Zaheer Ahmad Nasir

Characteristics of indoor/outdoor particulate pollution in urban and rural residential environment of Pakistan

UNLABELLED Particulate pollution has emerged as a serious environmental health concern in Pakistan. The use of biomass fuels in traditional stoves produces high levels of indoor air pollutants. In Pakistan, 94% of rural and 58% of urban households depend on biomass fuel. This study investigates variations in indoor/outdoor concentrations of particulate matter during various activities for three different micro-environments in Pakistan. At a rural site, the average indoor/outdoor ratios for PM(10), PM(2.5), and PM(1), in kitchens using biomass fuels were 3.80, 4.36, and 4.11, respectively. A large variation was recorded in the mass concentration of particulate matter during cooking with concentrations in the range 4000-8555 microg/m(3). In a living room at a rural site, the average indoor/outdoor ratios for PM(10), PM(2.5), and PM(1) were 1.74, 2.49, and 3.01, respectively. At the urban site, the average indoor/outdoor ratios for the same size fractions were 1.71, 2.88, and 3.47, respectively. Cooking, cleaning and smoking were identified as principal contributors to the high indoor levels of particulate matter. This study showed considerably high concentrations of particulate matter, particularly in kitchens using biomass fuels, as compared to living areas. Thus women and children face the greatest exposure due to the amount of time they spend in the kitchen. PRACTICAL IMPLICATIONS In the developing world, particulate air pollution, both indoor and outdoor, is a substantial health hazard to the public. The very high concentrations of particulate matter in both rural and urban sites, particularly in kitchens using biomass fuels, emphasize the severity of this issue in Pakistan. Women and children are extensively at risk due to amount of time spent in kitchens. This state of affairs calls for a large-scale intervention to reduce the exposure to indoor air pollution.

The state of ambient air quality in Pakistan—a review

Background and purposePakistan, during the last decade, has seen an extensive escalation in population growth, urbanization, and industrialization, together with a great increase in motorization and energy use. As a result, a substantial rise has taken place in the types and number of emission sources of various air pollutants. However, due to the lack of air quality management capabilities, the country is suffering from deterioration of air quality. Evidence from various governmental organizations and international bodies has indicated that air pollution is a significant risk to the environment, quality of life, and health of the population. The Government has taken positive steps toward air quality management in the form of the Pakistan Clean Air Program and has recently established a small number of continuous monitoring stations. However, ambient air quality standards have not yet been established. This paper reviews the data being available on the criteria air pollutants: particulate matter (PM), sulfur dioxide, ozone, carbon monoxide, nitrogen dioxide, and lead.MethodsAir pollution studies in Pakistan published in both scientific journals and by the Government have been reviewed and the reported concentrations of PM, SO2, O3, CO, NO2, and Pb collated. A comparison of the levels of these air pollutants with the World Health Organization air quality guidelines was carried out.ResultsParticulate matter was the most serious air pollutant in the country. NO2 has emerged as the second high-risk pollutant. The reported levels of PM, SO2, CO, NO2, and Pb were many times higher than the World Health Organization air quality guidelines. Only O3 concentrations were below the guidelines.ConclusionsThe current state of air quality calls for immediate action to tackle the poor air quality. The establishment of ambient air quality standards, an extension of the continuous monitoring sites, and the development of emission control strategies are essential.

