~THINGS WE DON'T SEE IN THE AIR~

What are the things in air that we cannot see?

There are many different types of gases and compounds found in the atmosphere. Some exist in a colourless, non-toxic state and play an important part for our survival. On the other hand, some are visible to the naked eye, are toxic and can harm our bodies in many ways.



What is a haze?

A combination of the different gases and compounds like dust or smoke can form an atmospheric phenomenon known as haze.


Why haze in Singapore?

Indonesian forests were annually cleared by farmers by burning to clear the land efficiently for the growing of crops. Due to the intense burning and wind direction, Singapore skies have fallen victim to the haze for many years but none were that serious till 2013. More than 100 hotspots were discovered by satellites which resulted in the Pollutant Standards Index (PSI) levels to be at their highest. All of these effects were caused by the mixture of harmful gases present in the haze like sulfur dioxide, carbon monoxide and particulate matter.



Taking a look at the haze in Singapore in 2013:

What Are pm2.5 And pm10???

Particulate matter are tiny pieces of solid or liquid that can exist in the atmosphere. They can be divided into two parts namely PM 10 and PM 2.5. PM 10 refers to particulate matter of 10 μm (1/5 the diameter of a human hair strand) and below. PM 2.5, on the other hand, refers to very fine particulate matter, equivalent and less than 2.5 μm (1/20 the diameter of a human hair strand).



More Importantly, What Do They Do?

These particles are able to penetrate deep into the respiratory tract. When present in high amounts, they can cause breathing difficulties as well as aggravate existing respiratory and cardiovascular diseases. PM2.5 is believed to be a greater health threat than PM10 since the smaller particles are more likely to be deposited deeper in the lungs. In addition, studies have shown that particles this small will penetrate into the indoor, home environment.

What Haze Has Got To Do With Particulates?

The particulates are emitted in the exhaust of vehicles and can also be found in haze.

HOW DO WE DETECT THEM INVISIBLE STUFF?

First, we collect them!
How?
Use: pre-weighed 47 mm Teflon Filter
1. Filter sample air at a constant through the Teflon Filter for 24 hours
2. Label the sample
* Make sure the used filter, now the sample, do not get contaminated by taking all neccesary precaution and following all proper handling of the sample. Disposable, powder-free gloves should be worn while handling filters both in the laboratory and in the field. Inspection of the individual filters should be conducted prior to use to ensure integrity of the filters.

3. Use a BAM (Beta Attenuation Monitor) or TEOM (Tapered Element Oscillating Microbalance)

BAM (Beta Attenuation Monitor)         TEOM (Tapered Element Oscillating Microbalance)        



     

1. The BAM or TEOM should be placed on a flat surface beneath the opening in the roof, and a sampling line should be installed based on the manufacturer's recommendations. Typically, sampling kits are available from the vendors to assist in the proper installation of these monitors. A PM2.5 cyclone should be installed on the end of the sampling line to provide appropriate size selectivity.
2. Set recording interval. After installation the BAMs or TEOMs should be configured to operate according to the manufacturer's recommendations and should be set to record data at least hourly. The sampling flow rates should be verified and other manufacturer's recommended diagnostics should be checked to ensure proper operation.

4. Gravimetric Analysis

1. Filters should be equilibrated in a temperature and humidity controlled laboratory, as specified in the Reference Method, for at least 24 hours prior to both pre-sample and post-sample weighing. 

Mean RH must be held between 30 and 40 percent, with a variability of not more than ±5 percent over 24 hours. Conditioning is permissible at a mean RH within ±5 percent RH of the mean ambient RH, but in no case less than 20 percent RH. Mean temperature should be held between 20 and 23o C, with a variability of not more than ±2o C over 24 hours. 

2. RH and temperature should be measured and recorded on a continuous basis during filter conditioning (either by a recording hygrothermograph or by electronic instruments).

An appropriate analytical balance is required for the measurement of filter weights. The balance should be calibrated prior to each weighing session, and a variety of calibration and QC checks should be conducted during each weighing session to assure the quality of the gravimetric measurements.

Picture References:
http://www.ohio.edu/airquality/capabilities/ambient.cfm
http://www.analysersindia.com/Beta-Ray-Attenuation-Air-Particulate-Concentration.html

                             

MAKING SURE WE ARE ALWAYS ACCURATE!

To obtain an accurate analysis of PM 2.5 particulate samples, there are the two things that need to be done.

1. Sample Calibration

Calibration of the PM2.5 samplers includes:

• Multi-point calibration of the sampling flow rate
• Calibrations of the internal temperature and pressure sensors.

