天氣及輻射水平資料-2002年12月及2002年12月天氣回顧

1. Research question 

Question Topic	Content
What is air pollution	Briefly introduce the definition of air pollution, include indoor and outdoor air pollution, the cause and the impact of air pollution
Situation in Hong Kong, which place have the most serious air pollution	List out the public transportation interchange that have the high level of air pollution in some criteria like NO2 and list out the measure result
Surveying Method	The preparation work before measurement. The way to measure the air quality index. The instrument utilize in measurement.
The situation of result measured	To descript the result measured, to compare the different result measure in different date and venue, and indicate the reflection of the result
Who is the sensitive recevior of air pollution	List out the persons that will impact by air pollution at public transportation interchange and predict different impact to them
The impact of air pollution to environment quality and human health	Point out the consequences after air pollution at public transportation interchange happened, and how air pollution influent to environment quality and human health
What is recommendations for improvement	List out different recommendations for improvements in different aspects

Table 1. Research question 

2. Introduction 

2.1 What is air pollution 

Air problem is the phenomenon of harmful substances and gas which generate by artificial activities  contaminate to air cause the air quality become worsen. Because air pollution can be appear no matter at indoor or outdoor places, so air pollution can be divide into indoor air pollution and outdoor air pollution, under indoor and outdoor air pollution, numerous of reason and effect will effect the air quality at indoor and outdoor place air quality, like “Street Canyon Effect”, weak ventilation at indoor place, harmful gas release by chemical substances etc. So indoor and outdoor air pollution will affect different aspect of human and environment, cause worsen of human health and environment quality. For this dissertation, air pollution at confined public transportation interchange belongs to indoor air pollution. The affective of indoor air pollution to human health are similar to general air pollution, and case “sick building syndrome” according to article “Indoor air pollution and exposure assessment of the gulf cooperation council countries: A critical review” indoor air pollution is a serious health which will case different diseases like lung cancer, pneumonia, ischemic heart diseases, stroke etc. The main factor of causing indoor air pollution is the pollutants on ambient air influent into indoor scape, poor ventilation at indoor environment and over-crowed. (Amoatey, et al., 2018)1. In addition, the air pollution at open-air public transportation belongs to outdoor air pollution. Compare to indoor air pollution, air quality at outdoor environment may be better because pollutants will be easier to dissipate, the barrier at outdoor environment are less than indoor environment lead the ventilation effective may be better than indoor environment.  

2.2 Possible air pollution source 

To view the pollution source of a interchange, it must be review the daily activities and the surrounding environment like the facilities nearby, some facilities like ventilation exhaust vent is one kind of air pollution source. Public Transportation Interchange is a place that let passenger vehicle to stay, pick up and drop off, so gas emission from passenger vehicles always is the main pollution source of interchange. Apart from this, ventilation exhaust vent mentioned above is a kind of air pollution source. Like Ping Shek Public Transportation Interchange, there are a MTR station ventilation facilities locate at the side of exit of interchange, and one exhaust vent is face to the exit of interchange and a bus waiting area, it is possible that exhausting of air ventilation is the main source of pollutants produce. For the aspect of Sze Mei Street interchange, the possible air pollutant source will be the construction site opposite to interchange. This is a public housing estate, railway station construction site, involve mining work, dust can be emit to environment nearby through airflow if that construction site do not conduct any dust control measure like watering and mud covering. For the aspect of Diamond Hill Station interchange,  

2.3. Factor of causing indoor and outdoor air pollution 

In a transportation interchange, there are numerous of factor, source that can case indoor or outdoor air pollution, it can be from movable and unmovable machine like vehicle and ventilation system, human activities like smoking, those activities are possible to produce air pollutants, chemical substances like SO2, NO2, PM2.5 etc. There are few aspect of factors that can causing indoor and outdoor. Poor ventilation, construction design and environment nearby. 

For the aspect of construction design, confined interchange will be have a higher risk on air pollution than semi-confined and open-air interchange because the effective of air circulation is bad, pollutants conduct at indoor space do not have air circulation to volatile, when human activities generate more and more pollutants, pollutants will be accumulate.   

For the aspect of surrounding environment , environment that conduct  gas emission and dust will be the culprit to outdoor interchange due to the fact that air or nature wind will contain those pollutants from pollution source to interchange. In addition, the layout of building nearby can be other factor that causing outdoor air pollution indirectly, this effect is “Street Canyon Effect”. The principle of “Street Canyon Effect” is the high rise building locate at two side of road construct a “artificial canyon”, base on the circulates downwards direction of air convection, air pollutants will sink, let the air quality at low position will be worse than high position. On the other hand, circulates downwards direction of air convection will also confine the pollutants inside “artificial canyon”, let the pollutants looping inside the canyon constantly through airflow. 

