Title: Risk assessment for Thai residents exposed to microplastics
Names of project members: Chalida Chompoobuta,b, Mirella Kanervab, Panida
Navasumrita, ,Mathuros Ruchirawata and Hisato Iwatab
aChulabhorn Research Institute, 54 Kamphaeng-Phet 6 Road, Laksi, Bangkok

10210, Thailand
bCMES, Lab. of Environmental Toxicology, Ehime University, Bunkyo-cho 2–5,790–8577, Matsuyama, Japan
Purposes: To understand the human health effects of airborne MPs and toassess the associated risks.
Specific Objectives
1.To characterized airborne microplastics in ambient air2.To assess individual exposure to airborne MPs by determining MPs
concentration in individual exposure and in urine.
3.To analyzed and interpreted transcriptomic and metabolomic data inblood and urine samples
4.To identify toxic, predicted effects and evaluate their risk assessments
Methods:
Study locations: The study area for this project consists of high-traffic site(Outdoor), medium-traffic site (Outdoor) and low traffic site (Indoor) in Thailand.
Bangkok was selected as the target area for this study because it has been
dealing with traffic problems for long decades.
A)B)

C)

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Figure 1 Location of the study area in Bangkok, Thailand
A) High traffic congested area (Outdoor) Taksin, Bangkok, ThailandB) Medium traffic congested area (Outdoor) Laksi, Bangkok, ThailandC) Control site (Indoor) Laksi, Bangkok, Thailand
Subject recruitment
A total 120 subjects (healthy and non-smoker) were recruited from 40 and41 subjects residing nearby roadside at Taksin and Laksi area, respectively aswell as 39 subjects from reference site. Subjects recruited from roadside areas
were represented as a high and medium traffic-exposed group, while subjects atreference site were a low traffic-exposed group. All of subjects were requested toprovide information in the questionnaire and signed consent form. The approvalof the research was accepted by Thai ethics committee.
Sample collection
1. Air sample collection
Air samples were collected using air sample pump connected with cascade
impactor. CF-300 Aluminium foil filters (25 mm diameter) were placed in eachstage (Stage A >2.5 μm, stage B 2.5-1 μm, stage C 1-0.5 μm, and stage D 0.50.25 μm) of cascade air sampler. Ambient air (n=27) and personal air (n=120)
sampling were collected at the flow rate approximately 9.00 m3/min for 6-8 hours.
After collection, all filters were kept in desiccator for one day to remove fieldhumidity. Each filter was weighed to determine particle mass (METTLERTOLEDO microbalances). Then, all filters were individually taken in AnalyslideTM
Petri Dishes and kept in a desiccator until analysis. The mass was calculated toparticles concentration in ambient and personal air samples as follow:𝜇𝑔Particle concentration (𝑚³) =2.

Particles mass (μg)m3)
minTime (min)x Air flow rate(Biological sample collection
2.1 Urine
Urine samples were collected, in the morning prior to start working andafternoon approximately 8 hours after finish working. Urine samples werecollected in 50 mL in a sterile polypropylene tube with screw cap, and keep in 4°C
of ice box during transport form field to laboratory and stored at -80 °C until
analysis.
2.2 Whole blood and plasma
Whole blood and plasma were obtained by sterilized venipuncture. Each2 / 5

