Monitoring and control of particulate matter in indoor air: A review
Anshu Gupta1* and Meena Bhandari2
JANS
1Department of Applied Sciences, World Institute of Technology, Sohna, Gurgaon (Haryana), INDIA
2 Department of Applied Sciences, PDM College of Engineering for Women, Bahadurgarh (Haryana), INDIA *
Abstract: The review discusses the sources and concentrations of particulate matter in different microenvironments, their effect on human health, monitoring and their possible control measures particularly in office and residential buildings. Effect of various ventilation strategies on particulate concentration in air has been discussed. The calculations suggest that if the outdoor particle concentration is not more than 5-10 times the indoor particle generation rate, ventilation could be a very effective tool to control the indoor particle concentration. For coarse particles the choice of ventilation strategy is not very crucial, but for fine particulate slow rate of ventilation is more effective.
Keywords: Particulate matter, Indoor air, Air speed, Ventilation, Fine particle
F:\Chakresh\JUNE_I~1.201\27_MS-
INTRODUCTION
It’s true that all of us face a variety of risks to our health due to air pollution as there is a variety of pollutants present in lower atmospheric zone, which may cause mild to severe human health hazards. Major sources of air pollutants are mainly coal combustion, diesel engines, vehicular emissions, construction, industrial smokes etc. Most of the people spend nearly 80% of their time indoors and often the air within homes, offices, and other buildings may be more seriously polluted than the outdoor air. Hence polluted indoor air presents higher risk to human health and deserves attention. Volatile organic compounds and Radon (Bhandari and Gupta, 2009, 2010) are the potential indoor air pollutants arising from sources within the building; whereas other pollutants like combustion products (CO, SO2, NO2, CO2, environment tobacco smoke, fine particles), ozone etc. arise from both indoor and outdoor sources. Small particles are among the pollutants that represent one of the biggest health hazards (CAI, 2004). Particulate matter (PM) is an air pollutant consisting of a mixture of particles that can be solid, liquid or both, are suspended in the air and represent a complex mixture of organic and inorganic substances. These particles vary in size, composition and origin. The particle size for PM can vary from 0.005 μm to 100 μm in diameter. All ambient PM are referred to as total suspended particulate matter (TSP). PM less than 10μm in diameter is referred to as PM10, that less than 2.5 μm in diameter as PM2.5 and so on. Particles less than 0.1 μm are called ultrafine particles (UFP). PM10 are inhalable and are referred to as respirable particulate matter (RPM). This work presents a discussion of various sources of
PM in indoor environment and its effects on human health along with a review of various monitoring studies. The effects of ventilation on deposition rates and airborne concentrations of various particle sizes are critically discussed.
PARTICULATE SOURCES
Outdoor sources: The outdoor sources of particles are coal combustion, diesel engines, vehicular emissions, windblown dust, agriculture, and construction and industrial activities such as mechanical grinding etc. PM in urban areas is mainly made up of metals, organic compounds, biological material, secondary PM (formed due to reactions of various atmospheric gases) and pure or elemental carbon. TSP may also contain fungal spores and pollen which cause allergic diseases. A major fraction of diesel particles are PM1 on which many organic compounds like carcinogenic polycyclic and nitro- polycyclic hydrocarbons are adsorbed (Kittelson, 1998). Toxic elements like Arsenic contribute appreciably to the airborne particulate matter (Deb et al., 2002). Particulates, after being emitted into the atmosphere from various sources, remain suspended in the urban atmosphere for an appreciable time. Subsequently they are deposited on various near ground surfaces and on street sediments. These PM enter the indoors through various passages and pollute the indoor air too.
Indoor sources: Indoor particle sources such as tobacco smoke, cleaning, cooking etc. have an appreciable effect on indoor particle concentrations and personal exposure. Cooking and heating with solid fuels such as dung, wood, agricultural residues or coal is probably the largest source of indoor air pollution globally and nearly half the world
Monitoring_and_control_of_particulate_maMonitoring and control of particulate matter in indoor air: A review