For the aspect of human activities, it is mentioned above that smoking in transportation will be the main factor that influent the indoor air quality, hazard chemical substances like Tar, Ammonia etc. are colorless substances with sharp odor and toxic, not only influent to environment quality, but also human health. So, Hong Kong government has been set the anti-smoke area in indicate transportation interchange to decrease the influent level to environment quality and human health. 

3. Literative Review 

3.1. Situation in Hong Kong 

The air pollution problem at public transportation interchange in Hong Kong is serious. According to “Report of the Panel on Transport for submission to the Legislative Council” point out that in 64 public transportation interchange which manage by Transportation Department ,the average value of NO2 concentration in 1 hour  measured in half of the public transportation interchange were excessed the limit of Air Quality Objectives of Hong Kong. (Panel on Transport, 2017)2. Environmental Protection Department had announced the value of air pollution measure in 64 public transportation interchanges which manage by Transportation Department between February of 2016 to February of 2019. Among 64 public transportation interchanges, 9 interchanges are exceed the limitation of average NO2 concentration in 1 hour (300 ug/m3), the exceed percentage were between 9% to 129%. In the aspect of SO2 and CO, no interchange are exceed the limitation, but the different of SO2 and CO concentration value are great. It shows that the NO2 pollution is a main issue of air pollution in public transportation interchanges (Finance Committee Member, 2019). 3The reason of causing the situation of not fulfil the criteria of average value in 1 hour may be the ventilation system at individual interchange are bad, like low air volume, operation time of ventilation system are short etc. 

3.2. Policy/Law about air pollution 

3.2.1 The Practice Note on Control of Air Pollution in Semi-confined Public Transport Interchanges 

Environmental Protection Department has established a practice note in 1998 called “The practice Note on Control of Air Pollution in Semi-confined Public Transport Interchange”. This practice note is a guideline on the design, operating and managing the ventilation system which install at semi-confined public transportation interchange and to manage the CO, SO2 and NO2 at semi-confined public transportation interchange, aims to protect public health and increase the air quality at interchange, Like practice note regulated that it is afford to build walls or barriers to brother the air flow to decrease the accumulate of air pollutants.4 Some of the citizens doubted that practice note is useless in manage the air quality at public transportation interchange because the air quality criteria of practice note is outdated.  

3.2.2  The Air Pollution Control Ordinance 

The Air Pollution Control Ordinance is a law that regulate the fixed source of air pollution from specified processes. In “The Air Pollution Control Ordinance” has already contain “Air Quality Objectives” that list out the air quality criteria, each air pollutant list out in “Air Quality Objectives” are having its upper limit of concentration at regulate average time, the detail of the criteria list at “Air Quality Objectives” have been shown in Appendix. Apart from the specified processes, “The Air Pollution Control Ordinance” have also regulate the vehicle emission in gas exhaust which must fulfil the gas exhaust standard which is the equal strict with United State, European Union and Japan; setting the decommissioning period to vehicles no matter before Euro 4 or register after The Air Pollution Control (Air Pollutant Emission) (Controlled Vehicles) Regulation available. 5 

3.3 Comments from civil organizations 

“Momentum 107” has been conducted an survey at 10 public transportation interchanges which have been indicated that the environment problem are exist. The items of air pollution surveying PM2.5 and CO2 were record. The result of survey shown that the index of PM 2.5 at 6 interchanges were exceed 25ug/m3 which is the 24-hour standard of WHO. Raymond Ho Man Kit, convener of Momentum 107 think that the poor air quality at interchanges is because the ventilation system are old and lack of maintenance, on the other hand, he also think that the situation of each does things in his own way of departments are also one of the reason that case poor air pollution at interchanges because this way lead the cleaning job of ventilation system stagnant. He will send the surveying result to government to expect the attention of government, and government can set the criteria which is about the environment quality of public transportation interchange. (Mingpao, 2019)6 

Capture the article on the website www.inmediahk.net, “Clean Air Network” has posted a article to criticism the ordinances establish by government that the critical of concentration of air pollutants formulate in“ The Practice note on Control of Air Pollution in Semi-confined Public Transport Interchanges” are  outdated base on the guideline relate to the upper limit of  average NO2 concentration in 1 hour are no update for 30 years, let this ordinance loss the usage of protecting public health. Beside, “Clean Air Network” indicate that the air pollution situation at interchange are serious base on the result of their survey, at the waiting area after the exhaust vent of bus, the concentration of NO2 was 343ug/m3, it has already excess the Air Quality Objectives by 71.5%, criticism that this situation is a threat to public health. (健康空氣行動, 2018)7 

