Chapter 1 - INTRODUCTION

Air pollution is the contamination of air by the discharge of harmful substances. The atmosphere

is a complex, natural, dynamic gaseous system that is essential to support life on planet earth.

While polluted food or water can be avoided, the air is inevitably breathed in any environment in

which people stay or through which they pass. The problem is encountered not only in large and

industrial areas, but also in different indoor environments - which in addition to penetration of

outdoor pollution - contain pollutants originating from the building and furnishing materials,

heating, cooking, cleaning, smoking and other human activities (Fugas et ai., 1999).

The quality of air in cities around the world and in particular in the developing countries is

getting worse as the population, traffic, industrialization and energy use increases. The role of

anthropogenic processes as the source of atmospheric pollution has been increasing gradually

with the onset of the industrial revolution (Kim et ai., 2002). In India, air pollution has become a

great topic of debate at all levels because of the enhanced anthropogenic activities (Goyal and

Sidhartha, 2002).

Outdoor air pollution has immediate implications for indoor environment as well, since the air in

both naturally ventilated and mechanically ventilated buildings is replenished to varying degrees

with ambient air, which may, or may not be filtered or otherwise conditioned before coming

indoors.

Several studies have demonstrated that ambient air may have significant impact on the indoor

environment (Yacom, 1882; Daisy et aI., Perry and Gee, 1994). The indoor air quality, which is

essentially governed by aerosol particles and gaseous pollutants, is of serious concern from the

health prospective. Indoor particles arise from a variety of indoor and outdoor sources. These

include soil, dust, combustion soots, pollen, fungal spores, moulds, bacteria, insect fragments,

animal dung, cooking aerosols, etc (EPA 1987). In general the particles can be directly added to

the indoor environment by any of the following processes:

i) re-entrainment of existing particles with activities such as vaccum cleaning and

dusting

ii) emission from cooking, cigarette smoking, stove leak and

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iii) being transported from outdoor via leakage through the wall, windows, door or the

ventilation system( Kamens et aI., 1991).

Till recently, the health effects of indoor air pollution had received relatively little attention from

the scientific community. Numerous studies suggest that members of the public perceive the risk

from poor outdoor air quality as being substantially higher than those from indoor contamination

(LHEA, 1999). However, indoor air quality at home should be under close scrutiny, as people

spend more than 13 hours at home daily (Chau et aI, 2002). It is estimated that on average

Delhites spend 68%of their time at home and the rest outdoors (Srivastava et aI, 2003).

[1.1] Pollutants

Substances not naturally found in the air, or in greater concentrations or in unusual locations are

referred to as pollutants. Pollutants can be classified as primary or secondary. Primary pollutants

are substances directly produced by a process such as ash from a volcanic eruption, or carbon

monoxide from a motor exhaust. Major primary pollutants caused by human activity are

Suspended Particulate matter (SPM), Sulphur oxides (SOx), especially sulphur dioxide, Nitrogen

oxides (NOx), especially nitrogen dioxide, Carbon monoxide (CO), Volatile organic compounds

(VOCs) whereas secondary pollutants includes, Particulate matter from gaseous primary

pollutants and compounds in photochemical smog, Ground level ozone (03) and Peroxy acetyl

nitrate (PAN). Gases such as carbon dioxide which contribute to global warming have recently

gained recognition as pollutants by some scientists. Others recognize the gas as being essential to

life, and hence being incapable of being classed as a pollutant.

Air pollution can damage environment and property. It has thinned the ozone layer above the

earth. Trees, lakes and animals have been harmed by air pollution. It also damages buildings,

monuments, statues and results in haze, which reduces visibility. Air pollution can cause health

hazards by affecting various people in different ways, with both short term and long term effects.

Young children and elderly people are more sensitive to pollutants than others. Air pollution also

affects people with heart and lung disease and with asthma. The duration of exposure and

concentration of chemicals inhaled is directly proportional to the extent of harm caused. While

symptoms such as headache, nausea and allergic reactions are known as "short term health

hazards", prolonged smoking of cigarettes and continued exposure to air pollution are

2

categorized as "long term health hazards". World wide air pollution is responsible for a large

number of deaths and cases of respiratory diseases. It is estimated that 3 million premature

deaths occur every year due to indoor and outdoor air pollution (Lee et aI., 1997).

[1.1.1] Atmospheric Aerosols (Particulate matter):

Aerosol is small solid or liquid particles suspended ill gaseous medium (Reist, 1987).

Atmospheric aerosols consist of particles ?f both natural and anthropogenic origin. The aerosol

contaminants with gaseous pollutant have a potential toxicological significance and some of

them produce mutagenic and carcinogenic effects (Goldsmith, 1980; Schuetzle et aI., 1980; Ross

et aI., 1987).

Atmospheric aerosols affect many atmospheric processes such as cloud formation, visibility

variation and solar radiation transfer (Bodhaine, 1983; Pueshel et aI., 1986 and Shaw, 1987) and

play a major role in acidification of clouds, rain and fog. Both the gaseous and particullate

components of atmospheric aerosol contribute to deterioration of air quality (Parmar et aI., I

2001).

