Indoor Air Quality at Rural and Urban Sites in Pakistan - Springer Link

Water Air Soil Pollut: Focus (2008) 8:61–69 DOI 10.1007/s11267-007-9139-5

Indoor Air Quality at Rural and Urban Sites in Pakistan Ian Colbeck & Zaheer Ahmad Nasir & Shahida Hasnain & Sikander Sultan

Received: 15 October 2006 / Accepted: 31 May 2007 / Published online: 11 December 2007 # Springer Science + Business Media B.V. 2007

Abstract In the developing world, the vast majority of people rely on solid biomass fuels for cooking and heating which results in poor indoor air quality. The present study determined indoor air quality in some rural and urban areas of Pakistan. Measurements were made of particulate mass (PM10, PM2.5 and PM1), number concentration and bioaerosols in different micro environments. PM10 concentrations of up to 8,555 μg/m3 were observed inside the kitchens where biofuels were used as energy source. Cleaning and smoking was identified as a major source of indoor particulate pollution and concentrations of more than more than 2,000 μg/m3 were recorded in the living room during these activities. Indoor number concentrations in Lahore were typically greater than those observed outdoors in European cites. At a rural site the highest Colony Forming Units (CFUs) were in the 0.5 μm–2 μm size fraction, while at the urban location CFUs were dominant for 2 μm–16 μm. It was I. Colbeck (*) : Z. A. Nasir Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK e-mail: [email protected] S. Hasnain : S. Sultan Department of Microbiology and Molecular Genetics, University of the Punjab, Quaid-e- Azam Campus, Lahore 54590, Pakistan

observed that CFUs(Colony Forming Units) counts were higher inside living rooms than kitchens. It is important to note that women and children were exposed to extremely high levels of particulates during cooking. Overall, indoor air quality in Pakistan was poor and there is a dire need to take a serious step to combat with it. Keywords Indoor air . Pakistan . PM10 . PM 2.5 . PM 1 . Number concentration . Bioaerosols

1 Introduction To calculate total human exposure to various air pollutants information on indoor air quality is fundamental. The nature and levels of indoor air pollution is different in the developed and the developing world. There is a growing body of evidence that poor air quality inside the homes poses a serious threat to human health. In addition, the section of the population exposed to indoor air pollution in the developing world is also different in comparison to developed world. In most of the cases, women, children and the elderly are the most vulnerable group due to the socio-economic setup of these societies. Although, a considerable amount of work has been done to measure the various characteristics of air pollutants both indoors and outdoors through out the world, there is dearth of knowledge on indoor air quality in the developing world.

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Water Air Soil Pollut: Focus (2008) 8:61–69

In the developing countries the major source of indoor air pollution is the use of biomass fuels. According to the World Health Organization more than 3 billion people rely on solid fuels, including bio-fuels, for their energy needs. The use of biomass fuels in traditional stoves produces high levels of indoor air pollutants. This indoor smoke contains a range of health deteriorating substances due to incomplete combustion. Indoor air pollution is responsible for more than 1.6 million annual deaths and 2.7 % of global burden of diseases (WHO 2002). The highest death toll is in developing countries which suggest biomass fuels have an adverse impact on indoor air quality. In Pakistan, almost 70% of the population lives in rural areas and use wood, dung, crop residue or natural gas as a fuel for cooking and heating. The use of biomass fuel in Pakistan is 86% with 54% using wood (Archar 1993). There are only few studies on outdoor air pollution. Recent surveys carried out in the country using mobile units revealed the presence of very high levels of suspended particulate matter in major cities (about 6 times higher than WHO guidelines). In Lahore, Rawalpindi and Karachi levels of CO, NOx and SO2 were also found in high concentrations (Hashami and Khani 2003; Yousufzai et al. 2000). With regard to indoor air pollution in Pakistan, there is less published evidence. Recently, a study was undertaken on the correlation of eye and respiratory symptoms among women exposed to wood smoke emitted from indoor cooking and concluded that these are significantly associated with wood use (Siddiqui et al. 2005a). Another study showed an independent effect of indoor air pollution on birth weight (Siddiqui et al. 2005b). According to the WHO, despite mounting evidence that biomass smoke exposure increases the risk of a range of diseases, there is very little intervention being done so far in Pakistan (WHO 2005). Therefore, the present work was conducted to monitor particulate matter and bioaerosols in rural and urban sites in Pakistan. The objectives of the present study were; ○ to measure the mass and number concentrations of particulate matter in both rural and urban areas in different households. ○ to investigate the concentration of bioaerosols in both rural and urban indoor environments. These findings will give an indication of the levels of indoor air pollutants, in different households in Pakistan.