3.4 Detection Method 

Pollutants	Indoor	Outdoor	Detection Method
NO2			Utilize graphene and RGO sensor  Base on the character of graphene and RGO---large surface area, defect etc.  Sensor utilize high resolution transmission electron Pd-SnO 2 -RGO to conduct the detection. When the sensor is explore in the NO2 gas, sensor will show the NO2 concentration trend. (Khan, et al., 2019)8
			Utilize TMD Based NO2 sensor  Utilize mixed NO2 flake to detect NO2 in room temperature, and then scan the flake to get the image. For the image, it will show as black and white in color, white in color means the part of flake rich in NO2 molecules. (Khan, et al., 2019)9
PM2.5			Utilize PM2.5 detector  The operation principle of PM2.5 detector is a laser light shot to the PM2.5 particles, and then those particles are scattering to different direction, light detector can measure the particles concentration from different scattering light, the range of particles that can be detector are 3μm to2.5μm (Chloe, 2019)10
SO2			UV-Fluorescence Method  A method that excite SO2 molecules by utilize UV light. SO2 molecules will emit light in the vibrational relaxation process. The photomultiplier tube can detect the fluorescence emission process afterward and finally produce SO2 by electronically process.

Table 2. Detection Method of different pollutions 

3.5 Treatment Technology 

Treatment Technology	Method and Benefit
Vehicle emission
Gas to liquid	Utilize liquid fuel that transfer from natural gas, for example GTL and DME. Utilize GTL and DME in heavy duty vehicle can reduce the emission of NOx and PM for 5-37% and 10-38%11
Hydrogen Fuel Additives	To improve the fuel combustion cycle and reduce the vehicle emission by utilize Hydrogen Fuel Additives. A UK develop has conducted a independent test to fill the hydrogen into the intake of vehicle, the result shows that this method can increase the fuel efficiency and also reduce NOx, PM, Hydrocarbons and Carbon Monoxide emission12
Photo-catalytic materials	A technology that can remove ambient air pollution. For example Photo-catalytic technology, this is a technology to remove the pollutants by air under sunshine. The report from Environmental Industries Commission indicate that utilize Photo-catalytic technology on road is a effective way to reduce NOx and PM13

Table 3. Treatment technology of air pollution 

4. Methodology

For this project, NO2 and the wind speed of indoor space will be the surveying objectives, the main reason are NO2 are the main pollution substances at transportation interchange, monitor the concentration of NO2 to view the real situation to find out the indication of exceed the limitation of NO2 concentration from other organizations is true or not. On the other hand, wind speed is a main factor that will impact to the air quality at transportation interchange, so wind speed will also be survey for this project.

4.1 Sampling location (map, describe surrounding environment)

For this project, semi-confined,confined and open-air public transportation interchange will be chosen as the sampling location to conduct a comparison of the air pollution situation at 3 kinds of public transportation interchange. Semi-confined public transportation Ping Shek Public Transportation Interchange, confined interchange Diamond Hill Station Public Transportation Interchange and open air interchange San Po Kong (Sze Mei Street) Public Transportation Interchange will be chose as the surveying location base on the reason of  to conduct the air pollution situation of 3 kinds of public transportation interchange that mentioned above, in addition, those public transportation interchange have been indicated by government, environmental protection organizations and residents that have the high level of air pollution like NO2 pollution, ventilation effective is not good and involve to different sensitive receivers and those interchanges are the main public transportation interchange of opposite district. So, there have the necessary to conduct the survey to understand the real situation of air pollution at those interchanges.

The basic information and the description to the surrounding environment are shown below:

Construction type	semi-confined public transportation interchange	confined public transportation interchange	Open-air public transportation interchange
Surveying location	Ping Shek Public Transportation Interchange	Diamond Hill Station Public Transportation	San Po Kong (Sze Mei Street) Bus Terminal
GPS location	22.334021,114.210148	22.340688, 114.201831	22.337630, 114.201677
Basic information	·           Enable in 2006 ·           This surveying location is divided into 2 stories, located at the ground floor of  Infinity 8 and upside to Choi Hung Station	·       Enable in November,1997 ·       Located at the ground floor of Plaza Hollywood and opposite to Diamond Hill Station	·       Opposite to Rhythm Garden ·       Without any mechanical ventilation system
Surrounding environment	surrounded by residential buildings (Ping Shek Estate), traffic road and schools.	there are surrounded by wall and shops, the exit/ entrance of interchange is face to Lung Poon Court. At the back of interchange is the entrance/exit of Plaza Hollywood, there has a semi-confined open air face to the direction of Sheung Yuen Street, this is one of the ventilation position of interchange	Surrounded by residential building, school and industrial buildings. At the front is a list of industrial building, at the south side is a primary school and at the back is a housing estate. At the north side there has a construction site, it is sure that construction site is one of the pollution source of this interchange
Ventilation method	Mechanical ventilation and nature wind	Mechanical ventilation and fan	Nature wind

