The document provides an overview of air sampling methods and their significance in monitoring air quality, particularly regarding microbial contamination. It details various types of air pollutants, methods of air sampling, and objectives for ensuring atmospheric safety. The conclusion summarizes the five primary methods used to collect air pollutants based on their physical properties.

1. VIVEKANANDA ART’S AND SCIENCE
COLLEGE FOR WOMEN SANGAGIRI SALEM,
TAMILNADU
DEPARTMENT OF MICROBIOLOGY
SUBJECT:MICROBIAL QUALITY CONTROLAND TESTING
TOPIC :COLLECTION OF AIR SAMPLE AND ANALYSIS
SUBJECT INCHARGE:
Dr.V.BHARATHI,
ASSISTANT PROFESSOR,
DEPARTMENT OF MICROBIOLOGY,
VIVEKANANDHAARTS AND SCIENCE COLLEGE
FOR WOMEN, SANKAGIRI, SALEM,
TAMILNADU
SUBMITTED BY:
M.NIVEDITHA
II-MSC MICROBIOLOGY,
VIVEKANANDHAARTS AND SCIENCE
COLLEGE FOR WOMEN, SANKAGIRI, SALEM,
TAMILNADU

2. • SYNOPSIS
• INTRODUCTION
• AIR SAMPLING
• CONTAMINANT DEFINITION
• TYPES OF CONTAMINANT
• OBJECTIVE OF AIR SAMPLING
METHOD
• TYPES
• CALCULATION OF CONTAMINANT AIR
• METHOD OF AIR SAMPLING
• CONCLUSION

3. • Air can harvest many different kinds of microorganisms.
•
• Monitoring air quality is an essential criterion in quality control in
laboratories.
•
• Air quality monitoring can be done either by collecting air samples or
passively by settled plate methods.
•
• The microbial air sampler is a way to collect air samples for active air
quality monitoring.
INTRODUCTION

4. • Air sampling acts as the pollutants monitoring tool, which detects the
concentration of the particulate matter and microbial content in the
atmosphere to ensure the environmental safety.
• Air sampling technique involves trapping of the surrounding air by using
various approaches through the specialized devices or air samplers.
• Later, the collected air is tested for the presence of hazardous chemicals,
gases, dust, fibres and microbial content in the air.
• It is one of the ways, by using which we can continuously monitor the level
of air pollution.
• Air pollutants are the potentially damaging substances like dust, fibres,
harmful gases, microbes, spores etc.
• That can adversely affect the living system or environment.

5. AIR SAMPLING
Air pollution sampling: Related to analysis of pollutants in a given volume of air.
Air sampling: Capturing the contaminant from a known volume of air, measuring the
amount of contaminant captured, and expressing it as a concentration
The air is passed through a filter medium (normally a paper for solid & liquid
contaminants and a sorbent for gases).
The volume of air is measured against the amount of contaminant captured.
This gives the concentration, which is expressed either as milligrams per cubic metre
(mg/m3) or parts per million (ppm).
The volume of air is calculated by multiplying the flow rate through the filter medium
by the time in minutes.

6. TYPES OF CONTAMINANT
There are three types of contaminant according to their physical
properties:
Particulates
Vapours
Gases
Particulates can be further subdivided into five types:
Aerosols
Dusts
Fumes
Smokes
Mists

7. CONTAMINANT DEFINITIONS
Aerosol: Dispersion of solid particles of microscopic size in air.
Dust: Solid particulate capable of temporary suspension in air.
Fume: Solid particles produced by condensation from the gaseous phase.
Fumes are usually derived from the heating of a solid to its melting point and
the subsequent cooling of the gas produced.

8. Smoke: Particles resulting from the incomplete combustion of organic matter
consisting predominantly of carbon and oxides of carbon.
Mist: Dispersion in air of liquid droplets usually large enough to be seen by
the naked eye.
Vapour: Gaseous phase of a substance that usually exists as a liquid or solid at
normal room temperature and pressure.
Gas: A substance which does not normally exist as a liquid or solid at normal
room temperature and pressure.

9. OBJECTIVE OFAIR SAMPLING METHOD
• The air sampling methods were introduced based on the given objectives:
•
• To ensure atmospheric pollution saturation by employing passive and active
air sampling methods.
•
• It also checks to what extent the air is polluted in the residential areas,
workplaces, outdoors, industrial areas etc.
• To ensure the volume of particulate and microbial content in the atmosphere,
so that the healthfulness and the forecast effects of a proposed new source of
pollutants can be studied.
•
• It provides a useful tool for the evaluation of air pollution, which can
continuously monitor the concentration of the air pollutants

10. There are five kinds of air sampling methods, depending
upon the source of air pollutants.
TYPES
Emission sampling: This type of air sampling method checks the constituents,
flow rate and physical properties of the exhaust gases that are released from the
sources like industrial chimneys, home ventilation systems etc.
Ambient sampling: It is the air sampling method, which evaluates the level of
outdoor pollutants in many areas.
Industrial hygiene sampling: This air sampling technique quantifies the air
pollutants in the workplace to ensure employee safety.

11. Residential indoor sampling: This technique evaluates the healthfulness of
the indoor air.
Process sampling: It is an air sampling technique, which monitors the
presence of air pollutants during the production process of many industries.

12. The concentration of the contaminated air is calculated by first measuring
the volume of air sampled that is equal to the product of airflow rate and
the time run. Here, the formula will be expressed as:
The volume of air sampled = Airflow rate X Time
CALCULATION OF CONTAMINATED AIR
We can get the value for the concentration of contaminated air by
dividing the amount of contaminant collected to the volume of air
sampled. Here, the formula will be expressed as:
The concentration of the contaminant = Amount of contaminant
collected / Volume of air sampled

13. METHODS OF AIR SAMPLING
Five techniques are commonly used to check the concentration of the atmospheric pollutants
like particulates, vapour and gaseous matter.
Depending upon a type of air pollutant that you want to measure, the air sampling

14. Whole air sampling: It measures the presence of volatile compounds, reduced sulphur
molecules and gaseous pollutants in the atmosphere. In this type, the air is actively
collected in Tedlar bags by using a pump and passively collected through a diffusion
method without using a sampling pump.
Active air sampling: It quantifies the volatile and semi-volatile compounds that are
present in the atmosphere. Here, the pollutants are collected inside a tube filled with solid
sorbent material, and the air is trapped into the glass-tube by using a sampling pump.

15. Passive air sampling: It measures the atmospheric pollutants mainly
microorganisms, and like active air sampling, it also makes the use of solid sorbent
material to trap the contaminants. However, it does not use any sampling pump to
collect the air. It depends on the principle of diffusion method.
Filter air sampling: It evaluates the concentration of the gaseous or vapour
pollutants that are present in the atmosphere. This method uses filter cassettes to trap
the contaminants. Then, the pollutants that are saturated over the filter cassette will
chemically react with the filter media and turned into a stabilized derivative. It makes
the use of different filter media.

16. Impinger air sampling: Here, the air is bubbled into the reactive liquid solution
and allowed to react with it. Impinger air sampling method is widely used
during high humidity and high temperature. It primarily evaluates the
contaminants of the stationary sources and analyses the air sampled through
colourimetric methods.

17. Conclusion
Therefore, we can conclude that there are commonly five methods of air sampling,
which use different criteria to collect the air pollutants of a specific type. The
pollutants in the atmosphere are categorized into the particulate, vapour and
gaseous matter based on the physical properties. Thus, different types of air
samplers are designed to collect the various forms of air pollutants as well as it
helps us to monitor the level of air pollution in many different areas.