Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere. Household combustion devices, motor vehicles, industrial facilities and forest fires are common sources of air pollution. Pollutants of major public health concern include particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide. Outdoor and indoor air pollution cause respiratory and other diseases and is an important source of morbidity and mortality. 

Air pollution kills an estimated seven million people worldwide every year. WHO data shows that almost all of the global population (99%) breathe air that exceeds WHO guideline limits containing high levels of pollutants, with low- and middle-income countries suffering from the highest exposures. WHO is supporting countries to address air pollution. 

Primary air pollutants, which are pollutants that cover 90% of the total air pollutants, can be divided into five groups as follows:

a)       Carbon monoxide (CO)

b)      Nitrogen oxides (NOx)

c)       Hydrocarbons (HC)

d)      Sulfur Dioxide (SOx)

e)   Particles

The main source of pollution comes from transportation, 60% of the pollutants produced consist of carbon monoxide and about 15% hydrocarbons.

The toxicity of the five groups of pollutants is different and Table 1. Below presents the relative toxicity of each group of pollutants. It turns out that the most dangerous pollutants to health are particles, followed by NOx, SOx, Hydrocarbons and the lowest toxicity is carbon monoxide.

Table 1. Concentration of Pollutants in the air

Pollution	Tolerance Level		Relative toxicity
	ppm	μg/m3
Co	32	40.00	1,0
HC		19.300	2,07
SOx	0.50	1.430	28
NOx	0.25	514	78
Particulate		375	107

Bobcock (1971)

 

Types and Properties of Particles

Air pollution due to these particles is an environmental problem that needs attention. various types of particulate pollutants and their forms in the air can be seen in Table 2. below:

Table 2. Forms of Air Polluting Particles

Component	Configuration	Component	Configuration
Carbon		Titanium	TiO2
Iron	Fe2O3, Fe3O4	Carbonate	CO3
Magnesium	MgO	Silicone	SiO2
Calisium	CaO	Phospore	P2O5
Aluminum	Al2O3	Potassium	K2O
Sulfur	SO2	Sodium	Na2O

 

An important physical property of the particle is its size, which ranges from 0.0002 microns in diameter to about 500 microns. In this range the particles have a lifespan in suspended form in the air between a few seconds to several months. The age of the particles is influenced by the deposition rate which is determined from the size and density of the particles and the air flow

Another important particle property is its ability to act as a site for adsorption (physical absorption) or chemisorption (adsorption accompanied by chemical interactions). This property is a function of the surface area which is generally wide for most particles.

The Effect of Particles on the Environment

1.   The effect of particles on plants is mainly in the form of dust, where the dust when combined with water vapor or rainwater will form a thick crust on the leaf surface and cannot be washed off with rainwater unless rubbed. The crust will interfere with the photosynthesis process in plants because it blocks the entry of sunlight and prevents the exchange of CO2 with the atmosphere, resulting in disrupted plant growth. Another danger posed by particle collection on plants is the possibility that the particles contain chemical components that are harmful to the animals that eat the plants.

2.   The effect of particles on humans will occur in the respiratory system. The factor that affects the respiratory system is particle size, because particle size determines how far the particles penetrate into the respiratory system. Particles that have a diameter greater than 5.0 microns will stop and collect mainly in the nose and throat. Particles measuring 0.5 – 5.0 microns can collect in the lungs to the bronchioles and only a small part reaches the alveoli. Particles less than 0.5 microns can reach and stay in the alveoli.

In Table 3 below, metal particles that are harmful to health.

Table 3. List of harmful particles

Source	Element	Effect on Health
Nickel	Diesel oil, residual oil, coal, tobacco smoke, chemicals and catalysts, steel and other metals.	Lung cancer (as carbonyl)
Beryllium	Rock, nuclear energy industry	Acute poisoning, and chronic, cancer
Boron	Coal, Cleaning agents, medicine, glass industry and other industries.	Non-toxic except in the form of boron.
Germanium	Charcoal	Mild poisoning
Arsenic	Charcoal, petroleum, detergents, pesticides	Possibility of cancer
Selenium	Charcoal, sulfur	Tartar, carcinogenic in rats, important in mammals at low doses.
Tritium	Charcoal, petroleum	Carcinogenic to rats on prolonged contact
Mercury	Charcoal, electric battery, other industries.	Nerve damage and death
Vanadium	Petroleum, chemicals and catalysts, steel and other metals	Harmless at present concentrations.
Cadmium	Charcoal, zinc smelting, water pipes, tobacco smoke	Heart disease and hypertension in humans interfere with the metabolism of zinc and copper.
Antimony	Industrial	Shortens the lifespan of mice
Lead	Car exhaust (from gasoline), paint (before 1948)	Brain damage, convulsions, behavioral disorders, death

 

Efforts to control air pollution

1. Research and monitoring, the management of air pollution is to conduct an assessment/identification of the types of sources, models and patterns of distribution and their effects/impacts. Sources of air pollution, which are often known as emission sources, are places where air pollution begins to be emitted into the air. The distribution model and pattern can be estimated through a study of the physical condition of the source (chimney height, shape, exhaust port and emission magnitude), initial local air quality (background), meteorological and topographical conditions. The study of the impact of air pollution is carried out on human, animal and plant health, materials, aesthetics and on the possibility of local (local) and regional climate change.

2.  Knowing and communicating about the importance of air pollution management by taking into account the social conditions of the environment, which are related to demography, socio-economic conditions, socio-cultural and psychological as well as economic considerations. There is also the need for political support, both in terms of laws, regulations, policies and administration to protect the implementation of monitoring, control and supervision.

3. Measurement in the field. To carry out field measurements in the context of monitoring air pollution, it is necessary to choose the right method according to the capabilities of the observation network, the placement of the equipment needed to take samples and the need for equipment and experts for analysis purposes.

 

You've probably come across the terms PM2.5 and PM10 when you read about air quality--a topic that's becoming more common with changes in Earth's climate-- but do you know what they mean?

PM2.5 and PM10 refer to particle size - terms for the mixture of solid particles and liquid droplets found in air.

It is possible to see PM10 particles, which are 10 microns in diameter, like specks of dust floating in sunlight. However, the most dangerous particles are invisible to the naked eye unless they accumulate in such high volumes that overall visibility is reduced, such as haze caused by forest fire smoke. These include PM2.5, the smallest reported measure of PM, and the main pollutant of concern. Exposure to PM2.5 particles in the air can cause phlegm, wheezing, persistent coughing and difficulty breathing.

Air quality measurement tool manufactured at Met One Instruments, Inc. used every day to detect and report levels of harmful particulates in outdoor and indoor spaces where we frequent and live. Local officials, regulatory agencies, and government agencies can use this data to establish plans and policies to protect local communities and the wider population.

To learn more about our instruments and what we do, visit our website https://eramitra.com/

or https://metone.com/