Table 4. The basic information and the description to the surrounding environment of 3 measuring public transportation interchange

4.2 Sampling procedure

Pocedure	Job
planning objective	measuring locations, time, measuring method, instrument and the criteria of measuring should be establish a clear goal of surveying occupational health and safety module should also be finish before surveying.
sampling	criteria of at different position should be record by machine and GPS location at different position should be record at the same time, reason of record the GPS location is to convenient to represent the sampling venue in the dissertation.
After sampling	result measure by machine is necessary to convert to Excel spreadsheet file which contain number and chart to convenient the job of data processing afterward
data processing	change the represent method of data collected by utilize table, map and chart etc

Table 5. Sample procedure

4.2.1 Record GPS location

GPS location (with latitude and longitude) of each measuring points and places should be record and present in report. It is convenient to represent the location of measuring points and drawing map by utilize GPS because GPS is a international universal positioning system, once enter GPS code (latitude and longitude), map with guide to the approximate location with match GPS code. So, GPS will be record and utilize to represent the approximate location of each measuring points.

4.2.2 Measurement steps

Steps	Duties
Before surveying	setting to the measuring machine is a must, the data need to setting at this moment is the data logging interval
After access to the surveying venue	turn on the NO2 analyzer and run the programme
After measurement,	save the data collected into the log data page of the analyzer
measure the wind speed of the public transportation interchange	measure the wind speed of the public transportation interchange and log the data manually
Data transferring	come back to laboratory, transfer the data logging by NO2 analyzer to software than conduct a chart and Excel spreadsheet to conduct the result part of dissertation.

4.3Result visualization

Result visulation form	Motivation	Advantages
line chart	comparison job should be conduct to show the different of all the data collected	Can show the rise and fall situation of data collected. Utilize line chart is a good method to show the relationship between the data measure at different day
floor plan with measuring points	To show the position of measurement points and the potential pollution source	let others to recognize the position of all the measuring points
Table	To show the survey result  in every surveying time clearly. Utilize table can also conduct a comparison usage with others surveying time	Can show the different of result between different surveying time and show the data in one surveying time concise

Table 7. Result visualization form in dissertation

5. Ethics and risk assessment

BSc(Hons) Environmental Science

KE6000 Geography and Environment Dissertation 2019-2020

Student Name: Yung Man Tat    Supervisor: Hung Ling Ho

Project Title: Air quality at Public Transportation Interchange

Dissertation Risk Assessment Proforma
Activity Description & Date(s):
December,2019 to April,2020 (actual date are waiting for confirm) Surveying air quality index
Significant Hazards :
a)Adsorb hazard/toxic gas b)Hit by vehicles if the surveying location is too close to traffic road c)
Persons Potentially Affected by Hazards & Potential Damage:
a) Surveyer (me) b)Driver and surveyer (me) c)
Likelihood (1-6) (for each significant hazard)	Severity (1-6) (for each significant hazard)	Degree of Risk without Control Measures (/36)
a)4 b)3	a)4 b)4	a)16/36 b)12/36
Control Measures to Mitigate / Remove Hazard
a) Wearing face mask when survey at the position near gas exhaust b) To elevate the location of surveying
Likelihood (1-6)	Severity (1-6)	Re-Calculation of Risk with Control Measures (/36)
a)3 b)2	a)2 b)2	a)6/36 b)4/36