The state of indoor air quality in Pakistan—a review

Background and purposeIn Pakistan, almost 70% of the population lives in rural areas. Ninety-four percent of households in rural areas and 58% in urban areas depend on biomass fuels (wood, dung, and agricultural waste). These solid fuels have poor combustion efficiency. Due to incomplete combustion of the biomass fuels, the resulting smoke contains a range of health-deteriorating substances that, at varying concentrations, can pose a serious threat to human health. Indoor air pollution accounts for 28,000 deaths a year and 40 million cases of acute respiratory illness. It places a significant economic burden on Pakistan with an annual cost of 1% of GDP. Despite the mounting evidence of an association between indoor air pollution and ill health, policy makers have paid little attention to it. This review analyzes the existing information on levels of indoor air pollution in Pakistan and suggests suitable intervention methods.MethodsThis review is focused on studies of indoor air pollution, due to biomass fuels, in Pakistan published in both scientific journals and by the Government and international organizations. In addition, the importance of environmental tobacco smoke as an indoor pollutant is highlighted.ResultsUnlike many other developing countries, there are no long-term studies on the levels of indoor air pollution. The limited studies that have been undertaken indicate that indoor air pollution should be a public health concern. High levels of particulate matter and carbon monoxide have been reported, and generally, women and children are subject to the maximum exposure. There have been a few interventions, with improved stoves, in some areas since 1990. However, the effectiveness of these interventions has not been fully evaluated.ConclusionIndoor air pollution has a significant impact on the health of the population in Pakistan. The use of biomass fuel as an energy source is the biggest contributor to poor indoor air quality followed by smoking. In order to arrest the increasing levels of indoor pollution, there is a dire need to recognize it as a major health hazard and formulate a national policy to combat it. An integrated effort, with involvement of all stakeholders, could yield promising results. A countrywide public awareness campaign, on the association of indoor air pollution with ill health, followed by practical intervention would be an appropriate approach. Due to the current socioeconomic conditions in the country, development and adoption of improved cooking stoves for the population at large would be the most suitable choice. However, the potential of biogas as a fuel should be explored further, and modern fuels (natural gas and LPG) need to be accessible and economical. Smoking in closed public spaces should be banned, and knowledge of the effect of smoking on indoor air quality needs to be quantified.

Bioaerosols in residential micro-environments in low income countries: a case study from Pakistan.

Our knowledge of the concentrations of bioaerosols in residential micro-environments in low income countries is scanty. The present investigation was conducted to assess the culturable concentration and size distribution of bacteria, gram negative bacteria and fungi in two rural and an urban site in Pakistan. The highest indoor culturable bacteria concentration was found at Rural Site II (14,650 CFU/m3) while the outdoor maximum occurred at the urban site (16,416 CFU/m3). With reference to fungi, both indoor and outdoor concentrations were considerably higher at Rural Site I than the other sites. The size distribution of culturable bacteria at all sites showed greater variability than that of culturable fungi. At all sites more than the half (55-93%) of the culturable bacterial and fungal counts were observed in the respirable fraction (<4.7 μm) and so had the potential to penetrate into lower respiratory system.

Nitrogen dioxide and household fuel use in the Pakistan.

More than half the worlds population use biomass fuels as a household energy source and, hence, face significant exposure to a number of air pollutants. In Pakistan about 90% of rural households and 22% of urban households use biomass fuels. In order to assess the levels of NO(2) in the residential micro-environment, two sampling campaigns were carried out at different times of the year (summer and winter) at an urban and two rural sites during 2005 and 2007. Rural site I used biomass fuels while natural gas was utilized at rural site II and the urban site. In winter NO(2) concentrations at all three sites were higher in the kitchens than living rooms and outdoors. ANOVA showed that, although, there was a significant difference among NO(2) concentrations in the kitchens, living rooms and courtyards, at all the three sites, there was no significant different between kitchens using biomass fuels and natural gas. During the summer NO(2) levels fell sharply at both rural sites (from 256 μg/m(3) and 242 μg/m(3) to 51 μg/m(3) and 81 μg/m(3)). However at the urban site the mean levels were slightly higher in summer (234 μg/m(3)) than in winter (218 μg/m(3)). The considerable seasonal variation at the rural sites was due to a shift of indoor kitchens to open outdoor kitchens at rural site I and more ventilation at rural site II during summer. There was no significant difference between kitchens using biomass (site I) or natural gas (site II), however the kitchens at rural site II and urban site showed a significant difference. Overall fuel selection showed no significant effect on NO(2) levels. However the NO(2) concentrations may pose a significant threat to the health of people, especially women and children.

