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Indoor air pollution (PM2.5) due to secondhand smoke in selected hospitality and entertainment venues of Karachi, Pakistan
  1. Asaad Ahmed Nafees1,
  2. Tahir Taj1,
  3. Muhammad Masood Kadir1,
  4. Zafar Fatmi1,
  5. Kiyoung Lee2,
  6. Nalini Sathiakumar3
  1. 1Department of Community Health Sciences, Aga Khan University, Karachi, Pakistan
  2. 2Department of Environmental Health, Graduate School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Republic of Korea
  3. 3Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, USA
  1. Correspondence to Dr Asaad Ahmed Nafees, Department of Community Health Sciences, Aga Khan University, Stadium Road, PO Box 3500, Karachi 74800, Pakistan; asaad.nafees{at}aku.edu

Abstract

Objective To determine particulate matter smaller than 2.5 μm (PM2.5) levels at various hospitality and entertainment venues of Karachi, Pakistan.

Methods This was a descriptive cross-sectional study conducted at various locations in Karachi, during July 2009. Sampling was performed at 20 enclosed public places, including hospitality (restaurants and cafés) and entertainment (snooker/billiard clubs and gaming zones) venues. PM2.5 levels were measured using an aerosol monitor.

Results All entertainment venues had higher indoor PM2.5 levels as compared to the immediate outdoors. The indoor PM2.5 levels ranged from 25 to 390 μg/m3 and the outdoor PM2.5 levels ranged from 18 to 96 μg/m3. The overall mean indoor PM2.5 level was 138.8 μg/m3 (±112.8). Among the four types of venues, the highest mean indoor PM2.5 level was reported from snooker/billiard clubs: 264.7 μg/m3 (±85.4) and the lowest from restaurants: 66.4 μg/m3 (±57.6) while the indoor/outdoor ratio ranged from 0.97 to 10.2, highest being at the snooker/billiard clubs. The smoking density ranged from 0.21 to 0.57, highest being at gaming zones. The indoor PM2.5 concentration and smoking density were not significantly correlated (Spearman's correlation coefficient=0.113; p=0.636).

Conclusions This study demonstrates unacceptably high levels of PM2.5 exposure associated with secondhand smoke (SHS) at various entertainment venues of Karachi even after 8 years since the promulgation of smoke-free ordinance (2002) in Pakistan; however, better compliance may be evident at hospitality venues. The results of this study call for effective implementation and enforcement of smoke-free environment at public places in the country.

  • Particulate matter (PM2.5)
  • hospitality and entertainment venues
  • secondhand smoke
  • Karachi
  • Pakistan
  • environment
  • environmental tobacco smoke
  • public policy
  • surveillance and monitoring
  • taxation and price
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Introduction

According to the latest estimates available from the WHO, more than 5 million deaths per year worldwide may be attributed to tobacco use, many deaths or disabilities occurring in the most productive years of life. The situation is worse in low-income and middle-income countries where the burden is expected to increase further in the coming decades.

Although progress has been made by some of these countries in terms of initiating smoke-free laws, currently only 9% of the countries mandate smoke-free bars and restaurants while 65 countries lack any smoke-free policy at a national level.1

It is estimated that secondhand smoke (SHS) contributes to 1% of the total global disease burden and leads to premature death among children and adults. It has been linked with a range of health effects, including immediate adverse effects on the cardiovascular system as well as coronary heart disease and lung cancer in adults, and increased risk for sudden infant death syndrome (SIDS), acute respiratory infections, ear problems, more severe asthma, developmental disabilities and behavioural problems in children. In utero exposure increases the risk of premature labour and low birth weight.1 ,2 There are no risk-free levels for SHS, which is the reason elimination of smoking in indoor places has been identified as the measure for protection from such exposure.