Calibration of the aerosol monitors must be done prior to the analyzer being put into service and at least every 6 months thereafter. Additional calibrations should be conducted if any of the following conditions are met:

• Major maintenance activities are performed on the samplers
• Audits of the flow rate indicate differences of greater than 5% from the nominal flow rate or greater than 4% from the audit flow rate measurement
• Audits of the temperature sensor show differences exceeding 2o C
• Audits of the pressure sensor show differences exceeding 10 mm Hg

2. Aerosol Monitors/PM2.5 Samplers

For the continuous aerosol monitors and the PM2.5 samplers, a PE audit of the sample flow rate should be conducted at least quarterly. 

For the aerosol monitors, the PE audit should be conducted by measuring the sample flow at the inlet of the monitor using a calibrated flow measurement device with an appropriate measurement range. 

The audit should be conducted at ambient temperature for readings to be valid. An STP flow device can be used if the temperature is within 5° C of 25° C. 

Record the flow rate measured by the audit flow meter and the flow rate shown on the aerosol monitor display. If the audit flow meter is a volumetric standard, the measured flow rate may need to be converted to STP for comparison to the aerosol monitor. 

The flow rate of the aerosol monitors should agree with the audit flow rate within 4%, and within 5% of the nominal flow rate of the monitor. If the flow difference is greater than these tolerances, the operator's manual should be consulted for appropriate corrective action.

~~THE THINGS THAT CAN HAPPEN WHILE CONDUCTING OUR EXPERIMENT~~ aka Risk Assessment

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Activity: Collecting PM2.5 using FRM designated sampler


Things that can go wrong: 

          1. PM 2.5 is not filtered properly

          2. Hands getting injured by sampler



What will happen then?

          1. Cause respiratory and cardiovascular diseases if inhaled 


What can be done about it?

          1. Wear a N95 mask 




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Activity: Handling and Post-Sampling Shipment of Filter


Things that can go wrong: 

          1. Release of concentrated sample into the environment 


What will happen then? 

          1. Loss of sample

          2. Contamination of sample

          3. Cause harm to anyone who inhale the concentrated sample


What can be done about it:

          1. Seal tightly after placing samples into sterile containers and properly labeling the containers to prevent cross contamination.

          2. Work in a vacuumed environment



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Activity: Preparing Filters for Filtration of PM2.5 


Things that can go wrong:

          1. Filters are faulty


What will happen then:

          1. Release of concentrated sample into the environment 


What can be done about it:

          1. Prenumber filter with unique identification number and must meet the requirements of the Reference Method

          2. Wear disposable, powder-free gloves while handling filters both in the laboratory or in the field

          3. Inspect the filters each time before use






















Photo reference: http://www.colourbox.com/vector/cartoon-scientist-after-a-failed-experiment-vector-3452764?ver=b&utm_expid=22365066-12.LQUruejPQVuO46hzBZUNtA.2&utm_referrer=http%3A%2F%2Fwww.google.com%2Fimgres%3Fum%3D1%26sa%3DN%26hl%3Den%26biw%3D1280%26bih%3D737%26tbm%3Disch%26tbnid%3DBVxA3mmBep1XnM%3A%26imgrefurl%3Dhttp%3A%2F%2Fwww.colourbox.com%2Fvector%2Fcartoon-scientist-after-a-failed-experiment-vector-3452764%26docid%3Don-abJ2aHgO6iM%26imgurl%3Dhttp%3A%2F%2Fwww.colourbox.com%2Fpreview%2F3452764-784369-cartoon-scientist-after-a-failed-experiment.jpg%26w%3D262%26h%3D480%26ei%3DFgf2UaLbEsaHkwXQvYCgAg%26zoom%3D1%26ved%3D1t%3A3588%2Cr%3A23%2Cs%3A0%2Ci%3A163%26iact%3Drc%26page%3D2%26tbnh%3D177%26tbnw%3D97%26start%3D21%26ndsp%3D27%26tx%3D71%26ty%3D120

ALL IN ALL~

So now you know what are PM2.5 and PM10, and also their effects on humans. Despite the potential adverse health effects they might cause, there are still cases and times when a large amount of pm2.5 and pm10 can be found in the atmosphere, in the air we breathe. These particulates not only harm a certain country, nor a certain group of people. These particulates affects us humans and also other living things sharing this planet with us. These particulates affects everybody breathing in the same polluted air and this must stop. 

Governments should encourage their citizens to stop burning forests and be strict about emission of pollutants in vehicle exhaust. By cutting down on the primary causes for the presence of these particulates, the possibility of suffering from the adverse effects can be greatly reduced.

If everyone does their parts in keeping our air clean and safer for all organisms, everyone will benefit and we will all live in a better environment. 

Thank you for reading!~ 

-Shan Hui & Xenia :D 

Photo Reference: http://memegenerator.co/instance/38203489