2 Materials and Methods 2.1 Sampling Sites To investigate the indoor air quality in Pakistan sampling was carried out during November–December 2005. Sites were selected bearing in mind the difference in household and fuel used. Air samples were collected from two rural sites: Chak NO.35/2.L. and Bhaun and an urban site (Lahore). Pakistan is predominantly an agricultural country and land is irrigated either by canals or is rainfed. The kind of biofuel used in these two areas varies due to different agricultural patterns. In canal irrigated areas people usually use crop residues along with dung. The inhabitants of rainfed areas mostly use wood as a fuel. The majority of houses in Chak NO.35/ 2.L were made of mud, grasses and bamboo. In Bhaun, there was a range of houses with different construction materials. Lahore, the urban site, is one of the mega cities of the Pakistan. The ventilation in all the cases was through windows or doors and they remained open during the day and were closed during the night. The detail description of houses is shown in Table 1. 2.2 Instrumentation A TSI model 3010 condensation particle counter (CPC) (TSI Incorporated, St. Paul, MN, USA) was used to measure the particle number concentration. The CPC measured the total number concentration of submicrometer particles in the size range from 10 nm to 3 μm. It offers an upper concentration limit of 10,000 particles/cm3 with 10% coincidence at 10,000 particles/cm3. The mass concentration of particles was monitored using two different GRIMM analyzers: 1) Model 1.108 2) Model 1.101 (Grimm Aerosol Technik GmbH, Ainring, Germany) and a DustTrack Aerosol Monitor (TSI, Model 8520). The GRIMM monitors had a sensitivity of 1 particle/ liter with a reproducibility of ±2% and flow rate of 1.2 L/min. The concentration range for the DustTrack was 0.001–100 mg/m3 with a flow rate 1.7 L/min. The GRIMM analysers monitored PM10,PM2.5 and PM1 while the DustTrack was used for PM10. Both of these instruments were run continuously and the measurement interval was 1 min. To investigate the bioaerosol the methodology developed by Bird (2006) was used. A May Cascade Impactor (May Research Engineers Ltd.) was used to


63

Table 1 General description of sites Site

Area

Experimental space

Age Height Ventilation Fuel used/activity (years) (feet)

Chak Rural, residential, lots of greenery, (trees) ,low Living room 20 No. traffic, mud buildings, large number of livestock (combined, used by 35/2.L. in most houses 3–7 persons)

12

Window opening (one ) Door/ window opening Door/ window opening Window/ door opening Window (two)

Kitchen – I

4

10

Kitchen – II

2

8

Bhaun

Urban, near road, low traffic, lots of greenery, mud, concrete and iron shed buildings.

Bedroom

16

18

Lahore

Residential, densely populated, close to road, no greenery, within the shopping market.

Living room (carpeted)

40

20

collect aerosol samples for bioaerosol analysis. The May Cascade Impactor was chosen due to its high collection efficiency and was operated by impacting particles through narrow slit orifices onto glass slides (Menzel Glaser). The samples were collected at a flow rate of 5 L/min. The most beneficial aspect of a multistage impactor is its ability to fractionate the aerosols into seven different size ranges. However, bioaerosols in the present study were analysed in three different sizes (Size A: 16 μm to >32 μm, Size B: 2 μm–16 μm and Size C: 0.5 μm–2 μm). The slides were removed from the impactor and placed into 50 ml centrifuge tubes. The sample was dislodged by shaking on a rotary shaker for 20 min at room temperature following the addition of 10 ml sterile filtered PBS containing 0.01% Tween 80. The initial sample extract was centrifuged at 4,500 rmp for 10–35 min at 25°C. The supernatant was then removed and concentrated samples were diluted. A volume of 50 μl from each dilution was used on each plate. Nutrient agar and MacConkey agar were used to culture the microorganisms. Nutrient agar was used for total bacteria while, MacConkey agar is a selective agar for the isolation of gram negative bacteria. All the plates were incubated at 25°C and 37°C. Colony enumeration was done on each incubated plate and results were expressed in colony forming units per cubic meter of air (CFU/m3). In all the settings the sampling instruments were placed at a height of 1 m. The sampling of particulate matter

None/normal household activities, smoking Dung and crop residues/cooking, cleaning Dung and crop residues/cooking, cleaning None/sleeping, reading and cleaning. None/student life, smoking, cleaning

mass concentration and number concentration was carried out continuously 24 h with a 1-min sampling interval. However, there were many breaks in sampling due electric failure during the sampling campaign. The sampling for bioaerosols was of 8 h duration. A record of occupant activity was also kept at each location.