Exposure to SHS occurs predominantly at homes and workplaces however, it also occurs in hospitality and entertainment venues such as restaurants, bars, casinos and gaming halls.1 The degree of exposure depends on the number of smokers, the amount of tobacco smoke, the duration of exposure, as well as the size and ventilation characteristics of the indoor environment.3 Various environmental markers can be used to determine and quantify exposure, such as airborne nicotine levels and fine particulate matter with an aerodynamic diameter <2.5 μg (PM2.5) to estimate the air pollution levels resulting from tobacco smoke.4–7

In Pakistan the only nationally representative health survey, The National Health Survey of Pakistan (NHSP) was conducted in 1990–1994.8 Results from this survey estimate the prevalence of smoking among individuals 15 years or older to be 15.5% to 19.4%.9 ,10 This prevalence is higher among men (28.6%) as compared to women (3.4%)9 and geographical distribution shows that Sindh province has the highest prevalence (16.1%), compared to others.10 The Government of Pakistan prohibited smoking and use of other tobacco products in places of public work through the ‘prohibition of smoking and protection of non-smokers health ordinance’, 2002. The ordinance explicitly states that: ‘No person shall smoke or use tobacco in any place of public work or use’, where place of public work has been defined to include hospitality venues such as amusement centres, restaurants, cinema halls, eating houses, hotel lounges, other waiting lounges and ‘the like which are visited by general public but does not include any open place’. However the ordinance has provision for allowing designated smoking areas in places where adequate arrangements are made to protect the health of non-smokers.11 Although the ordinance came into effect from 30 June 2003, its implementation is still far from being satisfactory;12 however, efforts are being made by the Government of Pakistan to improve implementation of the ordinance and Framework Convention on Tobacco Control (FCTC) through collaboration with the Bloomberg Global Initiative (BGI).13

Karachi, the provincial capital of Sindh and largest urban centre of Pakistan, is located in the south of the province, on the coast of the Arabian Sea covering an area of approximately 3530 km2. Divided into 18 towns and 178 union councils, the city has an estimated population of 15 million.14 Recent studies conducted in Karachi found prevalence of cigarette smoking among adults to be 34%15 and prevalence of all forms of tobacco use to be 36.9% among adults aged 40 years or more.16

There is lack of evidence regarding SHS in indoor environments at public places from Pakistan. Therefore the purpose of this study was to determine PM2.5 levels at various hospitality and entertainment venues of Karachi, Pakistan.

Methods

Study design and setting

This was a descriptive cross-sectional study conducted at various locations in Karachi, Pakistan during July 2009. The administrative areas where study was conducted include Gulshan, Pakistan Employees Cooperative Housing Society (PECHS), Saddar, Gulberg, North-Nazimabad and Jamshed Towns and Clifton area (including the Defence Housing Authority (DHA)). Sampling was performed at 20 enclosed public places that included hospitality (restaurants and cafés) and entertainment (snooker/billiard clubs and gaming zones) venues. Public places were classified as spaces that could be visited without permission; hence the management was not informed about the visit and measurements beforehand. Only places where smoking was permitted were considered, while places that had a separate area designated for smoking were excluded. The hospitality and entertainment venues were selected through purposive sampling and these were categorised into four types: (1) restaurants (places where meals are prepared, served and eaten), (2) cafés (primarily serving tea, coffee, other beverages and ice cream), (3) snooker/billiard clubs and (4) gaming zones (places offering various video games usually with provision for a snack bar, frequented mostly by children and adolescents).

Quality assurance of measurements

PM2.5 levels were measured using an aerosol monitor (Sidepak, Model AM510; TSI, Shoreview, Minnesota, USA), which has been used in other, similar studies.17 ,18 The Sidepak Personal Aerosol Monitor uses a built-in sampling pump that draws air through the device, and the PM in the air scatters light emitted from a laser. Based on the scattering of light and application of an impactor to remove particles larger than 2.5 μm, the device determines the real-time concentration of particles smaller than 2.5 μm. The monitor was calibrated against a previously calibrated light-scattering instrument, and based on the calibration experiments the monitor was used with a calibration factor of 0.295. The instrument was zero-calibrated prior to measurements on a daily basis by attaching a zero-calibration filter according to the manufacturer's specifications. The equipment was set to a log interval of 1 min.

Measurement procedure

Each venue was visited for a minimum of 40 min. The monitor was concealed in a backpack and was operated continuously throughout the visit. The outdoor air quality of the venue was measured for at least 10 min before and after entering the venue, while walking around a 5 m area outside the venue. If the venue was in close proximity to a road with heavy traffic or a traffic light, the outdoor air quality was measured for at least 20 min, as the PM2.5 concentrations may be unstable.