[1.1.2] Size distribution of Atmospheric aerosols

The single most important feature of aerosols is the size of particles. The extent to which

airborne particles penetrate the human respiratory system is determined mainly by their size,

with adverse health effects resulting from the presence of toxic substance (Balachandran et aI.,

2000).

Knowledge of size distribution of atmospheric aerosols is important in understanding the effects

on human health. For instance, the degree of respiratory penetration and retention is a direct

function of aerodynamic diameter of the particles. Particle larger than 30~m in aerodynamic

diameter have low probability of entering the nasal passage. (figl) shows the American

Conference of Governmental Industrial Hygienist's standards for particle sampling to

approximate the deposition in various regions of the respiratory tract (Phalen et aI., 1986; Owen

et aI., 1992). Deposition of large particles (5-10 ~m) is favoured by rapid and sharp change of

passage of the nose and pharyngeal region. Particles with diameter 1-5 ~m get deposited in the

tracheal bronchiolar region, where air velocity and directional change decreases. The smaller

particles « l~m) are deposited in alveolar walls mostly by diffusion due to decrease in velocity

3

to virtually zero (Owen et ai., 1992; McComac 1971, and Infante & Acosta, 1991). Elements

associated with natural sources such as soil and ocean are found to be present in the coarse

particles while elements emitted from anthropogenic sources are associated with fine particles

(Seinfeld, 1989.

°0 2 4 6 & \0. \2 14 16 181 AtrodYnarnlc ot.metor'fpnI)

Fig. I. The three aerosol mass fractions recommended for particle size selective sampling

Many epidemiological studies have revealed a strong link between increasing ambient

concentrations of particulate matter and increased concentrations of mortality and morbidity

(Dockery and Pope 1994; Schwartz et ai., 1996; Samara et ai., 2005). The knowledge of heavy

metals and PAHs in aerosol is vital in evaluating their impact on health and ecosystems (Park et

aI., 2006; Deng et aI., 2006).

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[1.2] Heavy Metals

Heavy metals associated with Suspended particulate matter (SPM) have been shown to cause

increased lung or cardiopulmonary diseases caused by particulate air pollutant exposure (Costa

and Dreher, 1997., Fernandez et aI., 2001; Khillare et aI., 2002; Samara et aI., 2005). A toxic

metal exerts its negative effects on human organs by either stimulating the normal metabolic

function of the organ, or depressing it. While small amounts of many toxic agents act as

stimulants to the function of an organ, large doses obstruct or destroy its activity (George, 1973).

A summary of the toxic effects of different metals is given in table 1.1

Table 1.1. Toxic effects of various metals

Metal

Mg

Magnesium salts

Calcium salts

Toxicity

Toxicity is usually acute

Not generally toxic when given

orally.

Non toxic except at very high

doses; toxicity depends upon the

nature of the calcium salt and the

mode of

administration.

Metallic Cu and its Inhalation of dusts and fumes

salts Can be toxic

5

Symptoms

Nausea, malaise, muscular

weakness and paralysis, general

depression, and paralysis of the

respiratory, cardiovascular and.

central nervous system

Congestion of nasal mucous

membrane, ulceration and

perforation of the nasal septum

and pharyngeal congestion

Cadmium

Lead

Mn

Toxic to all systems studied in

man and animals,

Very toxic. In adults 40 to 50

percent of lead particles

deposited in the lung is absorbed

in the blood

Persistent choking, coughing,

leading to bronchitis: damaging

to renal tissues and olfactory

nervous subsequently occurs

Mental retardation, diminished

intelligence, nervousness,

general fatigue, kidney damage,

anaemia, damage of central

nervous system and death

least toxic of the essential metals Inhalation of Mn compounds in

aerosols or fine dusts produces

.metal fume fever. Chronic

inhalation of manganese oxides

(dust particles of about 3 JIm in

size) for a few months causes

pulmonary pneumonitis.

Inhalation for over six months

results in manganism., a disease

of the central nervous system

involving psychic and

neurological disorders

6

Iron

Nickel

Cr

Mostly non toxic

Relatively nontoxic, ranking

Long term inhalation of iron

results in a mottling of the lungs

called siderosis, iron oxide

penetrates the bronchial and

Alveolar walls and enters in to

lung tissue without extensive

damage to the ciliary's or

mucous barrier.

Inhalation of nickel causes

with iron, copper and chromium. respiratory tract neoplasia and

myocardial infection

Hexavalent chromium

(chromate) is more toxic than

trivalent chromium.