3 Results and Discussion 3.1 Number Concentration The average of the 24-h number concentration for Lahore is shown in Table 2. These values refer to 1-h time intervals. Indoor number concentrations in Lahore were typically greater than those observed outdoors in European cites (Harrison and Jones 2005). The number concentration values ranged between 6,624 and 5,3053 #/cm3. Analyses and comparison of data with diaries of activities maintained by the resident enabled the identification of activities which contributed the elevated levels. The activities identified were: personal presence, normal household activities and cooking. 3.2 Mass Concentration With reference to the mass concentration of particulate it can be observed from the figures that at both

64


Table 2 Summary of number concentration data for Lahore Mean (#/cm3)

Min (#/cm3)

Max (#/cm3)

SD (#/cm3)

Time (hh:mm)

Sample length (h)

41108.01 41164.89 34531.76 31819.60 31631.72 31567.87 29734.39 22562.76

23026.30 27877.86 18239.86 15787.45 13658.66 13658.66 16761.81 6624.37

49837.33 51756.00 53053.72 48298.38 48802.85 48802.85 44764.28 40042.11

7604.06 6739.13 10216.00 10196.81 10482.62 10533.58 9016.64 10335.15

13:30–13:30 14:00–14:00 22:00–22:00 00:30–00:30 06:30–06:30 06:30–06:30 13:30–13:30 14:00–14:00

24 24 24 24 24 24 24 24

Lahore Room Sample Sample Sample Sample Sample Sample Sample Sample

1 2 3 4 5 6 7 8

the rural and urban sites, there was variation in mass of PM10, PM2.5 and PM1. This change in variation was principally governed by the activities of inhabitants along with other factors such as outdoor sources and meteorological conditions (Figs. 1 and 2). At Chak NO.35/2.L when cooking was in progress the mass concentration rose sharply and a peak concentration of 8,555 μg/m3 was observed (Fig. 2). A study conducted in rural Tamil Nadu , India by Parikh et al. (2001) on exposure from cooking with biofuel revealed that PM10 ranged from 500–2,000 μg/m3 during a 2-h cooking period and was dependant on kitchen type and fuel use. A large variation in mass concentration of particulate matter has been recorded during a 24-h cycle within the kitchen. Such variations were primarily due to the contribution from biofuel smoke inside the kitchen or cleaning of the courtyard outside. These findings are in agreement Fig. 1 Mass concentration of PM in kitchen (Chak No.35/2.L.)

with Park and Lee (2003), who reported the particle exposure and size distribution from wood burning stoves in Costa Rica. They pointed out that particulate levels increased rapidly during cooking and decreased quickly after cooking. In their study the maximum peak particulate levels ranged from 310 to 8,170 μg/m3 for PM 2.5 and from 500 to 18,900 μg/m3 for PM10. Wind is also an important factor. The effect of the outdoor environmental conditions can be clearly seen in Fig. 1 where the PM10 concentration does not corresponding with PM2.5 and PM1 due to the windy conditions outside. Ezzati and Kammen (2002) report the particulate concentrations in homes where biomass burning occurs are far in excess of those found in homes where it is not used, with 24-h average PM10 concentrations ranging between 200 and 5,000 μg/m3. It has been seen that in kitchens it can take an hour for the indoor air to reasonably clear after cooking.