A central location for the measurements was selected, away from the service entrance leading to the kitchen areas and as far away as possible from direct puffs of cigarettes. The concealed monitor was kept about 1 m from the floor. The number of people inside the venue and the number of lit cigarettes were counted every 10 min. Measurements were completed without being noticed ensuring that no changes in behaviour occurred. Relevant information (date and time, estimated room/area dimensions, number of persons present, number of lit cigarettes/cigars, description of the venue and maximum occupancy, ambient temperature and relative humidity) was collected on a predesigned data sheet/log book. Measurements were conducted during busy business hours (ie, between 01:00 PM to 15:00 PM and 17:00 PM to 21:00 PM). The sampling time was prescheduled and measurements were continued irrespective of the number of smokers and visitors. Data was collected by two investigators throughout the study.

Analysis

The analysis was performed using SPSS version 16.0 (SPSS, Chicago, Illinois, USA). The means of indoor and outdoor PM2.5 measurements for each venue were calculated. The first and last minute of logged data were removed because they were averaged with outdoor and entry way air. The remaining data points were averaged to provide an average indoor PM2.5 concentration. The outside PM2.5 concentration was calculated using the data points of outdoor measurements of the venue that were collected before entering the venue and after completing the indoor measurement. The smoking density (the number of burning cigarettes for 100 cubic metres of space (BC/m3)) for each venue was calculated by using the average number of burning cigarettes during the measurement period and the approximate size of the restaurant. The mean and median of each measurement for each type of venue was calculated. Spearman's correlation coefficient was used to determine the association between smoking density and indoor PM2.5 concentration.

Results

The indoor air quality was measured in eight restaurants, three cafés, seven snooker/billiard clubs and two gaming zones. Table 1 gives the mean outdoor and indoor PM2.5 concentrations and smoking density for each venue. All entertainment venues (snooker/billiard clubs and gaming zones) had higher indoor PM2.5 levels as compared to their immediate outdoors. The indoor PM2.5 levels ranged from 25 to 390 μg/m3 and the outdoor PM2.5 levels ranged from 18 to 96 μg/m3.

Table 1

Mean outdoor (O) and indoor (I) concentrations of particulate matter smaller than 2.5 μm (PM2.5) and smoking density in hospitality and entertainment venues (n=20), Karachi, Pakistan, 2009

Table 2 gives the outdoor and indoor PM2.5 concentrations and smoking density by type of venue. The mean indoor PM2.5 level was: 138.8 μg/m3 (±112.8). The highest mean indoor PM2.5 level was reported from snooker/billiard clubs: 264.7 μg/m3 (±85.4) and the lowest from restaurants: 66.4 μg/m3 (±57.6) (figure 1). The indoor/outdoor ratio ranged from 0.97 to 10.2, highest being at the snooker/billiard clubs. The smoking density ranged from 0.21 to 0.57, highest being at gaming zones. The indoor PM2.5 concentration and smoking density were not significantly correlated (Spearman's correlation coefficient=0.113; p=0.636).

Table 2

Outdoor and indoor concentrations of particulate matter smaller than 2.5 μm (PM2.5) and smoking density by type of venue (n=20), Karachi, Pakistan, 2009

Figure 1

Mean outdoor and indoor concentrations of particulate matter smaller than 2.5 μm (PM2.5) by type of venue (n=20), Karachi, Pakistan, 2009.

Discussion

This study reports high levels of PM2.5 in hospitality and entertainment venues of Karachi, Pakistan. All entertainment venues including snooker/billiard clubs and gaming zones had higher levels of indoor PM2.5 compared to their immediate outdoor environments where the indoor/outdoor PM2.5 ratio ranged from 3.05 to 10.2. The highest mean indoor PM2.5 level reported was 390 μg/m3 at one of the snooker/billiard clubs. The mean indoor PM2.5 within the hospitality venues was generally lower than the entertainment venues; 66.4 μg/m3 in restaurants and 68.3 μg/m3 in cafés with the indoor/outdoor PM2.5 ratio of 1.73 and 0.97, respectively.