The injury of nasal mucous

caused by inhalation of Cr6+

compound includes

inflammation and ulceration, and

the larynx is also affected. This

is a primary carcinogen, but does

not induce cancer in other areas

of the body. Trivalent Cr is

transformed in to an active

carcinogen during a latent period

(Venugopal, 1978; Waldbott, 1973; Ewers and Schilipkotes, 1984; Yaaqub et al., 1991)

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[1.3] Polycyclic Aromatic Hydrocarbons (PAHs)

Among the urban air pollutants, Polycyclic Aromatic Hydrocarbons (PAHs) are a large group of

over 100 different chemical compounds with 2-7 aromatic rings. Recently PAHs in the

environment have become a serious concern worldwide since the exposure to high concentration

has been linked to carcinogenic risk or co-carcinogen risk. More recently, concern has turned to

their potential effects on reproduction as well as their ability to depress the immune system.

PAHs have a ubiquitous presence in the atmosphere and are one of the first atmospheric

pollutants to be identified as suspected carcinogenic and mutagenic in nature (Harrison et aI.,

1996; Caricchia et aI., 1999; Panther et aI., 1999; Omar et aI., 2002; Zhou et aI., 2005).

[1.3.1] Sources of PAHs:

P AHs in the environment are apparently increased due to incomplete combustion of coal, oil and

gas (Richer et aI., 2000; WHO, 1987). In the urban atmosphere, the major sources of PAHs

include vehicular traffic, industrial process domestic heating system (Benner and Wise, 1989)

and waste incineration. (Jones, 1994; Omar et aI., 2002; Panther et aI.,1999; Mastral et aI., 2000;

Fang et aI., 2004). P AHs are also produced in the combustion processes and burning of many

organic materials due to chemical recombination of organic radical intermediates produced by

cracking of larger organic molecules. Hence, burning of garbage and other organic substances

leads to P AH production. The residual burning of wood is an important source of P AHs in the

atmosphere (US Public Health Service, 1994).

[1.3.2] Properties of PAHs:

P AHs are present in both vapour and particle phase in the atmosphere, depending on the

volatility of the PAH species. Higher condense molecules with four or more rings are particle

bound, whereas smaller PAHs mainly remain in the gas phase (Westerholm et aI., 1988; Beak et

aI., 1991). Most PAHs do not dissolve easily in water, although they are commonly seen in

miniscule quantities in waste water and effluents from various industrial and municipal activities.

However, such miniscule levels can have an impact on biological system with long term

exposure. P AHs under chemical and photochemical reactions probably result in more toxic

8

compounds than the parent compound. Most PAHs are likely to react with air, sunlight and other

compounds (e.g. 0 3, NOx, and S02) in the atmosphere to form PAH derivatives as nitro PAHs

and oxygenated derivatives. The behaviour of PAHs in the environment is greatly affected by

their source of origin.

Table 1.2: Physical and Chemical properties of P AHs

Anthracene: C l4H IO

Boiling point °c : 342

Melting point OC: 216.4

CO) Benzo(b )f1uoranthene: C20H 12

Boiling point °c : 481

Melting point OC: 168.3.

Phenanthrene: CI4HIO

Boiling point °C: 340

Melting point OC: 100.5

AcenaphthaJene: CI2Hg

Boiling point °C: 280

Melting point °C: 93

Chrysene: C1gH12

Boiling point °C: 448

Melting point °C: 253.8

Benzo(k)f1uoranthene: C2oH12

Boiling point DC: 480

Melting point DC: 215.7

~Yr-~J ~~:/,<.)Lf \~\

~.

Benzo(a)anthracene: C1gH12

Boiling point °C : 400

Melting point OC: 160.7.

Pyrene: CI6HIO

Boiling point °C: 150.4

Melting point °C: 393

Indeno(1,2,3cd)pyrene:C22HI2

Boiling point °C: 536

Melting point °C: 163.6

Fluorene: C13H10

Boiling point °C: 295

Melting point °C: 116

9

. Benzo(j)f1uoranthene: C2oHI2

Boiling point °C : 480

Melting point OC: 165

Benzo(a)pyrene: C2oHI2

Boiling point °C : 496

Melting point OC: 178.1

Fluoranthene: C I6HIO

Boiling point °C: 375

Melting point °C: 108.8

r:::8 :::J

Dibenz(a,h) anthracene

C24HI4

Boiling point °C: 524

Melting point °C: 266.6

Benzo(ghi)Perylene: C22HI2

Boiling point °C: 277

Melting point °C: 116

[1.3.3] Exposure and Adsorption in Humans:

Human exposure to P AH can occur through several environmental pathways due to the variety in

their sources. PAHs can enter the body through the lungs when the air containing them is inhaled

(Tornquist et aI., 1985; Sun J.D et aI., 1984). Drinking water, food, soil, or dust particles that

contain PAHs are the other routes for these chemicals to enter into the body. Under normal

conditions of environmental exposure, P AHs can enter the body if the skin comes into contact

with soil that contains high levels of PAHs or with heavy oils, or with other products (such as

coal tar, roofing tar) that contain PAHs. The rate of PAHs entering the body increases when they

are present in oily mixtures. They tend to be stored mostly in the kidney, liver, and fat, with

smaller amounts in the spleen, adrenalin glands and ovaries (Menzi et aI., 1992)

[1.3.4] Toxicity and Health Effects:

Although the health effects of the individual PAHs are not exactly alike, individual PAHs vary in

their toxicity and carcinogenic property. Mutagenic and carcinogenic properties of PAHs are

linked with their physical properties. The following fifteen P AHs are considered as a group of

priority pollutants by the US Environmental Protection Agency.