sample was pipetted into clean vials and transported to the lab on dry ice andstored at -80°C until analysis.
2.2.1 RNA from whole blood
Samples of 3 ml of whole blood were transferred to Tempus™ Blood RNA
Tube for transcriptomic analysis. RNA extraction was performed by using RNeasy
Mini Kit (Qiagen, Germany). RNA level was quantified by ND-1000 Nanodrop(Thermo Fisher Scientific, Waltham, MA, USA).
2.2.2 Plasma
Samples of 3 mL of whole blood were transferred to separated
polypropylene tubes and added 5% Ethylene Diamine Tetra Acetic acid (EDTA)
as anticoagulant agent. Next, all samples were centrifuged at 2,000 g at 20 °C
for 10 min, and the supernatant (Plasma) was reserved for metabolomic analysis,plastic additives and other chemical compounds.
ResultThis study consisted of three study locations including high-traffic
exposure area (Taksin, Bangkok, Thailand), medium-traffic exposure area (Laksi,Bangkok, Thailand) and low traffic-exposure area (Laksi, Bangkok, Thailand).
The collected area was conducted in indoor area in the same location at Laksi.
Ambient air samples were collected in high-, medium- and low-traffic locations.
Personal air sample and urine sample were collected from high traffic-exposed(n=40), medium traffic-exposed (n=41) and low traffic-exposed subjects (n=39).
Demographic characteristic
A total of 120 healthy volunteers were enrolled in this study. The low
traffic-exposed group is the subject working in indoor area, which consists of 19(49%) males and 20 (51%) females with a median age of 43 years (ranging from26 to 60 years). While the medium and high traffic-exposed group are the subjects
working at the roadside area where are located in traffic-congested areas. The
medium and high traffic-exposure group consists of 19 males (46%), 19 males(47.5%) and 22 females (54%), 21 females (52.5%), with a median age of 51years (ranging from 21 to 59 years), 47.5 years (ranging from 18 to 60 years),
respectively, which gender and age were not significant difference among thestudy groups. There was a significant difference in education level, occupation
and working period in three groups, with the majority of subjects in medium-andhigh-traffic areas being street vendors (36.5%, 55%), and security guard (41.5%,12.5%), and the majority of education levels being elementary school (27%,25%), and high school (41%, 45%), respectively. The majority of subjects in low3 / 5

traffic areas was officers (58.5%), with bachelor's degrees or higher being themost common educational level.
Characterization of particulate matter (PM) in ambient and personal air
samples
1. Determination of concentration of particulate matter (PM) in
ambient air samples
This study conducted to determine PM concentration in ambient air
samples in various sites among high-, medium-and low-traffic exposure. The
mean concentration of ambient PM collected from high traffic- areas was
significantly higher (p<0.01) than those of medium-, low-traffic areas byapproximately 1.3-fold and 2.5-fold (8.64 vs 15.97 μg/m3 and 8.64 vs 21.17μg/m3) respectively
2. Determination of concentration of particulate matter (PM) in
personal air samples
The increased of PM in ambient air at high-traffic congested area, humans
can directly and continuously inhale these PM into the body. Personal air wereused to determine the individual exposure to PM in ambient air. The study wasconducted in various sites in high-, medium- and low-traffic exposure. The
concentration of personal PM exposure from high- and medium-traffic exposed
subjects (29.15 μg/m3 and 17.85 μg/m3 , respectively) were significantly higher
than those of low-exposed subjects (6.49 μg/m3 ) by approximately 3.68-fold and2.67-fold, respectively.
Future challenges
This year, my study will be focused on transcriptomic and metabolomic
analysis. The RNA-Seq data will be analyzed using the CLC Genomic Workbench
program. I plan to use prominent databases such as KEGG, GO, andDiseaseComps, in addition to bioinformatics tools like ClusterProfiler, Cytoscape,and IPA, for transcription factor, pathway, and disease enrichment analyses.
The metabolome, including urinary metabolites, will be analyzed withliquid chromatography-quadrupole time-of-flight mass spectrometry (LC/Q-TOFMS). In addition, plasma will also be used for plastic additives analysis.
Differences in concentrations of toxic chemicals among the study sites will bestatistically examined. Thus, this analysis will help predict phenotypic effects
caused by disruption of biological information networks.
Furthermore, DIABLO (Data Integration Analysis for Biomarker

4 / 5discovery using a Latent component method for Omics studies) will be performed
using a dataset of all quantitative values with pollutant concentrations. Theseanalyses will enable to identify toxic chemicals that account for predicted effects
and to assess their risk. Finally, my ultimate goal is to prepare our research for
publication, with the intention of submitting it to international journals with highimpact factors.

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