics generation into the environment

MiPs were first discovered and reported in the 1970s (Carpenter and Smith,
1972). Later, global studies have shown their harmful effects on marine
environments, aquatic animals and the ability to affect human health due to MiPs
absorption through the food chain. Microplastics particles are made up of particles
that differ in size, specific density, chemical composition, and shape. (Duis and
Coors, 2016). They originate from the so-called primary sources, which are the
manufactured products (pellets, cosmetic products) and the so-called secondary
sources that are the fragments and fibers produced from breakdown of larger
macroplastic debris under environmental conditions (Table 2.1) (Auta et al., 2017).
Primary MiPs are microscopic particles based on their small size (Auta et al.,
2017). Their sources include intermediate sources of plastic products such as raw
plastic material (nurdles and pellets); wastes released from the maintenance and
breakdown of plastic products and by-products during the industrial production. They
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include plastic particles used in facial cleansers, tooth paste, resin pellets and
cosmetics like bath gels, scrubs, peelings (Cole et al., 2011), eye shadow, deodorant,
blush powders, make up foundation, mascara, shaving cream, baby products, bubble
bath lotions, hair coloring, nail polish, insect repellents and sunscreen (Costa et al.,
2010). Primary microplastics are usually released into rivers through domestic and
industrial wastewaters and finally enter to oceans.
Secondary MiPs are larger pieces of plastic fragmented from plastic materials
in marine and terrestrial environments (Norwegian Environment Agency, 2015). This
type is mainly released due to the decomposition process under solar radiation (UV
rays), which leads to the breakdown of chemical bonds in the polymer matrix because

of the oxidation. In addition, weather processes also affect the formation of these
fragments such as current, wind or by laundry process of synthetic textiles (Figure
2.6) (Barnes et al., 2009; Wagner et al., 2014).
Table 2.1 Overview of sources of two types of MiPs (Duis and Coors, 2016)
Primary Microplastics
-

Secondary Microplastics

Specific cosmetic products

-

General littering, dumping of plastic waste

containing MiPs as

-

Losses of waste during waste collection, from

defoliants/abrasives;
-

-

landfill sites and recycling facilities

Specific medical

-

Losses of plastic materials during natural disasters

applications (e.g. dentist

-

Plastic mulching

tooth polish);

-

Synthetic polymer particles used to improve soil

Drilling fluids for oil and

quality and as composting additive

gas exploration;

-

Abrasion/release of fibers from synthetic textiles

-

Industrial abrasives;

-

Release of fires from hygiene products

-

Pre‑production plastics,

-

Abrasion from car tires

production scrap, plastic

-

Paints based on synthetic polymers (ship paints,

granulate: accidental losses,

other protective paints, house paint, road paint):

run‑off from processing

abrasion during use and paint removal, spills,

facilities.

illegal
-

dumping

-

Abrasion from other plastic materials (e.g.
household plastics)

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