US Environmental Protection Agency (EPA) has determined benzo[a] anthracene,

benzo[b]fluoranthene, benzo[j]fluoranthene, benzo[k]fluoranthene, benzo[a] pyrene, dibenz[a,b]

anthracene, chrycene, indeno [1,2,3 ed] pyrene as probable human carcinogens, and

acenaphthalene, anthracene, benzo(ghi) pyrene, flouranthene, fluorine, phenanthrene, while

pyrene are not classified as human carcinogens (Hurtung et al,1990). PAHs act as genotoxic

carcinogens. Both vapour as well as particle bound PAHs, irrespective of their individual

physical properties, when inhaled gain absorption into the body and are capable of damaging

genetic material and thereby initiating development of cancer.

A number of studies on heavy metals and PAHs associated with suspended particulate matter

have been carried out in different parts of the world. PM IO samples of Brisbane area were

collected and fractionated into six size fractions by Chan et aI., (2000). They observed that the

42% aerosol mass were dominant in > 2.7 !lm size fraction aerosol with < 0.5 !lm size fraction

also contributing to 41 % of the aerosol mass. They also found that, the soil and sea salt factors

10

contribute more than 80% of the aerosol mass (> 2. 7 ~m) while the organics and vehicular

exhaust factors explain the remaining aerosol mass in the <0.61 Ilm fractions.

Geller et aI, (2002) measured the fine (0-2.5~m) and coarse (2.5-1O~m) particulate

concentrations in indoor and outdoor environment of 13 residential areas during the winter and

spring of 2000 in South California. Good correlation was observed between indoor and outdoor

trace element concentration in the fine particulate matter mode. Coarse particulate matter

concentration based on mass, trace elements and metals showed similar trends, with ratio of

indoor to outdoor concentration varying from about 50%-70%.

Wang et aI, (2002) studied the pH and conductivity of water soluble matter of PM 10 and PM2.S in

Nanjing, China. They observed that 70% of suspended particles are of sizes that can be deposit in

the respiratory tract below the trachea, whereas about 22% of the mass is respirable and will

reach the alveoli.

Marcazzan et ai, (2001 ) identified four major sources of PMlO and PM2.5 composition: vehicle

exhaust emissions, resuspended crustal dust, secondary sulphates and industrial emission in the

ambient air of Milan, Italy. They also suggested the existence of possible background

components with non local origin.

Breed et aI, (2002) carried out the study on possible source of PMIO by their morphology and

chemical composition in Prince George (Canada). The result showed that rounded, spherical and

oval shaped particulates were diagnostic for combustion sources, while irregular shaped

particulates were dominant in all samples including road dust. Combustion sources contributed

to < 2.51lm fraction while geological material is responsible for particulate with diameter 3-4

Ilm.

Measurement of PMO.OS6, PMO.IO, PMO.18, PM0.32, PM0.56, PMl.8 and PM2.5 were carried out at

Pittsburg by Cabada et aI, (2004). They found variations in concentration of different size

fraction particles and also observed higher concentrations during summer and lower in winter.

Ning et aI, (1996) measured the size distribution and elemental composition of aerosol in urban

areas of Northern China. They found that the fine dust (70%) is the major aerial contamination in

11

urban aerosol and the spectra of aerosol particles in the range 0.5-15.0/lm are all unimodal in

structure. The concentration of some elements such as Fe, Ti, Zn and Pb decreases during

summer as compared to winter.

Characteristics of indoor loutdoor PM2.5 and elemental component in generic urban, roadside and

industrial plant of Ghuangzhou city, China were studied by Hong et aI, 2000. They observed

higher concentrations of PM2.5 and elemental component in roadside area and in industrial areas

than those in generic urban area. A good correlation of PM2.5 and elemental concentrations was

found between indoor and outdoor concentrations.

A study on relationship between personal indoor and outdoor exposure to trace element in PM 2.5

was done by Adgate et aI., (2007). Their result indicated that community and seasons are

important covariates for developing long term trace elements exposure estimation and that

personal exposure to trace element in PM 2.5.

Lunden et aI, (2003) studied the transformation of outdoor ammonium nitrate aerosol in the

indoor environment of California. Their study results showed that indoor exposure to outdoor

ammonium nitrate in central valley of California are small and suggested that exposure

assessment based on total particle mass measured outdoor may obscure the actual causal

relationship for indoor exposure to particles of outdoor origin.

Hussein et aI, (2005) measured the aerosol particle number size distribution in both indoor and

outdoor environment. They investigated the indoor to outdoor relationship of aerosol particles.