4000

Contribution from outdoors

Mass Concentration(ug/m3)

3500 3000

Cooking

2500 Average of PM-10 Average of PM-2.5 Average of PM-1.0

2000 1500

Unoccupied

1000 500 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 28 Day:Time (Hour)

Water Air Soil Pollut: Focus (2008) 8:61–69 Fig. 2 Mass concentration of PM in kitchen

65

9000

Cooking


8000 7000

Cleaning


5000 4000

Unoccupied

3000 2000 1000

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

0 5 Day: Time (Hour)

Recently Dasgupta et al. (2006) conducted a study on indoor air quality in Bangladesh and reported that PM 10 over 24 h cycle, in wood using households, varied from 68 to 4,864 μg/m3. In the living room indoor activities (cleaning, smoking, moving and physical presence) triggered a rise in PM concentration. In Chak NO.35/2.L cleaning in the late morning and smoking in the evening was identified as major source of particulate pollution and concentrations of more than 2,000 μg/m3 were recorded during these activities (Fig. 3). During the day this room remained predominantly unoccupied. The high concentration is primarily because this was shared by 5–7 people in the evening for socialising (a traditional Pakistani village

Fig. 3 Mass concentration of PM in room (Chak No.35/2.L) Mass Concentration(ug/m3)

2500

2000

culture). A rise in PM10 during the afternoon reflects the cleaning while in the evening particulate matter rose in all the three fractions (PM10, PM2.5. PM1) due to smoking (Fig. 3). On the other hand, in Bhaun the living room was used by only one person (smoking), the PM concentrations never went beyond 300 μg/m3 (Fig. 4). The difference in PM mass concentration in the living rooms in 35.2 L and Bhaun indicates the effect of number of people smoking and construction material of the buildings. However, the majority of particulate matter was in PM10 size from morning till late night (Fig. 4). This is probably due to the fact that the window of the room opened towards the street and

Smoking Cleaning

1500

Average of PM-10 Average of PM-2.5 Average of PM-1.0

1000

500

0 0 1 2 3 4 5 6 7 8 9 10 11 13 14 15 16 17 18 19 20 21 23 22 Day: Time (Hour)

66


Fig. 4 Mass concentration of PM in room (Bhaun)

350

Smoking

Cleaning and outdoor contribution

3

Mass Concentration(ug/m )

300 250 200


150 100

23

22

21

20

19

18

17

16

15

14

13

12

11

9

8

7

6

5

4

3

2

1

0

0

10

50

13 Day: Time (Hour)

outdoor particulate matter contributed to the high PM 10 values. In Lahore the mass concentration fluctuated due to the personal activities (Figs. 5 and 6) of the inhabitants and peaked at 1,170 μg/m3. The room (student accommodation shared by three people) was located in a city slum with heavy traffic nearby. This can be seen in increased values of PM10 as compared to PM2.5 and PM1. The mass concentration of particulate matter in the rural living room (2,000 μg/m3 ) at 35 2/L was almost double that in an urban setting (Lahore; 1,170 μg/m3). This was probably due to the larger room size in Lahore with two windows as compared to the rural living room (Chak NO.35/2.L) with one window. Although the

Fig. 5 Mass concentration of PM in room (Lahore)

building structure and volume of rooms is important the number of occupants also play a major role for the higher concentrations in the rural living room at Chak NO.35/2.L. As in Bhaun, the living room with one occupant experienced a maximum mass concentration far lower (300 μg/m3) than at both Chak NO.35/2.L and Lahore. 3.3 Bioaerosol Concentration Although samples were incubated at two different temperatures (25°C and 37°C) it was observed that an increase to 37°C did not increase the total colony forming units in the samples from the rural area (both in room and kitchen). While, in Lahore the CFU were

1200

Smoking and outdoor contribution


600

400

200

0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23


1000

2 Day: Time (Hour)

Water Air Soil Pollut: Focus (2008) 8:61–69 Fig. 6 Mass concentration of PM in room (Lahore)

67

1000


900

Unoccupied – Contribution from outdoor

Smoking

800 700 600


500 400 300 200 100 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

0 4 Day: Time (Hour)

slightly higher at 37°C in comparison with 25°C for the nutrient agar. Overall, there was higher CFU on nutrient agar as compared to MacConkey agar, as it is a non selective agar. In Chak NO.35/2.L, this difference in the kitchen was small but in the living room, the CFU on MacConkey agar was approximately 50% that on nutrient agar (Figs. 7 and 8). A substantial fall in magnitude of CFU from nutrient agar to MacConkey agar was recorded in Lahore (Fig. 9). At Chak NO.35/2.L, inside the kitchen, most of the bacteria were enteric (MacConkey agar selects for lactose fermenting bacteria) while inside the room, half of the proportion of total bacterial population was shared by enteric bacteria. This is probably due to 600

