Air pollution has become one of the most environmental concerns in urban areas, especially in view of the adverse health effects associated with ambient atmospheric particles (Pope, 2000). In the urban environment, particulate matter may be generated among others by automotive vehicles (road dust), manufacturing processes, fossil fuel combustion, biomass burning and through photochemical reactions involving precursors gases. The identification of various sources of airborne particulate matter (PM) and the assessment of their impact on the aerosol composition are some of the major goals of contemporary atmospheric research.Among the various species present in the particulate matter, are toxic metals such as lead, zinc, copper etc, and on elements of great diffusion in the environment (IPCC, 2007). 

Morogoro is the only municipality reporting to the World Health Organization and has high levels of particulate matter contributing to poor air quality in Tanzania.

Outdoor air pollution is a mix of chemicals, particulate matter, and biological materials that react with each other to form tiny hazardous particles. It contributes to breathing problems, chronic diseases, increased hospitalization, and premature mortality.

The concentration of particulate matter (PM) is a key air quality indicator since it is the most common air pollutant that affects short term and long term health. Two sizes of particulate matter are used to analyze air quality fine particles with a diameter of less than 2.5 µm or PM2.5 and coarse particles with a diameter of less than 10 µm or PM10. PM2.5 particles are more concerning because their small size allows them to travel deeper into the cardiopulmonary system.

The World Health Organization?s air quality guidelines recommend that the annual mean concentrations of PM2.5 should not exceed 10 µm/m3 and 20 µm/m3 for PM10.

Volcanoes erupting volcanoes eject large quantities of particulates including volcanic ash and gases into the atmosphere, volcanic eruptions have been directly associated with climate change since studies began

Dust storms strong winds can pick up vast clouds of dust which in turn are dispersed into the atmosphere and can take years to return to the surface

Forest and grassland fires wood and grass smoke contain a complex mixture of particulates such as carbon monoxide and hydrogen cyanide, which are lifted into the air and rest in the atmosphere

Living vegetation vegetation that emits particles to the air, such as isoprene, methanol and spores. These particles can be carried upwards by the wind and add to the level of particulates in the atmosphere

Sea spray due to the large amounts of plastics that have broken down to Nano scale, particles and can be found in ocean water all over the world. These hazardous particles can be thrown into the air by strong sea spray

Tornado?s and hurricanes these powerful weather systems can pick up large quantities of resting dust and pollutants just from the countryside, let alone when they pass through cities and encounter cement dust and higher levels of overall pollutants

Coal Combustion coal burning is still used in the majority of countries to generate heat and supplying energy, the burning of coal directly increases the amount of carbon monoxide and other hazardous particles into the atmosphere

Oil Combustion used for fueling vehicles, which in turn emit a large number of exhaust fumes containing hazardous particulates all over the globe, in huge quantities. Due to the large amounts if these pollutants in cities, countless deaths are caused by particulates

Wood combustion the burning of wood is a wide scale cause of particulates, used for many purposes such as heating and generating power, the combustion process sends many toxic cocktails of pollutants into the atmosphere such as soot

Construction cement dust is a large portion of overall global pollutants, because of the dust?s small particle size, it can hang around in the air for quite some time. The use of vehicles in the construction industry and other known pollutants makes the construction industries in dire need of reforming

Demolition huge amounts of dust are thrown into the air during even the smallest demolition project, these particles are picked up into the wind, and again due to the small size of said particles, they can stay airborne for a very long time

Road dust roads are covered in microscopic dust and pollutants which are sent airborne by the air pressure changes and wind caused when a car uses a road, this happens all over the planet

Power plants that burn fossil fuels for energy and even nuclear plants disperse particulates on a huge scale, vast plumes of smoke will be found at most power plants, dispersing hundreds of cubic feet of pollutants every hour

Industrial manufacturing plastics and other materials which create toxic fumes are dispersed into the oceans, air and land. Which in turn adds to the huge amount of man-made pollutants

Agricultural pesticides and other volatile chemicals are sent into the air via sprayers and liquid jets. Again the agricultural industries use a large number of vehicles running on fuels such as petrol and diesel, which all attribute to the level of air pollution.

Livestock the livestock industry creates a huge amount of particulates which are dispersed into the air, ground and oceans. Even the animals themselves have been found to disperse great quantities of methane into the atmosphere

Deforestation felling trees for various industries impacts the rate at which trees would naturally produce carbon dioxide worldwide, however recent trends of replanting and harvesting cycles have reduced this.

Poor condition of anti-pollution technology in recent years the world has made a strong effort to combat the high levels of lethal pollutants, but unfortunately, some countries have produced very minimal reductions in annual pollution output

Tobacco smoke hundreds of toxic chemicals are present in tobacco smoke, and due to the millions of smokers worldwide, this leads to further pollution

What can we do to reduce particulate matter

SOURCES

http://www.conserve-energy-future.com/causes-and-effects-of-particulate-matter.php

 https://www.epa.gov/