They observed maximum penetration for particles between 100 and 400 nm in diameter. The

mean value of the I/O was 0.36 for ultra fine particles «lOnm) and 0.60 for particle larger than

1 OOOnm in diameter.

Fernanadez et aI, (2002) studied the chemical speciation of 11 metals in aerosols of Seville

(Spain). The chemical speciation of metals showed that the metals with highest percentages in

the different fraction are Vanadium 54.4% in the soluble and exchangeable fraction, calcium

39.7% in the carbonates, oxide and reducible fraction, magnesium 59.2% in the bound to

organic matte, oxidisable and sulphidic fraction, and iron54.6% in the residual fractions.

12

Potentially toxic metals, such as nickel, lead and cadmium were mainly accumulated in the

smaller particles with percentage of 72.6%, 69.4% and 68.3% respectively. Lead has a

concentration of 63.7 ng/m3, more than copper and magnesium (26.7 and 16.5 ng/m3) and above

al more than nickel, cobalt and cadmium (1.97, 0.54 and 0.32 ng/m\ (Fernandez et aI, 2001).

Viena et aI, (2006) carried out the source identification of particulate matter by Principal

component analysis (PCA) coupled with wind direction data. They identified seven independent

sources by PCA: Steel (Pb, Mo, Cd Mn), pigment (Cr, Mo, Ni) manufacture, road dust (Fe, Mo,

Cd) traffic exhaust (P,OC+ EC), regional scale transport ( NH/, S04-, ) crustal contributions

(Ah03, K, Sr, K) and sea spray (Na, CI». A number of methods are currently in use such as

(PCA), (Thurston and Spengler, 1985; Henry and Kim 1990), Chemical Mass Balance (CMB)

(Hopke and Sang 1997), Positive Matrix Factorization (PMF), or the Multilinkers Engine (ME)

(Paatero et aI, 1997).

Gao et aI, (2001) characterized trace elements associated with PM2.5 over the New York- New

Jersey harbor. The elements Pb, Cd, Zn, Cu, Ni, V, Sb, are enriched by factors of 200 to 20000

relative to their natural abundance in crustal soil.

A study was carried out by Eleftheriadis and Colbeck, (2001) to analyze P, K, Ca, Fe, Ti, Mn,.

Cu, V, Co, Cr, Br, Zn, Ni, Sc, and Pb. They concluded that a small fraction of the above earth

and trace elements metal mass was present in particles greater than 10 !lm. This fraction for earth

metals (Co, K, and Ti) was comparatively greater in the rural site than urban site.

Wang et aI, (2006) in their study of size distribution and source apportionment of airborne trace

metals in Japan, observed the association of Ca, Mg,Sr, Mn, Co, and Fe with coarse particles (>

2.1!lm), primarily from natural source, and Zn, Ba, Cd, V, Pb, and Cu in fine aerosols «2.1 !lm),

originating from the anthropogenic origin source.

Brewer et aI, (2001) studied the trace metals in atmospheric particulates at Burnaby Lake, in the

great Vancouver area of British Columbia. AI, B, Ca, Mg, Mn, Na, Sr had a similar time series

pattern and particle size distribution. Their study reveals that maximum metals concentration

occurred during weeks of low precipitation and exhibited a large peak in mid June.

13

The particle size distributions observed for Cu, Pb, Mn and Fe were bimodal with a gradual

progression from mainly coarse mode to mainly fine mode. AI, Ni and Zn were mostly

associated with coarse particle and vanadium size distribution was unimodal with maxima

associated with fine particles (Infante et al" 1991).

Samara et aI, (2005) determined the size distribution of airborne particulate matter and associated

heavy metals (Pb, Cd, Ni, Cr, V, Mn, Cu and Fe) in Greece. They observed bimodal distribution

for particulate matter with most of the mass (52%) contained in the submicron size range (0.8

).tm) and an additional minor mode (20%) in the coarse size fraction (>6.7 ).tm). Metals dominant

within the accumulation mode (Pb, Cd), Ni, Cu, Mn, were mainly distributed between fine,

intermediate and coarse mode only; Fe were found within particle larger than 2.7 ).tm.

Singh et aI, (2002) carried out the measurement of size fractionated ambient PMIO mass, metals,

inorganic ions(nitrate and sulphates) and elemental and organic carbon at source (Downey) and

receptor (Riversde) site within the Los Angles Basin. The main source of Crustal metals (e.g. AI,

Si, K, Ca, Fe and Ti) can be attributed to the re-suspension of dust at both source and receptor

side. All the crustal metals were predominantly present in Submicron particle. The majority of

metals associated with fine particles were in much lower concentrations at Riverside compound

to Downey.