Particulate air pollution in transport micro-environments

To understand the dynamics of particulate matter inside train coaches and public cars, an investigation was carried out during 2004-2006. For air-conditioned rail coaches, during peak journey times, the mean concentrations of PM10, PM2.5 and PM1 were 44 microg m(-3), 14 microg m(-3) and 12 microg m(-3), respectively. The levels fell by more than half (21 microg m(-3), 6 microg m(-3), and 4 microg m(-3)) for the same size fractions, on the same route, during the off-peak journeys. On the other hand, in non-air-conditioned coaches, the PM10 concentrations of up to 95 microg m(-3) were observed during both peak and off-peak journeys. However the concentrations of PM2.5 and PM1 were 30 microg m(-3) and 12 microg m(-3) in peak journeys in comparison to 14 microg m(-3) and 6 microg m(-3) during off-peak journeys. Over a period of four months the concentrations of PM10, PM2.5 and PM1 in car journeys were generally similar during both morning and evening journeys with average values of 21 microg m(-3) for PM10, 9 microg m(-3) for PM2.5 and 6 microg m(-3) for PM1. However during October the average concentration of PM10 was 31 microg m(-3). An analysis of nearby fixed monitoring sites for both PM10 and PM2.5 revealed an episode of high particulate pollution over southern England during one week of October. There was no statistically significant difference between particulate matter levels for morning and evening car journeys. A statistically significant correlation was found between morning and evening PM10 (0.45), PM2.5 (0.39) and PM1 (0.46). In train journeys, a statistically significant difference was observed for peak and off-peak levels of PM10, PM2.5 and PM1 in air-conditioned coaches. On the other hand, in non air-conditioned coaches a significant difference was documented only for PM2.5 and PM1.

Indoor Air Pollution

Population exposure to various air pollutants is likely to be higher in the indoor micro-environment than outdoors due to the amount of time people spend there. Consequently, indoor air quality has drawn considerable attention in recent years. There are noticeable differences in the types and strength of air pollution sources across the globe and they are closely linked to socio-economic developments. Typically higher indoor concentrations occur in developing rather than developed countries. The types, concentration, and sources of indoor air pollutants vary considerably from one micro-environment to another. Hence, an understanding of the concentration of pollutants in different micro-environments is of great importance for improving exposure estimates and, in turn, for developing efficient control strategies to reduce human exposure and health risk.

Role of poverty in fuel choice and exposure to indoor air pollution in Pakistan

Indoor air pollution, due to household solid fuel use, is responsible for a significant burden of disease in developing countries. Fuel choice is often associated with household income. However, many other socio-economic and environmental factors also influence the choice of fuel and the resultant indoor air pollution exposure. The aim of this paper is to assess the role of poverty on indoor air pollution in Pakistan through fuel choice. Furthermore, a multinomial logit model has been used to predict the determinants of fuel choice. The results indicate that although poverty makes a significant contribution, other factors such as household location and area, household size, low level of human capital, asset ownership structure and access to basic utilities are the important correlates of fuel choice. Knowledge relating to the proximate determinants for fuel choice is crucial to inform policy and can play a pivotal role in designing sustainable intervention strategies to reduce the risk of exposure to indoor air pollution in Pakistan.

Evaluation of total concentration and size distribution of bacterial and fungal aerosol in healthcare built environments

This study aims to assess the levels and size distribution of airborne bacteria and fungi in two different types of orthopaedic theatres (conventionally ventilated and laminar flow), a general ward and outdoors in a hospital. The sampling was carried out with an Andersen six-stage viable impactor over a period of eight weeks. The highest mean concentration of total bacteria was found outdoors followed by the general ward, conventionally ventilated theatre and laminar flow theatre. With reference to Gram-negative bacteria, the general ward had the highest mean concentration followed by outdoors and the conventionally ventilated theatre. No Gram-negative bacteria were detected in the operating theatre with laminar flow. Similar to bacteria, the higher concentration of fungi was present outdoors and in the general ward as compared to the operation theatres. In general, higher concentrations were found in the conventionally ventilated theatre than the laminar flow theatre. In terms of size distribution, in the ward and outdoors the dominant bacteria, Gram-negative bacteria and fungi were in the size range of 3.3–4.7 µm or 2.1–3.3 µm. The bacterial concentrations in the conventionally ventilated operating theatre were mostly in coarse size fraction compared to fine fraction for the theatre with laminar flow.

Development and application of a methodology to assess sanitary risks in Maputo, Mozambique

Sanitation-related health risks in low-income urban areas are concentrated in localities in which sanitation facilities and infrastructure are poorly developed and maintained. A simple and systematic approach to quantify these risks can be used to identify vulnerable communities and to support decisions about the types of interventions to mitigate these risks. The methodology described in this paper utilizes local stakeholder knowledge in a participatory process to score sanitation risks, using a framework of indicators that provides a quantitative assessment of the intensity and distribution of risk. The approach considers the extent of hazardous events related to faecal contamination of the environment, the level of local community exposure to this hazard, and vulnerability factors that exacerbate the impacts of infection. The paper describes the development of the methodology and its application in Maputo and outlines how this approach might be used to support the preparation of city sanitation plans. The approach is validated through the use of a conventional household survey, the results of which are compared with those from the community workshops.