PM2.5 concentration is an accepted marker for monitoring levels of SHS in indoor environments and has been widely used in research studies19–21 even though this method does not distinguish between different toxic and carcinogenic properties of the respirable suspended particles. Furthermore, there could be various sources of PM2.5 other than tobacco smoke in the indoor environment, and these include open fires, cooking emissions, and particles of dust adhering to clothing.22 In this study particular effort was made to ensure that particulate matter from burning cigarettes was the most likely source of PM2.5 at the venues. None of the venues had a kitchen directly opening into the area where the measurements were taken.

Although other more reliable methods for monitoring exposure to SHS are available such as airborne nicotine levels,2 ,4 ,5 we believe that PM2.5 measurement is a more cost-effective and less time-consuming method which does not require high expertise in training for data collection and interpretation. Reduction in content of SHS at public places has also been suggested as a key outcome indicator for monitoring and evaluation of smoke-free measures at public places specially entertainment venues such as restaurants.4 ,23 ,24 PM2.5 measurements can be used in this regard to monitor air quality at entertainment and hospitality venues since these are mostly without any regulations and control in many countries such as Pakistan compared to homes and work environments that are more controlled places where regulations can easily be made. The visits at entertainment places are increasing with time in developing countries as well, thus becoming very important source of exposure. Regular customers may spend on an average, 2 h daily at entertainment places such as computer and gaming zones.25

The Government of Pakistan in collaboration with BGI is working on a project to enhance tobacco control activities in the country since 2008.13 Objectives of the project include: enhancement of national capacity for tobacco control; formation of committees at national, provincial and district levels for the implementation of 2002 ordinance (which prohibits smoking at any place of public work or use) and FCTC; creating awareness among stakeholders; establishing communication infrastructure; developing a comprehensive and holistic national framework for tobacco control; strengthening of current ordinance through identified amendments; and monitoring and evaluation of the project. Some of the recent developments in this regard include: issuance of stringent tobacco advertisement guidelines 2007 (such as restriction of tobacco advertisements on electronic media between 3:00 and 4:00 AM), guidelines for clearly visible pictorial health warnings 2009, and the prohibition of sale of cigarettes to minors rules, 2010.13

Studies from several countries have reported a reduction of PM2.5 levels following the enactment of laws restricting indoor smoking. Lee et al reported a significant reduction in mean PM2.5 levels at various indoor workplaces (n=10) immediately after implementation of ‘100% smoke-free workplace law’.18 Similarly Valente et al report a significant reduction in the exposure to indoor fine and ultrafine particles at various hospitality venues in Italy (n=40) after the enforcement of a smoking ban in all indoor public places. Their findings were also confirmed by a simultaneous reduction of urinary cotinine in the study subjects.21 Such findings have also been reported from England, Delaware and Boston after implementation of local smoke-free legislations.26–28 No such data is available from Pakistan since the implementation of 2002 ordinance.

This study reports the highest mean PM2.5 levels among various types of hospitality and entertainment venues of Karachi to be 265 μg/m3, found at snooker/billiard clubs. These findings are higher than those found in five Chinese cities, where mean PM2.5 at restaurants and bars was 208 μg/m3.29 Similarly highest mean PM2.5 levels of 183.5 μg/m3 were reported at pool parlours in a study from Sri Lanka and these results are also lower than those found in Karachi snooker/billiard clubs. (S Nandasena, personal communication, 2009) Similar studies conducted in developed countries have reported varying results, with one study from Greece reporting mean PM2.5 levels of 268 μg/m3 and another from Germany reporting even higher mean PM2.5 levels of 333 mg/m at various hospitality venues.7 ,30

Exposure to such high levels of PM2.5 is associated with various harmful effects including cardiovascular disease, lung cancer and early death.2 ,3 In addition to the general public and regular customers visiting such hospitality and entertainment venues, the labour force employed in such settings is also exposed to harmful effects of occupational exposure to SHS. A large survey conducted among London casino workers determined that SHS exposure at work is strongly associated with the presence of one or more sensory irritation symptoms.31