Panther et aI, (1999) carried out the study on total suspended particulates (TSP) and polycyclic

aromatic hydrocarbons in Seoul (South Korea), Hong Kong, Bangkok (Thailand), Jakarta

(Indonesia) and Melbourne (Australia). They observed seasonal variations in both TSP and PAH

in tropical cities with higher concentrations during the dry season and lower concentration during

the wet season. P AH concentrations were higher during the cold season and lower during the

warm summer, however, TSP was quite variable over the years in the latter cities and clear

seasonal trend was observed.

Gigliotti et aI, (2000) measured the concentrations of polycyclic aromatic hydrocarbons in the

coastal New Jersey atmosphere. 36 PAHs were analyzed at suburban and coastal sites including

phenanthrene and benzo(a) pyrene whose concentrations ranged from 0.4 to 20.9 ng/m3 and

0.0020 to 0.62ngl m3 respectively. PAHs concentrations at suburban sites were 2 times higher

14

then concentrations measured at the coastal site. Methylated Phenanthrene and pyrene were

higher during winter whereas fluoranthene showed opposite seasonal trends with concentration

higher in summer.

Ohura et aI, (2005) studied the atmospheric levels of 12 chlorinated PARs associated with

particulates at urban sites in Japan. Chloropyrene(1CIPy) were detected in the highest

concentration(75Pgm3 ) followed by 6 chlorobenzo(a)pyrene (6ClBaP; 5.6Pg/m3) and 9-10

dichlorophenanthrene(5.1Pglm\The concentration of Chloro PARs observed to be higher in the

winter than in summer with the exception of 6CI B(a)p concentration, which was high in both

summer and winter.

Wang et aI, 2007 measured PARs, hopanes, pthalates and hydroxyl-PARs (OR-PAR) in PM2.5

aerosols in the Nanjing mega city in China during summer and winter 2004. PARs, hopanes and

OR-PARs were in higher concentrations in winter (26-178, 3.0-18 and 0.013-0.421nglm3) than

in summer (12-96, 1.6-11 and 0.029-0.171ng/m3, respectively) which was due to an enhanced

evaporation from plastics during the hot season and the subsequent deposition on the pre-existing

particles. They also found that the entire identified compound showed higher concentration in

night time than in daytime due to inversion and increased emission from heavy duty trucks at

night.

The total concentration of 17 PARs ranged between 0.84 and 152ng/m3, with an average of

116ng/m3 in urban area, which was 1.1-6.6 times higher than those measured in suburban area of

Beizing, China (Zhou et aI, 2005). Their study reveals bimodal distribution for PARs with two or

more rings, more than four rings PARs however followed unimodal distribution. Coal

combustion for domestic heating was probably major contributor to the higher PARs loading in

winter, whereas PARs in other seasons displayed characteristic of mixed source of gasoline and

diesel vehicle exhaust.

Wet and dry deposition concentrations and fluxes of PARs were determined by Pekey et aI,

(2007) in urbani industrialized area of Izmit Bay, North- eastern Marmar Sea, Turkey. They

observed high concentrations of PARs. Total dry deposition flux of the fifteen 3-6 ring PARs

was 8.30~g/m2/ day, with a range of 0.034-1.77 ~glm2/ day. The total wet deposition flux of the

15

fifteen 3-6 ring P AHs was 1716 )lg/m2/ 11 month with a range of 10-440 )lglm2111 month. Their

study reveals that winter fluxes of total PAHs were 1.5-2.5 times greater than those of the warm

period for wet and dry deposition sample respectively.

The total 14 PAHs concentrations at Gosan, Korea, were between 0.52 and 14.76 nglm3 and

about 3-15 times higher than those at other rural sites in the world where the concentrations of

PAHs were higher during summer or heating season (Lee et aI., 2006). They identified three

factors: combination of coal combustion and vehicular emission and natural gas combination

whereas unidentified factors for combined data of PAHs, inorganic ions and elements consists of

crustal species, sea salts, and four P AH compounds.

Ding et aI, (2006) studied the spatial distribution and source identification of atmospheric

polycyclic aromatic hydrocarbons at North Pacific Ocean and Arctic Sea. They observed

decreasing latitude trends for gas phase P AHs, whereas particulate phase PAHs showed! poor

latitudinal trends. Fluoranthene /pyrene and indeno (123-cd)pyrene/ benz(ghi)pyrene isomer

pairs whose ratios and conservative to photo degradation character, implies that biomass or coal

burning might be the major sources of PAHs observed over North Pacific and the Arctic region

in summer.

The spatial distribution and concentration profile of 39 vapour and particulate polycyclic

aromatic hydrocarbons were stuied in two Japanese industrial cities (Fuji and Shimizu) in

summer and winter season by Ohura et aI, (2004). PAHs concentrations were higher in winter

than those in summer. Significant correlation were found in most of the P AH concentrations

monitored in winter suggesting the presence of common emission sources.

Chemical Mass balance source apportionment of PM 10 and associated chemical element and

polycyclic aromatic hydrocarbons were measured in industrialized urban area of Northern

Greece (Samara et aI., 2003). They observed that major sources of ambient PM IO at all three sites

were diesel vehicle exhaust; significant contribution from industrial oil burning was also

evidenced at the site located closest to the industrial area.