Table 7. Dissertation Risk Assessment Proforma

Student Signature:______________________ Name: Yung Man Tat

Date: ______________________

Approved signature of dissertation supervisor: ________________________

Date: ___________________________

Nearest telephone (maybe mobile)	Ping Shek Public Transportation Interchange:2927 6322 (Choi Hung Station) 2327 4915(Ngau Chi Wan Sport Centre) Diamond Hill Station Public Transportation Interchange: 2118 8811(Plaza Hollywood) 2431 1588 (Diamond Hill Station)	Local Weather Forecast (if out of school area, check out met VTC SHAPE guideline)	Too far in time, the weather forcast still unknown now.
Nearest doctor (Name and Address)	Ping Shek Public Transportation Interchange: Dr. YUN LOK CHEUNG( Shop B104 Viva Medical Centre, Infinity Eight, 8 Clear Water Bay Road, Ngau Chi Wan) Diamond Hill Station Public Transportation Interchange: Dr. Lam Hiu Tan( Shop 11-12, G/F, Suet Fung House, Fung Tak Estate, Diamond Hill)	Communication Procedure for emergency (Who would you contact?)	Parents/Teacher
Nearest hospital (Name and Address)	United Christian Hospital 130 Hip Wo St, Kwun Tong Our Lady of Maryknoll Hospital 118, Sha Tin Pass Road, Tsz Wan Shan	Home contact for emergency	Home Tel.:27574813
Landowner (if out of school area, Company name  or area that you visit)		Emergency Procedure	If overdue emergency services will be contacted on your behalf by Mother  ______________________ Inform  Department of Applied Science / SHAPE Office on 22567240 / 22567135

Table 8. Other information about surveying

6. Appendix

Hong Kong’s Air Quality Objectives
Pollutant	Averaging time	Concentration limit [i]  (μg/m3)	Number of exceedances allowed
Sulphur dioxide	10-minute	500	3
	24-hour	125	3
Respirable suspended particulates (PM10) [ii]	24-hour	100	9
	Annual	50	Not applicable
Fine suspended particulates (PM2.5) [iii]	24-hour	75	9
	Annual	35	Not applicable
Nitrogen dioxide	1-hour	200	18
	Annual	40	Not applicable
Ozone	8-hour	160	9
Carbon monoxide	1-hour	30,000	0
	8-hour	10,000	0
Lead	Annual	0.5	Not applicable

Table 9. Hong Kong Air Quality Objectives set by Environmental Protection Departmrnt

Surveying location	GPS location	Photo
Ping Shek Public Transportation Interchange	22.334021,114.210148
Diamond Hill Station Public Transportation Interchange	22.340688, 114.201831
San Po Kong (Sze Mei Street) Bus Terminal	22.337630, 114.201677

Table 10. Measurement location

Figure 1.1. Measurement location at Ping Shek Public Transportation Interchange

Figure 1.2. Measurement location at Diamond Hill Station Public Transportation Interchange

Figure 1.3. Measurement location at San Po Kong (Sze Mei Street) Bus Terminal

7. ReFerence

1.Amoatey, P., Hamid Omidvarborna, M. S. B. & Al-Mamun, A., 2018. Indoor air pollution and exposure assessment of the gulf cooperation council countries: A critical review, s.l.: Elsevier Ltd.

2.Panel on Transport, L. C., 2017. Report of the Panel on Transport for submission to the Legislative Council, Hong Kong: Legislative Council.

3.Finance Committee Member, L. C., 2019. Replies to initial written questions raised by Finance Committee Members in examining the Estimates of Expenditure 2019-20-CONTROLLING OFFICER’S REPLY (Series No.2495), Hong Kong: Finance Committee Member of Legislative Council.

4.Department, E. P., 1998. ENVIRONMENTAL PROTECTION DEPARTMENT PRACTICE NOTE FOR PROFESSIONAL PERSONS(ProPECC PN 1/98), Hong Kong: Environmental Protection Department.

5.Department, E. P., 2019. Requirements and Procedure for Application of Environmental Permits/ Licences -Air Pollution Control Ordinance. [Online]
Available at: https://www.epd.gov.hk/epd/english/application_for_licences/guidance/application_maincontent32.htm

6.Mingpao, 2019. 調查：交通交匯處環境惡劣　彩明總站企兩分鐘可致耳鳴 (20:50). [Online]
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7健康空氣行動, 2018. 「專業」守則三十年不變 隨時等到2047. [Online]
Available at: https://www.inmediahk.net/node/1065782

8-9.Khan, M. A. H., Rao, M. V. & Li, Q., 2019. Recent Advances in Electrochemical Sensors for Detecting Toxic Gases: NO₂, SO₂ and H₂S. [Online]
Available at: www.ncbi.nlm.nih.gov

10.Chloe, 2019. IQ Air Art Visual. [Online]
Available at: support.airvisual.com

11-13. Howard, R., 2016. Policy Exchange-6 New Technologies Which Could Improve Urban Air Quality. [Online]

Available at: https://policyexchange.org.uk/6-new-technologies-which-could-improve-urban-air-quality/

[Accessed 13 11 2019].