While there are no occupational exposure limits or indoor air quality limits for SHS or PM2.5, studies in other countries have compared air quality measurements of PM2.5 levels with those recommended by the US Environmental Protection Agency's (US EPA) National Ambient Air Quality Standards (NAAQS) (35 μg/m3 for 24 h).18 Although these limits are for outdoor particulate pollution based on an exposure time of 24 h, the WHO recommends the same guideline (25 μg/m3) for indoor and outdoor environments;3 however, it needs to be emphasised that these standards are for PM2.5 levels and there are no safe levels for SHS per se.23 Although measurements taken for this study were only for 40 min in each location, the overall high mean value of 138.8 μg/m3 suggests a high exposure risk for all visitors and customers and especially for employees.

This study reports the mean PM2.5 levels at gaming zones to be 93 mg/m3, which is higher than those found in similar setting of computer game rooms in South Korea that is, 69.5 mg/m3.25

Exposure to SHS is even more harmful to children as compared to adults32 and the fact that children may spend considerable amount of time at these places33 is a cause for concern. Appropriate measures are needed to protect children and young adults from exposure to SHS at such entertainment venues through enforcement of smoke-free laws.

This study found generally lower levels of indoor PM2.5 at the hospitality venues compared to the entertainment venues. The indoor/outdoor ratio of 1.73 at restaurants and 0.97 at cafés show that PM2.5 levels at these venues were comparable to their immediate outdoors. This is encouraging, and may point towards better compliance to Pakistan smoking policy at these venues.

The WHO recommends 100% smoke-free environments as the only effective way of protecting the general population and workforce from harmful effects of exposure to SHS. Legislations and laws ensuring universal and equal protection for all are required for this purpose and these need to be followed by adequate enforcement as well as supported by educational strategies to motivate and guide people to protect themselves at homes and public places.23

Limitations of the study include a small sample size of hospitality and entertainment venues selected through purposive sampling which may limit the generalisability of our results. Although a large survey with appropriate sample size is needed to determine effects of smoking legislation in Karachi however, we believe that this study will add important data to the limited information available regarding PM2.5 levels associated with SHS from Pakistan. Another limitation was the lack of significant correlation between the smoking density and indoor fine particle concentrations. This may be due to several reasons including passive ventilation mechanisms at each venue, which may be dependent on the size and number of windows and doors, and whether they were open or closed; measurement of air quality for only 40 min; and smoking behaviours prior to the sampling period. It may suggest that the correlation with smoking density at a point in time is not the appropriate marker. It also suggests that the indoor environment remain affected for longer duration once it has been polluted.

Conclusions

Even after 8 years since the promulgation of smoke-free ordinance in Pakistan, PM2.5 levels associated with SHS at entertainment venues remain unacceptably high; however, better compliance may be evident at hospitality venues. The results of this study call for effective implementation and enforcement of smoke-free environment at public places in the country. Large scale surveys with appropriate sample size and provision for screening through biological markers in addition to environmental markers are needed to determine exact magnitude of exposure to SHS at public places in Pakistan.

What this paper adds

  • Pakistan promulgated the ‘prohibition of smoking and protection of non-smokers' health ordinance’ in 2002 however; to date there is lack of evidence regarding SHS exposure in indoor environments at public places in the country.

  • This study demonstrates unacceptably high levels of PM2.5 exposure associated with SHS at various entertainment venues of Karachi, however, better compliance may be evident at hospitality venues.

  • There is an urgent need for effective implementation and enforcement of smoke-free environment at public places in Pakistan.

Acknowledgments

We acknowledge the funding received from the University of Alabama at Birmingham (UAB). We also acknowledge the Graduate School of Public Health, Seoul National University for providing the instrument. We would also like to acknowledge the contribution of Dr Sumal Nandasena from Sri Lanka to the writing of this manuscript.

References

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Footnotes

  • Funding International Training and Research in Environmental and Occupational Health (ITREOH) programme, grant number 5D43TW05750, of the Fogarty International Center of the National Institutes of Health and NASA. The content is solely the responsibility of the authors and does not necessarily represent the official views of the UAB, Fogarty International Center, or the National Institutes of Health.

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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