16

The distribution of air particulate mass and selected particle component (trace elements and

polycyclic aromatic hydrocarbons) in the fine and the coarse size fractions in Thessaloniki,

Greece were investigated by Manoli et aI, (2002). The result showed fine sized trace elemental

fraction ranged between 51 % of Fe and 95% for Zn, while those of PAHs were between 95% and

99%. Source identification result demonstrated that the largest contribution to fine sized aerosol

is traffic (38%) followed by road dust (28%) while road dust clearly dominated in coarse size

fraction (57%).

The study carried out by Wu et aI, (2006) in China reported the concentrations of the total PAH

at rural site were generally less than those of urban site and mean fraction of 76.5% and 63.9% of

the total PAH were associated with particles of0.43-2.1J.lm at rural and urban sites, respectively.

Menichini et aI, (2007) studied the relationship between indoor and outdoor P AHs and PCBs in

Rome. Their results indicated that indoor air may contribute to the overall exposure to PAHs and

PCBs more than in urban air.

Lin et aI, (2002) carried out the study on polycyclic aromatic hydrocarbons (PAHs) in total

suspended particulate in indoor and outdoor atmosphere of a Taiwanese temple. They observed

indoor mean total P AH concentration, particle bound P AH concentrations and TSP concentration

were 6258 ng/m3, 490J.lg/g and 1316 J.lg/m3

, respectively and outdoor concentrations were

231ng/m3, 245 J.lg/g and 730 J.lg/m3• The showed that PAH levels inside the temple were much

higher than those measured in the vicinity and inside residential houses.

The concentrations of most of the PAHs are dominant in aerosol particles between 0.125 and

211m, and PARs concentration increases with decreasing temperature (Kiss et aI., 1998). The

particle size distribution of P AHs tend to shift towards a larger size in a suburban location than

in an urban location caused by aerosol aging process( Duan et aI., 2005).

Fine (PM2.S) and coarse (PM2.5-JO) particulate concentrations of ambient particle-bound

polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously from February 2004-

January 2005 at the Taichung Harbor in Taiwan (Fang et aI., 2006). The result of the study

indicated that vehicular emissions, coal combustion, incomplete combustion and pyrolysis of

fuel and oil burning were main sources of P AHs in Taichung Harbor.

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Kabeda et aI, (2005) studied the size distribution of polycyclic aromatic hydrocarbons and their

depositions to the human respiratory tract were studied. They found reveals that benzo (a) pyrene

contributed only 40% of the total cancer risk f whereas dibenzo (a,h) pyrene, dibenzo(a,c) pyrene

and benzo(a)pyrene contributed 93% of the over all risk. The particle size distributions of PARs

tend to shift toward a larger size in a suburban location than in an urban location caused by

aerosol aging process

Polycyclic aromatic hydrocarbons present in size fractionated road dust were measured by

Murkami et aI, (2005). They observed higher concentration of PAR in light fractions dust

«1.7g/cm3) than heavy fraction (>1.7g1cm3). The PAR contents in the light fractions were 1-2

order of magnitude higher than those in the heavy fractions.

Rien et aI, (2006) characterize the size distributions of atmospheric polycyclic aromatic

hydrocarbons with 4-6 rings at the roadside in Ro Chi Minn City, Vietnam. Their study reveals

that mass of coarse particles occupied a higher fraction than that of fine particles. Total PARs

were mainly concentrated in particles with aerodynamic diameter smaller than O.4J.lm. The

particle size distribution of PARs investigated were bimodal with a peak in fine particle mode

«2.1J.lm) and another peak in coarse particle mode (>2.1J.lm).

In Indian context rather limited studies have been made on indoor and outdoor environments

simultaneously specially on relationship between indoor and outdoor SPM and associated metals

and PARs. Some of the important studies in Indian context are as follows:

Factor analysis- mUltiple regression modeling technique were used for quantitative

apportionment of the sources contributing to the SPM at two traffic junctions in Mumbai, India.

(Kumar et aI., 2001). The results were indicative of the fact that road dust contributed to 41 %,

vehicular emission to 15%, marine aerosol to 15%, metal; industries to 6% and coal combustion

to 6% of the SPM observed at one traffic sites, whereas other traffic junction were 33%, 18%,

15%, 8%, and 11 % respectively.

Daily average PM 1 0, TSP and their chemical species mass concentration were measured by

Gupta et aI, (2006) at residential and industrial sites of an urban region of Kolkata during Nov

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2003- Nov. 2004. They found that the most dominant source throughout the study period at

residential sites was coal combustion (42%); while vehicular emission (47%) dominates at

industrial sites in PM IO• Paved road, field burning and wood combustion contributed 25%, 7%,

and 1 % at residential sites respecively; while coal combustion, metal industry and soil dust

contributed 37%, 1 % and 17% at industrial sites respectively.