Culturable microorganisms(CFU/m3)

Fig. 7 Comparison of CFU between Nutrient agar and MacConkey agar in different size ranges (Kitchen – Chak No.35/2.L)

the fact that in Pakistani villages, livestock (goats, cows, buffaloes) also stay inside the home most of time. This is clear in case of Lahore (urban), where a substantial fall in the number of CFU on MacConkey agar was recorded. With reference to size fractions, the samples from Chak NO.35/2.L (both in the kitchen and room) showed that most of CFU were in size range 0.5 μm–2 μm followed by 2 μm–16 μm and 16 μm to >32 μm on both of the agars at 25°C, respectively (Figs. 7 and 8). The CFU in the kitchen (incubated at 37°C) was almost same with a slight fall in 0.5 μm– 2 μm size range on nutrient agar but on MacConkey agar the highest number of CFU were seen in the range 2 μm–16 μm (Fig. 7). While in the room sample, on

Size A (16um - >32um) Size B (2u m - 16um) Size C (0.5um - 2um)

500

400

300

200

100

0

25Co(Nutrient agar)

37Co(Nutrient agar)

25Co(MacConkey agar)


68 1200


Fig. 8 Comparison of CFU between Nutrient agar and MacConkey agar in different size channels. (Room – Chak NO.35/2.L)


Size A (16um - >32um) 1000

Size B (2um - 16um) Size C (0.5um - 2um)

800

600

400

200

0

25Co(Nutrient agar)

nutrient agar (incubated at 37°C) the smallest size range was dominant and MacConkey agar showed approximately the same CFU for all the three size fractions (Fig. 7). In Lahore, on nutrient agar for both incubation temperatures, the highest CFU was enumerated for the range 2 μm–16 μm. The CFU remained roughly the same on MacConkey agar for both of the temperatures in all the three size fractions (Fig. 9). It can be clearly seen that in rural site the highest CFU were in 0.5 μm–2 μm, while at urban location CFU were dominant for 2 μm–16 μm. This could be the due to the high proportion of particulate matter above 2 μm at Lahore and it can be noticed in Figs. 5 and 6, where most of particulate matter falls into the PM10 range.



As for as CFU, the highest number was encountered in Lahore (approx. 12,300 CFU/m3). This huge number could be due to the fact the sampling site was very dump and old. In Chak NO.35/2.L, the number of CFU was almost double in the room (slightly over 1,111 CFU/m3) as compared to kitchen (approx. 506 CFU/m3). These concentrations are well above the recommended maximum limits. The limit set by National Institute of Occupational Safety and Health (NIOSH), is 1,000 CFUs/m3.while according to American Conference of Governmental Industrial Hygienists (ACGIH), culturalable count for total bacteria should not exceed 500 CFUs/m3 (Cox and Wathes 1995; Jensen and Schafer 1998). In short, at the rural site(Chak NO.35/2.L), most of bioaerosols

14000


Fig. 9 Comparison of CFU between Nutrient agar and MacConkey agar in different size channels. (Room – Lahore)

37Co(Nutrient agar)

12000

Size A (16um - >32um) Size B (2um - 16um) Size C (0.5um - 2um)

10000

8000

6000

4000

2000

0

25Co(Nutrient agar)

37Co(Nutrient agar)




were enteric, although concentrations were almost 10 times less compared to the urban site.

4 Conclusion In this study we have investigated the indoor air quality of some rural and urban households in Pakistan. The results provide several insights into the sources of indoor air pollution. The present study shows considerably high concentrations of particulate matter particularly in the kitchen using biofuel as compared to living areas. Thus women and children are exposed the most due to amount of time spent in the kitchen. The mass and number concentration of particulate matter in urban settings was well above of any standards for particulate matter pollution. The total counts of the bacteria were also substantially higher in residential areas. Half of the CFU’s were enteric at rural sites as compared to urban areas. This reflects the poor sanitation conditions in rural areas. The situation of indoor air was poor, particularly in the kitchens using biomass fuels. These concentrations were many times in excess of EU, US EPA and WHO standards/guidelines. This situation of indoor air quality warrants the need to take serious steps to improve it. In addition, the present investigation has studied only few households as it was first ever study on indoor air quality in Pakistan. A detailed study with more households focused on all parameters affecting indoor air quality should be carried out.

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