Mouli et aI, (2006) measured the atmospheric aerosol (PM IO) at a regional representative semi­

arid urban site, Tirupati over one year period. They found average mass of PM 10 to be 32.7)lg/m3

with a total water soluble aerosol load (total anion +total cation) of 13.56 Ilg/m3. A good

correlation was observed between crustal ions Ca and Mg(r =0.82) as well as acidic ions: Ca and

S04 (r =0.75) and N03 (r =0.67 and Mg and N03 (r = .0.78) and S04 (r = 0.73).

Size and chemical characteristics of surface aerosols were measured at Mumbai by Venkatraman

et aI, (2002) during the Indian Ocean Experiment Intensive Field Phase (INDOEX-IFP), January­

March 1999. Their findings revealed the dominance of crustal sources during late Febraury and

March with 69% of the aerosol mass present in the coarse mode.

Measurements on size distribution of atmospheric aerosols were made at Dayalbagh, Agra

during July to September 1998was done by Parmar et aI, (2001). They observed the mass size

distribution of total aerosol and the ions NH4, CI, N03, K, Ca, Mg, S04 and Na to be bimodal

while that of Fe was unimodal. S04, Fe, K and NH4, dominated in the fine mode while Ca, Mg,

CI, andN03 were in abundance in coarse fraction.

Size differentiated composition of suspended particulate matter and its water soluble ions have

been reported for samples collected in winter season at Agra by Kulshrestha et aI, (1998). It was

found that N~, K, N03 concentrations dominate in the fine fraction while Na, Ca, Mg, Fe, and

CI contribute to the coarse fraction.

Particle size distribution and its elemental composition were measured in the ambient air of

Delhi by Balachandran et aI, (2001). The results showed average concentration of coarse fraction

PM IO is found to be 68,3 (±)17)lg/ m3 while the fine fraction of PM 10 is 71.3(±) 15 )lg/ m3.Metal

19

concentration(Pb, Ni, Zn, Cd) in fine fraction exceed by a factor of upto 6 as compared to that in

Coarse fraction.

A study of the size distribution of total suspended particulate matter (TSPM) and associated

heavy metal concentrations was carried out by Srivastava et aI, (2007). They found that major

portion of TSPM concentration is in the form of PM 0.7. Most of the metal (Mn, Cr, Cd, Pb, Ni,

and Fe) mass was found to be concentrated in the PMO.7 mode.

Study on air quality and trace metal chemistry of different size fractions of aerosols in N··NW

India, was done by Yadav et aI, (2006). Their study reveals that the aerosol load in the

atmosphere increased to several order of magnitude for all size ranges (free fall aerosol = 21g/m3/day; SPM 10302 Jlglm3 and PM10 = 2907Jlg/m3

) during the summer dust storm period as

compared to winter. Metal like Sr, V, and Cr were dominantly crustal, Ba and Pb largely added

by fossil fuel burning; whereas Cu, Ni, and Zn were of various industrial activities.

The relationship between indoor and outdoor airborne particles was investigated for 24

residential, sensitive, commercial and heavy traffic sites in Delhi (Srivastava et aI., 2003). Their

study reveals that indoor SPM concentration was affected by outdoor SPM concentration and

metal like Cu, Cr, Cd, and Ni were highly correlated.

The annual average concentrations of total PAHs were found to be 668±399 and 62±388nglm3

by Sharma et aI, (2006) in the year 2002-2003, respectively. Seasonal average concentrations

were found to be maximum during the monsoon season. Principal component analysis indicates

that diesel and gasoline driven vehicle were the principal sources of PAHs in all the season.

The size distributions of urban PAHs were found to be predominantly associated with fine

particles in most cases, especially higher molecular weight PAH compounds. (Venkatraman and

Friedlander, 1994; Cancio et aI, 2004).

The concentration of various criteria air pollutants (SPM, PM IO, CO, S02, and NO) and organic

pollutants such as benzene, toluene, Xylene (BTX) and polycyclic aromatic hydrocarbons

(PAHs) were measured before and after the implementation of compressed natural gas in public

20

transport in Delhi,(Khaiwal et aI, 2006). PAHs, S02 and CO was found to be decreased while

NOx level increased in comparison to those before implementation of CNG.

In the Indian context rather limited studies have been made on indoor and outdoor environments

specially on relationship between indoor and outdoor SPM and associated metals and PAHs.

However, as far as heavy metals and PAHs associated with various size fractions of particulate

matter for the indoor and outdoor aerosol of Delhi are concenmed so far no extensive study has

been done. This has prompted the present study with the following objectives:

Objectives of study

1) To measure the suspended particulate matter and associated metals and PAHs

concentration in indoor and outdoor environments.

2) To measure the size distribution of SPM and the association of various kind of metals and

PAHs with size

3) To examine the relationships between indoor and outdoor environments /

4) To measure the seasonal variation of SPM and associated metals and PAHs in indoor and

outdoor environments.

5) To find out source apportionment using statistical tool technique

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